Post by: Crofton on 05 September, 2023, 11:08:11 pm
I have read countless articles about fitting and done this with great care and attention to try and ensure no undue stresses etc. but I always end up with the same result after a couple of years. Vibrations eventually lead to the rear mudguard cracking and breaking into two pieces where it is secured at the brake bridge. I have tried a couple of pairs of Velo Orange guards and the latest were Honjos so it’s not an equipment quality issue.
Post by: LittleWheelsandBig on 05 September, 2023, 11:34:06 pm
Post by: rogerzilla on 06 September, 2023, 07:29:20 am
Post by: Cudzoziemiec on 06 September, 2023, 09:54:46 am
Post by: CrazyEnglishTriathlete on 06 September, 2023, 10:06:52 am
My rear mudguard failed in exactly this way on Tuesday, although it was provoked by a screw that got lodged in the tyre. In failing the mudguard managed to progressively hammer the screw all the way into the tyre. Ho hum. Set Strava PBs like Johnny English setting off traffic cameras on the rest of the commute home, so I suppose it had some benefits :facepalm:
Post by: Kim on 06 September, 2023, 12:30:31 pm
Post by: vorsprung on 06 September, 2023, 01:55:31 pm
Post by: Ian H on 06 September, 2023, 02:05:51 pm
Post by: Danu on 06 September, 2023, 02:30:34 pm
Post by: Crofton on 06 September, 2023, 04:25:02 pm
- I can see the benefit of chromoplastic mudguards with an extra set of stays but they are too ugly
- Wider mudguards also sound like a good idea (current pair are 41mm and the frame might just accommodate 45mm)
- I did wonder whether stainless guards might be less susceptible to this sort of fatigue cracking - will investigate further
- I fear any repair will rattle unacceptably!
Post by: morbihan on 06 September, 2023, 05:59:36 pm
Post by: aidan.f on 06 September, 2023, 09:48:41 pm
Take the stays off the broken one
Fit another pair into place.
I presume your 'Chromoplastic is too ugly' refers to the material not an extra pair of stays.
Post by: Crofton on 07 September, 2023, 12:42:26 pm
Quote
Buy a new mudguard identical to one wot broke.
Take the stays off the broken one
Fit another pair into place.
Had the same thought myself and a mechanic at the LBS also came up with the same suggestion so will try it.
Post by: sparklyfish on 07 September, 2023, 09:50:26 pm
cork/rubber spacer to dampen the vibrations?
I had the same thought a couple of years ago, and have been using rubber washers as well as normal washers. Haven't had a mudguard fail since, but have had the rubber washer perish instead!
Post by: Dickyelsdon on 08 September, 2023, 02:53:08 pm
https://www.sjscycles.co.uk/mudguards/40-mm-gilles-berthoud-mudguard-stays-kit/
Post by: fruitcake on 08 September, 2023, 09:08:22 pm
Post by: Tod28 on 09 September, 2023, 03:55:45 pm
It's aluminimum being shaken about. It's going to fail somewhere eventually.
This - the fatigue life of aluminium is miserable. It will fail close to where it is securely fastened if the body of the material is relatively free to move about (albeit fractional movement). Stainless steel will have a significantly longer fatigue life in terms of number of cycles of flexure and the induced bending stress is a lower proportion of allowable bending stress also increasing the fatigue life in the same installation.
Post by: LittleWheelsandBig on 12 September, 2023, 07:32:40 am
cork/rubber spacer to dampen the vibrations?
I had the same thought a couple of years ago, and have been using rubber washers as well as normal washers. Haven't had a mudguard fail since, but have had the rubber washer perish instead!
The best mudguard washer material to damp vibration is supposed to be leather.
Post by: Shuggie on 12 September, 2023, 11:40:17 am
(https://uploads.tapatalk-cdn.com/20230912/6cab667361f8b0d8112f06d7b261eaef.jpg)
SKS Chromoplastic P-45 which had been on my Sabbath September AR-2 for about 1800 road miles and the rear mudguard broke on Sunday. I had added a B&M Secula battery operated rear light onto the back at about 800 miles which probably created much more stress. Several weeks ago I had to tighten the seatstay bridge screw as it had become really loose mid ride, maybe I did it too tight. I had thought of adding threadlock but this fracture beat me to it.
Have used SKS chromoplastics P-35 and P-45 with the same rear lights before on other bikes without a problem but the metal clips on the P-35 do wear the guards and have snapped in the past.
Will be replacing the guard but putting the rear light elsewhere
. Cheers, Hugh
Post by: hubner on 12 September, 2023, 12:13:53 pm
Would it make a difference?
Post by: Shuggie on 12 September, 2023, 01:03:40 pm
I was wondering how these broken mudguards were mounted, direct mount with a bolt through a hole in the mudguard or with a crimp on metal/clip on plastic bracket?This one was direct mount using the M5 bolt and washer provided with the frameset, I drilled the hole through the mudguard and was pretty pleased with its position. Can’t see how easy it would be to use the metal clip bent to 90 degrees, or in this case the plastic one which does pivot, it would certainly and unacceptably reduce the tyre clearance IMHO.
Would it make a difference?
Anyone else with better experience?
Cheers, Hugh
Post by: hubner on 12 September, 2023, 07:46:28 pm
Also, how thick is the mudguard? I would think anything less than about 1mm wouldn't be all that durable.
Post by: Lightning Phil on 12 September, 2023, 08:17:34 pm
Post by: hubner on 12 September, 2023, 10:03:57 pm
Post by: Cudzoziemiec on 13 September, 2023, 09:24:18 am
I had some Velo Orange mudguards (can't remember now if they were aluminium or steel) which were supplied with leather washers. It didn't take long for the leather to become a slimy pulp. The guards themselves seemed strong enough, and they looked ace, but they didn't stay still due to poorly designed stays (at least for my bike). I replaced them with SKS Edge (aluminium but no leather washers supplied – in fact no washers at all) which clatter a bit but do their job.cork/rubber spacer to dampen the vibrations?
I had the same thought a couple of years ago, and have been using rubber washers as well as normal washers. Haven't had a mudguard fail since, but have had the rubber washer perish instead!
The best mudguard washer material to damp vibration is supposed to be leather.
Post by: LittleWheelsandBig on 13 September, 2023, 09:27:44 am
Post by: Shuggie on 13 September, 2023, 11:08:08 am
Also, how thick is the mudguard? I would think anything less than about 1mm wouldn't be all that durable.
Just measured it at 2.0mm, 2 coats of plastic (can’t tell what type) with a thin film of aluminium foil sandwiched between.
Replacement just arrived from Spa, has a rear reflector on it which I’m minded to remove, just in case
Cheers, Hugh
Post by: Cudzoziemiec on 13 September, 2023, 11:26:40 am
Post by: Shuggie on 13 September, 2023, 12:30:21 pm
Post by: hubner on 14 September, 2023, 10:56:34 am
My suggestions:
use a brake bridge bracket or
direct mount:
make sure the surfaces around the hole are smooth to reduce stress risers,
use large washers, shaped to fit the mudguard curve, to reduce tension on mudguard
use rubber and/or leather washers to reduce vibration, although I would have thought rubber would be better.
Post by: mrcharly-YHT on 14 September, 2023, 03:45:28 pm
Oops, first time this has ever happened to me!I don't like the look of that weld.
(https://uploads.tapatalk-cdn.com/20230912/6cab667361f8b0d8112f06d7b261eaef.jpg)
SKS Chromoplastic P-45 which had been on my Sabbath September AR-2 for about 1800 road miles and the rear mudguard broke on Sunday. I had added a B&M Secula battery operated rear light onto the back at about 800 miles which probably created much more stress. Several weeks ago I had to tighten the seatstay bridge screw as it had become really loose mid ride, maybe I did it too tight. I had thought of adding threadlock but this fracture beat me to it.
Have used SKS chromoplastics P-35 and P-45 with the same rear lights before on other bikes without a problem but the metal clips on the P-35 do wear the guards and have snapped in the past.
Will be replacing the guard but putting the rear light elsewhere
Cheers, Hugh
Maybe (hopefully) it is just the angle.
Post by: Shuggie on 14 September, 2023, 04:03:01 pm