tubeless tyre question
 

something i collected and hope to use

it doesnt have a valve, and im wondering can it be fixed?

i blow air into it using my mouth, there doesnt appear to be a puncture it might be worth fixing...


http://bikeforums.net/attachment.php...hmentid=423670


http://bikeforums.net/attachment.php...hmentid=423671

Its a Sew Up, Glued On Tire, Missing the removable valve core .

It is a tubular tire missing its removable valve core. You cannot use it unless you have wheels designed for tubulars

just googled that and it requires a tubular wheel

looks like a pain to install too, and over my head, cheers mate

Buy the P/V valve Core , pump it up if it holds air it has resale value.

good idea

what would it be worth in aussie dollars? the tread looks ok

DIY research. IDK what the 'Pacific Peso' to Euro rate Is, it Fluctuates by the Day.

The correct term is either "tubular" or "sewup". I like "sewup" as there is less confusion.

How did you acquire this? Do you have the special rims for sewups?

My guess is that it is missing the valve because it had a flat, and someone chose to keep the valve and discard the tire. What does the tread look like?

Looking at the Continental Grand Prix 4000 pages, at least the newer ones have a "seamless casing design". In other words, they're marketing them as "one flat and they're done". DISPOSIBLE.

There was a type of true tubeless tubular that I had gotten about 20 years ago. In theory one would inject some glue into the hole to fix it. I forgot the brand. Anyway it wasn't very effective at that time. I don't know if they are better now, but it doesn't seem to be a widely discussed technology. I'm not sure if the Continental GP has a seamless construction with a tube anyway.

Anyway, the valve cores/extensions should be cheap enough.

Before doing anything though, I'd remove some of the tape and see if it has normal stitches under the tape. You can always glue it back down later.

Not really. A standard 700C tubular will mount up fine on a 27"/630 mm wheel. Although you might need to glue it anyhow, to prevent it from slipping on the rim.

Well, it's more work than clinchers, but it's not that bad.

Don't sell yourself short so easily. It's not rocket science.

Slap a little glue on the rim, and they are one of the quickest/easiest tires to mount. But, a pain to repair.

My guess it has a flat.

About $80 new.
Perhaps 1/4 of that in good used condition.

Not worth much if it is non-repairable with a flat, or completely worn out. I.E. The previous owner probably decided the valve core was worth more than the rest of the tire.

A tire can be a tubular without being a sewup. Tufo tubulars are not sewups and they have no inner tube. They can be repaired using sealant, if the hole is small enough, the sealant works.Sealant is also used in road and mountain bike tubeless tires

And you could try a sealant in it.

I wouldn't buy a tire on E-Bay that listed it as having a flat, no way to repair, but maybe could work with a sealant.

The correct term is either "tubular" or "sewup". I like "sewup" as there is less confusion.

How did you acquire this? Do you have the special rims for sewups?

a home mechanic who motorises bicycles.. as he sorts out his stuff he gives me his surplus, it came with a bunch of other tires and tubes. it didn't come with tubular rims. i haven't recieved any of those special wheels off him as yet.

My guess is that it is missing the valve because it had a flat, and someone chose to keep the valve and discard the tire. What does the tread look like?

sounds logical

Looking at the Continental Grand Prix 4000 pages, at least the newer ones have a "seamless casing design". In other words, they're marketing them as "one flat and they're done". DISPOSIBLE.

thx for the research

Anyway, the valve cores/extensions should be cheap enough.

Before doing anything though, I'd remove some of the tape and see if it has normal stitches under the tape. You can always glue it back down later.

it bit of tape is pulled back, was how i got it...

http://bikeforums.net/attachment.php...hmentid=423728

thx for the valuation

if it turns out to be in good condition, i would swap it for a good pair of regular road tires


i wonder what are the advantages of tubulars tires?

Here is what the classic "sewup" looks like.

http://www.outgunracing.com/tubular-tire-stitches.jpg

You can see the original stitches, and where a few stitches have been cut to reveal the tube. Assuming you're down to the casing, you don't have that. I do wonder, if your tire has a loose tube, one may still be able to open it up, repair, then sew it closed (assuming the stitches would hold).

However, the key with the sewups is to minimize the size of the opening makes to repair a flat as sewing them back up is a pain.

Anyway, it sounds like you have something to play with, or trade it at a swap meet. Perhaps your friend can dig up a valve core.

I haven't used them for years. I think there was a sealant that one could put in years ago, but it is likely that today's sealants are more effective.

Way back in the days before hooked rims, tubulars were the way to go if you wanted to run high pressures.
After that advantage had faded, tubulars could still be built with thinner sidewalls than clinchers, giving lower rolling resistance and another feel to the ride.
After that advantage faded, tubulars still did better at staying on the rim after a flat, where clinchers could simply roll off. Close enough to the line, one could finish a race with a flat and some degree of control, which isn't really possible on clinchers.

As far as the advantages of the sewups...

They always gave a good ride. The tires were lightweight, and perhaps the rims were strong and lightweight too as they don't have to support lateral forces from inflation. Wire beads also aren't needed to hold them in place, and can support quite high pressures. They have a perfect round profile on the road (minus the contact patch).

They're quick to replace on the road, but a pain to repair properly. Flat replacement gives one a new tire and tube without worrying about tire damage.

If properly glued onto the rim, they were quite secure... less so if not glued on.

Traditionally they were the choice for racing, and may still be, although there are now many lightweight clincher options available too. Heavier duty versions are apparently also being used in cyclocross.