Veloflex Carbon tubular mounting help

Discussion in 'Cycling Equipment' started by gil99, Jan 19, 2007.

  1. gil99

    gil99 New Member

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    First timer. FWIW, as an intro, I ride on average 12-15hours a week year round. Started mountain riding again in 2004 after 10 years of zero riding due to career obligations. A bad back led me to the road scene in 2005 and started racing in 2006. Am now racing as a cat3 to gain experience before I race with the masters. Race age is 39 this year. So, anyhoo...

    Mounted a Veloflex Carbon tubular and it has a good hop when it spins up. The "high" point is just forward of the valve stem, looking from the drive side. This is the second mounting of this tire and before I rip it off and start again, I was wondering if anyone has any ideas to "fix" it and avoid ripping and regluing. So far I tried riding on it at about 60psi on smooooooth concrete. Hop is still there.

    Most likely I pulled too hard on one side while mounting or the valve isn't seated properly, however, being aware of this and not having difficulty mounting Conti Sprinters/Comps and various Tufo products, I'm a bit frustrated. FWIW, the first glue was a thin layer followed 24 hours later with another, then mount. The second attempt was one layer and about 30 minutes later a second thicker layer was applied. 15 minutes or so later I mounted.

    I'll try pulling the affected area off the wheel and reglue before doing the whole tire again. Any ideas or links would be appreciated. Is there a trick with the Veloflex tires? Did multiple searches. Didn't find what I was looking for. Thanks, all.
     
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  2. JTE83

    JTE83 Member

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    If I was into tubulars - I would tape them as tape has less rolling resistance than glue.
     
  3. gil99

    gil99 New Member

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    Yeah. I've used it. They call it "extreme" tape because it's extremely difficult to get the tire removed from the wheel. Any chance to a link on the rolling resistance vs glue results?
     
  4. JTE83

    JTE83 Member

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    I saved my tubular data in a Word doc, so maybe the link is in there.

    You're using thew fastest tubular tire out there! How long do they last, how durable are they, how is the grip, are they prone to puncnture? Can you patch them?
     
  5. DCWD

    DCWD New Member

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    I flatted a taped tufo just last week and am happy to report that the tire and the tape pulled right off, slick as can be. Even better news: we taped the spare on and I was riding as hard as I wanted all the way home without any worries about glue drying or the tire rolling off. Really didn't take much longer than swapping out a tube in a clincher. I love that tufo tape!
     
  6. alfeng

    alfeng Well-Known Member

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    A key, but not necessarily the only one, to successfully gluing up a sew-up tire on a tubular rim is to PRE-stretch the tire(s) ...

    Pull the new tire onto a CLEAN & DRY rim, add about 15PSI to it, square the tread, and set it aside for a couple of days ...

    ALWAYS clean the old glue off the rim when gluing up a new tire ...

    The amount of glue you should use will depend on from whom you learn OR from your own trial-and-error -- from what I have read, some people apparently use a single tube of glue per tire & rim whereas I probably glue up between three-and-four tires per tube of glue.

    I don't race ... so, I'm not as concerned about the tire pulling off the rim.

    ALSO, it has been MY experience that an UNGLUED tire inflated to 95PSI-or-higher is ALMOST IMPOSSIBLE to pull of the rim. The experience of other people may be different.

    AFTER you have pre-stretched your "new" tubulars for a couple of days, add the glue to the rim, roll the minimally inflated tire onto the rim, square the tread, inflate to about 50PSI, let cure for at least 24 hours.

    BTW. You can pre-stretch your new tires on a 700c clincher (or, whatever equivalent clincher has an interchangeable brake surface circumference -- e.g., 650c) ... not quite as good, but it will do.

    Your current hop-along tires are pre-stretched (HEY, pre-stretch the spares you carry, too!), so you just have to ensure that the tread is properly "squared" when you re-glue them ...
     
  7. gil99

    gil99 New Member

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    JTE83, Thanks!

    DCWD, my thumbs hurt for days after trying to pry the tire off the tape. The regular strength tape must be much easier to work with?

    alfeng, I do all the above and have an old 700 rim to stretch with. I do use a tube per wheel/tire. I'll try half a tube and see what happens. The remark about being a first timer was in reference to being a noob here.

    Thanks again.
     
  8. DCWD

    DCWD New Member

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    I had used the "extreme" tape to mount the tires - never actually even tried the regular kind. ...and I was just saying to my buddy on the way out that morning, "you know, I was just thinking that I hope I never actually get a flat with these wheels because I forgot to pre-stretch the spare and I don't have any other sew-up rims to stretch them on. ...maybe when we can get back you'll let me borrow a wheel to stretch this thing out over the weekend." Probably, had I not said it, I wouldn't have gotten the flat!
     
  9. JTE83

    JTE83 Member

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    Hey gil99 - I gave you good feedback but you didn't give me feedback on my tire questions ! Can you tell me about those tires?
     
  10. gil99

    gil99 New Member

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    Roger that! Sorry for not responding properly. I haven't any empirical data to support my findings. Just a testimonial. Here is the deal...

    I used to have a cheap tubular on the rear wheel of a Zipp 303 set thinking I'd save money. How stupid is that. The 303 set felt like they had suction cups on them with the cheap tire. So, I switched back and forth between my Mavic K SSC SL's and the 303 set and found the 303's slower in rolling tests (pawls not engaged) and timed tests going up different grades (same HR, cadence). I kept the 303 front wheel and tire (Tufo S3lite) on and switched out the rear wheel only. I was dis-heartened to say the least and didn't want to believe my 303 was that slow. I even went so far as to send the rear wheel back to Zipp for an O'haul. They replaced the axle and hub cartridge bearings at my request but stopped short of a new free hub because it was perfectly fine. I even called the tech who worked on it and asked if something was bent or otherwise not normal and gave him a brief description of what I'm telling you. He laughed and said just ride it.

    So, the wheel comes back (no charge for shipping/labor BTW) and it feels the same. Another month or so of subjective wheel testing between the Mavic and now a barrowed Bontrager Race X lite and the 303. I ran the same tire which was a Michelin Pro2 Race, on the Mavic and Bontrager. Same results. I messed around with tire pressure on all the wheels with the 303 still being slower than the other two.

    I then barrowed a 404 rear wheel with a Conti Sprinter and found that combo to be and feel much faster. The lightbulb finally goes on during this ride as I'm now comparing the same free hub (202) which isolated the tire. I buy a Veloflex thinking if a tire can be that slow can one be equally fast?

    I did the same subjective testing between the Veloflex/303 combo and the Mavic and found the 303 now faster in all tests than the Mavics. The rolling test was done starting from the same point, stopped, no pedal, and rolling with hands on top of the bars, feet in the same position, past a certain point and monitering speed. The up hill test was a 1,200' climb over a distance of maybe 8 miles. I did the climb four times, two on each tire, and found the Veloflex faster at 3 different hacks along the way to the top each time. I just maintained the same HR and cadance and took times along the way. 30 seconds was the approx time difference, fwiw. Subjectively consistant. Laughable I know, but the trend to me was undeniable.

    What goes up must come down. The descents from these short climbs is a newly paved smooth road. Very curvy. Being a rear tire only I really couldn't notice an huge difference between the tires. Nothing felt bad per say, just didn't have one on ethe front.

    Now the bad news (for me) and the point of the OP. The tire always had a slight hop. I've mounted them three times and it's in the same place being just ahead of the valve stem looking from the drive side. The hop is even there with out glue. I've done my best to mount them properly and as I've said before, have had no problems with Tufo's and Conti's. So, after a few rides with speeds past 35mph (going down coasting) the hop is so bad I feel it's a safey issue especially when thinking about riding in a race.

    These are fast tires. No doubt! Grip seems no better or worse than other tires. I can't attest to the durability nor the puncture quality question you asked about as I've probably only ridden 300 miles on the tire. No opportunity to patch and I'd ruin a tire trying to do that.

    I'm going to run a Conti Sprinter for now and maybe try a wheel with a Competition to see if it's worth the extra $30. I've spoken with many cyclist about the Veloflex tires and they all said you are more prone to getting a tire with a hop than say a Conti. I haven't a clue why.

    I was impressed enough to buy two Veloflex clincher tire for the Mavic K's and have ridden a couple hundred miles so far and am very pleased so far.

    That's all I have.
     
  11. gil99

    gil99 New Member

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    That's borrowed, monitor, cadence and consistent. Is there an edit function on this board?
     
  12. alienator

    alienator Well-Known Member

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    Your results are inconsistant with the results of more rigorous tests. Michelin Race2's have lower rolling resistance than Conti Sprinters. FYI, Tufo tires have some of the worst coefficients of rolling resistance around.
     
  13. gil99

    gil99 New Member

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    IMHO I feel:

    1. Tubular Tufo S33 pro on a 303 vs Mich pro2 on Mavic K: Mich/Mavic faster.
    2. Veloflex/303 vs Mich/Mavic: Veloflex/303 faster.
    3. Conti sprinter/404 vs Tufo/303: Conti/404 faster.
    4. I did not compare the Conti/404 to Mich/Mavic. Sorry if it read that way...

    The whole point was to figure out why the 303 wheel felt so sluggish. At first I thought there was something wrong with the free hub or maybe the bearings. I should have added that the LBS looked it over before I sent it in for an O'haul to Zipp. In no way do I recommend one tire over the other. I have too little experience and no sound data to do so.

    Hope the snow melts in Tucson for you! Thanks for your straight shooting posts as always (here and RBR).
     
  14. CAMPYBOB

    CAMPYBOB Well-Known Member

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    alf,

    That's pretty much my expirence of 34 years of sew-ups with a couple exceptions. (and I've never rolled a tire)

    I stretch at maybe 60-80 psi and generally get 4 tire mountings out of a tube of glue (on previously glued rims).

    I only rarely clean the old glue off a rim...after the buildup gets pretty thick. The new glue application softens up the old glue and melts into it.

    Gm 'fastac' works too well! I've ruined casings getting that stuff undone!

     
  15. JTE83

    JTE83 Member

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    Ok gil99 - thanks for the tire feedback. You do a lot of training each week, as I have never done even 12 hrs a week!

    I'm just happy to get by with enough training that maintains my weight from overeating. I don't race, so actually I don't need that Zipp 404 clincher with Pro 2 Race tires that I lust for.
     
  16. mcginty_PB

    mcginty_PB New Member

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    i have recently mounted my first tubulars. i found that my continental race went on perfect first time no hassels. t was not the same with my continental sprints as i had a high hump just as you are describing. the way i resolved it was to put two coats of glue on the rim and tire which i let dry for a couple of hours then applied a third coat to the rim and tire about 10 minutes before i mounted them so thatit was still very very tacky to the touch. Then, while mounting the tire i put a lot of tension into the tire as i stretched it over the rim. at this point i still had my hump when i pumped the tire up to seat it so i rolled the hump side against the floor with almost all of my 200 lbs weight and this effectively rolled the hump away to the other parts of the tire. then i let the wheel sit and dry for about three days before i used it.
     
  17. 1x1

    1x1 New Member

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