Shop Talk 03 Oct 2007 06:57 pm
Experiments with Cyclocross Tubulars
Round 1 – Tubular Gluing Tape.
I haven’t messed around with tubulars much, because, well, gluing tubulars requires a lot of messing around. For the first round, I thought I’d try out tubular gluing tape. Gluing tape is essentially a gummy double sided tape, and is advertised as completely replacing the gluing process – apply the tape to the rim, mount the tire and you are done. Well, let’s see how it works. Today I mounted a Vittoria Evo XG cross tire on a Ambrosio Excellence tubular rim using Tufo Extreme gluing tape. The tire and rim were new. I scraped the cotton base of the tubular lightly, and cleaned the rim with acetone. The tape and tubular were installed following the Tufo directions.
Note that Tufo only recommends the use of gluing tape with Tufo tires, and recommends standard tape for cyclocross. Mounting the tire with the tape was easy….and rolling the mounted tire off was even easier! At 40 PSI the bond seemed pretty secure by hand – I couldn’t seperate the tubular from the sidewall of the rim. However, on the bike, deliberately pushing the front in a corner rolled the tire off. The force required was high, but definitely in the realm of what would be encountered racing. So, for this tire/rim combination at least, gluing tape is NOT recommended! Next I’ll try gluing the proper way.
on 03 Oct 2007 at 9:18 pm 1.Erik said …
Hey Dave,
Sorry to hear about your luck with the Tape. I use “only tape” on my road wheels, but for cross here is the secret; one layer of glue on rim, let dry for 2 hours, so it’s just tacky, one layer of glue on tire, let dry for the same amount of time and then run the tape on top off the glued-up rim and then mount the tire with the glue on it. Once the tire is centered, roll the wheel along a broom (it’ll make sense when you do it). This may be a bit messy at first, but I’ve been running this set-up for 5 weeks with 2 races and (knock on wood) no issues.
p.s. don’t run those tires in dry, semi-dry, flat, hill, grassy, damp, or wet conditions, they are UNsafe! the compound is too hard and feels unrealiable in corners; check out the Challenge Grifo or Dugast for a better all purpose race tire (just my 2 cents). I look good in Green
on 04 Oct 2007 at 8:08 am 2.Dave said …
Thanks for the feedback. I wasn’t expecting the tape to work well – but more than anything, I’m experimenting to see how well the different methods work – how far do you have to go to get a good bond. The tire and rim were selected for cost effectiveness – not performance. I’m not convinced the rim is going to work for CX tires at all. The ambrosio rim has small (1mm) sidewalls in the tire bed that would help cup a 21C tire, but I think are keeping the CX tire off the tire bed. We’ll see what a multi-layer glue bed does.
on 05 Oct 2007 at 6:17 pm 3.David Dermont said …
The poop on the course is, one layer each day for three days on the rim (for new rims). Inflate the tire off the rim to stretch it out so you don’t have to wrastle as much. Then one layer on the tire and one on the rim. Wait ten minutes and mount. I have seen some put masking tape on one side of the rim to guard against glue mess on the breaking surface. Once mounted pump the tire really high (100?). Let stand over night. The trick is to get the glue as close to the edge as you can. The tire will roll off easier if there is a bond flaw right at the edge. If you pull at it and see a flaw you can reglue that bit and reinflate.
on 06 Oct 2007 at 9:28 am 4.Dave said …
Yeah, that’s essentially the Barnett Bicycle Institute guidance:
http://www.engr.ku.edu/~kuktl/bicycle/Cusa1.pdf
I have a tire mounted in this way now, and it is a much more substantial bond than the tape.
on 07 Nov 2007 at 7:48 pm 5.David Singlespeed Unrau » Experiments with Cyclocross Tubulars said …
[...] the trying the Tufo gluing tape, I next glued the tires on in accordance with the Barnett method – three layers of Gommitalia glue [...]
on 08 Nov 2007 at 6:42 pm 6.David Dermont said …
Marty agreed that the dish on the ambrosio is more inclined to hold a smaller tire. He suggested a build up of glue to fill the void. When the tire rolled there were bubbles along the center of the rim where the glue did not contact the tire.