Tubulars for racing.

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Re: Tubulars for racing.

Postby softy » Sat Jun 14, 2014 2:04 pm

singlespeedscott wrote:
Causidicus wrote:Never found Rally to be inconsistent but having said that, don't see them very often as most people only carry them as a ride home spare. I guess it comes down to what you think is inconsistent. Rallys that I've seen aren't really inconsistent at all but some people might think they are if they are used to machine manufactured tyres. Try and find a laser straight tread strip or millimetre perfect carcass on any hand made FMB, Dugast, Veloflex, Vittoria or Challenge. Simply doesn't happen, and simply doesn't matter.

The tread on the Challenge tyres I have used are infinitely straighter then any Rally's. Not knocking the Rally's. I think they are good tyre for the money they just never seem to be straight.


I would also like to add, although vittoria cx and sc are good for the money the veloflex are nicer. You may argue they aren't worth the extra dosh, but they are the easiest tyre I have ever mounted and well made. They have this ability to stretch like an elastic band when mounting.

I suppose it is like a balance scale, price verses quality, some favour one over the other.
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by BNA » Sat Jun 14, 2014 2:10 pm

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Postby Causidicus » Sat Jun 14, 2014 2:10 pm

I don't think Veloflex quality is high enough to justify their price premium. I've seen so many of them that aren't that great and some that are definitely superior to wonder about their QC. Added to that is the reports of higher puncture rate and it makes you wonder why spend the extra. Being stretchy when mounting isn't a sure sign of super quality.

All that said, puncture rate is heavily dependent upon the rider, the pressures they run and whether they ride in the gutter or avoid the rubbish which causes flats. For those that ride appropriately, they could ride track tyres and get long life. Those that ride in the gutter amongst the road rubbish are asking to be parked up every few kilometres changing tyres.
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Re:

Postby softy » Sat Jun 14, 2014 5:44 pm

Causidicus wrote:I don't think Veloflex quality is high enough to justify their price premium. I've seen so many of them that aren't that great and some that are definitely superior to wonder about their QC. Added to that is the reports of higher puncture rate and it makes you wonder why spend the extra. Being stretchy when mounting isn't a sure sign of super quality.

All that said, puncture rate is heavily dependent upon the rider, the pressures they run and whether they ride in the gutter or avoid the rubbish which causes flats. For those that ride appropriately, they could ride track tyres and get long life. Those that ride in the gutter amongst the road rubbish are asking to be parked up every few kilometres changing tyres.


I agree getting a puncture can be just luck, road rubbish, tyre pressure or who knows. When you think about the very small contact area and the chance of running over something which may lead to a puncture, could be down to a multitude of variables. So I don't believe it as easy to just blame a rider for the probability of a chance puncture.

All that being said, if a rider is cycling over the same route in a similar enviroment and after using a number of a particular brand models compared to doing the same with another, I do believe a rough indication can be made between tyres.

I treat all my tyres the same, don't jump off kerbs, don't give them lock ups maintain pressure and do ride away from the kerb where practical.

Doing this, I do have distinct differences between the regularity of punctures with different brands. I can only come to conclusions from own experiences.
If vittoria cx, or whatever you run, give good service, keep using them. But remember, not all cyclist are cycling how you cycle or over the same roads or enviroments.

So in conclusion, everyone to own and the decisions they make from the experiences they have encountered.
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Re:

Postby PomBike » Sun Jun 15, 2014 2:15 am

Causidicus wrote:I don't think Veloflex quality is high enough to justify their price premium. I've seen so many of them that aren't that great and some that are definitely superior to wonder about their QC.
Agreed.
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Re: Tubulars for racing.

Postby Tarquin » Thu Jun 19, 2014 6:36 pm

Well, I though I did everything right, but then I wasn't happy with the result.

Stretched tyres for 24 hrs.

Two coats of thin glue on rims with 24hrs between one on tyres tape.

Third coat on rim and mount tyre with 25psi in the tyre.

Too difficult to mount, so let some air out. Mounted tyre, inflated to 50psi, rolled it on floor canted sideways both directions. Trued it slightly as require, had it pretty good, little spot where it was up/down a bit where the tape joined on the underside of the tyre. Inflated to 150psi.

Left for maybe 30 to an hour mins, had a quick look, didn't seem to be very much glue at all taking between the rim and tyre, I thought with all the layers I did I would have enough.

The glue seemed to pull off the rim very easily and I wasn't happy with it so I removed the tyre.

Image

The cement pulled off the rim by hand leaving the bare carbon very easily. I cleaned the wheels twice with acetone before adding glue, I didn't sand the rims as the Zipp instructions said not required.

Using Continental Carbon Cement as I couldn't buy Mastik one anywhere. It seems to go tacky VERY quickly to me, I was only doing less than 10% of the rim at a time and it would go tacky in the time it took me to do that small bit.

I removed the tyre and removed 90% of the glue from the tyre and all the glue from the rim. I don't want to throw away a pair of brand new $50 tyres if I don't need to.
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Re: Tubulars for racing.

Postby jcjordan » Thu Jun 19, 2014 6:58 pm

You need to let the glue harden for at least 24hr once you install the tire

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Re: Tubulars for racing.

Postby Tarquin » Thu Jun 19, 2014 7:30 pm

jcjordan wrote:You need to let the glue harden for at least 24hr once you install the tire

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I left the other wheel glued up to see what happens.

I have a full tube left so if the other looks OK after 24 hrs I'll reglue this one, but I expected to see more stringy looking glue contact when peeling the tyre back.
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Re: Tubulars for racing.

Postby softy » Thu Jun 19, 2014 8:49 pm

This glue doesn't look the right colour!
Maybe it is the colour palette on my tablet.

Used conti glue and it is fine, sticks well. Don't know what happened here??

I think you need more coats, the backing of the tyres varies and some are like a sponge to soak up the glue and lose their stickness, eg conties

Allow glue, especially the first coats to really dry well for 24 hrs

I like tape, and if you use glue and tape boy it sticks. One layer of glue on the rim and tyre let dry. Put tape on as normal. You will have a hard time getting this off after it drys.
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Re: Tubulars for racing.

Postby Tarquin » Thu Jun 19, 2014 9:22 pm

softy wrote:This glue doesn't look the right colour!
Maybe it is the colour palette on my tablet.

Used conti glue and it is fine, sticks well. Don't know what happened here??

I think you need more coats, the backing of the tyres varies and some are like a sponge to soak up the glue and lose their stickness, eg conties

Allow glue, especially the first coats to really dry well for 24 hrs

I like tape, and if you use glue and tape boy it sticks. One layer of glue on the rim and tyre let dry. Put tape on as normal. You will have a hard time getting this off after it drys.


The glue there seemed to pull off the tape and stick to the glue on the rim.

I left each layer 24hrs between gluing.

The tyre did seem to soak up quite a bit of glue, and it definitely shrunk, before I glued it they were quite easy to fit to the rim. I really had to fight with them to get them on once they had glue on.

See what the others like tomorrow, might be ordering more glue...
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Re: Tubulars for racing.

Postby softy » Fri Jun 20, 2014 12:41 am

Hmmmm, this is very interesting, just looking at the picture closely again. It just doesn't look like enough glue is on the tyre.

The last coat needs to be put on quite quickly so it is still wet so you can get the tyre on easily as it slides on the wet glue when mounting. I use to do this years ago but now use tape. IT's just easy pessy and clean. Even if you use the glue and tape method.
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Re: Tubulars for racing.

Postby Tarquin » Fri Jun 20, 2014 6:21 pm

I checked the other tyre tonight.

I was happy with it in places, the glue seemed to have taken and it was visible when peeled back as far as possible.

However in other spots the tyre could be peeled back quite a long way, and the glue came off either the wheel, or the tape easily.

It was a bit of a bugger to remove the tyre, I think I need to apply more pressure when installing it around the valve and the first 50% of the rim, then it should pop on the second half easier.

Rim cement peeling off the carbon rim.

Image

Rim cement pulled off the tape easily/still stuck to the rim.

Image

I have read about roughing up the tape, and/or sanding the rim.

Vittoria say roughing the tape/removing any latex isn't necessary. Zipp say the same about sanding the rims.....

What do you think?
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Re: Tubulars for racing.

Postby softy » Fri Jun 20, 2014 9:04 pm

I'm starting to think you have a bad batch of glue, it never pulls of that easy, and the colour doesn't look right for contie glue.

Get some tape to get you going, it's bullet proof. I use velox but the top layer tape breaks easy, so you need to use the pencil method. Tufo is just like falling off a log, very easy, but dearer.
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Re: Tubulars for racing.

Postby Tarquin » Fri Jun 20, 2014 9:17 pm

Ordered new glue today, more Conti stuff but from bikebug so should arrive quicker, this stuff came from wiggle with the tyres.

I think I'll lightly sand the wheels and use a file on the tape which should help remove the old glue as my thumbs are now raw from rubbing as much off as I could.
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Re: Tubulars for racing.

Postby softy » Fri Jun 20, 2014 9:46 pm

You know all this stuff is is contact cement, you can buy it from the hardware.

Years ago I used "bear" contact cement.
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Re: Tubulars for racing.

Postby singlespeedscott » Sat Jun 21, 2014 7:18 am

Shellac :lol:
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Re: Tubulars for racing.

Postby softy » Sat Jun 21, 2014 10:36 am

singlespeedscott wrote:Shellac :lol:

Don't use shellac.

Shellac is from beetles and is the old "french polish" of old. I have used it many times for furniture restoration.
It comes in flakes and needs to be desolved in methylated spirits. This takes days, then needs to be applied in many, and I mean many thin coats. It sets hard like lacquer on furniture.

Don't play with this it is only for track use and were you are chasing every last slither of rolling resistance.
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Re: Tubulars for racing.

Postby Tarquin » Sat Jun 21, 2014 10:55 am

I'll try the Conti stuff again since I have already bought it, perhaps I was just unlucky with technique or materials.

Removing all the remaining glue is a thankless task, using a fine file on the tape but it's very time consuming. Seems to have removed some of the coating that was on there before I prepped so I am a little happier with it.

I think I'll wet sand the rims too with maybe 200 grade very slightly.
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Re: Tubulars for racing.

Postby softy » Sat Jun 21, 2014 11:05 am

A good way to remove glue is to get a heat gun or hair dryer, + a rag.
Heat the glue on the rim till it starts to melt go soft, then wipe it with the rag pressing with your finger behind the rag. Use a few layers it could be hot. It doesn' t remove every last drop but does give you a uniform thin layer of glue to start working with.
Easier and cleaner.
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Re: Tubulars for racing.

Postby Tarquin » Sat Jun 21, 2014 5:37 pm

Wheels and tyres cleaned up. Wheels are immaculate, tyres I got all the Conti glue off and some of the latex on the base tape.

Got the tyres stretching now until the new glue turns up, should give me a few days easily of tyre stretching which should make them easier to fit as they only had 24hrs last time.
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Re: Tubulars for racing.

Postby ironhanglider » Sat Jun 21, 2014 5:56 pm

Shellite is pretty good for removing glue from rims too, but I'd follow it up with acetone to get rid of the residue.

How much glue were you using? I typically use an entire tube for one new rim/tyre combination over the course of the various layers. This is particularly so when the backing tape on the tyre is really absorbent. I use less if there is some residual glue to build upon.

Really well glued on tyres are both confidence inspiring for hard corners, and have less rolling resistance too. They are also very difficult to remove without a tyre lever.

Cheers,

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Re: Tubulars for racing.

Postby Tarquin » Sat Jun 21, 2014 7:26 pm

I used about 2.5 tubes, taking into account the loss on the brushes and a little in the spoke holes that would be about a tube per wheel.

Would it hurt to glue up the tyre this weekend and then put it back on the wheel to stretch, leaving it a few days between glue wouldn't matter?
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Re: Tubulars for racing.

Postby Tarquin » Mon Jun 23, 2014 8:00 pm

Well I sanded the rim lightly with 1200 grade to take the shine off it.

Glued up the tyres being slightly more liberal than I was first time round. The tape seemed to soak up quite a bit of the glue.

Put them back on the tubs to stretch a little as I found them tight after applying glue last.

I'll apply glue to the rims tomorrow and see how the tyres look.

They have a little hump where the valve sits in the rim and weren't quite flush, will have to focus on pressing this down firmly when I come to mount them.

It has been mentioned about opening up the valve hole on the rim slightly online but I think this only applys to alloy rims, would risk breaking the rim if attempted to enlarge the standard hole to help accommodate the tape around the valve stem.
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Re: Tubulars for racing.

Postby Ross » Tue Jun 24, 2014 10:36 am

jcjordan wrote:You need to let the glue harden for at least 24hr once you install the tire

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Ian's never done that on any of the tyres he's glued for me, or anyone else I know. Maybe leave 24hr once tyre is glued on before you go racing. Always use Conti glue too. Never bother to clean old glue off either or sand the rim.
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Postby Causidicus » Tue Jun 24, 2014 12:10 pm

Not enough glue.

For new rims I put down 5 layers of Mastik. All tyres get two layers. The thirsty base tape tyres might even get a third layer. Mastik is just rubber dissolved in Hexane. So, when the Hexane flashes off, it's a pure rubber bond. Flexible and low crr.

Never rolled a tyre and nobody I've glued for has ever rolled a tyre. The worst thing they can say about my method is that the tyre is glued on so damn well it's a bugger to get them off. I can live with that.

I have never, ever, been able to peel off Mastik in the way shown in the images above. Those images provide more similarity to tape than glue, even what I've seen of Conti's blend (I use Mastik exclusively).
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Re: Tubulars for racing.

Postby march83 » Tue Jun 24, 2014 12:58 pm

riding a tyre without allowing it to dry completely is a pretty good way to weaken a glue job. I'm no expert in this field, but i've done enough slow jobs and tried a few overnight turn-arounds to compare and to see that it's not ideal. sure, they'll probably stay on and they'll ride fine, but i want the best glue job possible and waiting 24-48hrs is part of that imho. you only glue tubs like once a season so it may as well be planned and done right.

OP, i did my first set of vittorias a few weeks ago and i wasn't impressed with my first efforts so i removed and re-did them. i had a similar experience with glue peeling easily from the tyre but adhering to the rim. I had lots of dry joints which I haven't had a problem with before which made me think that either the tyre was contaminated or it was just super thirsty so there wasn't much glue left near the surface to adhere once the tyre was mounted. in the end, i just cleaned the rims thoroughly, put 2 coats on both the tyre and the rim then wet glued them. next vittorias will get a gentle clean, probably just with water, before stretching and gluing.

when mounting, one of the things that i don't think is stressed enough in the guides you read online is to ensure you get as good a bond as possible with as little glue as possible by working the 2 glued surfaces together. the wet layer is meant to give you a slick layer to allow some time to position the tyre when mounting. instead of just forcing the tyre on, getting it straight and adding air, i find that it's worthwhile to work the tyre firmly into the rim bed as you're mounting it (ensuring full contact between the 2 surfaces), straightening, inflating, straightening and then again working the surfaces into each other as you check for dry joints along both sides. the wet layer will squirm around and should fill any thin spots as you go.


@Causidicus: where are you buying your mastik? i can't seem to find the tins ANYWHERE!
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