Brompton rattle

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Homersaysdoh

New Member
Hi anybody know what can be causing the rattle at the rear of my wife’s Brompton? Sounds a stupid question but I can’t find it. We have 2 and hers about 3 years old rattles like crazy, I have tightened the mudguard, I suspect it’s from the suspension which has a little more play than mine. Her block is a rubbed type but mine is solid. When bikes are stationary seems little difference if I rock them both.
 

mitchibob

Über Member
Location
Treorchy, Wales
What gearing? The jockey wheels in the 2 and 6 speed tend to add to rattling. The little wheels also. If you have one, and it's rubbers are a little worn, the pump (but you'd notice that more when it falls out).

On the Dunwich Dynamo last year, on that particularly rough bit of road up to Epping, a fellow rider opened the conversation with "the unmistakable rattle of a Brompton". I couldn't argue at the time. It was definitely rattling on that hideous bit of tarmac.

(I use superfirm suspension block, but apparently, that's not for everyone)
 

rogerzilla

Legendary Member
Let's get the obvious joke out of the way first: Ribbed. For Her Pleasure.

Now, if it's not the little plastic rollers, the suspension block itself can be noisy. Remove it and its bolt. Grease the bolt with a lot of silicone grease and refit. This has to be done quite frequently on some Bromptons.

Finally, Sturmey-Archer hubs can rattle, especially the SRF3 which has a kludgey non-slip mechanism. There is a thin steel shroud to trip out the extra set of pawls in the driver, and this soon gets rattly. Taking it apart and adding more of the special brown grease shuts it up for a while.

It is unlikely to be the rear hinge rattling, even if it's worn.
 

Gunk

Guru
Location
Oxford
The rattle maybe the slight play when the rear triangle is “locked” to the main frame, the clip has about 2mm of play and over rough surfaces this does cause the bike to rattle.
 

Gunk

Guru
Location
Oxford
Just another thought, check the locking disc under the rear brake calliper, on some Bromptons it’s only held on with a flat headed bolt making it difficult to tighten properly so they easily come loose. I’ve used a Allen stud off a brake calliper on mine so I can tighten it properly.

514534
 

12boy

Guru
Location
Casper WY USA
I used to be plagued by noise from the suspension block but that stopped when I put a section of rubber fuel hose over the bolt inside the block. This also made my firm block a lot firmer. I also think the jockey wheels on the tensioner for chain pusher hubs make some noise.
 

Gunk

Guru
Location
Oxford
I went out on mine today and over rougher services it rattles like a good ‘un I’m sure it is the rear triangle, either the frame catch, suspension block or jockey wheels, anyway it’s not a huge issue and perhaps they all do it.
 
Location
Essex
🤞 Awesome! If you've got kids you'll understand the brain's ability to tune out certain frequency ranges - you'll soon not notice it :okay:
 

avecReynolds531

Veteran
Location
Small Island
Have to say the rattles on our Brompton were putting the hurts on my ears today - I like a bike to be quiet - rough surfaced roads (plenty to choose from here in Kent) made the racket a lot worse. :blush:

...but it was still great fun and a 40k/ 25 mile loop was no problem regarding comfort or tiredness.

Has anyone got to the point where their Brompton is silent?
 
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