Author Topic: Brompton rear hinge  (Read 19861 times)

Brompton rear hinge
« on: September 04, 2009, 09:38:48 pm »
Anyone had their bushes replaced?  How much did you pay, and did they ream them properly?

EDIT: Cyclecare Kensington - and Purton, near Swindon - can do it for £45, assuming no serious complications, and they have the reamer.  CH White in Malmesbury don't have the tool.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Re: Brompton rear hinge
« Reply #1 on: September 05, 2009, 07:11:06 pm »
£45?  ;D

Sod that. Looking at the replacement bush kit on SJS the bushes look like a H4 adjustable reamer size.
Which are available for £5 (the reamer that is).
A quick check anyway of the bushes with a vernier will soon reveal what reamer was needed. (it certainly won't be the one that's priced at £200.00 on SJS)   ;D ;D ;D

I'm also confident of doing a much better job anyway.  :smug:
Quote from: Marbeaux
Have given this a great deal of thought and decided not to contribute to any further Threads for the time being.
POTD. (decade) :thumbsup:

Re: Brompton rear hinge
« Reply #2 on: September 05, 2009, 07:13:26 pm »
The factory charge £65 (including the retailer's cut).  People have successfully done it using a standard reamer, but keeping the bores perfectly aligned on both sides is the tricky bit.

One day they'll wake up, smell the coffee, and use some sort of cartridge needle bearing.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Re: Brompton rear hinge
« Reply #3 on: September 05, 2009, 07:16:09 pm »
but keeping the bores perfectly aligned on both sides is the tricky bit.


I'd say that only such a small amount needs taking out that it's not really an issue.

This is evident by the replacement bushes not even being solid bronze phosphor ones.
As on the SJS site.
Quote from: Marbeaux
Have given this a great deal of thought and decided not to contribute to any further Threads for the time being.
POTD. (decade) :thumbsup:

Re: Brompton rear hinge
« Reply #4 on: September 05, 2009, 07:20:13 pm »


One day they'll wake up, smell the coffee, and use some sort of cartridge needle bearing.

 ;D

They're made in Great Britain.  I remember when that meant quality.  ;D
Quote from: Marbeaux
Have given this a great deal of thought and decided not to contribute to any further Threads for the time being.
POTD. (decade) :thumbsup:

Re: Brompton rear hinge
« Reply #5 on: September 06, 2009, 07:38:08 pm »
Could we contemplate a group purchase of the tool? 

I'm happy to do the job for any forumites, or offer the workshop here for use, but even I can't justify the cost for the proper tool.  Alternatively someone offers to hold it centrally and post it out as and when it needs to be used.

border-rider

Re: Brompton rear hinge
« Reply #6 on: September 06, 2009, 07:52:46 pm »
Mine's towards the end of its third set

Both replacements done by Phoenix Cycles in Kensington(ish) at much less than Brompton wanted (can't recall how much, wasn't cheap)

Re: Brompton rear hinge
« Reply #7 on: September 06, 2009, 10:11:32 pm »
There are two tools; the removal tool is over £100 and the reamer is £200.  The removal tool is only necessary if your old bushes are really, really stuck, otherwise people seem to get them out using a tap to grip them.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Sigurd Mudtracker

Re: Brompton rear hinge
« Reply #8 on: October 11, 2009, 08:14:26 pm »
I stumbled upon this on Ben Cooper's Kinetics blog...

Re: Brompton rear hinge
« Reply #9 on: October 12, 2009, 06:31:54 am »
Yeah, but after a few years you'll give up waiting and buy a new bike.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Sigurd Mudtracker

Re: Brompton rear hinge
« Reply #10 on: October 13, 2009, 09:41:37 pm »
Maybe that's part of the business plan.

LittleWheelsandBig

  • Whimsy Rider
Re: Brompton rear hinge
« Reply #11 on: March 16, 2014, 05:04:26 pm »
Both our Bromptons in England need replacement bushes, I'll need to replace the swingarm on my Brompton in Oz when I'm over there next and I have a tool fetish.

Any suggestions where I can purchase the stupidly overpriced tool? Nothing available from a quick web search.
Wheel meet again, don't know where, don't know when...

Re: Brompton rear hinge
« Reply #12 on: March 16, 2014, 06:12:38 pm »
SJSC are out of stock, but I suppose any Brompton dealer can order one.  If you haven't done the job before, don't underestimate the difficulty of drilling the heads off the s/s allen bolts - unless you get lucky and they actually unscrew.  They are fitted with some never-to-be-undone threadlocker at the factory.  The best technique I found was a hand cranked drill using all my weight and turning the chuck itself slowly.  And lots of cheap Wilko HSS bits.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Re: Brompton rear hinge
« Reply #13 on: March 17, 2014, 11:05:13 am »
What are the symptoms of bush replacement being required - play, noise, something else?

My Brom's started squeaking terribly, and though I haven't investigated yet I'd like to be prepared for the worst ... (Lightly used though, so I'd be disappointed if it needed serious work.)

LittleWheelsandBig

  • Whimsy Rider
Re: Brompton rear hinge
« Reply #14 on: March 17, 2014, 11:12:18 am »
Mostly excessive play, though my Bromptons also develop an annoying squeak when pedalling.
Wheel meet again, don't know where, don't know when...

Re: Brompton rear hinge
« Reply #15 on: March 17, 2014, 09:12:47 pm »
Bromptons aren't a quiet ride. Between the bell rattling, the chain noise and the various squeaks. It means people hear you coming. 


Re: Brompton rear hinge
« Reply #16 on: March 21, 2014, 07:19:01 pm »
Don't forget the rattle of a Sturmey-Archer hub.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Re: Brompton rear hinge
« Reply #17 on: March 21, 2014, 07:47:10 pm »
Oh, yes, got used to the rattles, and the ticking, and quiet squeaks. It was the loud squeaks that were beginning to worry me, but they seem to have silenced themselves.

Little obvious play in the bushing as far as I could tell - maybe a mm or two lateral movement at the top of the swingarm if I tried quite hard.

Mr Arch

  • Maker of things! Married to Arch!
  • Gothic Arch
Re: Brompton rear hinge
« Reply #18 on: April 15, 2014, 03:42:06 pm »
What are the symptoms of bush replacement being required - play, noise, something else?

My Brom's started squeaking terribly, and though I haven't investigated yet I'd like to be prepared for the worst ... (Lightly used though, so I'd be disappointed if it needed serious work.)
When mine started squeaking I tracked it down to the rubber suspension block needing some lubrication.  The lube needed to go in the bolt hole through the centre of the block.  I squirted a bit of silicone spray in there.

Re: Brompton rear hinge
« Reply #19 on: January 07, 2017, 04:52:26 pm »
Thread necromancy.

I've been looking at a friend's Brompton. He actually ended up buying a replacement bike, owing to the frightening repair bill from our (very good) LBS, and needing to be able to get to work. I don't think they gave him bad advice, but I'm trying to make sure I understand what's happened to his old one, as he's looking at selling it on either as is (as a project) or repaired (and to be honest, I'd find it a fun project to take on).

The problem is that the jobs are specialist, so it may have to go to a shop anyway.

So, the LBS were worried about the "lack of metal" in the hinge owing to wear (it's a pretty old model and has served him well). I've now seen that, and it's clearly play in the bushes. These are pretty-obviously this kind of thing (his new Brompton looks to have nylon ones?) I'm aware of rust issues in Bromptons, but I can't see any - this one looks good to me.

I can see from that page and this thread, though, that a shop equipped with spectacularly expensive tools is needed to replace the bushes. Any update on discussions here?

The other non-trivial job is a slipping seat-post, which I gather is tricky because of ungluing the old bush to replace that.

So that's the summary explanation I'm going to give. Anything I've missed or options I could give? If it ends up on eBay, he wants to give a fair summary, or if I have a go I don't want to take on anything I can't do (or turn down something I can).

LittleWheelsandBig

  • Whimsy Rider
Re: Brompton rear hinge
« Reply #20 on: January 07, 2017, 05:12:08 pm »
There is something on the interweb showing how to ream the bushes adequately with a standard fixed reamer. Brompton won't sell the proper reamer to anybody other than a Brompton-approved shop with a Brompton-trained mechanic.

I tried to pay to get on the Brompton mechanic's course so that I could buy the reamer but no dice. I'll just have to bite the bullet and do a ghetto bush replacement, after getting the frame components repainted. I'll fit a grease nipple for the pivot so that I'll never need to do it again. Unfortunately I'll probably have to replace the hinge pins to get it repainted.
Wheel meet again, don't know where, don't know when...

Re: Brompton rear hinge
« Reply #21 on: January 07, 2017, 05:25:06 pm »
I'm not shy of mechanics.
I've built car and motorcycle engines (and pushbikes), and they have worked, for tens of thousands of miles.
But this thread, with insights of 'Brompton won't sell the proper reamer to anybody other than a Brompton-approved shop with a Brompton-trained mechanic.' make me think 'walk away, and pay to make it someone else's problem'.

It really goes against the grain, I've never been over-fond of anyone other than me spannering my ride, but in this instance, I'd be tempted to let Brompton (or one of their accredited dealers) get on with it.

Re: Brompton rear hinge
« Reply #22 on: January 07, 2017, 10:05:11 pm »
It's a bit puzzling really.

Brompton sell bush and spindle kits, which are quite widely stocked. These only make sense for the home mechanic, because a shop wouldn't need a new drill and Allen key every time. However, DIY fitting isn't recommended.

The guide mentioned by LWaB is probably the Shane Cycles one. This makes it look quite possible as a DIY job. However, it's better to have a 9.5mm reamer (see comments on Shane Cycles blog) with a pilot (if I've understood reaming technology properly), because that allows the two sides to be reamed completely in line with each other. You're reaming the plastic inner of the bush, not the frame, so the reamer doesn't need to be that hardy. A 13/32-inch tap or similar is also needed, to extract the old bushes. Calhoun Cycles' photo story illustrates the process.

Then you need something to do a job like a bearing press, to fit the new bushes. Shane Cycles used M6 threaded steel. It all sounds quite achievable, if you can source the reamer. Shane Cycles managed it with an over-sized reamer and no pilot.

Hmmm...

Re: Brompton rear hinge
« Reply #23 on: January 08, 2017, 09:49:38 am »
I'd be concerned about the shop's comments about lack of metal at the hinge. If the bushes are left too long then the frame can get worn/deformed. A second opinion would probably be a good idea before deciding whether it's repairable or scrap.
Quote from: tiermat
that's not science, it's semantics.

Re: Brompton rear hinge
« Reply #24 on: January 08, 2017, 02:31:38 pm »
I'm pretty certain that the current bushes are the original, factory-fitted ones?