Gluing Up Cyclcocross Tubular Tires

It’s CX season and time to replace some worn out tubulars. My Challenge Fangos are supposed to be mud tires but their tread is only a little bit more aggressive than Grifos. I pinch flatted a tire during a race trying to hop a low log barrier (I’m a total noob in doing anything that looks like a bunny hop). The tire was on it last leg because of a rotting sidewall with a bulging inner tube.

First order of business was taking the old tire off. My glue job from two seasons ago was superb with meant getting it off was quite a chore. After lots of elbow grease and prying, I got it off. Left on the rim was the Belgian tape, the cloth backing tape from the tire, and lots of glue. I went after it with mineral spirits and acetone. What a mess! Eventually I was able to get it back to the aluminum rim (Major Tom rims). The procedure I use has been adapted from several pros who have posted their procedures. You can use a truing stand but I’d rather not get glue all over the stand. So I put together a strip of metal with a hole in it, clamped to the bench vise

CX tub1

Day

Task

1

‘Stretch’ tubular tires for at least 48hrs on tubular rims. Stretch tire on rim and inflate to 60psi.

2

[nothing]

3

Remove tires and apply one thin coat of tubular glue, such as Vittoria Mastik One, onto the cotton backing tape using a metal handle acid flux brush.

Inspect tire for areas where the glue has soaked in exposing base tape; reapply glue to those areas

Mount wheels in truing stand or similar

Lightly sand the rim and remove the dust with acetone

Apply one thin coat of tubular glue to the rim. I find the easiest way is to dip the bush in the glue, dab it along the rim and the brush it for a thin coat

4

Deflate the tire(s) and mount it on a clean (unglued rim); inflate to 60 psi

Apply a second thin coat to the rim.

Wait 10-15 minutes (or while you apply glue to the second rim) and apply the Belgian rim tape to the rim by first peeling the yellow backing [if only one backing material; nothing to peel off] off one side and then, Using a truing stand, stretch and press in the Belgian rim tape  using a finger or back of a screwdriver handle to ensure it is pressed in well.

CX tub3  CX tub2

Remove the backing from the Belgian tape and apply thin coat of cement directly onto the rim tape.

Wait 15 minutes (or the time to do the second rim).

Mount the tire as follows:

(a) Stand the wheel up with the valve hole facing up.

(b) Put the valve stem through the hole, and, leaning over the wheel, grab the tire and stretch outward as you push the base tape into the top of the rim. Keep stretching down on the tire with both hands, using your body weight, as you push the tire down around the rim. I like to lean hard enough on the tire that my feet lift repeatedly off the ground. The farther you can stretch the tire at this point, the easier it will be to get the last bit of tire onto the rim.

(c) Lifting the rim up to horizontal with the valve side against your belly, roll the last bit of the tire onto the opposite side of the rim. If you can’t get the tire to pop over the rim, peel the tire back and start over, pushing down again from the valve stem. You want to avoid the temptation of prying a stubborn tire onto the rim with screwdrivers or other tools, as you will likely tear cords in the base tape and tire casing, leading to a bulge in the tire in this area.

Inflate the tire to approximately 35psi and spin the wheel on the truing stand or by grasping the hub on the sides with your hands. Check for wobbles and using your hand ‘knead’ the tire to take out the bumps. It won’t ever be perfect, but even it out as best you can.

Next, inflate the tire to about 55-60psi and beginning with the valve at the bottom nearest, the floor, place the wheel on the floor and press down on the wheel, rocking it back and forth, then rotate the wheel a little bit, and press down again. Repeat this, applying your weight onto the wheel, until you’ve gone all the way round the wheel.

Notes

1 can of Vittoria Mastik will do at least two wheel sets

 

Here’s a nice video showing a similar video.

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