Tyre size question

Obviously, the 23mms are 2mm narrower than the 25s. They will therefore roll a tiny bit better than 25s at any given pressure and will be very slightly lighter for any given make/model of tyre. But the 25s have quite a bit more volume of air in them so they will have more potential to absorb road vibration and (this may be controversial) should give a bit more protection to rims when hitting bumps, potholes etc. And you easily can get 23mms in lovely colours whereas almost all 25s are plain black (yes, I know, except for a few black/reds and black/greys. if you can find them in stock anywhere).
It's a matter of personal preference really. Being quite an old person I use 25mms for the comfort factor.

Bill D wrote:

Obviously, the 23mms are 2mm narrower than the 25s. They will therefore roll a tiny bit better than 25s at any given pressure

At the same pressure the rolling resistance of the 25mm tyre better will be better.

mattward1979 wrote:

redddraggon wrote:

Bill D wrote:

Obviously, the 23mms are 2mm narrower than the 25s. They will therefore roll a tiny bit better than 25s at any given pressure

At the same pressure the rolling resistance of the 25mm tyre better will be better.

How does that work?

A 25mm tyre at the same pressure as a 23mm tyre, needs to deflect less to maintenance the same contact, it's the energy required to cause the deflection that constitutes rolling resistance, so obviously if the pressures are the same the 25mm will have a lower RR.

Basic science.

mattward1979 wrote:

surely with that logic my MTB slicks would be faster on the roll than these slinky tyres.....

Well you seem to have no logic. MTB slicks will be 26" rather than 700c, and can you actually run them at the required pressure? MTB slicks are also likely to be of a different construction. I am of course in my example only changing the tyre width and nothing else.

The only pros of 23s are weight and aerodynamics, both of which are only a factor if you race or ride fast. Otherwise 25s give you: a better ride; more grip; less punctures; comparable if not lower rolling resistance, especially on rough roads. More people should be riding 25s IMO - 23s are only for racers, and even then a 25 might be a better bet in some circumstances (e.g. wet),.

skyd0g wrote:

Wouldn't rider weight also play a part in the above?

ie. for somebody as light as me (iro 8st) the 'advantages' of the 25mm's would be outweighed by the lower overall weight of the 23mm's, as compared to an 'average' 12-14st rider? :?:

I doubt it. The weight difference is negligible on its own, and expressed as a percentage of bike+rider rolling weight it's virtually non-existent. The RR reduction in 2mm wider tyres is also fairly academic, but is nonetheless there, and the extra tyre volume allows smoother (thus faster) progress.

Baybash wrote:

As the original poster let me expand my question. The choice I have is either keep the 700x25 Specialized All Condition Pro II that came with my new bike or replace them with some Continental GP4000s'. Any thoughts?

Wear the specialized tyres out in winter, then change them.

GP4000s will be faster but will puncture more and only last half as long; more of a summer/racing tyre.

Hi Guys,

You seem pretty clued up on the tyre front so i have a question for you.

I do a fair bit of road cycling but have started doing a bit of cycling with the mrs on sutrans/disused railway trails. The punctures are a pain the backside :roll: Rather than buying a hybrid with wider tyres, are there any tyres you could recommend for a road bike given the clearance between the forks for these type of trails?

Cheers

Have now done a 1000 miles on 25mm tyres and can honestly say I can find no difference between them and 23mm's for speed in general riding. For a TT I will use a thinner tyre for aerodynamics but other than that I can't see the point. I enjoy the greater comfort and puncture resistance. As for colour choices I don't know where you've been lookiing but my Vittorio Rubinos came in a very striking Blk/Yellow combo from Wiggle.

Once again, personal preference. I prefer 23's, notice no increase in comfort on 25's. Must be psychological because i get places quicker on 23's as well..........................................................................................................................................Actually for the sake of un biased opinion, my 25's were Bontrager race lites, i think theses are regarded as pretty standard tyres compared to the Pro race3/gp4000 which i prefer :roll: :arrow: