|Tubular came off the rim!||Bridgestoner|
Sep 26, 2003 4:36 PM
|Tonight I had a genuine "JRA,"(just riding along.) Well I was admittedly in a full sprint, and the 32mm Tufo/Empella tubular came off the rim (one race and one other training ride other than tonight) and jammed on the brake . I left a 15 foot patch in the grass while wrestling the bike as I came to an ugly stop.
I was wondering if it was a lousy, patchy glue job or if this, unfortunatly, is a normal possibility (I did feel the rear end skipping side to side a bit as I raced over the irregular schoolyard lawn.
My local roady bike shop mounted them and assured me that they work with "alot" of tubulars. And I believe him as he is the main wheelbuilder for a popular rim/wheel mfg co. However, he had never heard of tubular tape, so maybe cx needs are far more obscure and demanding?
Has anyone out there experience a similar problem? And does anyone run tubular tape?
Sep 26, 2003 5:20 PM
|CX tires are exposed to mud, water crossings and hopefully, more frequent washings than a regular roadbike. They need to be checked on a regular basis to make sure the tire is firmly affixed to the wheel. Tufo makes a good tubby tape that should help to lessen this problem. In Europe, the 'crossers use both glue and tape in conjunction with each to hold the tire on. However you may need tools to be able to get the tire off when it comes time to replace them. GOOD LUCK!|
|re: Tubular came off the rim!||flyweight|
Sep 29, 2003 9:47 AM
|Ask what they used for glue. If they say FastTack ask for your money back! 3M FastTack is NOT tubular glue. It doesn't dry completely and doesn't provide a solid bond. USA Cycling team mechanics never use the stuff and if you go to the mechanic's clinic they'll tell you specifically not to use FastTack.
Also ask how many layers of glue they put on the rim. If the answer is less than 3 they're wrong.
The method taught at the USCF clinic is to brush on at least 3 coats of glue on the rim allowing the first two layers to fully dry for at least 12 hours. Also put one layer on the tire and allow it to fully dry. The final layer on the rim should dry till it's tacky at which point you put on the tire. Inflate to at least 80psi and roll the wheel firmly along the ground to help seat it then let it sit overnight.
|re: Tubular came off the rim!||MShaw|
Sep 29, 2003 10:31 AM
|As someone that's been using Fastack for years, I can tell you that I've ripped base tapes off before the tire came loose. That said, I like Conti glue too.
Fastack seems to stick Ok for me, but then I'm particular.
First, for the OP: learn to glue your own d@mn tires! It isn't that hard. That way, you KNOW that it was done right. www.cyclingnews.com did a piece on gluing tubulars recently. Park tools probably has a page dedicated to gluing tubies, I haven't looked, but I think that's where cyclingnews.com got their info. The first times, you should probably have someone that knows what they're doing watch so you don't make any obvious mistakes.
Second: check tires frequently. That way you know if there's a problem developing BEFORE its an emergency.
Third: did I mention gluing your own tires? Using the three layer method is great if you don't have a bunch of glue left on the rim to start with. Glue sticks better to glue than it does AL...
Tubies are great, but they take a little more care than running your average clincher. If you pay attention to them, you'll get lots and lots of use out of them with no problems whatsoever.
|re: Tubular came off the rim!||flyweight|
Sep 30, 2003 8:30 AM
|"As someone that's been using Fastack for years, I can tell you that I've ripped base tapes off before the tire came loose."
Too funny. The reason you've ripped base tapes off when using FastTack is because FastTack actually disolves the glue used by some companies to hold the base tape to the tire! It's NOT because the FastTack has such great bonding strength. This is one reason why FastTack is a big no-no with the USCF.
USA Cycling commissioned a study where they found FastTack had the lowest adhesion of any cement. The other problem is that unlike other cements, FastTack never fully dries. I've used FastTack in the past without problems but I'm willing to defer to the expertise of the head mechanic for the US cycling team.
|Right on Fast-Tack dissolving glues||jw25|
Oct 2, 2003 9:41 AM
|but not as right on other glues drying. Road tubular glue (as opposed to track shellac, which does dry hard) doesn't dry, it just sets up thicker and thicker. Oh, sure, it dries eventually, at which point it doesn't stick worth anything. That's why you should check and reglue tubies every year.
Tubular glue is a contact cement, which is why only gluing the rim doesn't bond nearly as well as gluing both parts. When the two layers of glue come together, the solvents in the tacky layer resoften the layer on the tire, and you get one thicker layer between everything.
The fact that the glue remains soft can be seen in rolling resistance tests, where a tire glued with track shellac will have lower RR than one glued with road cement. On alloy rims, you'll also see aluminum oxide stains on the base tape after some use, from abrasion by the movement.
To get back to the first post, the tubie rolled from lack of adhesion, exacerbated by the large size of a cross tire compared to the rim. Road tubies are much closer in width compared to the rim, which offers more support when cornering. A cross tubular, though, can be 15mm wider than the rim it's on, which leaves a larger unsupported section. Usually not a big issue, as cross tires aren't leaned as hard into corners. Throw in water and maybe soap from repeated washings and wet riding, low pressures, and that unsupported section, and rolloffs will happen.
I'd definitely recommend getting to know how to mount your own tires. It's not that hard, not too messy after a while, and a good skill to have.
There's also some different products to try, namely Tufo's tubular tape and the stuff offered at cyclocrossworld.com. The Tufo comes in two strengths, regular and extreme. I'd say you want the extreme, which is made for a wider temperature range and should stick more tenaciously. Tire changes will be harder, but that shouldn't be an issue in a cross race (you have spare wheels, right?). It's made for bare rims, but a clean layer of glue on the rim shouldn't hurt adhesion. The big trick here, and one that's not noted in the "instructions" in the package, is to wet the surface down well before mounting the tire. This lets you align the tread; otherwise it's pretty much stuck as is.
I've been using the regular Tufo tape on some 22mm Tufos on Zipp 440's, and they stick extremely well. At 20 lbs, I wasn't able to move the tire once it had been ridden (this activates the adhesive). I'm extremely confident, but this is a TT setup, and subject to much less abuse than cross wheels and tires.
Good luck with it, and at least this learning experience sounds like it came cheap, with no loss of skin or equipment.
|Right on Fast-Tack dissolving glues||flyweight|
Oct 2, 2003 10:34 AM
|True, road glue doesn't completely dry up the way track shellac does but it does dry far more than FastTack. I've got about a dozen wheels that I'm having to reglue at the moment. Almost all of them used FastTack and it's downright scary how easy it is to pull the tires off.
I've used Tufo tape a couple of times and never had too much difficulty in aligning the tire even without wetting the surface down. Go figure. Works very well for cross tires. Used it on Ksyrium, Cosmic, Reflex and Campy Barcelona (my favorite) with no problems. On rims with a deeper, rounder bed I added an extra layer of glue to help give it a better foundation.