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Originally Posted by USAZorro
Here are a few things I've learned about preparing tubulars for installation in the past 6-7 months.
When you get them, inflate them to about 40 psi - don't mount them on anything yet. After a few days (maybe a week), deflate, and mount them on a rim (no glue), and inflate to about 40 psi again. I don't like inflating sewups when they are not mounted. They have a tendency to try to turn inside out and this stresses the glue joint between the basetape and the casing. I just mount them on a junk rim or spare wheel and inflate to full pressure. I leave them that way until I am ready to use them. Don't mount sewups on unlaced rims that you plan to use someday.
Originally Posted by USAZorro
Also, a few days before you want to glue them on, put a layer of adhesive onto the rim(s) you're going to mount the tire(s) to.
Unless you're dealing with really old tubulars, I suggest using 3-M Fast Tack for glue. I must say though that I've heard that Fast-Tack can cause the base tape on older tubulars to separate from the tires. I had a pair of old Wolbers that this happened with, but I haven't had it happen on any of the other tires I've used. Anyhow, here's a technique that I've used to mount tires with very little mess. I don't ride very aggressively, so I haven't ridden on any hairy, high-speed descents, so I can't vouch for how this holds under those conditions. Lots of people use Fast Tack for sewups but I stay away from it. It holds a bit too well, if that can be possible, sometimes stripping the basetape off the tire on removal. Its biggest problem is lack of residual glue to grip a spare installed on the road. An advantage is it sets up really quick, making an unexpected flat change before a ride possible. It's also cheaper than real tubular cement, which is probably the biggest reason why racers use it.
Originally Posted by USAZorro
Before you start, have some mineral spirits and a clean cloth rag at hand. Sit in a plastic chair in a clean well ventilated space, and put on vinyl or latex gloves - the very thin ones. Deflate the tire, put the stem of the tire into the hole in the rim. Make sure you have the tire oriented the way you want it. Once the tire is on the rim, sit in the chair, hold the rim with the stem up. Grasp the tire about one spoke hole away from the stem and lift it up. Squeeze a bit of glue onto the exposed sections of the rim. Move the glue tube around to get a light coating on the entire surface. Release the tire, being certain that the base tape is centered, rotate the rim two spoke holes, and repeat the process. Do this until you make it back to the stem.
If you get any glue on the tire, rim, spokes or yourself, wipe it off immediately. Use mineral spirits as necessary to clean the glue from any metal that it gets on. I used to do it this way. It's cleaner and it might work ok if you preglue as you recommended earlier. However, it's really important to preglue the basetape as well as the rim. Manufacturers recommend three coats of glue. I preglue the rim and basetape, let them both dry (this happens pretty fast, if you are in a hurry), then add another coat to the rim just before stretching the tire on. If the tire is prestretched and you are careful, this can be done with minimal mess. After 12 hours, the bond I get with Continental cement (which I buy in cans) grips like a vice. I have strong hands, but I need a key or tire iron to start working a flat tire back off the rim. Roughing up a new rim with sandpaper is also important. It's not a godd idea to use mineral spirits on a tire, as it can create problems if it gets to the tube.
Originally Posted by USAZorro
Once you've completed the gluing, inflate to about 25 psi. If any glue oozes onto the tire or rim, wipe it off immediately. Also make any manipulations you may want to center the tire if it hasn't gone on quite as straight as you want. You may need to decrease the pressure in the tire to do this. After 30 minutes, inflate the tire to about 40 psi and let the rim sit over night. I've had no problems riding on the tires the next day.
I totally agree. |
I'm in the process of gluing my first set of tubulars, and have a quick question: is it a problem to leave some of the old glue on the rim? I scraped and mineral spirited what I could, and I may be able to get some more off, but if I don't have to I'd rather not.
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Originally Posted by el twe
I'm in the process of gluing my first set of tubulars, and have a quick question: is it a problem to leave some of the old glue on the rim? I scraped and mineral spirited what I could, and I may be able to get some more off, but if I don't have to I'd rather not.
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OK, that's sort of what I figured. Thanks for the help.
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Try putting masking tape on the braking surfaces of the rim. Makes clean up much easier.
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I read that, thought, "Hmm, that's a really good idea," and then proceeded to not do that. Maybe on the next one...
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OK, just got the rear done. My hands are covered in Tubasti. Can I use mineral spirits to get glue off of the tire itself? How terrible is it to have the valve stem angled (not perpendicular to the rim)?
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Originally Posted by el twe
OK, just got the rear done. My hands are covered in Tubasti. Can I use mineral spirits to get glue off of the tire itself? How terrible is it to have the valve stem angled (not perpendicular to the rim)?
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Tire cleaning is gonna be fun - shoulda worn gloves.. The valve isn't actually not terribly off-center, so I'm just gonna leave it for now.
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el twe,
If you have tubasti all over the place you are working with glue that is too wet. Let it dry a bit before mounting the tire. It should be tacky, not runny. and you might be using too much glue! marty |
That and I don't think I stretched the tire quite as much as I should have. What should I do to get the glue off the tire now? I can perfect my "technique" on the front in the next couple of days, but for now I'd just like to get the white off the sidewalls.
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I've always been able to "chip" excess glue off the sidewalls. The glue dries
hard and the tire flexes, you might try deflating the tires and seeing if you can chip it off. don't use mineral spirits or any solvent as it could leach into the base tape, then you'd have the tape glued to the rim and a tenuous (at best) bond between the tape and the tire). Marty |
I cannot help with the white on the sidewalls, but I can recommend Continental rim cement. It is clear, at least what I get. Some say it comes in red.
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I was originally looking for Conti glue, but my LBS/employer only stocks Tubasti. Thanks for the cleaning advice.
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Originally Posted by el twe
I was originally looking for Conti glue, but my LBS/employer only stocks Tubasti. Thanks for the cleaning advice.
RE a valve stem that is not perpendicular to the rim, try to avoid this condition as it stresses the tube and thus could leak from there. Most newbies to sew-ups glue their 1st one like this. (Usually due to not pre-stretching the tire on an old rim.) All the trouble will be worth it the first time you lean deep into a turn at speed and the bike just grips and flys through. Good luck! Gerry |
So do you think it would be worth it to re-glue the tire?
(Please say no...) |
Originally Posted by el twe
So do you think it would be worth it to re-glue the tire?
(Please say no...) |
Alright, it's more like 20* off-center, I'm gonna leave it. I thought I had it set up fine, but apparently it slipped in the wrestling match to get it on (like I said, should've let it stretch some more). I was able to fix it a little before it dried.
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Glueing a stretched tire takes just a few minutes but centering the tires take me 3-4X longer!
Riding a good set of tubulars feels so good and rolls down a hill a few mph faster. I have tested this hypothesis on 2 of my bikes as I always build clincher and tubular wheelsets for all my bikes. My Waterford's tubular wheels just got finished and I have been to lazy/busy to glue on the leftover Vittoria CX/CG. Gerry |
Completely off-topic, but do you have any pics of that Waterford?
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Originally Posted by el twe
Completely off-topic, but do you have any pics of that Waterford?
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Didn't want to start a new thread, but wanted to alert any C&V tubular users to a set of wheels and tires in the For Sale section.
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A question to revive this totally tubular thread ...
I found a pair of barely used tubular tires in basement storage. They are probably 15-20 years old. One is a Panaracer, the other Clement. Nothing fancy, just normal everyday tubulars. They seem to hold air fine. They were mounted on rims but the glue was old and dried out, and they came off easily. Their treads look new with no signs of wear. The cotton base tape is coming unstuck from the tires in a couple places. Are these still usable, like could I pack them as spares with my flat kit? Should I reglue the cotton base tape to the tires? Or should these be considered unreliable, and tossed out? |
If you can figure out a good way to reattach the base tape, they're worth a try. I'd take them on a couple rides close to home first though - just in case..
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I'm not too sure about 15 - 20 year old tires. Tell you what, send them to me
and I'll (at my own personal risk) test ride them for a while. If after a few thousand kilometers they're ok, I'll send them back to you. . . seriously, I have no problem with old tires, I'd be a little concerned about the base tapes seperating from the main body of the tire. I've asked about regluing base tape on CR list and almost everyone said I'd be nuts to do it myself, but do send them to Tire Alert in Fla ( www.tirealert.com ). Last time I checked they were charging $8 per tire to replace the base tapes. Marty |
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