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Re: Tubular question [leegoocrap] [ In reply to ]
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leegoocrap wrote:
I can see how it could work... but man I just don't think I'd ever trust it.

I do sometimes wonder about some of the "wives tales" about 2-3 or even 4 layers of glue necessary to inhibit rolling. A good friend works in materials joining and argued that most glues and epoxies are designed to be used with one application at proper thickness. I have been doing one thick layer of mastik for the last two years for road and cross with no issues at all. Most of the rolled tubulars i have seen were either two year old glue jobs in cross or cases where people did not comprehensively glue the entire rim.
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Re: Tubular question [Ron_Burgundy] [ In reply to ]
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To get proper adhesion on a tubular tire, you need to do a coat on the rim and a coat on the tire. Let it dry overnight. Then apply another coat on the rim and mount the tire.
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Re: Tubular question [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
To get proper adhesion on a tubular tire, you need to do a coat on the rim and a coat on the tire. Let it dry overnight. Then apply another coat on the rim and mount the tire.

Agreed with the amount of glue, but I don't think there is any benefit to letting it dry overnight....I wait ~20min after applying the first 2 coats, put a third on the tire to ease centering of the tire and mount it.

Never rolled a tire in 25+ years of riding / racing tubs.

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Re: Tubular question [Power13] [ In reply to ]
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I find it a bit messy if I don't wait for it to dry before applying the last coat.
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Re: Tubular question [Ron_Burgundy] [ In reply to ]
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I think a lot of it is probably based less on science/data and more on "how you were taught."

The guy that taught me was kind of an old hermit type... leave the tire on the rim to stretch forever, (I think he left some on for so long the tire rotted before he ever glued it ;) ) lots of layers of glue with a day to dry between, etc. That's just how I've always done it since that's how I was taught... (probably from a guy that learned to glue them when the glue itself was not as great as it is now) I also glue track tires so I feel like it's a good practice for that, but others obviously have great success with other practices.

I will say almost all tires I've ever seen rolled (that were glued) involved a starved joint.

My Blog - http://leegoocrap.blogspot.com
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Re: Tubular question [Power13] [ In reply to ]
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Power13 wrote:
jimatbeyond wrote:
To get proper adhesion on a tubular tire, you need to do a coat on the rim and a coat on the tire. Let it dry overnight. Then apply another coat on the rim and mount the tire.

Agreed with the amount of glue, but I don't think there is any benefit to letting it dry overnight....I wait ~20min after applying the first 2 coats, put a third on the tire to ease centering of the tire and mount it.

Never rolled a tire in 25+ years of riding / racing tubs.[/quot

Agree, all that does is allow some solvent to evaporate and does nothing else. I just find it funny that somehow tubular adhesion is different than any other adhesive....it's not. One thick layer on the rim, small layer on the tire, put it on and pump it up, let sit for 24 hours. Not rocket science.
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Re: Tubular question [WD Pro] [ In reply to ]
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WD Pro wrote:
Has anyone tried this ?



If it has the bennifits of a glue with what appears to be the ease of fitment provided by a tape, could it be a winner ... ? :-)

WD :-)

http://weightweenies.starbike.com/...=136694&start=45

Some swear by it, other swear at it.

res, non verba
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Re: Tubular question [RoYe] [ In reply to ]
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I find it hard to believe that any person able to wipe their own bum can find gluing a tub on difficult.
Tyres pretty much centre themselves.

Now taking off the old one and cleaning the rim, that is a pain in the arse.
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Re: Tubular question [Ron_Burgundy] [ In reply to ]
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I have found that one coat on the rim and one coat on the tire doesn't result in complete adhesion.
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Re: Tubular question [jimatbeyond] [ In reply to ]
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I do one coat on the rim, two coats on the tyre as it soaks into the base strip.
Then one thin wet coat on the rim let just tack off to fit.
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Re: Tubular question [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
I have found that one coat on the rim and one coat on the tire doesn't result in complete adhesion.

I promise i am not intentionally trying to be frustrating, but i would honestly ask why? What is the mechanism for better adhesion? Likely we are working with some hydrocarbon that is in a fairly viscous solution with their chosen solvent. If you apply a layer, let it sit overnight you have now evaporated the solvent and just have the hydrocarbon/polymer adhesive that is now mostly solid. Applying another layer is essentially the same as applying a new layer on a fresh carbon rim as the adhesive is now dry.

Clearly it can be hard to get a thick layer due to most glues being fairly fluid, thus the reason people often layer. I would think a few layers 20 minutes apart would be ideal as you can start stacking layers but not allowing them to harden. If i was being extra cautious i would follow this protocol, anything else is dubious:

1. Completely sand and acetone/mineral spirits the rim
2. Apply very thick layer to rim
3. Apply layer to base tape on tubular
4. Apply another layer to the rim
5. Mount tire, adjust, inflate partially, readjust, inflate to 120+, roll tire with applied weight for a few minutes, let sit for 24 hours

The above process would require 1-1.25 tubes of mastik per wheel.
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Re: Tubular question [Ron_Burgundy] [ In reply to ]
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It sounds like you are suggesting three coats of glue. Correct?
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Re: Tubular question [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
It sounds like you are suggesting three coats of glue. Correct?

If one cannot get a thick enough first layer, yes I am. Assuming you don't let it dry for too long. I think the potential error is doing layers with extended drying times. The above method would be completed in 20 minutes.
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Re: Tubular question [Ron_Burgundy] [ In reply to ]
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If you do three coats, it should be good.
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Re: Tubular question [jimatbeyond] [ In reply to ]
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I do two on the tyre because it is dead easy to get 100% coverage on the rim, but the way a new base tape soaks up glue, it is hard to ensure total coverage and therefore full bond area.
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Re: Tubular question [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
If you do three coats, it should be good.

I think we are essentially in agreement and i was not being clear in my definition of "one coat". I defined one coat as an layer on the tire + layer on tubular base tape + final quick layer again on the rim all done in 20 minutes......which in reality is three coats.

The new vittoria looks interesting and i might give it a try next week.
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Re: Tubular question [RoYe] [ In reply to ]
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After posting the video above I continued to do some more digging. I had found the weight weenie link (but thanks anyway !) and a few others – views seemed to be either very positive or very negative i.e. no middle ground.

Reading between the lines, It seems to me that this product favours tubs with rubberised base tape i.e. Vittoria (no surprise there) and Michelin. The glue doesn’t seem to work well with plain cloth base tapes i.e. Conti and Challenge.

Note that the generalisation of manufacturer by rubberised base tape / non rubberised base tape may be model specific so please check accordingly – but I can confirm that Challenge Crono is non rubberised and Michelin Pro 4’s are rubberised (I own both types).

It’s also interesting that Vittoria rebranded the product from magic mastic to mastic pro (https://www.vittoria.com/...ries/road-accessory/ roll down to mastics) so read into that what you will – maybe a formulation change / improvement … ?

As I am looking for a solution for the Pro 4’s I think I am going to give this a shot, trouble is I can’t find anyone stocking it yet in the UK – any ideas … ?

Cheers,

WD :-)
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Re: Tubular question [WD Pro] [ In reply to ]
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They have just uploaded a new video :



WD :-)
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Re: Tubular question [lyrrad] [ In reply to ]
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This is exactly how I mount my tubulars--it has worked flawlessly since I started racing in '88. Never a tire roll (crossed fingers) even at 59 mph...which I really didn't enjoy going that fast on that downhill, sort of wigged me out ;-)
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Re: Tubular question [Rocky M] [ In reply to ]
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Rocky M wrote:
This is exactly how I mount my tubulars--it has worked flawlessly since I started racing in '88. Never a tire roll (crossed fingers) even at 59 mph...which I really didn't enjoy going that fast on that downhill, sort of wigged me out ;-)


Whenever I get going really fast downhill I always think back to this video and try and go faster

https://www.youtube.com/watch?v=iO7_Fq56g2c


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