# How much do mudguards slow you down ?



## Banjo (3 May 2017)

I tend to leave them on year round .
I wonder if any scientific experiment has been done.


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## I like Skol (3 May 2017)

Some, maybe, probably fark all. Are you in a race?


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## vickster (3 May 2017)

Not as much as all that crap plastered up your back


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## screenman (3 May 2017)

The difference is plus or minus and a tad more depending on wind direction


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## Drago (3 May 2017)

I've often felt that full guards make a slight but noticeable difference.


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## Dogtrousers (3 May 2017)

It's a little known fact that mudguards actually speed you up.

The upper surface of the tyre travels forward at a speed of pi/2 times the bike's road speed. This results in additional drag which is negated by the faring effect of the mudguard. Tests show a small but significant decrease (between 2and 5%) in aerodynamic drag when mudguards are used.

The reason that professionals don't use them is because they are illegal. They were controversially banned by Henri Desgrange after the 1935 Tour de France, as he considered them "unmanly" and "fit only for the English and the Dutch". Attempts to reintroduce them have failed due to safety concerns around the mudguard stays. 

Lance Armstrong used mudguards in all of his Tour de France wins, but everyone pretended not to notice. Phil Liggett still denies it and to this day claims that it is "impossible and inconceivable" that he could have done such a thing.


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## Pro Tour Punditry (3 May 2017)

Did bonj not prove you don't actually need mudguards if you cycle fast enough?


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## screenman (3 May 2017)

Vernon was the expert on pi.


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## palinurus (3 May 2017)

Marmion said:


> Did bonj not prove you don't actually need mudguards if you cycle fast enough?



If your arse is moving fast enough how're the drops gonna catch up? stands to reason.


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## Banjo (3 May 2017)

Should have known better shouldn't I ......


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## Pro Tour Punditry (3 May 2017)

palinurus said:


> If your arse is moving fast enough how're the drops gonna catch up? stands to reason.


I think that was the extent of the proof


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## ianrauk (3 May 2017)

My commuter has mudguards all year round. But only because I can't be arsed to take them off.


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## mjr (3 May 2017)

[QUOTE 4787227, member: 259"]Mine does too, but only because I can't be arsed to scrape all the mud off my arse.[/QUOTE]
Never mind that, what about the face of the guy behind?


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## Dan B (3 May 2017)

The full mudguards on my commuter probably account for less drag than the hub dynamo which is also attached all year round


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## Welsh wheels (3 May 2017)

Dogtrousers said:


> It's a little known fact that mudguards actually speed you up.
> 
> The upper surface of the tyre travels forward at a speed of pi/2 times the bike's road speed. This results in additional drag which is negated by the faring effect of the mudguard. Tests show a small but significant decrease (between 2and 5%) in aerodynamic drag when mudguards are used.
> 
> ...


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## Welsh wheels (3 May 2017)

I ride so fast that mud and water spray can't keep up with me


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## tommaguzzi (3 May 2017)

About as much as clippie pedals speed you up.


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## Mr Celine (4 May 2017)

Depends if you count the time spent tracing and fixing rattles.


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## Banjo (4 May 2017)

Mr Celine said:


> Depends if you count the time spent tracing and fixing rattles.


And time cleaning out built up mud that is now rubbing on your tyre. (at least you hope its mud...)


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## derrick (4 May 2017)

Banjo said:


> I tend to leave them on year round .
> I wonder if any scientific experiment has been done.


It's the rattling that's the problem for me, i like a nice quiet bike, They make me go faster when i come across a bike with them on, I need to get away from the noise.


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## MrGrumpy (4 May 2017)

Mudguards IMO do slow you down and they rattle and rub or can do at least . Just taken them off my CX bike for now since its summer nearly  . Will look at purchasing a clip on guard for the rear for quick off and on . Come winter it will probably go back into full commuter winter mode.


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## phantasmagoriana (4 May 2017)

Mine slow me down when they get clogged up with mud and the wheel can't turn round.


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## ChrisEyles (4 May 2017)

It's got to be negligable, hasn't it? Unless maybe you are already on an aero-tastic tri bike in a skin suit I suppose. I must say while I've often justified my difficulty keeping up with a friend as the product of a heavier bike, or panniers attached etc etc I've never thought to blame my mudguards... possibilities there


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## derrick (4 May 2017)

[QUOTE 4788503, member: 259"]They only rattle if you use sellotape to attach them. I use them newfangled bolt things. [/QUOTE]
Even with them new fangled bolty things give them a couple of weeks and there rattling like a little ratley thing.


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## Ming the Merciless (4 May 2017)

Less than the fat lump on top


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## iandg (4 May 2017)

My fastest 10 miles was on a bike with mudguards (indoors on the rollers)


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## Milkfloat (4 May 2017)

Ok my mudguarded winter bike I am about 2mph slower than my summer bike. There are lots of differences, about 1.5kg in weight, thicker clothing, different wheels etc. Plus usually wet ground and mud.

All this makes my post irrelevant to the conversation.


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## Vantage (4 May 2017)

derrick said:


> Even with them new fangled bolty things give them a couple of weeks and there rattling like a little ratley thing.


Even while careering out of control down a rock strewn fire road mine dont rattle. And theyve not needed tightening since they were fitted over a year ago.
What are you doing wrong?


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## lutonloony (4 May 2017)

As my usual speed is slow, my non- rattly mudguards don't make a lot of odds, on my commute, club run, and anything else, all in one bike


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## dave r (4 May 2017)

As all my bikes have mudguards attached permanently I don't know if they slow me down or not.


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## tyred (4 May 2017)

I see no point in taking them off as it rains for 363 days of the year. I simply wouldn't buy a frame that doesn't have mudguard clearance.

I don't understand why they would rattle or rub either if of decent quality and fitted properly.


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## Dogtrousers (5 May 2017)

Oddly enough my "winter" bike is the one _without_ mudguards. Because there isn't clearance to fit spiked tyres and guards.


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