Brompton bottom pivot and BB replacement

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

Crankarm

Guru
Location
Nr Cambridge
My Brompton has rather a lot of play in it's bottom bracket. Can it only be replaced with like for like ie a FAG 1.37" x 24 BB? I wish to keep the standard chainset which is still fine. What specific spanner do I need to remove and replace the FAG BB as I have lots of bike specific tools, just not a tool specific to a Brompton BB? A link to one would be very helpful.

Also the bottom hinge has quite a bit of play in it. I figure the bushes need replacing. I have been using it to commute to work round trip 35-40 miles the last couple of months in all weather. Does the bike have to go back to Brompton for them to replace the bushes / service the hinge or can any LBS that sells Bromptons change the bushes? Or can I do it myself?

Help gratefully accepted.

C.
 

Rohloff_Brompton_Rider

Formerly just_fixed
bb can be replaced with anything that's the same size....BUT.....the FAG can be really easy or if the flanges break off really difficult, it took me 4 hours of drilling, heating and bashing to get another bromptoneers out. they're made out of some sort of nylon and get brittle....a well known issue on the yahoo group.

rear bushes, if the bike is less than 2 years old it's a warranty issue (i.e., free). if not and again provided you have the tools an easy job, the specific reamer is £250. but i've been told you can buy a 'will do' reamer off the internet for a tenner.

the bushes are abut £7 from sjs.

hope that helps.
 

Brommyboy

Über Member
Location
Rugby
The Fag BB needs the correct tool to remove easily. The folding joint: the bearing replacement is a factory job, but usually the pin goes first, and this can be done yourself. A kit with new pin and bolts, plus drill bit to remove existing end bolts (which are loctite'd in!) can be purchase quite reasonably.
 
OP
OP
Crankarm

Crankarm

Guru
Location
Nr Cambridge
Thanks for the advices.

I found Simpsons Cycles that do a FAG BB for £20 and the pivot kit for £17. The pivot kit consists on new bushes, metal tube and new screws/bolts. I guess getting the old one out is the tricky bit, then possibly reaming the inside of the frame before pushing in the new bushes. Fortunately I have a vice which should be big enough. I'll need to get a FAG specific BB removal tool as well. The knackered BB appears to have a metal casing and flange not nylon as suggested by bromptomfb. I guess the new one will be Nylon.
 

Rohloff_Brompton_Rider

Formerly just_fixed
The Fag BB needs the correct tool to remove easily. The folding joint: the bearing replacement is a factory job, but usually the pin goes first, and this can be done yourself. A kit with new pin and bolts, plus drill bit to remove existing end bolts (which are loctite'd in!) can be purchase quite reasonably.
nahh did mine in the garage once, didn't ream them either, was a bit stiff folding at first but was ok after a while.
 

Rohloff_Brompton_Rider

Formerly just_fixed
Thanks for the advices.

I found Simpsons Cycles that do a FAG BB for £20 and the pivot kit for £17. The pivot kit consists on new bushes, metal tube and new screws/bolts. I guess getting the old one out is the tricky bit, then possibly reaming the inside of the frame before pushing in the new bushes. Fortunately I have a vice which should be big enough. I'll need to get a FAG specific BB removal tool as well. The knackered BB appears to have a metal casing and flange not nylon as suggested by bromptomfb. I guess the new one will be Nylon.
you ream the plastic bushes not the frame. 10 minutes job, knock 'em out, knock 'em in. then your supposed to ream the bush after installation. i never bothered, the proper reamer is expensive, however a very experienced bromtpneer told me he bought his reamer for £10 from internet.

the original fag bb's are nylon, sounds like yours was replaced at some point.
 
OP
OP
Crankarm

Crankarm

Guru
Location
Nr Cambridge
you ream the plastic bushes not the frame. 10 minutes job, knock 'em out, knock 'em in. then your supposed to ream the bush after installation. i never bothered, the proper reamer is expensive, however a very experienced bromtpneer told me he bought his reamer for £10 from internet.

the original fag bb's are nylon, sounds like yours was replaced at some point.

Nope mine is the original BB and pivot as I bought it new about 7-8 years ago.

Thanks again for your kind help.
 

Rohloff_Brompton_Rider

Formerly just_fixed
oh ok, as far as i know brompton only fit fag ones, but i've only been a bromptoneer from 2009.
 
Top Bottom