Fitting SKS Mudguards to CAADX 105 Disc (Picture heavy)

[ColinJ]

I have a small Boardman so i think it well maybe a size of frame thingy

View attachment 435921

Yes, I'm sure that it is.

Having said that, frame geometry also comes into it ... I checked my other (similarly-sized) bikes (which currently do not have mudguards) and discovered that I have exactly the same degree of marginal overlap on them. That has never been an issue - in fact, if I hadn't just checked them I would have been unaware of it! However, I remember that adding Crud Roadracer mudguards to those bikes DID create an overlap issue. It almost caught me out once when zigzagging up a 25% ramp.

 

[ColinJ]

I did a 44 mile test ride today.

The back mudguard was great - it was very stable and quiet, and gave full protection.

The front was rattling and annoying me so I will have to sort that out. The other thing with the front mudguard is that it covers more of back of the front wheel than any mudguard I have seen before, which is great from the point of view of protection of myself and the bike from filth, but it is very easy to catch it on kerbs etc. I did quite a lot of offroad today and it kept getting snagged on boulders and ruts. I'm going to think about whether to trim the flap down an inch or two. It would be a shame to lose that extra protection, but I could see me damaging the mudguard if I keep catching it on things.

The real answer would be to get my mountain bike working again, use that for serious offroad riding, and keep the CX bike for roads, towpaths, and less gnarly offroad trails. (The tyres on the CX bike are not really chunky enough for proper rough stuff anyway.)

 

[ColinJ]

The front was rattling and annoying me so I will have to sort that out.

OMFG, I just found out what the problem was and it was NOT the mudguard. I can't believe that I made the mistake that I did ... When I put the front wheel back in after fitting the front mudguard, I forgot to tighten its quick release properly. Today I rode 44 miles with the front wheel trying to fall out!

The only thing that saved me was the 'lawyer lips' on the dropouts!

 

[Bonefish Blues]

If you had rim brakes it would have been obvious the first time you used them, I guess!

 

[ColinJ]

If the QR hadn't been done up I would have noticed immediately. What caught me out was that it was closed but incorrectly adjusted. It seemed to be tight but the wheel could move about when riding over bumpy surfaces.

I could hear the mudguard slapping against the wheel but it turned out to be as much a case of the wheel moving towards the guard as the guard moving towards the wheel

I will go out later and ride over some bumpy surfaces to see if the bike is back to being quiet.

 

[alecstilleyedye]

for those without the diy skills of the op, i recommend bontrager mudguards.

https://www.evanscycles.com/bontrager-ncs-road-mudguard-set-700c-x-18-35c-EV138150

really easy to fit and do a fine job without fuss. pricy, but worth it.

had them on my commuter for over a year, and 10000km later they’re still good as new with no signs of cracking where the mounts meet the plastic...

 

[ColinJ]

I will go out later and ride over some bumpy surfaces to see if the bike is back to being quiet.

I'm back ... The alarming clunking sound of the wheel moving in the dropouts has gone, but 50% of the irritating rattling and guard-tyre slapping noises are still there. More fettling required!

 

[ColinJ]

Mudguard fettling - lesson #3!

The rubbery plastic flap on the front mudguard had scraped on quite a few boulders, kerbs etc and was already starting to look tatty after 175 kms of use. The plastic is fairly soft so I was able to trim a few mm off to tidy it up, without having much impact on the protection that the guard offers. I have noticed how much less the guard is catching on things now. I may even trim another 5 mm or so off at some point, but I will leave it at that for now and see how I get on.

As for the noises from the front guard ...

It sounded like some of the noise was due to the front part of the guard slapping against the wheel when going over bumps in the road. There was quite a long length sticking out over the wheel from the tab attached to the back of the fork and it was not difficult to get it to contact the wheel. I improvised another temporary tab (cut from a baked bean tin!) and bolted that on at the front of the fork, reducing the unsupported length of mudguard by about 25%. It has stiffened the guard nicely and has reduced the amount of noise coming from the front of the bike. I'll replace the bodged tab with a more solid and neater one when I find a suitable piece of metal in one of my junk boxes.

There is still quite a lot of rattling coming from the back of the front guard though. I thought that the flap seemed slightly loose so I wedged some slithers of plastic between the flap and guard to reduce any movement between the two. The worst of the remaining noise problem is due to the fact that the stays and the guard itself are not stiff enough to stop the bottom of the guard flapping from side to side. It isn't a problem on the rear mudguard because its stays are spread much wider where they are attached to the bike, which makes them adequately stiff in that direction. I have 2 ideas to reduce the remaining problem - (1) Bolt a strip of metal along the back of the front mudguard to stiffen it laterally. (2) Put roller bearings on the front stays located so they would roll along the sides of the front tyre if the guard started to move sideways, thus preventing further movement.

 

[Heltor Chasca]

*If your front mudguard is too low at the rear of the tyre, perhaps you could bolt the mudguard bracket to the front if the fork which will bring the whole guard around and forward.

*Assuming you have it bolted to the rear of the crown.

 

[ColinJ]

*If your front mudguard is too low at the rear of the tyre, perhaps you could bolt the mudguard bracket to the front if the fork which will bring the whole guard around and forward.

*Assuming you have it bolted to the rear of the crown.

It is bolted to the rear and I did consider doing that but I like the extra coverage that having the guard that low offers. My feet and the bike chain remained totally clean on my test ride, despite riding through quite a lot of mud and puddles. Also, it would mean a longer length of unsupported mudguard at the front. I can live with the occasional minor scrape but the frequent rattling is annoying me. It is definitely a lateral stiffness problem. I can move the back of the guard sideways easily but it is adequately stiff vertically.

 

[ColinJ]

I have reduced my rattling front mudguard problem by at least 75% simply by lowering the front tyre pressure. I did a 63 mile ride on the bike a couple of days ago, including some rough roads and fast descents, and the bike no longer sounded (or felt) as though it was trying to shake itself to pieces!

I had also done some bodgery, which I suspect didn't make much difference, but the only way to be sure is to do another test ride with those bodges taken off and see if the noises come back.

I trimmed about 3 mm from the flap on the front mudguard. It had been catching on kerbs, boulders etc. and the plastic was getting tatty. It was easy to cut with sharp scissors. It hasn't made a lot of difference to the amount of protection offered (which is still fantastic!) but a surprising difference to how often I am catching the flap on things. Before, I kept scraping the flap on the edge of the kerb outside my house. Now I can just ride straight onto the road without thinking about it.

I would still like to stiffen the guard to reduce the lateral movement of the bottom section on rough surfaces. The top half is well-supported and doesn't move much but the bottom half can twist and flex.

 

[Levo-Lon]

If i had rattles id bin my mudguards..i hate rattles.mine are silent.
So something is not right @ColinJ

 

[ColinJ]

If i had rattles id bin my mudguards..i hate rattles.mine are silent.
So something is not right @ColinJ

The rear mudguard is perfect.

The top of the front mudguard is nice and rigid now and silent. The problem is that these are incredibly long mudguards (hence the name - Longboards!) which is great from the point of view of protecting my feet and the transmission from crap thrown up by the front wheel, but it means there is a lot of mudguard to flop about.

This picture summarises the problem...

The problem is that the bottom end can flap from side to side and it is proving difficult to stop it. If the bottom stays were a little longer then I could push the flap further away from the wheel, but there isn't a lot of scope for that, though I could try. (I think the noise is mainly coming from the flap contacting the wheel when riding over bumpy surfaces at speed.) I could cut the flap down or even remove it but it would be a real pity to do that because the mudguard is giving so much protection as it is.

My other idea is to stiffen the mudguard by attaching something down the back of it. Since the guard is pretty rigid at the top stay, if I could stop the guard twisting then it wouldn't be able to move sideways.

 

[ColinJ]

I took another look and there was just enough spare length in the bottom stay to push the flap clear of the wheel. It means that the guard is now a bit further away from the wheel than I'd like but it looks as though it should still give full protection with the tyres fitted.

I'll go out in the morning and ride some of the rough local roads that caused it to rattle before and see if it still does.

 

[ColinJ]

I did a short test ride today. The mudguard isn't making much more noise now than the chain slapping about on bumpy roads. I have one last idea that I am going to try. If I can reduce the residual noise just a little more then I'll be satisfied.