Bicycle Mechanics - Tubulars - Three Glue Coats Or One, On Rim?

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I am mounting new Vittoria tubular tires on some older wheels. I have removed the old glue from the rim using a wire brush, stretched the tires for a few days over the rims, and trued the wheels for good measure.
Now I am reading in some places that you must apply three coats of glue to the rim, successively drying the first and second coats overnight, and a coat to the tire, and when the third rim coat and the tire coat are tacky, mount the tire and straighten, check edge adhesion, and inflate to 120 psi for 24 hours to cure. But other reading says just one coat on the rim and tire, when they are tacky, mount, straighten, check, inflate and wait 24 hours.
Which is it - three coats over three days, or one coat and mount?
First experience with tubulars, as if you can't tell. I wasn't going to try them, but when I realized how light this wheelset will be, I figured it was worth a try.
For example, front is 470 g including skewer. Campagnolo Record rims, Hi-E hubs and skewers, oval bladed spokes. Dang, my other wheels, the rim alone weighs that much.
Homebrew01
09-19-12, 03:46 AM
I put 1 coat on the tire, then one coat on the rim, wait about 15 min, mount tire, center it, pump to 80 psi or so. Done.
About 1 tube per tire I think.
No problems racing them in tight criteriums over the years.
bikeman732
09-19-12, 06:03 AM
I agree with Homebrew 01.....I use one fairly generous coat of glue on the rim, a thinner coat on the tire. wat 10-15 minutes, then set your tire.If you can let it dry overnight that is great, but I have ridden them immediately and havent lost one yet. The weight savings is nice, and you will love the ride!
Andrew R Stewart
09-19-12, 08:16 AM
The standard I grew up with (and have done professionally since the 1970s), based on new rims and tires, is to coat both rim and tire first. Let dry fully then second coat on rim and install tire with this coat still wet. Glue coats are thin. The biggest condition that change this are when the tire's base tape is not already coated with a sealent (like latex) and the cloth is porous. This might require several thin coats to seal and set up a surface that takes the rim's wet coat well. At the shop i allow a couple of hours to go through this. Of course some of that time is allowing the initial coats to dry and other work can be done (like the second wheel/tire) during this dry time. This technique has been written about and recommended many times in popular cycling publications, over the 4 decades I've be riding. Andy.
The weight savings is nice, and you will love the ride!
But if you don't use some Stan's tubeless sealant, you'll find out why I went off sew-ups 20 years ago...
Pretty keen to give em another shot these days.
fietsbob
09-19-12, 08:58 AM
Cross racing, I'd go with 3.. one on the rim , one on the tire, and they can dry
and like meat in the sandwich, third coat bonding with both..
Low PSI traction Pressures wont press the glue job down so well..
like 120 psi in road race tires, so rolling off in corners becomes more possible..
ultraman6970
09-19-12, 01:40 PM
You are sweating this too much :) Seen guys putting one whole tube per wheel...
Just one coat in the rim 1st... then put one coat in the tube, mount the tube (the glue in both has to be tacky if one side is dry then you might be calling problems)... inflate like to 60 or 80 psi so you CAN TWIST the tubular if you need to... if you do 120 you wont be able to correct the tubular position. Once you are happy, put like 100 psi... after 8 hours or even 4 hours that thing is already well dried. I do it overnight... 24 or 48 hours is like way too.
Tubulars work by constriction, is the air pressure the one that will keep the tubular in place, because the tubular will shrink and constrict around the rim. If you want to do a test just put a tubular with no glue and put 120 psi in there, try to get it off the rim with your thumbs. You wont be able to unless you are hulk. Obviously if the tubular is old and all floppy the situation changes but with new tubulars is not like super critical if you missed a part of the rim of glue because maybe you are running outta glue.
If you put like 3 coats in the rim and in the tubular when you mount the tubular you will get so much glue everywhere that you wont be willing to deal with tubulars no more... this is the 1st newbie mistake.. to put like zillions of coats.
Good luck....
Andrew R Stewart
09-19-12, 05:49 PM
"Tubulars work by constriction, is the air pressure the one that will keep the tubular in place, because the tubular will shrink and constrict around the rim. If you want to do a test just put a tubular with no glue and put 120 psi in there, try to get it off the rim with your thumbs. You wont be able to unless you are hulk. Obviously if the tubular is old and all floppy the situation changes but with new tubulars is not like super critical if you missed a part of the rim of glue because maybe you are running outta glue." (ultraman6970)
Boys and girls beware of what this man says. While the sewup will contract into the rim there is no way enough retension strength to withstand the forces a tire sees, without proper gluing. YOU NEED TO USE GLUE ALL THE WAY AROUND. Do i need to repeat?
If I took a tire to a shop to mount and there was no glue that squeezed out along the edge I would not trust that there was enough glue used. It's like grease. It's easy to more then you need (and clean off) but dangerours to use too little. If this means that someone won't want to deal with sew ups again THAT"S A GOOD THING. Better they figure this out at home then while sitting on the side of the road, picking gravel out of their skin and wondering why the tire rolled off the rim. Andy.
zonatandem
09-19-12, 06:01 PM
I always used (past tense . . . back in the 1970s) one coat of Tubasti glue.
Had a friend that never glued on his sewups, claimed tire pressure kept them on properly. Then he rolled one off the rim in a race . . .
Quit doing sewups in the late 70s as clinchers are easier to repair and now are quite light with Kevlar (instead of wire) beads.
What a coincidence, I just mounted new sewup tires on my two wheelsets these past two weekends.....
I haven't had any problems using Continental's gluing instructions on their glue tubes...
1 coat on rim first, set aside to dry for 15 minutes.....then one coat on the tire base tape (I make sure I'm a bit more generous with glue on the base tape as it absorbs some of it).....then back to the rim for a second coat. Although Continental did not say so, I wait 5 to 10 more minutes before I put the tire on the rim to avoid having a mess with too wet glue getting all over the rim and tire....
So far, no problems...
Chombi
ultraman6970
09-19-12, 06:30 PM
Andrew never said to ride w/o gluing... said if you want to test... just to find out how hard is to get a tubular off the rim even if not glued... so pretty much big difference. As for using tubulars unglued i met a couple of guys that do it and read of a few more here in the forums. Not a thing that I recommend doing anyways specially for trackers or sprinters, the other good reason is that tubulars slide if the tubular is not glued and will buldge at the valve area and you will get home with a bump in the valve area and the valve in a nasty angle... 1st symptom that probably the tubular needed more glue.
Shops in general wont get into gluing a tubular for a client unless they know the guy for a very long time just because of liability... makes sense too. Would you glue tubulars for somebody you dont know having a store? I wouldn't, and don't have a store either... neither glued tubulars for somebody else... but if somebody wants to know what to do or how to fix them is not a problem for me to teach them...
Well the op will figure it out anyways, is not like rocket science and is not something to get to anal about it either, after almost 30 years using them pretty much you know when it is too much glue, or if it needs more or not or even how to get them straight in the rim when you get them all twisted... right?
Andrew R Stewart
09-20-12, 02:28 PM
Ultraman6970- One of the dangers of this medium is that people read into the posting what the want to believe in. Your comments about testing a sew up's retension to a rim can very easily be miss understood. As i have said before much of my replies are for the other readers VS the poster. I read your post and cringed with the possible results if some one was to test your method while actually riding the bike. Would have this been your fault, not really. But we owe it to the unimformed to be careful in how we talk about something so basic as tires that stay on their rims.
The reason the shops that I have worked for (and the one I owned for 15 years) are hesitant to mount sew ups is because of the time VS cost. It's hard to explane to a customer that the time to do a proper job costs so much. Note I said a proper job. Not a quicky, once the tire's on no one knows how little glue was used job.
There are a few things I feel are worth getting anal about. This is one. Andy.
cranky old road
09-20-12, 04:29 PM
I've found in the past few years that if I use too much glue on the base tape and/or don't let the glue dry long enough on the rim, the base tape will separate from the tire after a few months, puckering along the edges. Never used to happen to me during the 70's and 80's. Could it be a problem of compatibility between glue brand and tire brand? Anyone else experience this?
And the spare tub, I should put glue on that too, enough to thoroughly coat the base tape, and let it thoroughly dry before folding the tire up and fastening it to the saddle?
Do you carry tubular glue in your toolkit, or do you figure the spare, if mounted by the side of the road, should be ridden like an unglued tub, i.e. gingerly?
fietsbob
09-21-12, 12:25 AM
now there is Tufo made double stick tape ask around Portland for anyone that has experience..
bikeman732
09-21-12, 09:37 AM
"Shops in general wont get into gluing a tubular for a client unless they know the guy for a very long time just because of liability... makes sense too. Would you glue tubulars for somebody you dont know having a store?"
Really? 25 years working in shops (including my own) who were all willing to mount tubulars. No more liability should be incurred with that than any number of operations performed by a full service shop!
bikeman732
09-21-12, 09:39 AM
And no I never carried glue in my seat bag. I did often carry a previously mounted sew-up as a spare and the residual glue will help....but as OP said "ride gingerly" , especially when cornering!
Andrew R Stewart
09-21-12, 02:26 PM
As to the spare i carry Jantex rim tape. Basicly the Tufo type but predates Tufo by a few decades. One Jantex roll does two tires. The only time i ever rolled a sew up off the rim was after mounting a used (and old glued) spare earlier in the day, then forgrtting about the not really glued tire and honking through the turns. The sound that a bare rim makes on asphalt is still fresh in my mind, after close to 35 years.
I learned the hard way about not having fully glued sew ups. I never want another to have to do the same. Andy.
JohnDThompson
09-21-12, 03:40 PM
now there is Tufo made double stick tape ask around Portland for anyone that has experience..
In my experience, the Tufo tape works well and allows clean and easy mounting of tires. Unless you're using "Tufo" brand tires, use the "extreme" version of the tape instead of the standard version. Jan Heine has suggested that tape increases rolling resistance compared to glue, but I haven't noticed.
Off for my first ride on my first set of tubulars and my first try gluing them. If I don't come back, I did something wrong.
Survived. Rode about 10 miles doing errands, didnt die. Didnt wail through any turns either. Dropped by my bike shop, they looked over my glue job and said it was passable, though they were referring to straightness not glue adhesion I think. I can't say it felt like riding on butter, basically felt like my other bike on clinchers. I will try some back to back wheel swapping, since the bikes themselves are quite different. The bike with tubs is a 52 (?) cm Cannondale est 20 lb. The other bike is a 58 cm Super vitus 980 est 30 lb with all the stuff hanging on it. Not really apples to apples.
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