Which bottom bracket for this Brompton?

Page may contain affiliate links. Please see terms for details.

Ajax Bay

Guru
Location
East Devon
Brompton did a recall for BB replacement of 150,000 bikes built between April 2014 and May 2017 with frame numbers: 1403284144 to 1705150001. The OP's friend's bike has the serial number: 1202194675 so probably earlier than 2013.
As far as 'bang for your buck' the 118mm JIS spindled UN-55 from Amazon @ £14 to which I linked ^^^, seems good to me.
 
Last edited:

12boy

Guru
Location
Casper WY USA
I would have to respectfully disagree..... I have used cartridge bearings in many of my bikes for tens of thousands of miles and never had any trouble. The tool I use to remove and install them fits on a 2ft breaker bar which works a lot better for me than the hook tool or oval slot wrench needed for the ball bearing ones.
 

berlinonaut

Veteran
Location
Berlin Germany
Brompton did a recall for BB replacement of 150,000 bikes built between April 2014 and May 2017 with frame numbers: 1403284144 to 1705150001. The OP's friend's bike has the serial number: 1202194675 so probably earlier than 2013.
Clearly. For one it has a fixed chainwheel - which means the bike was built before April 2013; affected by the recall were only bikes with JIS bottom brackets and spidercrank anyway. Secondly from the serial of the OP's friends bike you can see that it was built in February 2012. So totally unaffected.
 

rogerzilla

Legendary Member
The FAG one often gets a bit stuck and then the metal tool simply chews up the plastic cups. It isn't my favourite design.
 

Gunk

Guru
Location
Oxford
Clearly. For one it has a fixed chainwheel - which means the bike was built before April 2013; affected by the recall were only bikes with JIS bottom brackets and spidercrank anyway. Secondly from the serial of the OP's friends bike you can see that it was built in February 2012. So totally unaffected.

If it is a fixed chain wheel then it will need a IOS sealed BB. No longer available from Brompton.
 

berlinonaut

Veteran
Location
Berlin Germany
The FAG one often gets a bit stuck and then the metal tool simply chews up the plastic cups. It isn't my favourite design.
They have been using a Thun one for a couple of years already, FAG is long gone. Never had a problem with the FAG cups anyway - usage of proper tools and sorrowful handling of it avoids any issues.
 

berlinonaut

Veteran
Location
Berlin Germany
If it is a fixed chain wheel then it will need a IOS sealed BB. No longer available from Brompton.
As said before: ISO bottom brackets in Brompton size are close to impossible to get hold of for a couple of years already and Brompton themselves are no exception. But, according to Brompton and again as said before, you can use the JIS bottom bracket with the older fixed cranks despite they were originally used on a ISO bracket. So where is the problem?
 

Ajax Bay

Guru
Location
East Devon
Problem - just needs care. Measure the current ISO spindle and procure a JIS cartridge BB with a spindle 4mm shorter, if I read Sheldon's advice correctly (I have not needed to do this).
(Sheldon): "If you install an ISO crank on a JIS spindle, it will sit about 4.5 mm farther out than it would on an ISO spindle of the same length." The 118mm spindle quoted above is for a Brompton 'spider' chainset with a detachable chainring.
But this discussion maybe nugatory.
we are going for a new chainset, new chain as that needs replacing and a new bottom bracket with JIS
 
Last edited:

Gunk

Guru
Location
Oxford
As said before: ISO bottom brackets in Brompton size are close to impossible to get hold of for a couple of years already and Brompton themselves are no exception. But, according to Brompton and again as said before, you can use the JIS bottom bracket with the older fixed cranks despite they were originally used on a ISO bracket. So where is the problem?

It’s just at odds at the advice I received from Brilliant Bikes.
 

12boy

Guru
Location
Casper WY USA
I've used a JIS 118 BB for years on my Brompton with the one piece, and then when I switched to a 2 chainring 110 BCD set up, put the same one piece on a Xootr Swift with a JIS BB and put another couple 1000 miles on that without a hiccup. That has a 1 x 8 derailleur system and I like the one piece because it is lighter than an aluminum 2 piece and because it had 54 teeth which added a couple of gear inches over the 52 it came with.
 
OP
OP
jay clock

jay clock

Massive member
Location
Hampshire UK
The parts Arrived from SJS today, and all fitted. The really difficult but I thought might be removing the old BB, but it was actually fine and the BB shell was immaculate inside.

All fitted and looks fantastic. Thanks to everyone for their advice
64EDF9A3-1D98-4344-848A-5B1EAC84B318.png
 
Top Bottom