My commuter has identical 28mm tyres front and rear, it’s had the guards on since early October and all has been well since then, up until a couple of weeks ago when I started picking up lots of rear tyre punctures, looking at the tyres the other night I noticed the rear is pretty much cut to ribbons while the front is basically pristine…

At first I just put it down to my lardy arse putting more weight over the rear and the seasonal increase in road debris and shite…

But thinking about it further the rear guard has a position, just below the seat stay bridge where it’s comes pretty close to the tyre, it doesn’t make contact but clearance is minimal maybe as low as 2mm, the front guard clears nicely all the way round but the rear has this “Pinch point” and it did occur to me that the wheel could draw larger items of crap in to the guard, drag them round to that point and then being too large to pass through they simply end up damaging the tyre…

I’ve just got a 25mm tyre to go on the back to try and marginally increase the clearance (although it won’t be by much), although I was enjoying having 28s for a comfier ride…

Am I imagining an issue here or can you run guards too close?

you can run guards to close, in theory. something gets pulled up and they jam.

The cuts, welcome to road bikes, more weight, more wear, the back tyre always gets trashed faster than the front. I work on two back tyres to every front tyre.

Slap me Silly and call me susan!

I should have mentioned, it’s a fixie, with horizontal Dropouts, I could either add a half link or change the rear sprocket by 1 tooth (might help me man up a bit too) allowing me to move the rear axle further back, increasing the clearance to that bridge. That at least test my theory about them being oo close…

Why did I not think of that sooner? FFS!

TBH MrMo I fear you are probably right, it’s just normal wear and seasonal detritus on the roads, but the rear tyre has gone quite quickly (Fantastic, plastic, cheap Vittoria jobbies).

23mm version of the same tyres are still doing fine on my geared road bike, in fact they’re older and have done more miles I think…

I’ll bung the 25mm on the rear, tweak the gearing/axle position, see if that makes any difference it should get me through to January, then I can start thinking hard about the next pair of tyres…

I read somewhere your rear gets more cuts/punctures is that the front tyre flicks up the hitherto flat-lying piece of glass/metal etc so it’s perfectly positioned to puncture the rear. Not saying it isn’t the fault of your mudguard, but it certainly seems true for me. Have just put Crud Roadracers on my fixie with tiny clearances, so will find out if it gets worse soon enough.

You can drill out the hole in the rear mudguard bracket to elongate it and raise it slightly at the rear brake bridge. This should give you a couple of extra mm clearance. I am assuming you have short drop brakes? EDIT: No, 28 mm tyres 😉

I found that my front tyre cuts up more than my rear, but the rear will wear much faster – particularly fixed. Once worn I suspect it may bemore liable to cutting. Adding an extra link in the chain will move the wheel back, of course, but I think you’ve been unlucky. I ride Schwalbe Durano S and have a few cuts, also Mavic which has a harder compound on the rear to reduce wear.

Cheers TiRed but I can get no more clearance at the bridge as it is, the guard is butted right up against it already I had to drill a couple of small holes and use a zip tie to do that, moving the wheel back is the better option now…

It’s a good thing anyway, I’m going from a 16t to a 15t sprocket which I believe will ensure all the segments on my way to work shall now fall to me…

I’ve started eyeing up Schwalbe Marathons as well after reading a few comments on other threads about them, are the “Marathon Plus” worth the extra £5, the bumph suggests they can survive small arms fire and the odd claymore blast, but they do weigh the best part of 1kg apparently…