Tubs

There is a gp4000s I I tubular tyre in 22mm width only though. Very nice tyres and very durable. Conti gatorskin tubs is what will be appearing on the training bike soon. Winter is almost here.

Vittoria have new versions of the corsa out with magical graphene that they claim lowers rolling resistance but 20%.

320tpi.

TPI does not really matter that much. While, in general, finer fibres could allow a tyre to be made lighter, stronger and more flexible its all too often used as a marketing specification (like clock rate and number of cores in PCs). Those 300+ TPI tyres are not really 300 TPI but multi layer and they are counting them all. Finer fibres too is not really the answer. And even with the same fine fibres higher density means "more stiff".. So even looking at a single layer it also not as simple as "more is better".. Is ultrafine nylon really better than silk? Silk better than cotton? Can be but must not be.. A number of higher end tyres on the market have lower TPI counts than some of these and yet are more supple, lighter and stronger.. The Conti Olympic, for example, is "only" 220 TPI. And FMB Setas.... So TPI? Does not tell much of the story...

@germanmarc

Thank you, so they work out at £29.11, cheapest in UK is £36 from PBK. Think I may try some 25's though.

thanks a lot for sharing great information.

as its my first attempt glueing a tub, i do wonder about a few things. i am doing the 3layers on rim 1 layer on tub method. my first 2 layers on rim did dry very quickly and werent "tacky" after 45mins. the zipp video claims to let the last layer dry for 45mins than to mount the tire.
the temperate at the moment is quite high and i assume that the mastik one does dry quicker in higher temperatures. my question is, how long should i let dry the last layer before i mount the tire, or how "tacky" is tacky ?

You don't really need it to be that tacky when you mount the tyre. It's contact cement so will bond once it's in contact, regardless of whether the glue is wet or dry. The problem is more the bond between glue and wheel or glue and tyre.

Schwalbe Ones came today, went for the 26 over 24, as I have been running 25s on my clinchers which have been pretty good on the country roads. Weren't too much of a pain to mount, though required myself and another person to get them on as thy kept on slipping off as I was trying to get them over the rim.

Currently riding some 40 carbon clinchers as a demo whilst my tubs are being set, they have the Ones mounted and they are superb, looking forward to riding the tubulars

Ive got some old Vittoria Evo tubs that have the removable cores and use standard extenders, but all the recent ones I've bought have the pointless 30mm non removable core valves. I use the Leyzene extenders but would like something not so long (they are 60mm)
Any suggestions or recommended options?

You can use a zipp, HED, enve etc. These screw over the existing valve that you leave open.

Topeak do one that you carry with you and use to poke into the rim and open the valve as you screw it on. I hate these though.

Topeak do one that you carry with you and use to poke into the rim and open the valve as you screw it on. I hate these though.

I've got on with these...until it was discovered, too late, that they don't fit in the valve hole on my C40s.

If you could fit it in. Any kind of force applied to unscrew the valve woul demolecularize it. I've destroyed 4. Luckily they are so shit I've never made it out of the workroom.

Are there certain brands, or models, which are known to always latex inners? From a brief look at a selection of tubs on Wiggle, they don't tend to clarify what inner is used.

I have a spare Vittoria Corsa Evo CX which I pumped up a few days ago and is still going strong, which suggests to me of having a Butyl inner. Is this the same for all Vittoria tubs?

Or am I missing something and is the type of inner used in a tub not as important as the type used in a clincher?

Corsa's are latex.
Veloflex are latex
Fmb latex
Dugast latex
Challenge latex
tufo butyl.
Most contis are butyl (pro special editions aside).
Schwalbe seem to be movingly butyl.

The problem is more the bond between glue and wheel or glue and tyre.

The bond is always basetape to rim and basetape to tyre. The bond is created by, resp., mastic and contact cement. The bond rim to basetape is elastic and "sticky" and the bond basetape to tyre is non-sticky. That is why one needs to choose cements to attach basetape to rim that are less "strong" than used to attach the basetape to tyre to prevent basetape seperation. The strength is the weakest of the two. Since the road mastic (cement) used to attach basetape to rim is intentionally "sticky" by design it means that the bond can be rebuilt. That is why one does not need the glue to be wet. A little bit of heat from braking will soften the road mastic and the pressure of the inflated tyre will create a very good contact bond. Track technique is, however, quite different as one uses non-sticky hardening cements (shellac or industrial cements such as Terokal 2444) whose bonds once broken are broken--- similar to the bound between the basetape and tyre.
NOTE: note all cements are good for attaching basetapes to tyres. While latex glues work well with cotton and silk tyres they are suboptimal with nylon. Other contact cements are better choices--- Terokal, Patex etc.

Track technique is, however, quite different as one uses non-sticky hardening cements (shellac or industrial cements such as Terokal 2444) whose bonds once broken are broken--- similar to the bound between the basetape and tyre.

whats the reason for using different cement on track ? isnt the road mastic strong enough to handle the forces on track ?

whats the reason for using different cement on track ? isnt the road mastic strong enough to handle the forces on track ?

Two reasons... really.. strength and bond reliability is one... The other is rolling resistance.. Tyres glued with "stickly" road mastics have higher rolling resistance than those glued with hardening cements...

My Schwalbes have been in the shop for a week and lost their pressure. Thin butyl maybe?

Or you have the older ones with Latex inners.

Maybe maybe. Ordered a week ago through RaleighB2b, perhaps they have some old stock.

@thecycleclinic

Vittoria have new versions of the corsa out with magical graphene that they claim lowers rolling resistance but 20%.

Any idea on how to ID these new versions?

They should have G+ written on them somewhere.

dont think they will be available until Nov

My Schwalbes have been in the shop for a week and lost their pressure. Thin butyl maybe?

Don't know which tyres you have. The Ultremo HTs have latex and lose a lot of pressure within hours.. If you have one of the butyl models and it looses air within several days it could be you have a tiny pinhole defect called a "Schleicher" in German.

I have Ones. Thanks for the info. Took about 5 days to get to half pressure, guess there isn't much I can do about it though, other than keep topping them up. Perhaps if I am unlucky enough to have a flat, the sealant might help

maybe valve extender is leaking?