Page last changed December 20, 2004

Spotlight on wheels (rims, spokes and hubs)

• Spotlight on tyres - Alternative tyres
• Taking a Brompton aboard motorised transport - Another bit not to loose

Broken spokes

The problem

• Custfold:
  Broken spokes on pre 1990 Bromptons were a problem it seems, my early wheels did fail this way, but rebuilds and new wheels much better, SA hubs are designed for 13swg spokes. Note thatb the old front hub and SA rear ended up with spokes the same length when front was switched to radial spoking - useful for spares.
• Mike Hessey:
  [...] a number of broken spokes in the FRONT wheel over the last few months. My front wheel had less spokes than are standard - I've replaced the front wheel after this problem, and it's now fine.
• Clive Page, Mar 1998:
  I've had spokes break every month or two for the life of my Brompton, now over 6 years old. It's always on the rear wheel, and those under tension when you pedal. I now never start in 1st gear (of 5-speed) and try to tension them evenly, but it still happens. I consulted Messrs Brompton and was told that newer models have stronger spokes but, unfortunately, these require a different rim. I was about to buy a new rim and spokes when I saw messages here recently saying that the latest type of rim suffers from rather rapid wear. So I guess I'll just put up with replacing them every few weeks. But it's a real design fault, in my opinion, in nearly all other respects the Brompton is very well engineered.
• Channell Wasson, Mar 1998:
  I ride my Brompton every day and often pull a trailer with a heavy load. I have broken two spokes in about 4 years. Both were on rear wheel. I at first agonized about getting the right guage replacement spokes and worked hard to find a shop that could cut to length and roll on the proper thread for the spoke nipple I had. This all was going nowhere so I simply bought two spokes with new nipples which happened to be of smaller guage than the 13g Brompton spoke. I took them home in my Brompton pannier, entered my tool room and cut them to a useful length with enough left over to bend a hook in one end so that the spoke would properly hold in the hub. The job took about 10 minutes. The replacement spokes have been installed for about 2 years and are still just fine. Recently, however, I replaced my rear rim because it had a wall crack. Maybe I hit a pot hole too hard and weakened the rim. The rim didn't seem to be worn excessively thin from braking friction. To do this new rim installation I taped the new rim to the old and moved the same old spokes over from old rim to new one by one. I tuned the newly rimmed wheel on the bike by eye and finger flicking spoke tension method. All is well and I like my new rim and spoking job.
  Now that our Brompton enterprise is growing or shall we say maturing a bit, let me add that our company now carries plenty of replacement spokes. From comments lately there may be a run on them!
• Willi Mindak, Sep 98:
  I went through 10 spokes on the rear wheel during the first year of ownership. During that time the bike has done approx. 1500 miles. Now I'm a tad on the heavy side, but I still find that excessive. I take out the rear wheel more often to replace a spoke than to repair a puncture. It has come to a point where all the remaining spoke nipples are more or less rounded off from adjusting the tension, even though I use the correct tool.
  While talking about it at a bikeshop they offered to rebild the rear wheel, using a kind of brass washer between the rim and the spoke nipple. Has anybody experience with this type of repair? And how is it supposed to work?
  My Brompton is little over a year old ( with alloy rims).
• Clive Page, Sep 1998:
  I've found exactly the same thing - I replace a spoke every few weeks, and now buy them in batches of a dozen or two (from the only cycle shop out of dozens which stocks the right length).
  I was told (by Andrew Ritchie actually) that newer Bromptons use stronger spokes, but these are thicker and won't fit the steel-chromed rims that I have (and modern Bromptons have alloy rims, which have their own problems, I gather, so I'm not too anxious to change). So it's darned annoying. By trying very hard to tension all the spokes exactly equally, I can sometimes induce a gap of around 2 months before another spoke goes.
• Phil Gough, Sep 1998:
  My 1988 T5 had exactly this problem, and I am only a puny 130lb rider. The flanges were too sharp for the spoke material on the bend. The solution was to havenew alloy wheels, built up with 2BA brass washers under each spoke head, and 13guage spokes. The front wheel was built radially, and I havn't had a spoke loose let alone break in 3 years. Incidentally, the spole holes in the Sturmey Archer hub flange were worn oval by riding with a slack wheel, and this necessitated a new hubshell, not that easy to find as the old S5/2 hubs are now obsolete.

Replacement spokes

The cure?

• Phil Gough:
  You don't say whether your machine had steel rims, my 1988 T5 did, they were standard then. The front wheel spokes kept breaking one after another at the bend. I replaced them with 13g spokes, but the best thing I did was to have a new wheel built up on to a Union juvenile hub (Brompton hubs are narrower than standard), using 13g tandem spokes and brass washers under the heads and alloy Alisa rims. Perfect, not a millimetre off true in over 2 years
• Stein Somers, Sep 1997:
  I broke 5 of them in as many months and none at the front. Some months ago I tightened them according to John S. Allen's musical method (http://web0.tiac.net/users/jsallen/bicycle/index.htm) and they all seem pleased. Maybe the lazy ones had already quit. I ruined and replaced several nipples doing this.
• David Henshaw, Mar 98:
  Ignoring VERY early Bromptons; early machines had slender 14g spokes front and rear, but these were later changed to chunkier 13g spokes at the rear, following some failures. This happened in about 1991, so I suppose your machine could be either type, but from the problems you've had, it sounds as though you have 14g spokes and steel rims. I can see no reason why 13g spokes should not fit the steel rims, but they might need some gentle drilling here or there. A better bet is to change to the later aluminium rims, use 13g spokes, tension them well, and fit good aftermarket brake blocks... both the rims and the spokes should last well. Unless you're heavy and/or equipped with bulging thighs, that is. But even Dave H doesn't break that many spokes... only frames.
• David Edge, Sep 1998:
  Yes; similar to the advice of Alf Scrote in A2B, get it tightened up properly. I did it myself. The factory wheels, as with most similar bikes are way too loose for us portlies, they need at very least another full turn. If you're not into wheelbuilding, let the shop do it. If your nipples are rounding (oo-err missus) throw away the lot and start again though. I don't know about the brass washers, at 2p each you can hardly go wrong. A stainless steel rear spoke kit is also available. Finally remember that the wheel not quite centred as you'd expect - I set mine half way between locknuts, not flanges - can someone more erudite help me out on this?
  Eric the Brompton is three years old and has alloy rims. The proof of the pudding (drool) is in the eating - the only spoke I have broken since (2 years now) was when a rock went through the frong wheel when I was downhilling off road.
• David Henshaw - A to B, Sep 98:
  Brompton have suffered a few problems with rear spoke failure over the years, and that's why they now use 13g spokes on the rear. The problem appears to be caused by the sharp edges on the Sturmey Archer hub flange holes, which cut through the spokes - the little brass washers help to prevent this. If you are a largish person cycling a fair mileage, it's worth keeping the spokes well tensioned. This helps prevent the spokes squirming around against the hub flange. Another option that we've found very effective is to fit an old aluminium S.A. hub casing. The soft alloy will not damage the spokes. If you own an older bike with 14g spokes, upgrade to the newer ones or sell the bike to someone lighter and buy a new one.
• Clive Page, Sep 1998:
  [...] the broken spokes are, I think, no so much because of terrible roads, but because I tend to pull away from rest rather fast. I've now trained myself to pull away from traffic lights in 2nd gear not 1st (I have a 5-speed gear), and this helps.
• Custfold, Sep 1998:
  Examine any old or cheap hub when it is dismantled for a wheel rebuild and you will see oval spoke holes and grooves worn by spokes, hence the use of small washers, the coutersinking of the 'bend side' of flange holes to stop damage to the inside of the spoke bends, and an option to lace all the spokes inside the flange, and other individual solutions.
  Keep spoke tension as a regular check, and also the wobbles of the rim which give early clues of trouble in store.
• Phil Gough, Oct 1998:
  Smaller wheels store less stretch than bigger ones, which means IMHO that they have to be tensioned more and this puts a bigger stress on the spoke bend and hub holes. Initially you have a stronger wheel, but when something starts to give under the high tension then the spokes go slack one after the other, eventually breaking at the bend. The slack spokes ovalise the holes in the hub flange and after a while the hub is a write-off too! That's why brass washers under the spoke heads are a good idea. Especially for steel hub flanges which are thinner than alloy and give less support to the spoke head.
  This could be rubbish I'm not an expert but both of the original steel rimmed wheels on the Brompton (1988 model) suffered an endless succession of loose and broken spokes to the extent that I used to carry a spoke key and a small bundle of spokes around all the time. Finally cured by the brass washers and 13G spokes.
• Channell Wasson, Jun 1999:
  Recommend you replace any broken spoke ASAP. And while you are at it tune up front and back wheels with spoke wrench (14 gauge green wrench for front wheel, 13 gauge red for rear). If you don't know how to do this watch your bike mechanic do it and you will soon learn (in most cases). If you can not find a spoke of correct lenght, just cut any normal spoke to approximate Brompton length and then bend a hook in it at the hub end and install the spoke. Parameters of bike repair are not always as critical as we might think. "Just do it"
• Custfold, Jun 1999:
  I break spokes, and have a WIGATI with the 7 speed hub which I took out of service when over 30% of spokes had failed, generally you can endure a careful and wobbly ride home on a 28 hole wheel with 7 broken spokes, as we did one day with a Moulton AM7 - from Aberfoyle to Glasgow, but it is useful to have a spoke key or good set of pliers handy to correct the pull from the remaining spokes.
• Channell Wasson, Jun 1999:
  I've never seen a broken spoke in a Brompton front wheel. But it occasionally happens in the rear, always at the bend at the hub and usually always on the driving sprocket side. The front wheel is exceptionally strong and ridgid due to radial spoking. The rear wheel has "two cross lacing", and thus spokes have a chance to work a bit in the hub sockets as one pedals the bike. Some times a user will install radial spoking on the non driving side of rear wheel which tends to provide more rigidity to the rear power wheel. Keeping spokes tight and wheels "tuned" and clean helps too in avoiding broken spokes. The Brompton with 28 spokes in each wheel is engineered for rigorous daily use.
• Len Rubin, Jun 1999:
  I have always used 16 spokes (has to be divisible by four for a "normal" rear hub (drive, non-drive, pulling, non-pulling). Also, although we are dear friends, and at the (small) risk of offending, I would disagree with my esteemed colleague regarding much of his lay analysis of wheelbuilding "theory"; for a better understanding, I highly recommend Jobst Brandt's classic text on the subject.
  The age old problem of spokes breaking at the elbow in wheels using thin steel hub flanges (e.g. Sturmey Archer's rear hubs) has very little to do with cross patterns. It is the result of unrelieved stress due to the thin and hard steel flange (hence the rarity of spoke breakage on similar, properly built wheels using thicker, softer alloy hub flanges.)
  The classic treatment is to rebuild with high quality, 14-gauge stainless steel spokes, adding a couple of tiny brass washers under each spoke head, to relieve the stress on the unsupported elbow, by snugging it up against the flange. This helps, as does proper spoke tension.
  In a properly built very small wheel the tensioned structure is much more nearly static, rather than highly dynamic, and as such, cross patterns and other variables don't have a large effect. Insufficient, excessive or uneven tension and trauma/damage are the main variables affecting spoke breakage due to fatigue or notch failure.
  Wheelbuilding is a fine art and science, despite the enormous amount of myths, anecdotes, convictions and opinions that are offered up as "knowledge".
• Willi Mindak, Jun 99:
  Yes, it works. I can only offer anecdotal evidence, but after replacing more than a dozen spokes the rear rim finally split and the wheel had to be rebuild. It was done with the brass washers Len mentions, and since then I didn't have to replace a single spoke in about 800 miles. I'm convinced that my weight (104 Kg naked with glasses) is _the_ deciding factor in these breakages.
• VELODROOM -- urban mobility concepts, Jul 2000:
  One little tip for the slightly heavier Bromtponist: Should you still experience problems due to spoke stress even after tightening the original wheel, have your rear wheel rebuilt with butted (2.34-2.00mm) stainless Sapim Strong spokes crossed only once (because of the better spoke angle at the rim entry). These spokes are not available in the right length, but can be cut to size with... Yes, the above mentioned machine (We use a Hozan, cheap and cheerful and really essential for any Brompton dealer). We did such a wheel for our heaviest customer (roughly 260lbs) and there haven't been any problems in over a year of harsh daily abuse. Also make sure to have washers (M2.5) put under the spoke heads to emulate a thicker hub flange.

Rim design: is the spoke angle wrong?

• willimindak, Sep 97:
  [...] the rims seem to be drilled for radial spokes (which is o.k. for the front wheel), but the rear wheel uses a crossover pattern, so the spokes enter the rim at an angle. This [wrong drilling pattern] makes them prone to become loose and they tend to break. I've read the handbook and had the spokes re- tigthened after initial use, but had a breakage nevertheless. The spoke nipples protrude too far into the tube space, and the rim- tape is fairly thick to prevent damage to the tube. This may lead to a problem when tyres with higher pressure are used.
• Willi Mindak, Oct 98:
  While having a close look at the wheel I couldn't help noticing that the spokes are not really straight. They are slightly bend just before they enter the rim, where the nipple grips them. That's because the rim has a 'radial' bore. The nipple therfore can only take spokes that enter the rim radial (give or take the odd degree or two). The spokes with their crossover pattern enter the rim under a greater angle than the nipple can accomodate. This results in a slightly bend spoke, no matter how tight you scrw the nipple on.
  I don't know whether I make myself terribly clear; it is difficult to describe without a drawing. But check with your bikes.
  I believe this is a problem, because surely spokes can only take forces in a straight line. Can the spoke breakages that myself and others experience be caused by that (apart from our weight)? The front wheel is not a problem, because here the spokes run radial.
• Custfold, Sep 1998:
  The ideal angle for the spoke to meet the rim is I understand less than 5 degrees, to minimise the side thrust at the nipple end and reactive forces at the flange. The Brompton and other SWB cannot easily achieve this unless the nipple seats are profiled to suit.

Rims worn out

Some have complained about the rapid wear of their Brompton's rims, and potential accidents when the wheel suddenly "explodes" under the tyre's pressure.

To avoid it: Preventing problems - taking care of your Brompton - Basic brake care

Victim's accounts

• Stein Somers:
  [...] I was alarmed by an unusual sound: the rear rim bumped into a break pad due to a 1cm crack on the side of the rim! [...] At some 10km from home, the rim gave up on me and I had to walk. The crack had grown to 15cm and couldn't resist the tire's push anymore. Now for the facts: after 2700km of what I would call "normal road use" during 6 months, the sides of the rear rim have been polished away by the brake pads. Only recently I read this problem exists. I felt long before, while trueing the wheel, that the rim sides seemed curbed, but I thought this was just the way they were made. Some of you wrote how they spent thousands and thousands of miles on their Brompton, without a serious problem. So why does this happen to me?

  It was probably due to a lack of maintenance on the original brake blocks (Spotlight on brakes - Brake blocks), and bad braking style. Lesson learnt: minimize brake block contact by braking hard, intermittendly and preferably on the front wheel.

• Peter Hubbard, Jun 1998:
  [...] I purchased a Brompton L3 last Monday. By Thursday I could hear the brake blocks grinding the rims and the rims are already well scratched. The blocks are marked 'for alloy'. I cleaned the surfaces of the blocks still on the bike using a thin nylon 'pan scourer' backed by a piece of thin cardboard to protect the rims.
  This seems to have removed the grit (or whatever) and braking is now all quiet. Is this standard for alloy rims? It seems I'm going to have to do this every day or wear out the rims in no time.
  Not a problem, it just adds to the fun, right?
• Willi Mindak, Sep 98:
  Yesterday the rear rim failed on my Brompton after 14 month and approx. 2000 miles. Trouble is: nothing spectacular happened that could have caused the failure. I was riding through Richmond park, and became aware of the failure when I applied the rear brake. A couple of hundred yards before I had used the brake and not noticed a thing. Apart from me feeling nothing: there were no marks of an impact on the rim. The wear on the outer surface of the rim due to brake action is negligible (hardly noticable, and not half as bad as on the front wheel).
  The side of the rim is split on approx. 10 cm in length and bend outwards. It follows the part of the rim where the bead of the tyre presses against. The tyre had 80 psi pressure.
  Now I was going to have the wheel rebuild anyway, because I seem to be the world record holder for broken spokes.
• Andras Toth, Feb 1999:
  After riding my Brompton with a broken spoke in the back wheel for about a month, the side of the rim split on a lenght of about 10 cms. Please take a look at
  http://www.protrade.matav.hu/andras/broken_wheel.htm [photo copied here]
  where you can find a photo of the incident.
  I gotta admit that I am completely dumb when it comes to bicycle reparation so I took it to a bicycle repair shop near me where they told me they could not do anything with it, the entire wheel has to be changed. Is this complete rubbish, or do you too think it is hopeless?
  • Alasdair Baxter, Feb 1999:
    I don't think there is any connection between the broken spoke and the split rim. The fact that the rim split is just one of these things probably down to a defect in the metal or in manufacture. You may have pumped up the tyre too hard, of course.
    There is no cheap way of fixing this, I'm afraid. Welding aluminium alloy is a highly specialised procedure and is likely to cost as much as a new wheel from London if not more. If your university has an engineering department, they might be prepared to help as a type of educational project but I doubt it.
    A rim is not a heavy item and if you contact Brompton Bicycle in London and tell them of your problem, they may well send you a new one out and you could be pleasantly surprised at the low price including freight. If, as you imply, the bike is not very old, they could well send you a new rim for free.
  • David Edge, Feb 1999:
    Humbly beg to disagree. A broken spoke will cause the rim to bulge and thus increase force and wear from brake block. Of course, the rim may well have been close to the edge, and the little extra wear there pushed it over sooner.
  • Custfold, Feb 1999:
    The 2 occurrences are only related by a slight chance that the weakened rim stressed the spoke sufficiently to break it, before the rim itself gave way.
    My back wheel currently has 3 broken spokes (of 36) and this is less than it had before I rebuilt it.
    Basic wheelbuilding is not a mystic art - ask Andy Follis who received a rim and 28+ spokes from me with a little encouragement, and went on to rebuild his rear wheel over a couple of days. With practice you can usually lace up or respoke and roughly true a wheel on a typical 1 hour train trip as I frequently did when commuting between Edinburgh & Glasgow, occasionally driven by the fact that I needed the wheel back on the bike to ride away at the other end.
• richard lighton, May 1999:
  Add me to the failed rims list. 9 miles from home, 10:30 at night, funny feeling to the back wheel--a sort of rhythmical bump. Stop and check by a poor street light. Nothing obvious. Brakes apparently aligned as far as I could see. Get back on--same problem. Oh, well, hope it's nothing serious and Arnold will get me home. Half a mile later it's getting worse, but I still can't see what's wrong. Another hundred yards and whatever it is won't let the back wheel turn. By the light of my (detached) headlight it is now obvious, as several inches of the rim are sticking out. And that's at about 1800 miles with the occasional checking/cleaning of brakeblocks and I think about half a dozen tire changes.
• Roland Elsenberg, Jan 2000:
  Last week my rear rim failed. This time it lasted for about 10,000 km. This was achieved with KoolStops and is about twice as much as with the standard brake blocks. I carried the hub to my Brompton Dealer, riding on my old Brompton. On my way back the front rim failed on that. I admit to put more than the allowed 100psi into my Schwalbe tires.
• Jeff Dauvin, Jan 2000:
  I have had my Brompton since last May & have done about 2000 miles. I weigh about 86kg. Am I compatible with Brompton use?
  I had to change to soft (Fibrax) front brake blocks as the bike was virtually unstoppable on hills. I tried to run a couple of chains because mine gets very dirty but already the rear sprocket is too worn to the current one to have another one clean all the time. Today the rear rim joint failed on one side (splaying out) & the tyre was pushing a split into the braking surface of the rim at about 1cm per 10 minutes when my wife took it away in the car boot to the cycle shop. This bike is going to cost me a fortune to run.

Explanations (anodized rims, brake blocks etc.)

• Obviously, small wheels wear quicker as there is less rim to spread it over.
• Spotlight on brakes - Brake blocks
• David Henshaw, Jan 98:
  Some people get through a lot of rims, while others barely scratch the surface. Aztec blocks [Spotlight on brakes - Alternative brake blocks] help quite a bit, but there's no cure other than to clean the blocks and rims at frequent intervals. 1997 bikes have anodized rims that can wear out particularly quickly thanks to the anodizing becoming embedded in the blocks. The very latest rims are unfinished alloy, and hence a little better.
• Andrew Henry, Apr 1998:
  See "Anodized vs. Non-anodized Rims" in the rec.bicycles.tech FAQ. [which states anodized rims are a "cosmetic nuisance". Still:]
  • Hanel, Steven D., Apr 1998:
    Annodizing usually makes a rim last longer unless you are using the original Brompton brake blocks. Hint: change the blocks. An un-annodized rim is actually softer and much more prone to wear and oxidation. The annodizing is a process where a coating to protect the aluminum is electro-chemically bonded to it. Personally I wouldn't ride a bike with the cheaper, softer, un-annodized finish.
• David Henshaw, May 98:
  There have been a few problems with the 1997 Bromptons. It appears that the rim manufacturers forced Brompton to adopt anodised rims and in a few cases these have reacted badly with the brake blocks causing quite rapid failure. A very good answer is to fit larger, softer after-market blocks such as the excellent Aztec... these cause much lower rim wear. Not all bikes are effected, but failure can be quite rapid on those that are.
  1. Pre-anodised rims are polished. Unfortunately anodised and post-anodised rims are of very similar appearance. The new rims are plain milled alloy - sort of mat grey finish. They should be fine.
  2. The post-anodised rims were not fitted to bikes until January/February this year, so there's no certainty that you were sold 'old stock'.
• Alan rowe, Mar 1999:
  Interestingly, I was talking with a fellow L3 owner on the train this morning, and mentioned the brake rim wear problem I had had with mine, and he had the original shoes, but he didn't seem to have any roughness or scoring on the rims - he said he had had his L3 for about 5 months. I wonder if the problem is avoided if the dealer / owner / brompton clean up the rims when they are new. I think a lot of the initial crud in the shoes came from the welds in the rims - if this had been sanded smooth in the first place, would it have ruined the shoes & rims?
• Meryl Prestidge:
  I have heard of this happening on a Dawes Galaxy, as the anodizing wears off the rim and becomes embedded in the brake blocks, making them abrasive. The advice is (a) check the blocks regularly and dig out any bits of metal, and (b) change the blocks after about 500 miles on a new anodized rim. That includes silver anodizing, BTW. You did change the blocks, but maybe most of the damage was already done?
• Meryl Prestidge:
  Fibrax leather blocks (great for steel rims) can wear away alloy, and some rubber pads are harder than others.
• Tony Jowett, Feb 1998:
  I've just bought a T3 and have experienced alot of wheel rim wear - but mostly this has been due to grit embedding itself in the block and carving the rims! I'm getting quick at taking blocks off to clear them.
• Channell Wasson, Mar 1998:
  [...] I talked at length to a major brake block manufacturer's agent about advantages in using longer brake blocks. His bottom line response was that efficient braking can be obtained from something the size of a pencil eraser, but the bike riding public likes the long brake pads so we make them! I think Brompton is on the right track with the brake pads that are currently being used. I'm not a rocket scientist so I will let others comment on this.
• Cartmell Anthony, May 1998:
  This discussion reminds me of my engineering training, where we learnt about grinding wheels. To grind a relatively soft metal like aluminium you should use a harder grinding wheel abrasive. To grind harder metals like tempered steel you should use a softer grinding wheel abrasive. So I would guess to minimise the wear on rims you should use soft brake blocks on soft rims (plain aluminium) and hard brake blocks on hard rims (anodized, ceramic, and steel). Harder brake blocks will also wear less as road grit will be less likely to get embedded in the block, and even if it does it won't change the block's characteristics so much.
  I guess the problem with anodised rims is caused by soft brake blocks being used. These pick up road grit and grind away at the harder rim surface nicely. No amount of cleaning will prevent this happening, only cycling on perfectly grit-free roads...
  If you have steel rims, get hold of the leather-faced Raleigh Rain-check blocks. They work well in the dry and excellently in the wet. The blocks will last thousands of miles too.
• Custfold, Jan 2000:
  I am getting wind of a deterioration in quality in Alesa rims since the company 'changed hands' - could this be making itself felt in the failure department.
• Larry Chinn, Feb 2000:
  Since the Bromptons have mudguards, the rims will get dirtier faster in the rain and require even more maintenance.

Alternative hubs

Pantour suspension front hub

• Custfold, Dec 2004:
  The Pantour hub offers suspension - bit of a pig to build as it has a thick flange. Not supplied with 80mm skewer in 80mm size, just like SON, so you have to change the capscrew on a 100mm SON skewer. A cut-down 100mm x M5 SON bolt with the end 'nuts' will work - not q/r but 5mm socket key, and does not work properly with B latch for front forks
• Herman van Ommen, Dec 2004:
  SON advises to use 150 mm spokes instead of the 148 mm the standard B spoke length (as far as I know).
• Thorsten Rentel, Dec 2004:
  Did anyone else have to modify his/her fork dropouts, too? Mine were only suitable for 8mm axles and the Pantour needs 9mm. I did not dare cutting down the material on the hub.
  Making your own skewer isn't a problem provided you find a standard one that's thick enough (with a cut thread, not a rolled-on one) and have a 5mm thread cutter.
  I like the hub a lot and consider the hassle worthwile. I even decided against the SON hub dynamo after waiting for it to come into production for years.
• Simon Watt, Dec 2004:
  Yes I had to file out the dropouts on my 2000 model L5 to accommodate the Pantour 9mm axle. Worth the effort though. I've had to replace the original elastomers once, and the replacements are in two pieces, not the four of the original. They appear to be longer lasting...
• John, Dec 2004:
  I have a Pantour fitted to one of my Bromptons. The hub works very well indeed. I did not have to modify the drop outs, maybe my 2004 with longer frame (hinged area) did not require it? I would heartily recommend this hub, bearing in mind the cost and need to get a suitable scewer sorted.

Loose/worn front hub

Problem

• Stein Somers, Sep 1997:
  A terrifying cracking suddenly sounded from the front fork. I anxiously inspected it and found I could move the front wheel left and right over something like a centimeter. It was the bearing balls making the noise. I never loosened the front wheel let alone the hub.
  At home I opened, cleaned, regreased and tightened the front hub and it spins silently and smoothly now. But I don't understand what caused the play in the hub, and particularily why the sound came out of the blue.
• Stein Somers, Mar 2000:
  Three years later now: I didn't experience any more problem and didn't do any maintenance on the front hubs of either T5. One has been used regularly (over 10 miles a day) for 27 months, the other regularly for 9 months, and casually for 24 months.
• Roland Elsenberg, Jul 1999:
  The ball-bearings of my Bromptons front hub sound worn. The outer parts are o.k. The inner parts (are they called cones?) are worn. As the axles of common hubs are not only longer but also thicker, it seems to be difficult to get spare parts for the Bromptons front hub. All my dealer can find for replacement is the entire hub. Is it possible to get parts of it in the U.K.? Is the manufacturer known? [...] less than 10 000 km on both my Bromptons. On the old one I got similar cones for a thicker axle. I filed the thread in the axle to make it fit into the front fork.
• Robert Payne, Mar 2000:
  My front hub is giving me problems too. After about 8 months it was in dire need of an overhaul. The mechanic said it had already taken a lot of abuse and would probably need to be replaced soon (he also said it had a cartridge used in cheaper hubs to save on the number of bearings needed). Three months later I'm starting to see the signs of bearing problems. I have the original front hub. What options are there for replacement that will last longer than the Brompton factory hub?
• Robert Payne, Mar 2000:
  I've already had mine repacked with new bearing and grease once and it is already wobbling again. This is after one year of pretty heavy use.
• Roland Elsenberg, Mar 2000:
  5000 km seem to be possible. The cones are not easy to obtain here in Germany. I try to rotate the axle so that the worn parts of the cones face upwards. About one year ago someone on this list suggested to buy a new wheel instead of replacing the hub. Replacing the front wheel is cheaper than a new hub and the work to built a wheel with it, at least here in Germany.
• David Cox, Mar 2000:
  I bought my L3 in 1994 and have no recollection of doing any maintenance on the front hub beyond the odd squirt of oil. It is an earlier design than the current ones and looks very basic. It may be that Gascoigne Cycles who looked it over 2 years ago made some adjustments but there was no charge for new parts.
  I've not kept a record of mileage and am on my third computer which is playing up ) but I do 5000 per year and a fair bit of that (say 25%) has been on the Brompton including two years of regular commuting all weathers 18 miles a working day. I guess it is well up to 5000 miles probably more.
  The Brompton has also been taken abroad by plane in a softbag and a case and ridden down rough tracks. It really has been a robust and jolly companion needing more cleaning but probably less fundamental maintenance than my other bikes.
  I wonder if the new hub is superior but requiring more attention and adjustment.
• Peter O'Reilly, Mar 2000:
  My expectation is that keeping the B's bearings clean and well greased, the hub should far outlast the eventual wear and inevitable failure of the rim.
• PHolden960, Mar 2000:
  My cones went bad after 1200 mi. was told the hub was "cheap" (a whole new wheel did cost less than many hubs.) May try rebuilding the Ft wheel next time.
• Peter O'Reilly, Jun 2000:
  This past winter I re-greased my front hub. While riding the B the front wheel totally locked up! This was after a couple of rides subsequent to the hub work. I am not completely sure why it happened - maybe a combination of the front bolts and cups/cones being too loose. I guess there was some movement going on with the lockrings/cones against the fork.
  Afterwards I then reassembled the front wheel - trying to get the cones set just right as much as possible. I erred on the conservative side - meaning having the cones set a tad bit too loose, than too tight before placing the wheel back on the fork. After placing the wheel on the fork, there was only the slightest detection of play. I also made sure the outer bolts clamped the wheel and the inner lockrings were real tight to the fork.
  Months later and probably a couple hundred miles more on the B - the front hub has become loose. Enough so to detect it while riding the B. I never experienced such a problem with my other bikes (all which use quick release skewers - possible hint?).
  When I re-greased my hub, it was after about a year of use. There was a modest amount of grease left. The cartridge bearings looked like they were in good shape and no pitting had occurred. Interestingly enough, I have had the B for about 1.5 years now.
  It has been my observation that wheels that leave the factory do not come with well greased bearings. Yes, I may be over generalizing, but I speculate such happens more often than not. I base my comments on experiences with the B, my other bike with expensive hubs and others I have talked too.

Cure: adjust for wear & grease the bearings occasionally

• Custfold, May 1998:
  It is possible to build several specialist hubs with central 'tubes' to suit this - I've checked out Hope in the UK, and they could make a hub for front and rear of brompton.
  On the topic of Front Hubs, I'm gettin reet brasst off wi't'ub called Kevin. It seems impossible to get this hub to maintain sufficient slack for free running without gaining sloppy sideplay (making the front end feel unsure - is this, combined with a slack headset what constitutes foreplay I wonder (<ducks>>)
• Andy Follis, Jul 1999:
  I gave up looking, rode the front wheel till the hub was more or less a write-off and the rims well worn, then replaced the whole wheel. Not what I wanted to do, but in the absence of parts it seemed the best balance of resource use and effort.
• Roland Elsenberg, Mar 2000:
  Do most of your braking on the front wheel and replace it regularly (5000 km). So you save the rear rim and the work to built a rear wheel and true it.
• Peter O'Reilly, Mar 2000:
  I just regreased the bearings in the front hub recently. It's a fairly simple process; easier than removing and reassebling the rear wheel (w/ gear adjustment) in my experience. With that in mind I will be more inclined to check the fron hub after riding in wet weather. I estimate that I have about 1,200 miles on the bike and the front wheel (rim and hub) are in fine shape. Using KoolStop brake pads and keeping the rim surface reasonably clean, I suspect the front wheel may last a long time.
• Peter O'Reilly, Mar 2000:
  You need to tighten the cones. Tighten them completely on the axel and then turn them a 1/4 turn or so loose. Spin the wheel with your hands, if it wobbles, repeat the previous step with an 1/8th of a turn. If it is too tight, you hear/feel a grinding noise or the wheel does not spin, turn the cones more than a 1/4 turn after initially tightening them. err on the side of too loose as when you reattach the wheel more pressure will be placed on the cones. Adjusting the cones/hub takes some trial and error. Afterwards, retighten the the outer nuts (ones immediately adjacent to the cones) and while doing so make sure the cones remain stationary as you tighten the hub (requires a pair of flat wrenches to do). Hope this helps.
• PHolden960, Mar 2000:
  Might be good idea to check, and re-pack, your bearings. The new wheel didn't have all that much grease in there.

Ditch the cage

• Toby Riddell, Jun 2000:
  [We are] talking about:
  • balls in a cage (cage made of pressed metal) with cup in the hub and cone on the axle
  [as opposed to]
  • ball race, balls cannot be removed from between two solid rings of metal
  Ditch the cage! It seems like a convenience to have it, indeed it probably is very convenient when the bicycle is being assembled in the factory, but what generally happens is that the cage gets chewed up over time and you end up with bits of metal in amongst the grease and balls and in not too much time you have pitted balls (and maybe a seized bearing as Peter had).
  You can do without the cage when regreasing by making a making a nice "bed" of grease in the cup and embedding the balls in it before replacing the cone.

New bearings

• Robert Payne, Jun 2000:
  I had a mechanic look at the hub and he suggested replacing the cartridge with new bearings. He thought this would improve the performance of the hub.
  I finally gave up on the hub after about a year and a half and got a new front wheel (factory standard) because my hub became so worn I couldn't get it adjusted without a lot of play.
  The first thing I did to the new hub was open it up and re-grease (there was not a lot of grease in the hub even when new) and replace the bearings and catridge [balls and cage] with new bearings [balls without cage].
  I'm hoping this will make the hub last longer with less adjustments. We'll see...
  You might be able to hold of on [a] new wheel. When I originally took out the "cage" the cone and race already looked pretty bad.
• Peter O'Reilly, Jun 2000:
  This weekend I reassembled my front hub. I am glad I did not wait another ride longer. Toby's comments were spot on correct: "...the cage gets chewed up over time and you end up with bits of metal in amongst the grease and balls and in not too much time you have pitted balls..." This is exactly what happened to my B's front hub.
  Luckily though there was no pitting of the cones. Packing copious amounts of grease and detecting such defect early helped I reckon. I packed the hub with a loose set of bearings.
  Word to the wise - replace your B's bearings with a quality set supplemented a fair amount of grease. The cost is nominal; much less than that of a new wheel. Lesson learned. -Peter

Alternative front hub

• John R. Bolt, Jun 2000:
  Yes, although I don't know about "readily available." I substituted the front wheel and hub with an elegant replacement setup from Len Rubin--including an extremely high quality (and light, naturally) sealed-bearing hub. I agree that the factory-supplied hub is not particularly good quality. The wheel from Len did require slightly enlarging the dropout on the front wheel, which you can do satisfactorily with a round file of the proper size--albeit with some care.

Alternative rims

• Zach Kaplan:
  What rims (make/model/hole drilling) comes standard on the Brompton? I'd like to know what people think about replacing the stock box section rims with Sun M14A aero section rims. The M14As are probably lighter, stronger, and more aerodynamic but don't look like they would support the wide 37mm tyre as well and could make the handling more difficult in terms of trying to control the bike if it had a front blowout.
  Also has anyone put Moulton 32-369mm tyres/rims on a Brompton? If so how did it work out?

  {Leonard Rubin} What's all this foolishness? The Brompton uses 16" (ETRTO 349) tires, Moultons use 17" (ETRTO 369), Fridays use two 20" standards (ETRTO 406 and ETRTO 451), depending on the model. The original equipment rim on the Brompton is an Alesa "Alloy 219" with an outer width of 25mm.
  Zach knows (or should--he's seen the bike enough times:-)) that I have had made and use exclusively Sun M14A aero section rims on my Brompton (dubbed by others here the "Super Brompton"), and have found them quite suitable. I use the Primo tires and special 1" superlight inner tubes (that I initially bought from Zach!). I have had no punctures, nor other undesirable side effects, and have realized a very substantial weight reduction and improved ride. As far as providing adequate support for wide tires, this is a legitimate concern, but the combination of the Primo tires and the Sun M14A section seems to work quite well, as long as you take care in mounting and inflating the tires, as is standard necessity with narrow rim/wide tire combinations.

• Dave H, Sep 1998:
  The 1 speed I have uses a Suntour freewheeel housing with only the 14T sprocket on , and a Sachs 28 hole New Success Q/R minus the skewer and with nuts instead - it works brilliantly and I'm thinking of making some more.
  I could use a Magura LH straight bars lever though, as mine has fractured when the bike went off downstairs without me last month.
• Channell Wasson, May 1998:
  For Rigida 16" steel rims with 28 holes, contact Peddlers, a store in England tel 011 44 1905 24238. Cost about $30 ea
• Custfold, May 1998:
  Many cheaper kids bikes with 349 tyres in the UK use these [steel rims] - were standard on Bickerton (rear only), Moulton Mk 1-3 (?), the original Micro and if I recall correctly the first 400 Bromptons.
• David Edge, Feb 1999:
  I got a Rigida [steel rim] from Phoenix Cycles>. I've never built it into a wheel, partly because now I look at it, the weld dressing at the joint is awful.
• Phil Gough, Feb 1999:
  Worth mentioning, as steel wheel rims get such a bad press, that they don't split, and if kept trued their life can be measure in decades rather than months for a heavily used alloy rim. I am still useing a 1960's Sturmey Archer 16" rim on a Moulton de Luxe, but I admit to using duct tape to keep the rusty rough bits away from the inner tube.
• Custfold, Feb 1999:
  Rims for Brompton are either Alesa(OEM) or Primo which we import in 28 and 36 hole drillings. Rebuilding is usually best with new rims AND spokes.

Alternative wheel sizes

• Zach Kaplan:
  Primo is coming out with a 37-305 tyre. This is nominally a 16x1.5 in the archaic terminology. It will have the same casing as the 37-349 people have been using on Bromptons and recumbents. The advantage of this smaller diameter rim size is even less weight (less material in tyre, rim, and spokes) and a more compact size for a potentially smaller folded package. Also for certain configurations of recumbents there will be more crank clearance. The disadvantage will most likely be worse rough road performance as the smaller diameter tyre tends to slow down more on bumps and go deeper into potholes. For those switching to the 305mm wheel size it is good to know this size is used on most 16" children's bikes so cheap emergency replacements are readily available. Schwalbe also makes a 54-305 City Jet slick.
• Custfold, Feb 1999:
  You've prompted me to look again at fitting the Tactic size rims and 305 size tyres to a Brompton - these and 349 seem to be most prolific sizes in SWB's with the 305 having greater air volume and thus cushioning to bike & rider.

Building a (small) wheel

• Channell M. Wasson, Feb 1999:
  Easy way to install new rim is to tape new rim to old and move spokes over one at a time. Of course new spokes (quite inexpensive) are best in this one at a time method. Suddenly a new wheel appears--it's like a snake shedding its skin to start a new life.
• Andy Follis, Feb 1999:
  I was surprised how easy it is to build a small wheel. Basic lacing took me a couple of hours fiddling around one evening, then an hour the next day with the wheel loosely in place using the frame as a truing jig. The most difficult part was plucking up courage to start.

The Brompton Folding Bicycle FAQ - please comment