not all mudguards are equal

[alecstilleyedye]

i bought a ribble cgr sl last autumn and, as mudguards were offered as part of the build, added them. the bike’s been great, but for the fact that while the sks guards keep me clean, they do nothing to stop the bike getting filthy on the daily commute.

the boardman cx comp that i used prior had some very effective bontrager mudguards, which were very easy to fit and adjust. they also kept the bike a lot cleaner than the sks guards.

so today i’ve removed the sks guards from the ribble and replaced them with the bonties from the boardman. i guess i’ll see on monday if that solves the dirty bike problem…

 

[I like Skol]

Don't see how properly fitted guards of similar sizes change how effectively the bike is protected depending on the make. Surely this is just a function of how mucky the roads are and how often you ride on them in inclement conditions?

 

[alecstilleyedye]

well as both bikes did the same commute but one stayed clean but the other dirty…

i think it may be due to the fact that the sks mudguards are less wide than the bontragers, and also that it’s very easy to adjust the bontragers to just the right height over the tyre with just an allan key…

 

[Spiderweb]

You need long flaps!
https://rawmudflap.uk/

 

[alecstilleyedye]

oddly the sks were longer at the back, and i’d even added a homebrew mudflap from a muc-off bottle…

 

[Blue Hills]

i think it may be due to the fact that the sks mudguards are less wide than the bontragers, and also that it’s very easy to adjust the bontragers to just the right height over the tyre with just an allan key…

So ribble fitted SKS guards too narrow for the tyre used?

Thinking this was "the rules"?

 

[Spiderweb]

oddly the sks were longer at the back, and i’d even added a homebrew mudflap from a muc-off bottle…

From my experience it’s not the back that messes up your bike, a long flap at the back will stop riders behind you getting splashed that’s all. You need a long wider flap at the front, the RAW ones linked above are excellent.
The only other explanation is that Ribble have fitted mudguards too narrow for your tyres or you have replaced the original tyres with wider rubber?

Can you post a pic of your bike?

 

[alecstilleyedye]

So ribble fitted SKS guards too narrow for the tyre used?

Thinking this was "the rules"?

to be fair to ribble the size of the guards was right. they may have erred have on the side of caution as the bike can take 40mm tyres...

 

[Yellow Saddle]

Mudguard width has nothing to do with how much spray comes off the tyres.

Bicycle tyres (note, I didn't say car tyres) only shed water at its highest perimeter i.e. the centre of the tyre.

A mudguard only has to cover a small area to be fully effective. However, breaks in the guards's continuity, such as those Raceblade things, will let water onto the headset and other brakes and BB.

To be effective, a mudguard needs to be continuous, and width has very little to do with it all.

Something else is at play here. Let's see some photos and a real, comparative test under similar conditions.

 

[the_mikey]

I too bought a Ribble CGR a few years ago, the default spec at the time came with 28mm tyres and the mudguards were the appropriate size for those tyres, I still have the original order confimation which lists 35mm mudguards on the parts list.

 

[I like Skol]

I swapped the SKS guards from my previous hybrid commuter to my current drop bar commuter. I never really clean my bikes but 18 months in the new bike is filthy, much dirtier than the old bike ever was. I think it must be the drop bars that are the problem....

 

[Blue Hills]

I too bought a Ribble CGR a few years ago, the default spec at the time came with 28mm tyres and the mudguards were the appropriate size for those tyres, I still have the original order confimation which lists 35mm mudguards on the parts list.

Some say guards should be 10mm bigger than the tyres.

 

[BalkanExpress]

Mudguard width has nothing to do with how much spray comes off the tyres.

Bicycle tyres (note, I didn't say care tyres) only shed water at its highest perimeter i.e. the centre of the tyre.

A mudguard only has to cover a small area to be fully effective. However, breaks in the guards's continuity, such as those Raceblade things, will let water onto the headset and other brakes and BB.

To be effective, a mudguard needs to be continuous, and width has very little to do with it all.

Something else is at play here. Let's see some photos and a real, comparative test under similar conditions.

This is interesting. If I understand correctly, the classic commuter issue if a bike with clearance for 28mm tyres without guards and 25mm with guards is a false choice. Fir the 28s, cut the sides of the guards but leave enough on to cover the centre and job done Assuming, of course, that the structural integrity of the guards has not been compromised

 

[Yellow Saddle]

This is interesting. If I understand correctly, the classic commuter issue if a bike with clearance for 28mm tyres without guards and 25mm with guards is a false choice. Fir the 28s, cut the sides of the guards but leave enough on to cover the centre and job done Assuming, of course, that the structural integrity of the guards has not been compromised

Yes.

 

[alecstilleyedye]

the previous bike used 32/35mm tyres with no issue. the ribble runs 32mm conti gatroskins. i usually use vittoria randonneurs, maybe that is the problem. if i get a wet commute on monday i'll see if the bike stays cleaner than with the sks guards...