Tyre Sizes

[PaulF]

OK, I bought my first road bike in November which came with mudguards and hence was limited to 23's.

Now I'm happy with them but that's because I probably don't know any better

What are the pros and cons of moving to larger tyres?

Is it a straight narrower are faster/wider are more comfortable? Or is it more complex?

Or will I start the rubber equivalent of the Campagnolo vs. Shimano debate?

[Biggsy]

The only simple one is weight.  Wider tyres of the same model are heavier.

All the other factors are complicated by air pressure - which generally should be lower with wider tyres to provide acceptable comfort and grip.  Tyre manufacturers don't always make this obvious and sometimes stupidly recommend the same pressures for different sizes.

Due to the different ways they flex, wider tyres have lower rolling resistance when at the same pressure (but see above).  They also take longer to wear out.

On the smoothest roads, highly inflated 23mm tyres should be faster than softer 25mm tyres of the same model, but I think the 25s are faster on average roads.

[border-rider]

I tend to use 25s or 28s, and for the fixed distance bike I use 28s or 32s.  Yes they're heavier but on bumpy roads they're no slower, and may even be faster in some circumstances.