Mudguard Spacing

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MikeF
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Mudguard Spacing

Postby MikeF » 31 Dec 2017, 5:40pm

I've just fitted a new rear mudguard. The previous one broke because on two separate occasions a stick became trapped between it and the tyre forcing it to buckle. On the second occasion it broke.
Would reducing the the gap between the tyre and mudguard especially at the rear make this less likely to happen? I've thought about a safety clip for the stays as used on the front, but I'm not sure this is wise. Anyone had the same problem?
"It takes a genius to spot the obvious" - my old physics master

pwa
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Re: Mudguard Spacing

Postby pwa » 31 Dec 2017, 5:46pm

I prefer to have the rearmost part of the guard as the closest part to the tyre, so that it (hopefully) deflects stuff before it gets between tyre and guard. Any object small enough to pass that narrow point is unlikely to catch seriously elsewhere.

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Heltor Chasca
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Re: Mudguard Spacing

Postby Heltor Chasca » 31 Dec 2017, 5:50pm

Not exactly the same issue, but I saw a nasty crash on an Audax in the dark. A stick was flicked up into the space between the wheel and fork crown.

I would consider having the safety release on the front stays because of this. SKS do them.

I have found that when my mudguards are too close to the tyre, autumn road chutney and mud just puts the breaks on gradually and annoyingly. I like a quiet, efficient bike. I prefer at least 10mm, but it’s interesting to consider closing the gap to keep the sticks out.

Hung jury sorry.

MikeF
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Re: Mudguard Spacing

Postby MikeF » 31 Dec 2017, 6:37pm

pwa wrote:I prefer to have the rearmost part of the guard as the closest part to the tyre, so that it (hopefully) deflects stuff before it gets between tyre and guard. Any object small enough to pass that narrow point is unlikely to catch seriously elsewhere.
Thanks. My thoughts were along those lines as well.
"It takes a genius to spot the obvious" - my old physics master

MikeF
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Re: Mudguard Spacing

Postby MikeF » 31 Dec 2017, 6:46pm

Heltor Chasca wrote:Not exactly the same issue, but I saw a nasty crash on an Audax in the dark. A stick was flicked up into the space between the wheel and fork crown.

I would consider having the safety release on the front stays because of this. SKS do them.

I have found that when my mudguards are too close to the tyre, autumn road chutney and mud just puts the breaks on gradually and annoyingly. I like a quiet, efficient bike. I prefer at least 10mm, but it’s interesting to consider closing the gap to keep the sticks out.

Hung jury sorry.
Those safety clips on the front seem to work quite well. I've had 2 or 3 occasions when they've released a stick. Mudguards where the stays clip onto their outer edges tend to break free if jammed, but SKS ones, such as I'm using, are held firm with nuts and bolts. Old type plastic mudguards just broke, and therefore didn't jam the wheel.
"It takes a genius to spot the obvious" - my old physics master

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531colin
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Re: Mudguard Spacing

Postby 531colin » 1 Jan 2018, 10:19pm

Whatever you do, mudguards are a consumable. I like to try to make sure that when a mudguard fails, it doesn't try to kill me, so my rear guards are all done like this now.....
https://www.flickr.com/photos/52358536@N06/14769931149/in/album-72157624571269648/
There is a loop of metal comprising the 2 stays and the bolts and strip that fixes the stays to the guard. If this gets caught on the tyre and carried round, by the time it gets to the chainstay your wheel is locked.
Close-fitting guards are more at risk from mud, but if you get a stick in the spokes it doesn't matter how much clearance you have got.

Brucey
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Re: Mudguard Spacing

Postby Brucey » 1 Jan 2018, 10:44pm

SJS fit their 'thorn' bikes (which have carriers fitted, being most of them I suppose) in a particular way, like this;

Image

In general having the mountings further back/higher up is a good idea but most positions allow some kind of a theoretical tangle with the wheel along the lines that Colin describes.

In the above picture the rear stays are mounted to the carrier; there is a 'collar' (made from a short length of stainless steel tube) fitted to keep the stay loop the correct shape and the stays are bent to a whole new shape. It works OK but causes a lot of trouble if you want to run without the rack fitted.

I'd happily see a similar arrangement with the SKS secu-clip fitted front and rear; they are not perfect, but they don't cost much, seem to do more good than harm and if they work loose, re-flaring the stay loop usually makes them snug again.

cheers
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foxyrider
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Re: Mudguard Spacing

Postby foxyrider » 2 Jan 2018, 9:19am

I invariably have the narrow to wide set up on my bikes, sometimes i've used QR stays too. Crud still gets caught in the gap but it tends to free itself quickly as the gap increases in the direction of travel. As the bikes with guards all have racks too they act as an extra deflector.

TBH i've broken more rear guards by up ending the bike than having stuff caught in them. On the front it's usually me kicking the damn things that does the damage!
Convention? what's that then?
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MikeF
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Re: Mudguard Spacing

Postby MikeF » 2 Jan 2018, 8:39pm

531colin wrote:Whatever you do, mudguards are a consumable. I like to try to make sure that when a mudguard fails, it doesn't try to kill me, so my rear guards are all done like this now.....
https://www.flickr.com/photos/52358536@N06/14769931149/in/album-72157624571269648/
There is a loop of metal comprising the 2 stays and the bolts and strip that fixes the stays to the guard. If this gets caught on the tyre and carried round, by the time it gets to the chainstay your wheel is locked.
Close-fitting guards are more at risk from mud, but if you get a stick in the spokes it doesn't matter how much clearance you have got.
My concern as well!
I notice you have made a top clamp to the rack. That looks a pretty sure way of ensuring the mudguard isn't jammed into the seat stay. I can't see from the photo, but is there the "usual" clamp to the seat stay as well or have you abandoned that?
The type of tyre has an effect on "mud" build up, and it doesn't suddenly jam a wheel so that's not too much of a problem; I avoid tracks with mud unless it's a thin layer.
The rear mudguard mounting on the Thorn bike in Brucey's post seems to be trying to achieve the same purpose, but in a different way. ( I'm not sure if I like the front mudguard mounting.)
The sticks that have caused me problems are almost unnoticeable ones on the path, but nevertheless somehow the tyre has carried them into the mudguard causing it to buckle and the wheel to lock. Fortunately it's happened off road to date.
"It takes a genius to spot the obvious" - my old physics master

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CJ
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Re: Mudguard Spacing

Postby CJ » 5 Jan 2018, 3:49pm

I like to be able to see daylight between edge of guard (and I mean normal-shaped guards) and top of tyre. And I can on most of my bikes, none of which have ever suffered a broken rear guard from a stick catching in them - and I do a lot of sticky rough-stuff - ask anyone - I'm quite notorious for it! So I don't think less can be better.

You've just been unlucky. Or unobservant.
My motto: Never ride over the end of a stick - or you may have a sticky end!
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reohn2
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Re: Mudguard Spacing

Postby reohn2 » 5 Jan 2018, 3:56pm

CJ wrote:I like to be able to see daylight between edge of guard (and I mean normal-shaped guards) and top of tyre. And I can on most of my bikes, none of which have ever suffered a broken rear guard from a stick catching in them - and I do a lot of sticky rough-stuff - ask anyone - I'm quite notorious for it! So I don't think less can be better.

You've just been unlucky. Or unobservant.
My motto: Never ride over the end of a stick - or you may have a sticky end!

+1 :wink:
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Phileas
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Re: Mudguard Spacing

Postby Phileas » 5 Jan 2018, 4:11pm

CJ wrote:My motto: Never ride over the end of a stick - or you may have a sticky end!

+1
I was on the way to work once in stormy weather when a short piece of branch appeared on the road in front of me. I swerved to avoid it but still managed to clip the end, which flipped it into my shin causing a surprisingly large cut. :oops:

cycle tramp
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Re: Mudguard Spacing

Postby cycle tramp » 6 Jan 2018, 9:37am

Thanks very much for writing about this issue. When I'm better, I'll make the suggested changes to my bike and endeavor not to run over the ends of any sticks...

MikeF
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Re: Mudguard Spacing

Postby MikeF » 6 Jan 2018, 10:31am

CJ wrote:I like to be able to see daylight between edge of guard (and I mean normal-shaped guards) and top of tyre. And I can on most of my bikes, none of which have ever suffered a broken rear guard from a stick catching in them - and I do a lot of sticky rough-stuff - ask anyone - I'm quite notorious for it! So I don't think less can be better.

You've just been unlucky. Or unobservant.
My motto: Never ride over the end of a stick - or you may have a sticky end!
I live in probably the most wooded part of country where trees are like weeds. Too much so in some areas eg downland, heathland, meadows! Therefore twigs are a fact of life - they're everywhere, especially on off road leafy tracks eg NCN!! These are not sticky muddy paths, but paths covered in débris. Leaf littered tracks can easily conceal a small twig lying underneath. Avoidance is not an option.

Quite a small twig, say 4 inches long, can cause a problem by becoming jammed behind the rear mudguard stays forcing the mudguard to be carried round with the wheel and buckle before jamming under the seat stays. I've now tried moving the rear of the mudguard quite close to tyre so that maybe a twig cannot be caught, but I'm still wondering if safety clips for the rear mudguard are a better option.

On several occasions I've had this happen. On the front mudguard the safety clips have always worked.
"It takes a genius to spot the obvious" - my old physics master

Brucey
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Re: Mudguard Spacing

Postby Brucey » 6 Jan 2018, 10:58am

MikeF wrote: .... I've now tried moving the rear of the mudguard quite close to tyre so that maybe a twig cannot be caught, but I'm still wondering if safety clips for the rear mudguard are a better option...


why not do both?

BTW this whole discussion is making me rethink mudflaps; for yonks I have put them (for neatness) underneath the mudguard, but I am now wondering if that presents a nice wedge-shaped gap into which twigs can get easily jammed. By contrast if the mudlflap is attached to the outside of mudguard, maybe jamming is less likely?

In a similar vein I am also wondering if the lower stays (one of two sets on each mudguard of course) are best set flush with the end of the mudguard; again there is then no gap into which twigs can get easily stuck.

Where I am for a few weeks every year there are leaves and twigs to contend with on some local paths. It has been my observation that some trees cast small twigs that are brittle and break easily and other trees don't. The former tend to break easily in almost any jamming/running over situation but not the others. I have yet to firmly associate particular types of tree with particular twig consistencies.

cheers
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