Specialized plug and play fender (a.k.a. mudguard) rattle

[backnotes]

I am trying to help a friend reduce the rattle on a 2017 Specialized Diverge fitted with Specialized "plug and play" fenders. There is no brake bridge, and hence nothing to attach a mudguard bridge to. There is a pair of single stays at the back, and the only other anchor point is at the front by the bottom bracket. The guards are alloy rather than plastic, and are designed to fit this bike. The stays slide into a dedicated mounting and it is all quite tidy. There isn't a missing accessory to make a bridge where a rear caliper brake would normally go, as you get on BMC, Cannondales etc.: it's really designed to be supported at both ends only. The guards look like this https://www.lexpertvelo.com/documents/I ... 2015-7.jpg

Unsurprisingly, things are all a bit "boingy" with this long arc of unsupported aluminium, and every time you go over anything there is a "thunk" as the mudguard slaps the seat tube. The kit has a rubber spacer to stop any metal on metal contact, but it still clatters away in normal riding. Taking it as read that this is not a brilliant design and that there are probably better mudguards / fenders that could have been chosen, does anyone have a tried and tested way of solving this problem neatly?

I was thinking of adding a plastic mudguard bridge just above where the mudguard slaps the seat tube and using an O-ring stretched round the seat tube to brace the mudguard against the seat tube (with a rubber spacer in between mudguard and frame to stop the paint being worn away). This feels a bit Heath Robinson, so there must be a more elegant way? I don't think Sugru or similar would hold, and I don't want to damage the paintwork. The other way might be to make a fake brake bridge out of e.g. Perspex that bungees onto the seat stays with O-rings and gives an extra attachment point for the mudguard closer to the middle, but that feels even more Heath Robinson and I can see it wearing the paint away over time.

Thanks for any ideas, apart from "I wouldn't have started from here", because I wouldn't have, if it was my bike!

[Chris Jeggo]

How about fitting a seat-stay bridge clip to the mudguard and threading a cable tie through the brake-bolt hole of the clip and round the stays. Probably best to thread the cable tie through the clip twice, once in each direction, to finish up with a symmetrical arrangement. Still a bit Heath Robinson but dead easy. Maybe easier and neater than putting O-rings round frame tubes which don't have a free end so that the O-ring has to be doubled and secured elsewhere. If using a clip made of metal a possible problem is a sharp edge fretting through a cable tie or O-ring.

[backnotes]

Thanks Chris,

I like that idea - much simpler than any of my ideas and quick to try. I have ordered a plastic mudguard bridge and will report back in due course.

In many ways it is a clever design - the front mudguard is really solid, and the rear has a long integrated mudflap that curves with the wheel, and the way the stays attach to the rear dropouts is the neatest I have ever seen. It's just a shame the designer never took the prototype out for a ride!

[alexnharvey]

How about p clips on the seat stays with a bridging piece of metal that attaches to a bridge mount, or a bolt through the guard.

Or could some mount be attached to the seattube and fix to the mudguard at the closest point? Maybe a front derailleur mount would fit?

You could span up to the seat clamp with a piece of bent stainless steel too.

[backnotes]

Thanks very much. That would work too - and I have some rubber covered p-clips.

The owner of the bike has this afternoon found this online https://www.thebikefactory.co.uk/produc ... tube-clamp which seems to do the bracing the mudguard away from the seat tube thing. Not clear if it fits a 2017 frame but worth a punt at £5. You might have thought it would have come with the guards in the first place! Looks a bit like an afterthought to fix an unforeseen problem.

Slightly embarrassed if there is already a Specialized part that potentially sorts this Specialized problem, but thanks again to the community for two great solutions I hadn't thought of. Please don't invest any more time in this for now - sorry - the question was asked in good faith at the time it was asked!

[Dave W]

Pretty sure there is a threaded hole under the fork crown. Might need to drill the mudguard to push the bolt through. I took mine off in the summer, lbs fitted them, never rattled.