Mudguards, bridge mount, grommets ?

[mangid]

Mudguards snapped this morning on a particularly rough bit of A road, should have cottoned on a bit earlier in the ride, there was a slight rattle on bumps before it failed...

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This is the second time it's they've failed there, get about 20K out of them. I'm guessing it's just fatigue, but is there a solution ? Maybe there exist m5 grommets which would allow some movement, and not rattle ?

 

[si_c]

Hmm, seems like it's flexing a bit too much there. A rubber or nylon washer might help, but perhaps reinforcing the underside by attaching (sugru or the like) a strip of metal might help by reducing the stress at that point.

 

[Tenacious Sloth]

Tap washers with a washer between them.

Looks like you’d only need one tap washer on yours.

 

[alicat]

Mine did that. I found I could screw the mudguards directly into the underside of the bridge.

Alternatively what Adrian says.

 

[Milkfloat]

Tap washers with a washer between them.
View attachment 407141

Looks like you’d only need one tap washer on yours.

I use a bit of old inner tube for the ultimate close fit and rattle proofing, but I really like this approach.

 

[Ajax Bay]

Doesn't that markedly reduce clearance between the mudguard (head of the bolt going up to the bridge) and the tyre?
Make/model of mudguard is?

 

[youngoldbloke]

I simply remove the bridge and rely on the correct positioning of the mudguard stays to hold the mudguard in shape. If the guard is likely to contact the frame I use a small self adhesive felt pad.

 

[Deleted member 1258]

Mudguards snapped this morning on a particularly rough bit of A road, should have cottoned on a bit earlier in the ride, there was a slight rattle on bumps before it failed...

. View attachment 407117

This is the second time it's they've failed there, get about 20K out of them. I'm guessing it's just fatigue, but is there a solution ? Maybe there exist m5 grommets which would allow some movement, and not rattle ?

I've always found that these are prone to breaking, I usually find I get 4 or 5 years from them, but sometimes they only last a year or so. I like Tenacious Sloth's idea but on a bike with rim brakes its not going to work.

 

[mangid]

Thx all, ordered some tap washers (hadn't thought of those), and have a plan on how to use the bridge mount that comes with the mudguards

I'm thinking I can drill a hole in the rear bridge support and cut off the excess, that might provide the required support.