Glueing tubulars [the tubular thread]

[Geoff]

Personally, I find that the best way to prepare the tire for that 'adjustment' is to put the last layer of glue down on the basetape, rather than the rim bed. I find that the tire 'moves' better once installed.

Procedurally, once you have the tire on, inflate it just enough to round it out. Holding the wheel at arms-length, spin it slowly while looking down the tread. Don't look at the basetape, that has almost no relationship to the tread and can be very deceptive. When you find a 'wiggle', place your thumbs on either side of that spot and press firmly across the rim bed (do not try to 'lift' the tire up, that will not end well) and 'slide' the tire across to straighten the tread. After a few spins, you will see how quickly the tire centres. Once straight enough, inflate it fully. Spin it one more time to make sure.

[sanrensho]

Thanks for the comments and tips. I've decided to ride the tire for now, even though the tread is not centered.

In hindsight, I needed to work faster getting that last wet layer down (to prevent excess drying), and I should have practiced the final mounting several times using a spare wheel/tub.

[Geoff]

You should be fine. It isn't perfect, but really, what is the harm? The important part is to make sure that you do a good job gluing the tire down. Perfecting the process will come with practice.

[sanrensho]

^^^Thanks.

The tire rides perfectly fine even though the tread isn't centered. I've had a couple of rides on the wheel and am cornering with full confidence.

My process gleaned from the combined knowledge of the board:

1. Remove old glue using Goof Off and rag, but not anally. Clean rim with alcohol.
2. Two thin but even layers of Mastik 1 on rim and one slightly thicker layer on tire (accounting for basetape absorption), 24 hours drying time for each layer.
3. Final layer on rim, mount pre-stretched tire.
4. Center and pump up tire in stages, checking for hops/lateral unevenness on truing stand.
5. Pump to full pressure and leave 24 hours.

Next time, as a precaution, I will ride the tire immediately after gluing to make sure the tire is bedded. Also will try reducing the drying time for the 2nd rim layer to 12 hours per Chip Howat's recommended procedure.

Due to my inability to muscle the tire over the rim, I will also keep a plastic tire lever handy to pull the tire over the last part of the rim.

[Geoff]

Sounds pretty good. Personally, I prefer the last layer on the basetape, as opposed to the rim bed (I find that the final mounting of the tire and its adjustment is easier that way). I don't know that I would recommend riding the tire to 'bed it in' immediately after gluing. That sounds like a recipe for disaster.

[sanrensho]

Sounds pretty good. Personally, I prefer the last layer on the basetape, as opposed to the rim bed (I find that the final mounting of the tire and its adjustment is easier that way). I don't know that I would recommend riding the tire to 'bed it in' immediately after gluing. That sounds like a recipe for disaster.

I can see how the last layer on the basetape would be the way to go. If I didn't have weak hands I would try this, otherwise I can see myself removing the glue from the basetape while struggling to get the last part of the tire over the rim.

By riding I meant mounting the wheel on a bike and rotating the wheel (straight line) with pressure on it. Although I didn't find it necessary this time and may skip it again.

[sawyer]

I ride immediately after mounting the tyre and inflating to 150psi ... just a slow round the block ride with some gentle cornering left and right. IME the pressure just helps seat the tyre and gives you a good feel as to whether it's centred properly as opposed to just relying on sight

[nemeseri]

I came across this study about glue performance and I thought there might be others out there who hasn't read this yet. I found it kind of interesting. https://drive.google.com/file/d/0BwhVX- ... view?pli=1

[parajba]

Quick question...

I have a set of carbon tubs glued in 2012 but I need to remove the tubs because the wheels need to be serviced.

Is it OK if I try Tufo tape? My current situation does not allow me to have the time required to look after the tubs properly, so I either find a quick solution or I will have to sell and switch to clinchers. Tyres are Veloflex Carbons and the current glue is Mastikone.

Thanks all

[sungod]

if you insist on using tape, you shouldn't put tape on top of old glue, you've no way of knowing if the bond will be ok

that means you'll need to take off the old glue, followed by a thorough degrease with acetone/similar

cleaning a rim is far more effort than it takes to glue a tub

if the old glue seems ok (not peeling/peeled off the rim), i'd just put a new layer on rim and tub, it'd be much faster

[parajba]

The Veloflex Carbons are almost new, does that mean that I have only 1 option with those? i.e. To use the same Mastikone (or to bin them?)

Yes re rims I have already cleaned them when I transitioned from Conti to Vittoria/Veloflex, took me 4 hours of hard work and beers...

[sungod]

for cyclocross some people use tape+glue (aka the belgian method), but this is with fresh glue, whereas you mention 2012 glue

the trouble with old glue is it's hard to know the condition, i've had some where the (vittoria) glue had become so dry that it was really crumbly/dusty when removing, in that condition i can imagine tape peeling off as it is just sticking to dust

but if you remove any lumps and loose bits, then refresh the glue with a new layer it should be much better as the solvent will penetrate into the old glue, but then you may as well forget the tape and put the tub on the rim while the glue is tacky!

[parajba]

Thanks. Just to clarify, does that mean that I have only one option to save the almost new tub? (And that this option is to reglue it using the same glue (Mastikone)?

[sungod]

it depends on how well whichever tape you used would adhere to the old glue on rim and tub, if the glue is still firm maybe it'll be fine, but it's not something i've ever tried

personally i'd just glue it, it doesn't take long

[parajba]

Thanks, looks like I have to glue it this time. I will try the tape next time then on new tyres (and cleaned rims).