Cycling UK Forum

Kentish Man wrote:I'm off to the New Forest in a couple of weeks. Given the number of cattle grids, is it folly to ride 700x23s when I could change to 28s? I will not be going off road, at least, not intentionally! NB, I'm not the lightest meringue in the pack.

I ride 25s in the forest all the time. The grids are no problem at all. in fact I quite enjoy them.

The new forest day out on Sunday will be ace. I did it a couple of years ago. Does anyone have the official route sheet? I've found a route here http://www.mapmyride.com/routes/fullscreen/25082472/#from a previous year but I'd prefer the official route sheet.

CJ that was an awesome post. Thanks to CJ and everyone else for their assistance here. In some ways I am pleased of the outcome. I'll get hold of a second gauge to test things, and also take more care when pumping. I like the theory about the pressure being in the pump etc.

I wonder if I should pump up to 130 or 140 psi to allow for the pressure in the pump and subsequent accidental leakage when removing the pump? Or am I missing the point?

How old are the tubes did they come with the bike?

It happens with brand new tubes.

Incidently how are you measuring the pressure?

I use a Joe Blow Sport pump. It seems pretty accurate I guess. As I pump the gauge goes up.

How careful are you with fitting tyres? Are your tyre and rim combination a tight fit? Are your spokes too long?

The spokes came with the bike wheels when I bought it last year. As did the tyres and rims. I am pretty careful with fitting tyres, and also I find it happened after a recent bike service where my local shop fitted them. A very good shop (Specialized dealer) so they would have fitted correctly.

Are there really no tubes that have a reputation for especially non-leaky valves?

Thanks James. Yes both Presta. Also they both lose pressure but the problem is worse on the rear tyre.

Yes, I tighten the value nut as tight as I can after every pump!

Hi there. I'd really appreciate it if any of you think you can help. I think I need tubes with VERY high pressure valves.

I run a Specialized Sirris Elite with 700x28 tyres. I am big and tall and have found that after an hour cycling, my tubes go from 120psi down to 80-100.

Is there anything I can do? It happens on new tubes so I am sure I've not got a slow puncture.

I currently use standard Specialized tubes. I've seen more expensive tubes but they seem to be advertised as more lightweight rather than having better valves that don't leak.

There is the Specialised "turbo" range but I'm not sure the valves are better? And if so they only go to 700x25 so not sure they'd fit in 700x28 tyres??

Any help would be appreciated. I am fed up with pumping my tyes all the time, and planning a cycle to France this summer so really need to get it sorted!

Thanks again

Jonny