Have just taken a pair of healthy 2.25 Rocket Rons off my (26") HT and replaced them with skinny(ish) part-worn 1.8 Nobby Nics.
Took for a fast spin over the dry gravelly Malverns ... tentatively in many places that I would normally go flat out, half expecting to die.
Got home and I appear to have set a number of PBs on Strava.
Slightly perplexed ...
There's a theory that wider tyres are faster, but I guess it depends on the terrain. I switched to 1.8s a few years ago, and found it much easier to hold a line, instead of pinging off rocks.
I've been using Storm Controls, but they're no longer available in 1.8, so I've just bought some (very cheap) Nobby Nics.
Yeah, a few more rides with these on and then make a decision I reckon.
...just in time for the autumnal slop!
No clearance for much above 1.95s on either of my hardtails, on the rear anyway; if there's a lot of quick acceleration sections could be they're quicker to get going? lower rotational mass and all that..
Probably right - and was running them with fairly high pressure (to avoid pinch flats).
The back end was fairly squirmy and interesting so may need to fiddle with the set up a bit.
fat tyres have better rolling resistance like for like. But a cheap fat tyre will have worse resistance than a good thin tyre.
eg. I know this is road tyres but the difference in feel between a Pro4 and a gatorskin is huge, the way they respond to pressure, the way they ride etc.
But yes terrain also matters, and depending on how fast you are moving don't forget that thin tyres are more aero than fat ones. Rocks and thin tyres aren't much fun but if your on loam different story.
Agreed MrMo, I guess that's why I'm a bit baffled, it was fairly sketchy loose stones in a fair few places. With PBs on some more 'interesting' sections.
... perhaps I was concentrating more / picking better lines
It's a bit counter-intuitive, but . . .
[url= http://www.schwalbetires.com/tech_info/rolling_resistance ]Why wide tyres roll better than narrow ones[/url]
It's a bit counter-intuitive, but . . .
Why wide tyres roll better than narrow ones
but i suspect it only works if you are using equivalent tyres. Compare the rolling resistance of a 33tpi tyre with a 320tpi tyre.
Then consider the air resistance between a 1.8 and a 2.4,
(yes i am bored, but if the difference between a 23c and a 25c is such that by the time your doing much above 20mph aero trumps rolling resistance, i can't see rolling trumping air resistance on faster mtb trails, particularly where the ground is fairly smooth, such as woodland single track.)
When I used to race I used Conti XC 1.5's a lot of the time, yes they where sketchy on certain parts of the course, but great for cutting down through the mud and finding grip and they didn't pick up the huge amounts of mud some of the bigger tyres did. They had to be run pretty hard though 65psi to avoid snake bites and I found they worked best on my FS bike.