23mm tyres on wide rims - harsh?

on-yer-bike

I cant run 25mm tyres on my frame due to clearance issues. So I'm running 23mm Vittoria evo corsa on new Bora 35 clinchers and its very uncomfortable. Is it the wheels or the narrow tyres? Ive run old narrower Bora tubs and never noticed them being this harsh and they were 50mm.

keezx

IF you're running the same pressure then it will be harsher indeed.
Tyre gets more volume> lower pressure....like you're changing to 25's.
The parameters relate in a subtile manner and you have to find the best combination for yourself in relation to weight, roads, desired comfort level.

string78

I've just gone from ksyrium elite's running to GP4000's 25mm wide to some hand build 50mm deep sections running 23mm GP4000's and can't believe how smooth they ride compared to the ksyrium elites, running the same pressures (100 psi). The hand builds are 23mm wide rims.

mamba80

Tubs tend to run smoother for the same or even higher psi.

All you can do is experiment with pressure, the veloflex corsa 23 i ve got measure 23mm wide and are lower, much like a tub, the vitt corsa 23 is bigger and wider, i find the veloflex to be a very nice tire, so you could try this in a 25mm? ribble do them for £52 a pair

on-yer-bike

The thing about Corsa CX is that the min pressure is 115 psi! Ive run them at 100 and it felt like I had a puncture and didnt really help the situation. I guess 23mm on wider rims is a bit like low profile tyres on cars - uncomfortable. Will check out Veloflex next time.

sloppyschleckonds

The Veloflex corsa have a flatter profile on the rim, so 25's in those may be more comfortable. Always difficult to compare tubs/ clinchers as the wheels they are mounted on will be different also giving a stiffer ride or even skittish feel.

on-yer-bike

Interesting – on the Ribble website it says Veloflex Corsa not to be used with carbon rims?

on-yer-bike

Apparently says on the box too.

svetty

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19636849#p19636849]on-yer-bike[/url] wrote:

The thing about Corsa CX is that the min pressure is 115 psi! Ive run them at 100 and it felt like I had a puncture and didnt really help the situation. I guess 23mm on wider rims is a bit like low profile tyres on cars - uncomfortable. Will check out Veloflex next time.

115 PSI is way too high unless you're 90kgs.

Check this out: http://www.bikequarterly.com/images/TireDrop.pdf

on-yer-bike

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19639909#p19639909]Svetty[/url] wrote:

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19636849#p19636849]on-yer-bike[/url] wrote:

The thing about Corsa CX is that the min pressure is 115 psi! Ive run them at 100 and it felt like I had a puncture and didnt really help the situation. I guess 23mm on wider rims is a bit like low profile tyres on cars - uncomfortable. Will check out Veloflex next time.

115 PSI is way too high unless you're 90kgs.

Check this out: http://www.bikequarterly.com/images/TireDrop.pdf

Interesting. doesnt fit with Vittoria's recommendations at all which are 120 front and 125 rear for a 320TPI tyre! It also says based on a 40 60 weight split on 177 lbs that I should have 80 psi in the front and 110 psi in the back which is a much larger differential than I would have expected. Is that right?