new tubular tire= death wobble?

[jimcav]

never experience the high speed death wobble--until today
yesterday removed a front flat tire (veloflex) on my reynolds stratus DV46, put on a conti sprinter
coming down off MT Soledad at about 38 mph had to corner right and wam--i nearly lost control. i was in the drops, tried to relax, clamp the top tube, etc.
was all over my lane and facing another corner--was about to lay her down or head for a grassy yard and then was able to regain control
scared the crap out of me.
checked my tire--seems centered on the rim
am guessing it was just a weird combo of wind and speed
maybe had a little residue on the brake track from when i removed the LAYERS of old glue: tire came off leaving chunky patches, so i acetoned it clean and used tufo tape)--maybe that pulsed my braking and started the wobble?
next descent, hard left, felt rear tire slip a bit--or so i thought. checked rear as i had to corner and brake a bit today--it is off center--the whole tire has moved or slipped--this is also tufo taped and the tire base tape is pulling free of the tire on a few spots--never have had a tire "shift" before?

so i guess this is 2 questions, the conti sprinter is a bigger rounder shape than the veloflex, so maybe that contributed to wobble, and has anyone had a tufo taped tire shift position after mounting--this is tape on top of an old, but thin base layer of glue.
i have 3 bikes i ride tubular: KOM, reynolds stratus dv, corima aero. i started with glued tires (not done by me), now have taped KOM, and taped DV, and the corima is one of each--never have had any issues with speed or shifting before.

have ridden faster and turned harder on all of them--hard to remember, but this rear tire i believe i got caught in the rain the last day of my TOC training camp--my guess is it got wet enough for the glue in the tape to soften--apperently more on the rim bond than the tire as the tire base tape is peeling, and the tire has essentially rolled/slipped toward one edge of the rim




thanks
jim

[rustychain]

Before you blame the tire make sure everything else is OK. Headset, quick releases, wheels still true. If all is OK check to see if the tire was installed correctly, straight and no hop. Also note the wheel balance. Sprinters are not my fav as I have had some quality control issues before. Have you done this descent before on this bike with the same wheels? Try some other wheels if you can but wear a helmet ;)

[jimcav]

Before you blame the tire make sure everything else is OK. Headset, quick releases, wheels still true. If all is OK check to see if the tire was installed correctly, straight and no hop. Also note the wheel balance. Sprinters are not my fav as I have had some quality control issues before. Have you done this descent before on this bike with the same wheels? Try some other wheels if you can but wear a helmet ;)

tight, wheel is as true as it has been. only difference is the tire and there was a good head wind on this descent

tire is centered--not sure on balance or hop--will check on that--not even sure how to balance a bike tire
thanks

[Ken Robb]

I guess you were going down Via Capri? A couple of bikes I had would do this when I hit ripples in LJ Shores Drive. Via Capri has plenty of bumps and ripples. It will be interesting to see if the same thing happens on perfect pavement.

[bironi]

but don't discount the headwind. Damn variables. :beer:

[jimcav]

I guess you were going down Via Capri? A couple of bikes I had would do this when I hit ripples in LJ Shores Drive. Via Capri has plenty of bumps and ripples. It will be interesting to see if the same thing happens on perfect pavement.

just before you have to turn right--i braked to slow slightly, and even now i can't say if it was as or just after braking that the wobble began--anyway once it got going i was trying to brake as i was literally jittering all over the lane

have done via capri several times, almost always on this bike

scared me good, when i later went down torrey pines i did not pedal at all (which was about 32mph)--no wobble

jim