would mudguard improve the aerodynamics?

pcandyhk

Have been using the Crud Roadracer mudguard with my old-beginner-rb, very satisfy with it generally.
Now I am considering whether to transfer and put it on my new Cube Streamer bike, then a random question came up in my mind...
Would a mudguard actually smooth the airflow over the wheel, and therefore improve the aerodynamics of the bike?
May be more specific would it be the case for Crud Roadracer?

My initial thought is yes, why not?! as the rolling surface of the tyre generates turbulence. However I never see someone race with a mudguard (such as Crud Roadracer with is act very light) Confusing... :?
Welcome to share your thoughts!

Pseudonym

racing with mudguards is banned for safety reasons. Either way, you won't be going fast enough for the airflow to make any difference...

cougie

I'm no aerodynamacist - but I'd have thought you'd get extra drag with mudguards anyway. I use mine for comfort in the winter - not extra speed.

Monty Dog

Any form of fairing is banned so you'd need to demonstrate that the mudguard was an integral structural component - pretty tricky when UCI's bike design parameters are stuck in the dark ages with round-ish tubes and 'diamonds'

pcandyhk

oh no wonder... I heard the structural restriction, but for safety reasons??!! emmm ...
It is known that "the exposure of the wheels to the airstream causes a very high aerodynamic drag at high speeds" at
http://en.wikipedia.org/wiki/Open_wheel_car
Well I guess we would only know the exact answer from a wind-tunnel test, but wts the point if it is banned~

Pseudonym

'safety reasons' should be self-explanatory. Most mudguards are plastic, some are aluminium - you don't really want pieces of shattered plastic or sharp aluminium edges flying around in a multi-rider stack-up....

jim453

Good job frames and running gear are usually made out of cotton wool and puppies really.

Pseudonym

jim453 wrote:

Good job frames and running gear are usually made out of cotton wool and puppies really.

you haven't really thought this through, have you...?

ChrisSA

Monty Dog wrote:

Any form of fairing is banned so you'd need to demonstrate that the mudguard was an integral structural component - pretty tricky when UCI's bike design parameters are stuck in the dark ages with round-ish tubes and 'diamonds'

I laugh at the UCI

I'll fit mudguards to my 5:1 aerotubed bike for my next tri. I'll still come last though

Do the UCI ban frames that hug/shelter the rear wheel?

jim453

Pseudonym wrote:

jim453 wrote:

Good job frames and running gear are usually made out of cotton wool and puppies really.

you haven't really thought this through, have you...?

On the contrary, and with respect, I'd sooner take my chances with a set of crud racers than with a frame and chainset in a multi rider pile up. Wouldn't you? I hardly think the cruds are adding to the potential danger.

Ben6899

jim453 wrote:

Pseudonym wrote:

jim453 wrote:

Good job frames and running gear are usually made out of cotton wool and puppies really.

you haven't really thought this through, have you...?

On the contrary, and with respect, I'd sooner take my chances with a set of crud racers than with a frame and chainset in a multi rider pile up. Wouldn't you? I hardly think the cruds are adding to the potential danger.

Thing is Jim, take away the frame and/or the chainset and - well - it ain't cycle racing no more. I agree I'd rather come a cropper on a Crud mudguard than a chainset, but mudguards are not necessary items so I suppose why have them there if they might ADD to the complications in the event of a stack?

jim453

Oh for goodness' sake.

I am aware that without a frame or transmission there is no bike. I am only saying that the 'safety reasons' are far from 'self explanatory' as in the event of a multi bike pile up crud road racer's will be the very, very, very least of an individuals concerns, if even a concern at all.

I suppose the concern may be that they could come loose and end up causing a pile up by getting in someones wheel or something. However, these are not the 'self explanatory' reasons alluded to by Pseudonym. Perhaps he hasn't thought it through either.

This is ridiculous,

For the record, I'd be surprised if they provided any aero advantage either.

Ben6899

jim453 wrote:

Oh for goodness' sake.

I am aware that without a frame or transmission there is no bike. I am only saying that the 'safety reasons' are far from 'self explanatory' as in the event of a multi bike pile up crud road racer's will be the very, very, very least of an individuals concerns, if even a concern at all.

I suppose the concern may be that they could come loose and end up causing a pile up by getting in someones wheel or something. However, these are not the 'self explanatory' reasons alluded to by Pseudonym. Perhaps he hasn't thought it through either.

This is ridiculous,

For the record, I'd be surprised if they provided any aero advantage either.

Possibly a slight misunderstanding of my view on this, Jim. I agree a plastic mudguard is the least of a rider's worries if he's in a stack. But it is also a source of risk which can be successfully and easily removed from the equation.

tonye_n

Hmmm

jim453

Quite.

Ben6899

Well this is bizarre.

OP. Fit mudguards to protect your mates and your arse from road spray. Don't worry about aerodynamics.

pcandyhk

Have tried to transfer the rear guard anyway.
Seems the clearance below the brake of my new bike is too little, fiddled with it for an hour it still rub against the tyre slightly (but constantly) near the brake. (fits my old rb perfectly though)
Looks like I have to get wet without a choice.

pcandyhk

Back to the point...
I think a small mudguard just cover the top might actually reduce the drag even at slower speed, look at the motobikes... most have a small "wheel cover" above the front wheel.
even those at MotoGP, which I would assume aerodynamic performance would be preferred then mud-preventing performance.
Some points to consider, if u r going at 30mph, the relative speed at the top of ur wheel is actually doubled, which is 60mph. At 60, would be 120mph! Though the tyre surface of 23 is tiny.

If one does consider the tiny drag reduction on different bike components, then I think this is also the place to reduce extra grams of drag.
I guess if there are less restrictions, road bikes will look similar to motobikes at some parts.

John.T

The drag from the guard itself would far out-way any savings in tyre drag. A large proportion of the wheel drag comes from the spokes anyway.
I would suspect that the small guards on race motorcycles are to try to keep the levels of spray down and away from vital engine components and the rider.

albothegreat

WTF? :roll: Drag reduction i don't think so.

b16 b3n

You sure you've got your glasses on and not looking at your motorbike? I would understand the down force and drag at the front wheel on that, then this topic would be debatable as they can reach speeds of 215mph! If this was the case, we could even fit a rear hugger for more down force.

ROAD BIKE? get a grip or not if the aerodynamics are wrong! ZzZzZz
Mudguards are fit for one purpose, to keep you dry!

pcandyhk

Dont get me wrong. The primary purpose of a mudguard is to keep u dry and clean! otherwise it is not called a mudguard.
However if the drag reduction=the drag addition, then I think everyone SHOULD get a mudguard, and leave it on FOREVER!

bsachs

Actually a small mudguard closed in on the sides covering the top portion of a wheel has the potential to significantly reduce drag because that is where the spokes and tyre are moving in the opposite direction. Would love to see a computerised fluid dynamics analysis of this or wind tunnel test. Thinking of building a prototype and doing some “coast down” tests on my road bike.

lettingthedaysgoby

A suitably designed front mudguard would absolutely reduce drag. Not sure any on the market right now would work though as from what I can see they’re all designed simply to reduce spray.

imposter2.0

What's the current record for a thread revival..?