Triumphrat

mhanson · 06-10-2004

On the subject of tires:

When using a tube in a "tubless" tire that is rated for "X" speed, is the tires rating affected?

It seems to me that once you stick a tube in that tire it is not the same tire anymore. Or am I just being paranoid?

Mike

Slinky · 06-11-2004

I think you are right, the rating drops.

I read the same thing somewhere recently.

gararnett · 06-11-2004

Yes, it definately drops one level for speed rating. I road race spoked wheel bikes, why I know.

jimballard · 06-11-2004

I believe that the temperature of the tire/tube combination goes noticeably higher in use, and that drops the speed rating, but I'm not an expert. Best to check with a reputable tire store.

Ride Safe: Jim

06-13-2004

If the tire is a tube/tubeless type, the marked speed rating is correct whether you use a tube or not. Most radial tires are not rated for tubes and are not recommmended for such. If you have a radial tire that came with a tube, such as the spoke wheeled triples, you would do well to use the O.E.M type and brand tubes, as those are tested and approved by the manufacturer.

mhanson · 06-14-2004

Thanks everyone. Trispeed, my mechanic (Triumph) said basically the same thing. He stated there was no effect on the speed rating but, to be sure and use the proper "approved" tube type when replacing the tubes.

Mike