Many roads in Ireland are constructed with a top dressing of loose clippings rolled into the Tarmac. This is not terribly bumpy but is very rough and on occasion I have lost speed on shallow downhills. Under these conditions my ill informed guess is that lower pressure would considerably increase resistance.
I'm not implying that lower pressure will roll better, but that the optimal pressure will be lower than for a smooth surface. e.g. on track 'boards' (or rollers as it the rolling road drag tests above) you want the tyres as high as they will possibly go and that as the surface becomes rougher the best pressure falls - at some point on every surface there will be a crossover where the extra tyre flexing causes more drag than the tiny ups-and-downs and jiggling of the harder tyre - I'd guess that the rougher the surface the lower this optimal pressure is.
But it's only a guess...
38 years of cycletouring, 33 years of running cycling holidays, 8 years of running a campsite for cyclists - there's a pattern here...
well, all this talk of tyres and especially the Schwalbe Spicer, I bought 2........soon to be another 2 for the other bike. Do I like them ....? Yes. providing they stay ''visitation' proof.
yostumpy wrote:well, all this talk of tyres and especially the Schwalbe Spicer, I bought 2........soon to be another 2 for the other bike. Do I like them ....? Yes. providing they stay ''visitation' proof.
I see one of the people answering you claimed that he'd found my article on tread patterns http://www.bretonbikes.com/homepage/cyc ... ycle-tyres and that 'the writer' (me) had confused "makes the mistake of thinking tyre pressure on the road depends on the load (rather than the inflation pressure of the tyre)" - I'd appreciate it if you pointed out that he should read the artcle again where he sees I refer to the pressure of the tyre ON the road, not the pressure inside the tyre - it's found by dividing the contact area into the load:-) - yes the contact area varies with pressure too but there's a limit on how complicated I wanted to make a simple point ...
I'll register on the forum (is it any good?) to bend his ear myself;-)
38 years of cycletouring, 33 years of running cycling holidays, 8 years of running a campsite for cyclists - there's a pattern here...
bretonbikes wrote:I'll register on the forum (is it any good?) to bend his ear myself;-)
No, it's awful. It doesn't allow people who can't pass an eye test or a hearing test to register themselves.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk All the above is CC-By-SA and no other implied copyright license to Cycle magazine.
yostumpy wrote:put it this way... its as good as this site. people everywhere are like marmite
No, it really isn't. This site doesn't block some disabled users like that. That's just sick, if not illegal.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk All the above is CC-By-SA and no other implied copyright license to Cycle magazine.
mjr wrote:This site doesn't block some disabled users like that. That's just sick, if not illegal.
It’s ignorance or laziness by the forum software developers. It doesn’t say much about the forum itself, which is interesting but so heavily (and pointlessly) divided into sub-forums that I only ever catch about half the posts that would interest me.
This CTC forum suffers from pointless sub-division too, but to a much lesser extent.
mjr wrote:This site doesn't block some disabled users like that. That's just sick, if not illegal.
It’s ignorance or laziness by the forum software developers. It doesn’t say much about the forum itself, which is interesting but so heavily (and pointlessly) divided into sub-forums that I only ever catch about half the posts that would interest me.
This CTC forum suffers from pointless sub-division too, but to a much lesser extent.
Wow - I thought it was a joke - but now I see what you mean.
38 years of cycletouring, 33 years of running cycling holidays, 8 years of running a campsite for cyclists - there's a pattern here...
If you bookmark "Board Index / View active topics" you wont miss a thing?
Al
Reuse, recycle, thus do your bit to save the planet.... Get stuff at auctions, Dump, Charity Shops, Facebook Marketplace, Ebay, Car Boots. Choose an Old House, and a Banger ..... And cycle as often as you can......
people everywhere are like marmite