Tyre / rim compatibility?

[Brucey]

another way of looking at it is that if you are going to use wide tyres anyway, you may as well use a wider rim than is absolutely necessary; the net result is usually that the rim is stiffer, and the whole wheel can be a bit more aero than it would be with narrower rims.

As to whether racing cyclists were 'definitely mistaken in favouring 23mm tyres for as long as they did', that is not the whole truth. Most of my chums never road-raced on tubs that were as narrow as that, and favoured models that came up 24-25mm wide. If riding TTs, narrower tyres would be used then, and the favoured courses were of course paved with smoother than average tarmac.

In more general terms it kind of depends how fast you intend to be going; at 25mph well over 90% of the drag is likely to be aero drag, of which the wheels are a significant fraction. Even if narrow tyres come with a small Crr deficit, there may still be a net benefit if they are more aero. Modern designs make for lower drag, but there is no getting away from the increase in frontal area with wider tyres.

Cynically I think that since many amateur cyclists aspire to look like racers (even if they are going slower and may weigh a lot more than real racers) a move to wider tyres on road bikes is a good idea; it allows more bikes to be shifted that will work better for the average user. Real racers may still use something different to that.

The takeaway is that if you have a bike that has clearances and mudguards, and are not averaging 20mph plus, you are probably going to be better off fitting tyres that are about as wide as will fit under your mudguards.

Remember too that years ago, most available wider tyres were basically crap; they were slow because they had cheaply made carcasses and heavy squidgy treads. For many years a narrower tyre would be likely to roll better than a wider one, because they were more likely to be made without these inherently crippling disadvantages.

For years I used to tour happily on training tyres (with a rib and file tread, and a nylon carcass) that came up about 27mm wide; they were so much faster than the 'touring tyres' that were then available, it wasn't even funny...

cheers

[FatLad1980]

Since these are actually 28C I'll give them a bash. I'll still have to return the mudguards I bought though as the widest tyre that will fit under them is 25C (depending on the tyre). Sadly, the website won't have the wider version in stock for a couple of months. No big deal, I haven't seen my Titanium bike for almost 2 months as it is, Evans are very kindly looking after it in their workshop and what should have been a simple job (brake service) has turned in to an absolute nightmare.