tubular gluing advice

[Kines]

I'm sure that title is met by a big eye-rolling from the veterans, (or they probably haven't even read this far). It has been a decade since I glued a pair, and I just finished the current job.

Here's my Q: getting them straight was not a problem at all, but they are out of round, and I assume it is because I was unable to put enough tension on them initially to stretch the tire evenly. The "flat" area is the furthest from the valve. I'm sure this is a common problem, but how much would you tolerate before regluing them (perhaps after they stretch a bit)?

It's hard to quantify in mm, but I would just say it is significant; neither subtle nor dramatic.

TIA
KN

[djg]

Just out of curiosity, what tires are you using?

When you say you had problems stretching them, am I right in assuming that you pre-stretched the tire? If so, was the tire round when you stretched it at that time?

[11.4]

I'm sure that title is met by a big eye-rolling from the veterans, (or they probably haven't even read this far). It has been a decade since I glued a pair, and I just finished the current job.

Here's my Q: getting them straight was not a problem at all, but they are out of round, and I assume it is because I was unable to put enough tension on them initially to stretch the tire evenly. The "flat" area is the furthest from the valve. I'm sure this is a common problem, but how much would you tolerate before regluing them (perhaps after they stretch a bit)?

It's hard to quantify in mm, but I would just say it is significant; neither subtle nor dramatic.

TIA
KN

Yes, the tires actually narrow in diameter when stretched hard, and you were localizing too much of the stretch in the last part to go on the rim (which for most people is just opposite the valve stem). You often need to stretch the tire before it's glued (inflated on a dry unglued rim), then stretch it again after you've put the glue on the base tape and allowed it to dry (because the glue can cause the base tape and tire to shrink again), and then simply roll it off the stretching rim and immediately mount it on the wheel with fresh glue in place.

When you stretch, everyone has their own technique, but since I do a lot of tires, I actually got a couple of those stainless rails for handicapped restrooms and mounted them on a wall, positioned horizontally, at a couple different levels (you can simply use a table top or the like with much the same result). I start mounting with the valve hole at the top (in contrast to many people) so I can literally use body weight to stretch and pull the tire down. Then I just flip it in my hands while holding the last point on each side where the tire is mounted. Then the last portion should slip over at least reasonably easily. Pump up hard, leave for 24 hours, and you should be fine.

The better tires do tend to stretch more in the way you described, simply because the casings are more supple. But they also usually respond to prestretching the best so you don't have as much trouble actually mounting them. Tires like Vittorias, Veloflexes, Dugasts, FMBs all mount easily. Contis are the toughest so if you are learning on them just be aware you are starting out with some extra work ahead.

[tbushnel]

Contis are the toughest so if you are learning on them just be aware you are starting out with some extra work ahead.

I'll second that.
Enjoy the ride.
ted.