Mudguard clearance...how much?

[Crepello]

I think there is between 1 and 2 mm between tyre and guard on my Defy pictured with 25mm tyres on it. Bike stays reasonably clean and although I would prefer to have the safety aspect of the snap on(off?) fixings of the SKS guards, these don't seem to pick up much crap at all (probably helps sweep detritus off of the tyre tbh)

As they fit to the brake\frame\fork attachment, they would should fit any bike with minimal clearance. I know the old Crud Race 1's couldn't fit the Defy, but these do...not sure if the 2nd revision of the Crud guards do, but in any case these look like an option for the clearance challenged.

So what are they? They are mighty close. Do you find the guards skitter on the tyres over rough surfaces?

Although the guards on my old Dawes Audax do skitter and the clearance is too close for my liking, I want to experiment with gluing a crud catcher at the bottom of the front guard. I will epoxy a piece of plasticard next to the flap at right angle (probably). The card may be slightly curved to the tyre profile, but the idea is that most objects will be thrown up centrally, where this device will hopefully deflect them from any further travel upwards. It won't deal with tree branches obviously, but stones won't get a look any further.

 

[2Loose]

So what are they? They are mighty close. Do you find the guards skitter on the tyres over rough surfaces?

Although the guards on my old Dawes Audax do skitter and the clearance is too close for my liking, I want to experiment with gluing a crud catcher at the bottom of the front guard. I will epoxy a piece of plasticard next to the flap at right angle (probably). The card may be slightly curved to the tyre profile, but the idea is that most objects will be thrown up centrally, where this device will hopefully deflect them from any further travel upwards. It won't deal with tree branches obviously, but stones won't get a look any further.

Giant Defy\Avail Guards Just checked the mounting for these and the rear attaches to a gromit on the seat tube at front mech height, as well as the caliper bolt and stays...so I guess they'll have difficulty fitting another make\model. But to answer your question, no they don't rub on the tyre and are held very securely. I do get a bit of noise when the tyre sweeps a leaf up, but not for more than a second or so before the spinning tyre ejects it.

 

[jimboalee]

So what are they? They are mighty close. Do you find the guards skitter on the tyres over rough surfaces?

Although the guards on my old Dawes Audax do skitter and the clearance is too close for my liking, I want to experiment with gluing a crud catcher at the bottom of the front guard. I will epoxy a piece of plasticard next to the flap at right angle (probably). The card may be slightly curved to the tyre profile, but the idea is that most objects will be thrown up centrally, where this device will hopefully deflect them from any further travel upwards. It won't deal with tree branches obviously, but stones won't get a look any further.

A rubber car mat from Wilkinsons and a couple of pop rivets....

 

[Crepello]

Giant Defy\Avail Guards Just checked the mounting for these and the rear attaches to a gromit on the seat tube at front mech height, as well as the caliper bolt and stays...so I guess they'll have difficulty fitting another make\model. But to answer your question, no they don't rub on the tyre and are held very securely. I do get a bit of noise when the tyre sweeps a leaf up, but not for more than a second or so before the spinning tyre ejects it.

Well, I'm impressed if they don't skitter on the tyres. It seems to be a front wheel issue more and much worse with the Secu-clips, which don't contribute any side ways rigidity. I might see if I can wedge some ends pieces of zip ties as packing between the clips and the stays.

I wonder if the fact that it looks like you couldn't even get a cigarette paper between guard and tyre means that nothing bar leaves and small grit is going to get up between and jam the wheel. Still, I would be concerned as we don't really know all the dynamics that can lead to a wheel locking up.

I also think it's better to have the guard closer to the tyre at the mud flap level in relation to the fork crown.
That way anything that gets past the mud flap should be small enough to pass the crown section.

Then there is fallen branches (cue autumn winds). I think the Secu-clips may work better with these. I've had two branches get caught in the front guard. Both were without Secu-clips, but both were thankfully slow speed incidents. The second time trashed the guard and would probably have lead to a wheel seizure as the branch lifted the guard all the way up towards the fork crown.

 

[dellzeqq]

I'm puzzled by this thread. There's just over 4mm between my forks and the tyre. In 50,000 miles on this frame and its predecessor (which had even less clearance), including a fair bit of off-road on gravel and mud paths, I've had the occasional leaf get stuck in there, but I've only once jammed the back wheel with mud. No stones, no twigs. I feel like I'm missing out!

 

[ColinJ]

I've had the occasional leaf get stuck in there, but I've only once jammed the back wheel with mud. No stones, no twigs. I feel like I'm missing out!

There was a report in Cycling Weekly (?) a few years back about a cyclist who had been very seriously injured going over the bars and face-planting on the road. The cause of the accident was an acorn somehow getting wedged up under his front mudguard!  

 

[jimboalee]

There was a report in Cycling Weekly (?) a few years back about a cyclist who had been very seriously injured going over the bars and face-planting on the road. The cause of the accident was an acorn somehow getting wedged up under his front mudguard!

By the time the inquest was concluded, the front wheel of the bicycle was inside the trunk of an oak tree.

 

[slowmotion]

I'm puzzled by this thread. There's just over 4mm between my forks and the tyre. In 50,000 miles on this frame and its predecessor (which had even less clearance), including a fair bit of off-road on gravel and mud paths, I've had the occasional leaf get stuck in there, but I've only once jammed the back wheel with mud. No stones, no twigs. I feel like I'm missing out!

But you have no mudguards, perhaps? If you do, stuff gets entrained and has to go somewhere round the wheel, and might send you over the bars when it jams up. I do not want a repeat performance from a jammed front wheel again, even though it had nothing to do with debris. Actually, I'm not that concerned about having water up my back, and would be happy to ride without them. Dog shoot is another matter, and that was why I stuck them on, and sought advice.
Maximum respect.

 

[jimboalee]

If you want a tiny little gap, have a tiny little gap. If you want a large gap, have a large gap. Whatever you think looks good on the bike.

I like a gap where the tyre will drag a piece of kitchen towel round without getting jammed up.

 

[ColinJ]

If you want a tiny little gap, have a tiny little gap. If you want a large gap, have a large gap. Whatever you think looks good on the bike.

I like a gap where the tyre will drag a piece of kitchen towel round without getting jammed up.

How often do you ride over kitchen towel?

The most worrying thing I've (nearly) run over was an empty Coca Cola can. Those things can really be a problem if they get wrapped round your wheel. I'd rather than a close guard trying to scrape the can off than a distant guard welcoming it in!

 

[jimboalee]

How often do you ride over kitchen towel?

The most worrying thing I've (nearly) run over was an empty Coca Cola can. Those things can really be a problem if they get wrapped round your wheel. I'd rather than a close guard trying to scrape the can off than a distant guard welcoming it in!

The kitchen towel is for wiping out dead slugs and crap without taking the wheel out. Its done purposefully.

I would rather have a Coke can become entangled in the mudguard stays than it be swept round and scratch the paint or varnish off forks or rear brake caliper.

I've never had a complete endo because of stuff in the guards. When it did happen, the wooden object made a whirring noise and rubbed 500 miles off the tyre.

 

[snailracer]

The optimal gap depends on the mode size of debris you expect to ride through on your route. Debris that is bigger than the gap will be scraped off by the mudguard, smaller and it will pass under the mudguard without snagging. So choose the gap depending on the size distribution of debris you expect to encounter on your route.

 

[jimboalee]

The optimal gap depends on the mode size of debris you expect to ride through on your route. Debris that is bigger than the gap will be scraped off by the mudguard, smaller and it will pass under the mudguard without snagging. So choose the gap depending on the size distribution of debris you expect to encounter on your route.

I once saw a spark plug lying in the road. How the motorist lost THAT without noticing, ?????

A black snake,,,, or was it a broken alternator belt.

 

[zigzag]

i find that optimal clearance is around 1" away from slick tyre. if they are closer, you get small stones rolling between the tyre and mudguard and making noise, which is not ideal. if the gap is bigger than that, you get unnecessary water spray from the sides. tourers, mtbs, most hybrids, cx bikes have decent clearance for mudguards. old steel racers built for 27" wheels have good clearance with 700c wheels.

 

[jimboalee]

You'll probably find that on a frame that is supposed to have mudguards fitted, the chainstay bridge, rear brake bridge and forks will be positioned so that when the mudguards are fitted close to the metalwork, there is an appropriate gap to the tyre.

Width between the chainstays and chainstay length will determine maximum tyre size. Don't fit a tyre that won't get in the frame fully inflated.