Brompton bottom bracket

[ben4watches]

My Brompton has started to develop an annoying creek from the bottom bracket, I’m sure it’s coming from there as I have removed and greasers the pedals and its still there.

Bottom bracket is only £15 so thought about doing it myself.

I would need to buy a couple of tools also totalling about £35 so I will be in for £50 or so.

The big question is how easy it to do myself and what a local bike shop charge for doing the job.

[BillN]

My Brompton has started to develop an annoying creek from the bottom bracket, I’m sure it’s coming from there as I have removed and greasers the pedals and its still there.

Bottom bracket is only £15 so thought about doing it myself.

I would need to buy a couple of tools also totalling about £35 so I will be in for £50 or so.

The big question is how easy it to do myself and what a local bike shop charge for doing the job.

There were initial problems with the BB on some Brompton's - and they offered a free replacement - I think that there was a link on their web site to check your Bike.

I know that it may be a pain to take it back to Brompton if they are not nearby

I believe that it is an easy job and quick to replace the BB

[trident-7]

My Brompton has started to develop an annoying creek from the bottom bracket, I’m sure it’s coming from there as I have removed and greasers the pedals and its still there.

Bottom bracket is only £15 so thought about doing it myself.

I would need to buy a couple of tools also totalling about £35 so I will be in for £50 or so.

The big question is how easy it to do myself and what a local bike shop charge for doing the job.

It should cost a lot less than £50 for your LBS to do it.

[mijyou]

The halfords toolkit for £50, should have everything you need to change a bottom bracket, if its threaded. I've changed mine using it. Plus there is a lifetime warranty on the tools. Then just watch a few you tube videos.

https://www.halfords.com/cycling/bik...it-171953.html

Sent from my ONEPLUS A3003 using Tapatalk

[trident-7]

I phoned Avon Valley Cyclery who are Brompton specialists & my LBS. £20 labour plus the cost of the bbkt. The Brompton one is £15 but they usually put a Shimano one in at £25 because it's much better than the Brompton one.

[mijyou]

Double post deleted

[BillN]

Shimano one in at £25 because it's much better than the Brompton one.

This is what I have (had) - Shimano BB

[Carlton-Browne]

Ben, are you absolutely sure it's not either the rubber suspension block or a pedal? Make sure you lubricate the clasp on the suspension block (assuming yours is not an ancient model without that fitted yet).

[higham5]

If in doubt that the bottom brackets starting to fail try moving / rocking the pedals across the axle. Eg hold one Crank arm in each hand and push the crank in towards the frame centreline. If there is any side to side movement then pop it into your LBS.

I have 5 bikes and do most things myself but i normally pop my bike into the LBS for headsets And BB

[ben4watches]

I checked my bike out when the recall was announced, my bike was not effected.

There were initial problems with the BB on some Brompton's - and they offered a free replacement - I think that there was a link on their web site to check your Bike.

I know that it may be a pain to take it back to Brompton if they are not nearby

I believe that it is an easy job and quick to replace the BB

[ben4watches]

Checked pedals and crank arms, which seem fine.

Defo not suspension block, creaking on the downstroke of the left side.

Ben, are you absolutely sure it's not either the rubber suspension block or a pedal? Make sure you lubricate the clasp on the suspension block (assuming yours is not an ancient model without that fitted yet).

[catch21]

St John's St cycles should be fairly near you. They're highly regarded as Brompton experts.

[mijyou]

It might sound daft but have you checked it's not the seat rails creaking?

Sent from my ONEPLUS A3003 using Tapatalk

[ben4watches]

I use them regularly.....................they are shut though.

St John's St cycles should be fairly near you. They're highly regarded as Brompton experts.

[ben4watches]

I’m going to order a Shimano replacement, as they are a better bb the the Brompton ones apparently.

The size according Brompton is 68mm - 119mm but the closest Shimano BB UN-55 is 68mm - 118mm. Is 1mm (0.5 either side) going to make a difference or should I be looking at something else.

[trident-7]

If in doubt that the bottom brackets starting to fail try moving / rocking the pedals across the axle. Eg hold one Crank arm in each hand and push the crank in towards the frame centreline. If there is any side to side movement then pop it into your LBS.

I have 5 bikes and do most things myself but i normally pop my bike into the LBS for headsets And BB

Exactly the same here.

[swisstony]

It might sound daft but have you checked it's not the seat rails creaking?

... and also take the seat post out and reinsert....

I spent months chasing down what i thought was a bottom bracket creak (not on Brompton though ...).... and it turned out to be the seat post.
I would have bet the house that the noise was coming from the BB and was amazed that reseating the seat post with a bit of grease fixed it.

[trident-7]

... and also take the seat post out and reinsert....

I spent months chasing down what i thought was a bottom bracket creak (not on Brompton though ...).... and it turned out to be the seat post.
I would have bet the house that the noise was coming from the BB and was amazed that reseating the seat post with a bit of grease fixed it.

Front wheel skewer is another common culprit. I was overjoyed when I tracked down a long-term creak to that. Bit of lube & did it up tighter & immediate cure.

My last unexplained creak did turn out to be bottom bracket though. I wasn't sure and there was no play in the bearing when I moved the cranks side to side. With the lockdown I was forced to keep riding the bike as it was. After 2 weeks it did develop plenty of lateral movement & sounded horrendous. So you could just keep riding it to destruction to be sure.

[Carlton-Browne]

Ben

Tolerances on Bromptons are obviously tight becasue of the fold - I have no idea what the answer is to your question but it sounds like you're going to open a can of worms.

I'm also not as confident as you are that it is the bottom bracket. If you do swap the BB out and it doesn't solve it, when you inevitably take it somewhere, they're going to immediately start sucking their teeth and then reverse the BB swap.

I’m going to order a Shimano replacement, as they are a better bb the the Brompton ones apparently.

The size according Brompton is 68mm - 119mm but the closest Shimano BB UN-55 is 68mm - 118mm. Is 1mm (0.5 either side) going to make a difference or should I be looking at something else.

[ben4watches]

That’s an interesting point Alan.

Bottom brackets are not that expensive so if changed and it’s not resolved the issue it’s not the end of the world. My bike is 6 years old now so could only benefit from a new one, Shimano or Brompton.

The noise only occurs on the downstroke of the left side, defo not pedal, saddle or rear damper block. Could be the crank arm but I cannot remove, grease and retighten as I don’t have a crank puller.

Could be that the BB needs to be removed, cleaned, greased and refitted, but if I’m going to that trouble I just as well replace the BB for the cost involved.

Time will tell.

Ben

Tolerances on Bromptons are obviously tight becasue of the fold - I have no idea what the answer is to your question but it sounds like you're going to open a can of worms.

I'm also not as confident as you are that it is the bottom bracket. If you do swap the BB out and it doesn't solve it, when you inevitably take it somewhere, they're going to immediately start sucking their teeth and then reverse the BB swap.

[swisstony]

Does it creak while pedalling standing up?

[ben4watches]

No idea Tony, I get out of the saddle.

Does it creak while pedalling standing up?

[jmitch]

It's an easy job and the tool should be considerably less than that!
Maybe £5, maybe the same again if you need a crank extractor.
Have a word with brilliant bikes re the tool.

I may be able post you tools on loan if necessary, if so, PM me.

[Captain Morgan]

Ben,

I’ve never done a Brompton bb, but I do most of my own cycle maintenance apart from major shock or fork services and I’d have a go at a Brompton bb.

At six years old without a replacement I’d say it’s a probable cause and likely due replacement soon either way.

I found this that might help guide you through the process if you do go ahead.

https://handsonbike.blogspot.com/201...nkset-and.html

Apologies I posted the wrong link first, that’s a upgrade of the whole crank set.

This is the bb type one
http://blog.brilliantbikes.co.uk/201...-brackets.html

[ben4watches]

Thanks for the input Si, Ive reads both those threads and watches loads of videos and reckon its doable by a novice like me.

As well as a Shimano style BB remover I would need the park tool BBT-4 too as my drive side has the FAG type. That would seem a pointless purchase for a one of use.

Ben,

I’ve never done a Brompton bb, but I do most of my own cycle maintenance apart from major shock or fork services and I’d have a go at a Brompton bb.

At six years old without a replacement I’d say it’s a probable cause and likely due replacement soon either way.

I found this that might help guide you through the process if you do go ahead.

https://handsonbike.blogspot.com/201...nkset-and.html

Apologies I posted the wrong link first, that’s a upgrade of the whole crank set.

This is the bb type one
http://blog.brilliantbikes.co.uk/201...-brackets.html

[Captain Morgan]

Thanks for the input Si, Ive reads both those threads and watches loads of videos and reckon its doable by a novice like me.

As well as a Shimano style BB remover I would need the park tool BBT-4 too as my drive side has the FAG type. That would seem a pointless purchase for a one of use.

Have you seen this?
I suspect significantly cheaper than the park tool, and if it looks like it matches the fag bb you could sell it back on via eBay once your done.

https://www.ebay.co.uk/i/27403717406...xoC3KYQAvD_BwE

Scratch that same price into more with p&p

[Meesterbond]

A couple of thoughts on the above... You pay a premium for Park Tools and they’re not always worth it. Some of their tools are really poor considering the price so don’t feel you have to buy blue to get quality.

Another consideration is that a decent lbs will chase and face the bb before fitting. Not always necessary but good practice. The tools to do that properly are really pricey though so not really one for the home mechanic...

[ben4watches]

Popped into my LBS and he said he would be happy to do the job for me but next workshop slot was end of June

Anyway, after a little chat he agreed to do it as and when he gets the chance as he was feeling sorry for me having to buy tools just for a single job.

What a nice chap.

I happen to mention that he did not have that many bikes in and he laughed, he has sold virtually all his stock, restocked and sold all those too + the workshop is flat out and he’s never been busier.

I’m glad someone is doing well out of this awful state of affairs.

[wileeeeeey]

Bike shops are laughing all the way to the bank right now - no discounts needed on the end of season stuff. Sounds like a good LBS I would pop them a review on Google maps once done, I'm sure they'd appreciate it.

[ben4watches]

Squeezed me in and I collected my bike this morning, bb arrived Tuesday and the bike was ready Wednesday.

Nice to have another little upgrade.