DAK If there's a reason why I can't put mudguard connector behind rear bridge

General cycling advice ( NOT technical ! )
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The utility cyclist
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DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby The utility cyclist » 27 Sep 2018, 12:04pm

I want to place the rear bridge connecting bracket behind the bridge (inside of the rear triangle) so I can get the guard as high as possible without conflict with the brake arch.
Is there any valid reason not to do this?

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foxyrider
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby foxyrider » 27 Sep 2018, 12:51pm

It will raise the brake a little - not an issue in itself provided there's enough drop to set the blocks on the rim properly.

With recessed brake bolts this is the only place to mount the bridge.
Convention? what's that then?
Airnimal Chameleon touring, Orbit Pro hack, Orbit Photon audax, Focus Mares AX tour, Peugeot Carbon sportive, Owen Blower vintage race - all running Tulio's finest!

slowster
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby slowster » 27 Sep 2018, 1:21pm

That is precisely how I installed the bracket on the last pair of SKS mudguards I fitted. I did not do it to minimise interference with the brake arms (the bike has cantilevers, not calliper brakes), but because I wanted the bracket to be as easily accessible as possible afterwards to allow it to be adequately crimped onto the plastic mudguard with pliers*.

NB The bracket is not symmetrical, i.e. it could be fitted to the front of the seatstay bridge with the part of the bracket that wraps around the mudguard either forward of the bridge (where it is exposed and accessible), or rotated 180 degrees, in which case that part of the bracket will be in line with the seatstays (and so largely concealed and awkward to crimp with pliers).

Apologies if this is patently obvious, but I only fully appreciated this after installing SKS mudguards with the bracket either under calliper brake arms or in line with the seatstays, and finding that I could not properly crimp the bracket on the mudguard, resulting in the mudguard moving in the bracket and making irritating noises while riding.

* I put a piece of cloth between the bracket and the pliers to minimise the pliers marking and scratching the bracket surface.

foxyrider wrote:With recessed brake bolts this is the only place to mount the bridge.

With a recessed brake bolt you cannot mount the bracket on the forward side of the bridge, unless you use a Sheldon fender nut. I presume you've misread the OP, where TUC clarifies by saying 'behind the bridge (inside of the rear triangle)'. Either that or it's me that has completely misunderstood.

https://www.sjscycles.co.uk/brakes/problem-solvers-sheldon-fender-nuts-10-13-mm-per-pair/

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The utility cyclist
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby The utility cyclist » 27 Sep 2018, 2:45pm

slowster wrote:That is precisely how I installed the bracket on the last pair of SKS mudguards I fitted. I did not do it to minimise interference with the brake arms (the bike has cantilevers, not calliper brakes), but because I wanted the bracket to be as easily accessible as possible afterwards to allow it to be adequately crimped onto the plastic mudguard with pliers*.

NB The bracket is not symmetrical, i.e. it could be fitted to the front of the seatstay bridge with the part of the bracket that wraps around the mudguard either forward of the bridge (where it is exposed and accessible), or rotated 180 degrees, in which case that part of the bracket will be in line with the seatstays (and so largely concealed and awkward to crimp with pliers).

Apologies if this is patently obvious, but I only fully appreciated this after installing SKS mudguards with the bracket either under calliper brake arms or in line with the seatstays, and finding that I could not properly crimp the bracket on the mudguard, resulting in the mudguard moving in the bracket and making irritating noises while riding.

* I put a piece of cloth between the bracket and the pliers to minimise the pliers marking and scratching the bracket surface.

foxyrider wrote:With recessed brake bolts this is the only place to mount the bridge.

With a recessed brake bolt you cannot mount the bracket on the forward side of the bridge, unless you use a Sheldon fender nut. I presume you've misread the OP, where TUC clarifies by saying 'behind the bridge (inside of the rear triangle)'. Either that or it's me that has completely misunderstood.

https://www.sjscycles.co.uk/brakes/problem-solvers-sheldon-fender-nuts-10-13-mm-per-pair/

No, you are correct and the only way I can get the recessed nut through the mounting tab is to snip a bit from the middle of the slot so I can get the recessed bolt through, there's actually not much to take off tbh. I don't need to spend £16 on a bolt to resolve that minor aspect.
If having the mounting slot on the inside is fine then I'm all good

slowster
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby slowster » 27 Sep 2018, 7:05pm

The shoulder of a typical recessed brake nut is only 1mm. That's not going to provide much surface area for the nut to hold the bracket in place, and for the brake bolt to be adequately secured by the nut.

If it doesn't work and the nut cannot get adequate purchase on the bracket in which you enlarge the hole, I would be concerned that this this might only reveal itself when using the rear brake while riding, i.e. if the nut lost purchase on the bracket, the nut might become loose without warning.

Given your recent experience of your chainring bolts coming undone, I think I would be inlined to err on the side of caution with something like a brake bolt.

Brucey
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby Brucey » 27 Sep 2018, 9:23pm

another method is to replace the brake centrebolt (or indeed the whole brake) with a 'front' one, use a spacer (eg from a V brake block) in the recess and then use a boring old set of nuts and washers as normal.

FWIW the bridges last a lot longer if the slotted part of the bracket is sandwiched between two large(ish) washers so that none of the slot is visible.

also NB you can tap a (not very good but workable) M6 thread inside the hex on a standard recessed brake nut, good enough to use for mounting a mudguard onto. Both the parts are best retained with some threadlocking compound.

cheers
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tim-b
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby tim-b » 28 Sep 2018, 5:57am

Hi
IME the easiest solution involved a couple of small cable ties and four small holes in the guard; four dabs of epoxy made everything watertight and some tape protects the paint on the brake bridge
Regards
tim-b
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iow
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby iow » 28 Sep 2018, 9:16am

GB do a cheaper option than problem solvers.
mark

pwa
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby pwa » 28 Sep 2018, 9:20am

The utility cyclist wrote:I want to place the rear bridge connecting bracket behind the bridge (inside of the rear triangle) so I can get the guard as high as possible without conflict with the brake arch.
Is there any valid reason not to do this?

I'm sure I've done it with no issues.

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The utility cyclist
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Re: DAK If there's a reason why I can't put mudguard connector behind rear bridge

Postby The utility cyclist » 28 Sep 2018, 11:40am

All sorted, just did a quick brake test and all seems fine, just been a worry wart.
thanks all.