Extra bit of front mudguard?

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cycle tramp
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Re: Extra bit of front mudguard?

Postby cycle tramp » 14 Nov 2020, 9:14pm

Mick F wrote:Just thinking ..................

Why don't mudguards extend down to road-level on both wheels?

Why do they stop ........... rear at the BB bridge and the far end rear of the bike ................ and front at above BB height and less than a foot beyond the forks?


I like your thinking, I've still got my old front mudguard, I could cut a bit off that and extend my rear mudguard to below the bottom bracket...
...I guess the reasons why mudguards aren't extended beyond the 'social norms' is that such a design would cost manufacturer's more money, and some cyclist's won't like the look of them, and unless they use them, won't understand or believe the benefits that they can bring

cycle tramp
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Re: Extra bit of front mudguard?

Postby cycle tramp » 14 Nov 2020, 9:40pm

Mick F wrote:Just thinking ..................

Why don't mudguards extend down to road-level on both wheels?

Why do they stop ........... rear at the BB bridge and the far end rear of the bike ................ and front at above BB height and less than a foot beyond the forks?


Just seen these mudguards on a home constructed folder - they look like they have the coverage we're taking about

https://theradavist.com/2020/11/readers ... -road-bike

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Vantage
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Re: Extra bit of front mudguard?

Postby Vantage » 14 Nov 2020, 10:04pm

Mick F wrote:Just thinking ..................

Why don't mudguards extend down to road-level on both wheels?

Why do they stop ........... rear at the BB bridge and the far end rear of the bike ................ and front at above BB height and less than a foot beyond the forks?


Clearance mostly I think.
With the front wheel off, my bike rests on the back of the front mudguard and has bent it many a time. Getting over some cycle gates can catch the back of the guards too. Then there's those gates which require the bike to be tilted up onto its back wheel to be pushed through. The guard gets squished into the ground.
The problem with the guard hanging longer over the front wheel is that it requires extra stays and that can be more fiddling about to keep them straight.
Bill


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NickJP
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Re: Extra bit of front mudguard?

Postby NickJP » 14 Nov 2020, 11:21pm

What you need is a mudguard that has enough length in front of the fork so that the front of the guard extends past the highest point of the wheel, so that spray coming out is already heading downwards rather than still going upwards. Metal mudguards - eg Berthoud, Honjo, Velo-Orange - are long enough that this is the case.

Velo-Orange:
Image

Honjo:
Image

Berthoud:
Image

nomm
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Re: Extra bit of front mudguard?

Postby nomm » 15 Nov 2020, 8:17am

NickJP wrote:What you need is a mudguard that has enough length in front of the fork so that the front of the guard extends past the highest point of the wheel, so that spray coming out is already heading downwards rather than still going upwards. Metal mudguards - eg Berthoud, Honjo, Velo-Orange - are long enough that this is the case.


thank you for that morning bike porn :oops:

Brucey
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Re: Extra bit of front mudguard?

Postby Brucey » 15 Nov 2020, 9:10am

re the rear mudguard protruding down well beyond the chainstays. I'm not sure how much benefit this might accrue. If crud spumes out where the mudguard usually ends, it just goes downwards onto the road. Provided the mudguard doesn't end above the chainstays (some do), I think that is 'job done'.

It is worth noting that because of the way crud flies off the tyre, some of it always ends up bouncing out of the (rear) mudguard sideways. I think that, on bikes with decent front mudflaps, this is where a lot of the crud that ends up on the chain comes from. Just look at the top of the chainstays after you have been riding on a mucky road; they'll be pretty dirty, and so will the chain be. If the rear mudguard protruded down well below the chainstays, I think that there would just be more crud bouncing out of the mudguard near the lower run of the chain, and the chain would get more dirty.

Very much longer mudguards are either unnecessary or impractical in many cases; if front mudguards stick out at the front more than a few inches (without extra stays) they often either get knocked or flap about. Longer mudflaps (front and rear, provided they are not too large or too heavy) are a practical way of improving things without turning the mudguards into a liability.

There are a lot of mudguards on the market which are basically a bit marginal or are just plain hopeless. Unfortunately this includes many of the prettier, more expensive ones. One stay/support on the rear mudguard? Usually hopeless. One stay on the front mudguard? Not as bad as one stay at the rear but still pretty hopeless.

Another factor which is often overlooked is the importance of tyre design in how (and how much) crud flies off them and the mudguards have to deal with. Wide tyres with tread on throw lots of crud off and skinnier, smoother tyres throw less. The main thing that is an exception to this is the amount of crud thrown out of the front wheel forwards. This also seems to vary with wheel diameter, the speed at which you ride, and the consistency of the crud on the road. So a certain speeds water comes out forwards, but at another slightly different speed it might be mud instead.

FWIW if the front mudguard comes 'past the top' forwards, some of the water that is collected by the mudguard may run forwards and drip off the mudguard onto the tyre, where it can cause additional splatter. Quite a common modification is to ensure that the stays/stay brackets are secured to the outside of the front mudguard rather than the inside; on the inside they can interrupt the flow of water such that some of it comes out of the mudguard sideways, all over your feet. However this doesn't always play well if you don't have good toe clearance.

Mudguards are always a compromise of one kind or another; you just have to hope that over their lifetime, you get more benefit from them than hassle.

cheers
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Mick F
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Re: Extra bit of front mudguard?

Postby Mick F » 15 Nov 2020, 9:33am

Off topic a bit ...............

I see those photos of the bikes with the longer mudguards have Deore XT M772 rear mechs! :D :D
Mick F. Cornwall

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nick12
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Re: Extra bit of front mudguard?

Postby nick12 » 15 Nov 2020, 8:13pm

I've been getting my bike ready for winter of late currently running land cruiser tyres which definitely throw out more crud than the tyres I've been running during the summer. (Vittoria voyager). I have fitted mudguard extensions at the rear of both the front and back guards. I've also fitted an extension to the front of the rear guard it seems to be doing a decent job keeping the bottom bracket area cleaner the chainstays and chain still get splattered as usual though
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IMG_20201115_194645_1.jpg

slowster
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Re: Extra bit of front mudguard?

Postby slowster » 15 Nov 2020, 11:09pm

Brucey wrote:One stay on the front mudguard? Not as bad as one stay at the rear but still pretty hopeless.

I think SKS mudguards with ESC stays are an exception to that rule. I've recently fitted my MTB with SKS mudguards which use a single ESC stay on the front mudguard, and my experience so far is that for very wide mudguards, e.g. 65mm, they are much better than the standard double stays supplied with other SKS/Bluemels mudguards. In particular the combined mudguard and stay is much more rigid. I should add that I have fitted the rear mudguard to the front for the reasons given by other posters above, so I have a single stay behind the fork crown plus a 'front' stay ahead of the fork crown, but when I was experimenting with fitting the mudguard I came to the conclusion that the front stay did not make a significant difference to the rigidity of the rear part of the mudguard behind the fork crown.

Brucey wrote:Another factor which is often overlooked is the importance of tyre design in how (and how much) crud flies off them and the mudguards have to deal with. Wide tyres with tread on throw lots of crud off and skinnier, smoother tyres throw less. The main thing that is an exception to this is the amount of crud thrown out of the front wheel forwards. This also seems to vary with wheel diameter, the speed at which you ride, and the consistency of the crud on the road. So a certain speeds water comes out forwards, but at another slightly different speed it might be mud instead.

I think a major factor in how much spray and muck comes off the top of the tyre and is not blocked by the end of the front mudguard is the amount of clearance between the mudguard and tyre. The centrifugal spray is projected forwards at a tangent to the tyre. If the mudguard is very/too close to the tyre and ends at the 12 o'clock position, it will not only limit the amount that is sprayed off but crucially will also only allow it to be sprayed horizontally or downwards. Conversely, with a large tyre/mudguard gap the spray projected from the tyre around the 11 o'clock position will pass under the tip of the mudguard and will have an upwards trajectory. Consequently at speed, such as going downhill, the spray will result in muddy deposits not only on fork crown mounted lights as in the OP's case, but also on the rider's clothes. I found this out the hard way and realised the wisdom of reohn2's set up. Hence my MTB now sports a rear mudguard on the front.

With regard to the suggestion above of extending the rear mudguard below the bottom bracket, I cannot see that there would be any benefit.
However, I have a Hebie Chainglider and there is muddy spatter on the plastic cover over both the top and bottom chain runs immediately adjacent to the tyre. Muddy water is clearly being thrown off the side of the tyre down onto the chain/Chainglider and chain stay at that point. Because of that, I think there would be benefit if the rear mudguard profile several inches above the chain stays was a full semi-circle to provide better side coverage (or if some kind of screen could be affixed on the drive side similar to an old style dress guard).

Brucey
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Re: Extra bit of front mudguard?

Postby Brucey » 15 Nov 2020, 11:20pm

I agree that a side guard near the chain runs has a lot going for it and I have mentioned this before now. However neat implementation is quite another thing; best scheme so far is perhaps to use Velcro (plus a zip tie around the chainstay) to secure the additional side guard part; it could of course be easily mounted using additional holes in the mudguard, but I am leery of adding further holes in mudguards because this nearly always gives them yet another way of breaking.

A problem with single stays in a front mudguard is that not every thrust on the mudguard is in the plane of the machine; the result is that the unsupported part of the mudguard can deflect sideways and this normally fatigues the mount to the fork crown. Not all mudguards are equally susceptible to this.

cheers
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NickJP
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Re: Extra bit of front mudguard?

Postby NickJP » 16 Nov 2020, 5:56am

A secondary advantage of metal mudguards is that unlike plastic mudguards, they have a rolled edge, which helps prevent water coming out of the side of the mudguard.

KM2
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Re: Extra bit of front mudguard?

Postby KM2 » 16 Nov 2020, 5:22pm

Probably best to move the stay bridge to the outside of the mudguards as well, so the water can run continuously down and not flick out when it hits the stay bridge.

ElCani
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Re: Extra bit of front mudguard?

Postby ElCani » 27 Nov 2020, 7:33pm

Brucey wrote:There are a lot of mudguards on the market which are basically a bit marginal or are just plain hopeless. Unfortunately this includes many of the prettier, more expensive ones. One stay/support on the rear mudguard? Usually hopeless. One stay on the front mudguard? Not as bad as one stay at the rear but still pretty hopeless.


Brucey, do you happen to know if the single-stay Velo Orange mudguards linked to below fall into this “hopeless” category? Or does anyone else have any experience of them? I’m considering replacing my rather tatty SKS Longboards with them.

Thanks.

https://freshtripe.co.uk/velo-orange-70 ... mudguards/

MikeF
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Re: Extra bit of front mudguard?

Postby MikeF » 27 Nov 2020, 9:02pm

Back to the original problem.
An option would be to mount the light on the handlebars. It's well out of the way of any crud from the front tyre. I think anything near the front forks is likely to be sprayed with crud.
"It takes a genius to spot the obvious" - my old physics master

Des49
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Re: Extra bit of front mudguard?

Postby Des49 » 3 Jan 2021, 4:11pm

Spray from the top of the front guard is an issue I have suffered with at times, going downhill, into a strong wind or anytime when over about 15mph.
The tyre makes a huge difference, I used to run 26 x 1.75" Travel Contacts, but since changing to 2" Marathon Supremes the amount of water retained by the tyre has noticeably increased.

With the really wet weather the last few months it got to a point where I had to do something as the amount of mud and grit on the front of the bike and myself had become a real nuisance.

So I took off the plastic flap I had added to the rear mudguard, replaced this with a longer rubber flap and have tried the plastic flap over the front tyre.

Not as neat as the rear guards on the front pictured earlier (which I may do sometime), looks a bit like a duck bill and does give an increased shadow at night from the fork crown mounted main light. But so much cleaner to ride.
I had to curve the end down and may trim it a bit narrower, but will leave it on.
Image Attachments
Front mudguard extension2.jpg
Front mudguard extension1.jpg