Road tyres that can cope with shards of flint?

[SixPotBelly]

yellowjack said:

Speaking of GP 4Seasons, anyone know of anywhere online, or perhaps local to Farnborough, Hampshire, which has stock of the 700 x 25c size?

None of the 'usual suspects' has stock of that size, yet everywhere seems to have the 23c and 28c sizes at around a third off RRP. They're for a bike I haven't yet bought, so not keen to splash out on 700 x 28c rubber until I can be sure the bike has clearance for them, and don't really want the 23c size because I'd prefer a bit more volume for comfort, and a smidgin more of a contact patch for better grip. I'm also well aware of the current school of thought regarding the advantages of slightly wider tyres over thinner ones. I had hoped to nab a couple of 25c's in plenty of time to whop them onto the bike prior to 'first ride'.

Don't know if it helps you, YJ, but The GP4S actually comes up under-width. I've just changed my tyres and, on my rims, the "28mm" GP4S only measure 26.1mm at 95PSI. That's just 1mm more than the 25mm Swalbe Luganos (at the same pressure) I took off. (Inidentally, the GP4000SII I put on my summer wheels are visibly wider, and too wide for my micrometer. It's just the GP4S that are narrower than their sizing would suggest.)

If you can't find 25mm GP4S, might it be worth a punt that the 26.1mm "28mm" would fit a frame designed for 25mm?

And, OP, I'll let you know if I'm the exception to the rule and puncture with the GP4S tomorrow. But they certainly look and feel a very resilient tyre.

[TSCfree]

I've been using Vittoria Randonneur II since October with no issues. Yes they're heavy, but you want puncture protection, which funnily enough more rubber provides...and they're cheap too....and cope with turbo abuse. I even raced on them at spillingdon last month and stayed shiny side up, so they can't be too shabby.

Edited by TSCfree on Monday 2nd March 19:34

[yellowjack]

SixPotBelly said:

Don't know if it helps you, YJ, but The GP4S actually comes up under-width. I've just changed my tyres and, on my rims, the "28mm" GP4S only measure 26.1mm at 95PSI. That's just 1mm more than the 25mm Swalbe Luganos (at the same pressure) I took off. (Inidentally, the GP4000SII I put on my summer wheels are visibly wider, and too wide for my micrometer. It's just the GP4S that are narrower than their sizing would suggest.)

If you can't find 25mm GP4S, might it be worth a punt that the 26.1mm "28mm" would fit a frame designed for 25mm?

Thanks, SPB. I'll wait until the shop phones to say they've got my bike in. 'Stock' factory fitted tyres are Bontrager R2 Hard-Case Lite, 700x23c, so I'd like to wait, and see how much clearance there is around those 23's before going for the Conti 28's. It does sound like a plan, though, to get the 700 x 28c 4Seasons on if I can. Bike press reviewers report that the bike (Trek Emonda) is plenty comfortable with standard 23c tyres on, so I'd expect it to be as plush as a plush thing with decent quality, larger volume rubber on it. So for now I've sacked off the idea of buying tyres before the bike, just to make sure there's space for them. Won't do any harm to ride it for a few miles with the factory tyres on anyway, just to see if I can tell the difference when I fit the Continental 4Seasons '700 x Magic Carpet c' tyres