Brompton T5. How To Remove the FAG Bottom Bracket.

Location
London
Hello Gunk,
Thank you for your kind offer to lend me your FAG tool.
I have bought one online and it has just arrived.
I did so before you posted.
This community is very considerate.
Can I ask where you got it from/how much?
I also have a Brommie Traveller.
Must admit that I was a bit P'd off to find a few years ago when I had a peer at it to find that they had used something so "non standard". Luckily I didn't try to bodge anything - and wasn't entirely sure what it was.
All working OK I stress - I was just thinking of taking the BB out to grease the threads.
Spare BBs are available I hope so that I can retain the cranks if the BB ever packs in?
 

berlinonaut

Senior Member
Location
Berlin Germany
to find that they had used something so "non standard".
FAG type bottom brackets are the absolute opposite of "non standard". Just not as common today as they used to be. But your bike obviously has some years on the counter already.
I was just thinking of taking the BB out to grease the threads.
Why? There's absolutely no reason to do that.
Spare BBs are available I hope so that I can retain the cranks if the BB ever packs in?
No. As said before on older Bromptons you do have have an ISO bottom bracket and these are close to impossible to get hold of for some years already. For quite some years it has been replaced with JIS, you can use them with the old cranks but it is a bit off. Never change a running system... BTW: The Brompton manual recommends replacing the cranks every 5k miles.
 
Location
London
@berlinonaut

>>FAG type bottom brackets are the absolute opposite of "non standard". Just not as common today as they used to be. But your bike obviously has some years on the counter already.

Well I suppose after a few adventures in the outer reaches of biketech I tend to favour Shimano bits and bobs. If a standard FAG clearly wasn't a standard to last if, as I understand, you can no longer get those old bits. I have several bikes older than that brommie - no issues with their bits. Yep, mine is getting on - it's not actually done too many miles.

>>Why? There's absolutely no reason to do that.

I've always understood that it's good practice to take BBs out periodically to degrease the threads. I have definitely had one stick. Factory fitted stuff is also often I think rather lacking in grease so I always take BBs out of new bikes soon after buying.

>>No. As said before on older Bromptons you do have have an ISO bottom bracket and these are close to impossible to get hold of for some years already. For quite some years it has been replaced with JIS, you can use them with the old cranks but it is a bit off. Never change a running system... BTW: The Brompton manual recommends replacing the cranks every 5k miles.

Thanks for the info. You seem to be an expert on this stuff. If you could recommend a Shimano BB and a crankset from whoever that would fit I'd be very interested/grateful. Won't be doing until I need to obvs.

As a sign of how much I have thought about all this on this relatively lightly used bike it was only your comment on the cranks needing to be swapped every 5,000 miles that alerted me to the fact that chainrings can't be replaced. That wasn't very clever of them was it? And definitely not green.

So down the line I'll be looking for a new crankset with a standardish BB and a replaceable chainring.

Thanks for your post.
 

12boy

Veteran
Location
Casper WY USA
I have gone tens of thousands of miles on Japanese cranks, and Sugino RD cranks in particular. After many on and offs I've seen them get too worn in the area where the crank meets with the square spindle and also having the threads of the pedal insert become damaged. The pedal thread problem can occur with cross threading. Otherwise they seem bullet proof to me. A 118 Shimano U55 bottom bracket has worked well for me. I like to grease the BB threads, as well.
 
Location
London
[QUOTE="12boy, post: 6339415, member: 45924"\]A 118 Shimano U55 bottom bracket has worked well for me. I like to grease the BB threads, as well.
[/QUOTE]
Was this on a brompton traveller T5 5 speed?
I ask as I know the rear triangle is different than on more modern bromptons.
 

rogerzilla

Legendary Member
A Shimano BB 113mm long works with Sugino XD2 cranks (or Spa Cycles' unbranded XD2 cranks) if you put the chainring on the inside of the spider. You must get the XD2 DOUBLE crankset, not the triple. You will need a 110mm BCD ring - 52T is reasonably easy to find.
 

12boy

Veteran
Location
Casper WY USA
No, Blue Hills, it was on a 2010 and worked fine with the stock one piece, a Sugino 130 BCD RD with 54 and 38 tooth chainrings and later with a Sugino 110 BCD with a 58 and a 38.
 
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