Brompton Mudguard replacement

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T4tomo

Legendary Member
Has anyone done this? My rear mudguard has just about worn / corroded through - brackets are all fine though. how much of a job is it to fit new guard to existing brackets? I need to change rear tyre 9so have thefun of battling a new marathon overthe rim) and chain could do with renewing so was thinking whislt teh back wheel is off might as well do it too if its a simple-ish job.
 

alicat

Legendary Member
Location
Staffs
Fitting a new mudguard is not difficult but never seems as straightforward as it ought to be. If you have to take the back wheel off anyway go for it.
 
Wheel will need to come off to get the mudguard stays unscrewed. Pop some threadlock or a dab of paint on the new ones on the underside to ensure they stay on.
 

Brommyboy

Über Member
Location
Rugby
If changing the chain, then you will definitely need also to fit a new sprocket, and possibly, a new chain ring/crank. For the chain, you would need a chain splitter which is not too difficult to use but is best done first under guidance, especially for joining the new chain. The link has to be loosened after tightening! Most repairs can be done by the owner, although some need a bit of expert advice.
 
OP
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T4tomo

T4tomo

Legendary Member
Yes i'm happy wielding my chain splitter, is it right you can't use quick links on a Brommy chain though -sure I read that somewhere or is that just on a the derailler models? mine is just a 3 pseed 1./8th chain.

"If changing the chain, then you will definitely need also to fit a new sprocket, and possibly, a new chain ring/crank." WHY? I usually work on the basis of change the sprocket/cassette every other chain change - sprockets last longer than chains and their is no sign of excessive wear. Chain rings last substahtially longer. is there something about Brommies I'm missing that make them different to other bikes?
 

Brommyboy

Über Member
Location
Rugby
The small sprocket wears faster than the chain, and is usually the cause of the chain 'stretch', which then wears the chainring out quite quickly. Put a new chain on and then apply power and see how quickly the chain jumps the sprocket teeth! As far as quick links go, the 1/8" is of a different type as it works on the principle of a cir clip rather than a double-sided locking link, which is prone to open up over the small sprocket/tensioner curves.
 

Night Train

Maker of Things
The tyre, chain, sprockets and wheel are easy if taken methodically.
The mudguard I found fiddly to get right. I ended up refitting the wheel to check for clearances and then refitting the mudguard again, with the wheel left on, to get the clearances right.
 

Brommyboy

Über Member
Location
Rugby
Just fitted a new front mudguard. Yes, very fiddly! I eventually took the wheel out to make it far easier to fit the little bracket around the stay. Returning the wheel to the fork, I always clamp the brake on before finally tightening the nuts. This centres the wheel. If the stay is not centred, then just loosen the bracket and move it before re-tightening.
 
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OP
T4tomo

T4tomo

Legendary Member
All sorted last night whilst waiting for my son at hockey training, the back of a volvo estate makes a good mobile workshop. All relatively straightforward to be honest and mudguard alignment seemed to be right first time. trickiest part was getting the split ring thingy back on after chnaging the sprocket - its one of thiose tasks where 3 hands would be useful.
Gear cable and handlebar grips tonight and she's be as good as new.

One slightly odd thing, I noticed the new Schwable marathons (not the +) are rated to 85 psi whereas the old ones were rated to 100psi. slightly odd.
 

Brommyboy

Über Member
Location
Rugby
Did you manage to remove the old grips all right? I find that opening a gap with a fine screwdriver and dribbling some water in helps to loosen the grips for pulling off. Equally, some water on the bare bars helps the new ones on, and evaporates soon, allowing them to grip firmly. Thumb pressure and a fine screwdriver opposite the gap in the sprocket ring will make the job fairly easy to reinstate.
 
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