Brompton folding pedal bearings
- Thread starter Wobbles
- Start date
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rogerzilla
Legendary Member
Wobbles said:Quick question - when the bearings go on these, can they be replaced or do you have to replace the whole pedal?
Forgive me being lazy and not phoning the LBS.....
Probably a bit late for a reply now, but you can buy the plate with the bearing for £20 (a new folding pedal complete can be had for £30 on eBay, and is a better option if yours is worn in any other way).
Tinkerers may like to get hold of a 62032RS bearing for £3.69 - or a stainless one for £10 - and try and fit it themselves. In principle you just whack the old one out and then tap the new one in using a socket which presses on the outer race (outside diameter 40mm), thus ensuring that the insertion force never goes through the bearing itself. I shall probably do this.
rogerzilla
Legendary Member
OK...they've peened over the edges of the bearing "plate" so the bearing can't be tapped out. I suppose this stops it coming apart in use, but it does mean a worn bearing is £20 to replace rather than £3.69.
Real tinkerers could probably open up the lip around the bearing and get it out - I may do this when I have a replacement anyway.
EDIT: And I did. Reposted from Another Place. It's done a fair mileage now with no signs of shifting, so I pronounce it a success.
The Brompton left-hand pedal uses a standard 62032 cartridge bearing, which is a single-row, deep groove type. As an engineering solution this is pretty rubbish, since this type of bearing *hates* a bending load and all other pedals have two rows of bearings to support the cantilevered pedal body, but it's how the pedal folds with such little projection and we're stuck with it. Anyway, the bearings don't last very long under hard use.
The problem comes when you have a good pedal - i.e. one that hasn't fragmented from being struck on a kerb - but a shot bearing. You can't just knock out the old bearing and press a new one in, because the plate that carries the bearing has a retaining lip machined after the bearing (a Russian one of unknown quality) is fitted at the factory. This stops the pedal body falling off the bearing, I suppose, but means you either have to (a) buy a new pedal for £35 or (
buy the carrier plate for an outrageous £20, and fit it yourself - which looks rather tricky.
So, with nothing to lose, I filed off the retaining lip. This is really easy to do because the plate is aluminium and the old bearing is steel - so you know as soon as you've gone far enough and it's virtually impossible to go too far.
Next, the old bearing can be whacked out from behind. Use a socket as a drift to avoid marking the bore. As long as the whole bearing comes out, it doesn't matter in what state it ends up, because it's going straight in the bin. It will require quite astonishing force to shift it if it's been there for a few years.
Now you can clean up your filing with some fine abrasive paper, rounding off the new ridge around the bearing bore so it looks nice and there is no remaining swarf to impede the new bearing.
Finally, take your new bearing (all of £3.69 for a best quality SKF one - you can get a stainless one for £10 if you like, but they're not as robust). Clean the bore and the outside of the bearing with meths, let it dry and then coat both with Loctite #271 bearing fit. Then simply smack the bearing into the pedal using a block of wood to avoid damage, ensuring it starts square. Because the bearing will finish perfectly flush with the body (assuming you didn't overdo it with the abrasive paper) there is no need to use the old bearing to seat it. Allow the Loctite to cure before riding.
It remains to be seen whether the pedal body will work loose. Given how hard it was to shift the old one and the use of Loctite, I very much doubt it, but if it does then a large washer held by four screws (drill and tap the plate) would retain it mechanically. Future bearing changes are, of course, trivially easy now.
Real tinkerers could probably open up the lip around the bearing and get it out - I may do this when I have a replacement anyway.
EDIT: And I did. Reposted from Another Place. It's done a fair mileage now with no signs of shifting, so I pronounce it a success.
The Brompton left-hand pedal uses a standard 62032 cartridge bearing, which is a single-row, deep groove type. As an engineering solution this is pretty rubbish, since this type of bearing *hates* a bending load and all other pedals have two rows of bearings to support the cantilevered pedal body, but it's how the pedal folds with such little projection and we're stuck with it. Anyway, the bearings don't last very long under hard use.
The problem comes when you have a good pedal - i.e. one that hasn't fragmented from being struck on a kerb - but a shot bearing. You can't just knock out the old bearing and press a new one in, because the plate that carries the bearing has a retaining lip machined after the bearing (a Russian one of unknown quality) is fitted at the factory. This stops the pedal body falling off the bearing, I suppose, but means you either have to (a) buy a new pedal for £35 or (
buy the carrier plate for an outrageous £20, and fit it yourself - which looks rather tricky.So, with nothing to lose, I filed off the retaining lip. This is really easy to do because the plate is aluminium and the old bearing is steel - so you know as soon as you've gone far enough and it's virtually impossible to go too far.
Next, the old bearing can be whacked out from behind. Use a socket as a drift to avoid marking the bore. As long as the whole bearing comes out, it doesn't matter in what state it ends up, because it's going straight in the bin. It will require quite astonishing force to shift it if it's been there for a few years.
Now you can clean up your filing with some fine abrasive paper, rounding off the new ridge around the bearing bore so it looks nice and there is no remaining swarf to impede the new bearing.
Finally, take your new bearing (all of £3.69 for a best quality SKF one - you can get a stainless one for £10 if you like, but they're not as robust). Clean the bore and the outside of the bearing with meths, let it dry and then coat both with Loctite #271 bearing fit. Then simply smack the bearing into the pedal using a block of wood to avoid damage, ensuring it starts square. Because the bearing will finish perfectly flush with the body (assuming you didn't overdo it with the abrasive paper) there is no need to use the old bearing to seat it. Allow the Loctite to cure before riding.
It remains to be seen whether the pedal body will work loose. Given how hard it was to shift the old one and the use of Loctite, I very much doubt it, but if it does then a large washer held by four screws (drill and tap the plate) would retain it mechanically. Future bearing changes are, of course, trivially easy now.
Fields Electric
Active Member
Looks to fiddly, buying a new one looks a better / safer bet. At the time of writing they look to be going for £55.00
Fields Electric
Active Member
Oldest Document I have ever used from my day Job was 18 years old from the beginning of my Career.
berlinonaut
Veteran
- Location
- Berlin Germany
I guess some people may have read the bible...
Fields Electric
Active Member
The Brompton pedal has not changed in that time either. I am collecting the parts together for an Xmas 'renovation'. I am keeping oiled till then and hope it does not disintegrate in the meantime!
berlinonaut
Veteran
- Location
- Berlin Germany
Would not say so. This may be true for the bearing of the folding pedal but else not:
- in 2009 the right side pedal was changed from plastic to aluminium
- in 2012 the folding pedal was relevantly increased in size, the reflectors are now bolted on and the nasty 24mm bolt that required a very slim nut was exchanged for a hex bolt.
- since 2015 black versions of the pedals are available
- in 2022 the removable pedal was introduced on the T-line which will be on the P-line as well from 2024 on.
Not exactly "has not changed" in 18 years.
