Specifically with 28C tyres or bigger?

Currently running wide SKS Chromoplastics.

They fit my 28C gatorskins (which are my go to commuter do-it-all tyre) absolutely fine and they fit my 35mm speed kings absolutely fine.. they are excellent, but required some bending to get round the disks which is fairly normal for fitting guards on a bike with discs. They keep me bone dry, fit nicely and are quiet.

However, taller tyres are a bit tough to work with guards on the rear end. Currently the guards wont fit right down at the BB or seat tube with my 35C ice spikes. so i cut the bottom section of the rear and relaly only run 2/3rds of the rear guard to accomodate. But its still working fine 🙂

chromoplastics on my pompino.

32mm Panaracer Pasela with 45mm Bluemels (nicer round profile than the SKS Chromoplastic but cheaper hardware). Bit tight between the chainstays near the BB but ok. Could do with shaving a bit off each side there to increase clearance. Usual bending and spacing out of the stays to clear the discs. Used the mount on the underside of the seatstay bridge to bolt the guard staight to the frame.

so i need 45mm guards regardless?

i went for 35-38 which are classed as “wide”. 45 seems huge

For 28mm tyres, no. For 32mm, probably yes. You can make 35mm guards work with 32mm tyres, but it’s a bit tight.

SKS Bluemels 700×42 for me (took a bit of tracking down as they seem to be less common than the 45mm variety) – fitted the chainstays perfectly and allows for 700×32 tyres with sufficient clearance but don’t look stupidly gappy with narrower tyres.

SKS chromoplastics. Work fine over the Gatorskins thar have been binned due to them being crap and the 28mm Ultremo’s as well

When I had one I used SKS chromoplastics narrow 20-28mm on 28’s Conti 4 season, no problem at all.

Same as above.