Re-tensioning a deep carbon wheel

[Wayne77]

Hi - one more question for the experts here:

I'm riding a pair of fairly new OEM Reynolds 46/66 tubulars. 2012 model year I believe, but brand new when I mounted them in the spring. DT hubs, aerolite spokes, 20 front & rear. I weigh 172, 6'-0"

The deep CF wheels I've ridden in the past have been pretty stiff, even with lower spoke counts. Today, on a climbing ride I was getting some brake rub during hard out of the saddle efforts. I did have my pads a few mm from the brake surface but not crazy close. Anyway, I was surprised to get this wheel flex with a 66mm deep rear wheel / 46mm deep front wheel. I opened up the calipers a bit and no issues for the rest of the ride.

Do you think this flex would be typical for this particular wheelset, even with it's depth, or do you think re-tensioning would help? I had some Edge 1.38 a couple years ago and didn't notice wheel flex. If it's inherent in this particular wheel / or configuration, no biggie - I'll ride with a little more play in my brakes. They still brake fine with more play in the levers.

Thanks!

[jdp211]

I'd check QR and hub tightness before retensioning the whole wheel. They shouldn't be flexing enough to rub the pads, even when running them pretty close.

[ergott]

Unless the spokes are going slack more tension won't solve things. I doubt the spoke lack sufficient tension.

This is a good read.

http://www.slowtwitch.com/Tech/Debunking_Wheel_Stiffness_3449.html

[Dead Man]

Not to be a doofus, but are you sure your skewers are clamped down nice and hard? seems to me a tight skewer versus a not-as-tight skewer has made a difference in how much sssk sssk sssk I get..

I get flex/rub on all three of my carbon tubulars - EC90s, DA C24, and Reynold MV/T.... all of 'em. I'm not a featherweight, but I'm pretty light.. 150 when I'm in good shape. I also tend to use lightweight/flimsy forks, which is going to compound the flex.. what kind of fork you using?

In just my own personal experience, the exception is to NOT get any ssskt, ssskt, ssskt, ssskt climbing out of the saddle, with a set of wheels.

But how much of it has to do with how you tension your calipers? I like mine to be really tight... like .5mm tight. I'll open up the calipers on ascent, if my wheels are really wiggly and it's bugging me, but I really like the feel of my pads making contact pretty much right away, so that's how I roll. There's not really a standard.. I see some guys rolling around with like 2mm gapped out on either side, sometimes. You know those mofos aren't getting any rub.

Seems like your Reynolds wheels should be pretty stiff. "retensioning" probably isn't really gonna be an option, as I'm sure they're already tensioned to spec, and you don't want to go OVER that.. but I'm certainly no wheelbuilding expert.

[Wayne77]

Thanks guys - very helpful. I'll double check the QR. The B, I'm using an Enve carbon fork.

[TimD]

To build on what ergott wrote, I would recommend against simply tightening the spoke nipples to some arbitrary point in the hope of improving the situation.

If you want to check the spoke tension, use a spoke tension meter (probably < 5% of the cost of a carbon wheelset) and compare the measured values to the maximum recommended spoke tension for the rim.

[oldpotatoe]

Hi - one more question for the experts here:

I'm riding a pair of fairly new OEM Reynolds 46/66 tubulars. 2012 model year I believe, but brand new when I mounted them in the spring. DT hubs, aerolite spokes, 20 front & rear. I weigh 172, 6'-0"

The deep CF wheels I've ridden in the past have been pretty stiff, even with lower spoke counts. Today, on a climbing ride I was getting some brake rub during hard out of the saddle efforts. I did have my pads a few mm from the brake surface but not crazy close. Anyway, I was surprised to get this wheel flex with a 66mm deep rear wheel / 46mm deep front wheel. I opened up the calipers a bit and no issues for the rest of the ride.

Do you think this flex would be typical for this particular wheelset, even with it's depth, or do you think re-tensioning would help? I had some Edge 1.38 a couple years ago and didn't notice wheel flex. If it's inherent in this particular wheel / or configuration, no biggie - I'll ride with a little more play in my brakes. They still brake fine with more play in the levers.

Thanks!

Take it somewhere who has a proper tension meter and check the actual tension.

[Wayne77]

Unless the spokes are going slack more tension won't solve things. I doubt the spoke lack sufficient tension.

This is a good read.

http://www.slowtwitch.com/Tech/Debunking_Wheel_Stiffness_3449.html

That's a great article -thanks

[carpediemracing]

Having ridden DV46 tubulars and clinchers for a while (still have the tubulars), I noticed the Reynolds wheels take much more tension than what I expected.

I'd contact Reynolds and ask for their recommended spoke tension. I've contacted them on a couple occasions and they've been super helpful.

[TimD]

+1 on Reynolds customer service.

Meanwhile, https://www.reynoldscycling.com/uploads/Spoke%20Chart.pdf

[Hindmost]

On the Tour de Suisse the other day Tony Martin was on one of his solo breaks. He was back on a flat valley road and the camera moto was right behind him, Tony with his left hand starts fiddling with his rear caliper quick release, closing it.

The commentator explains quite matter-of-factly that, "many riders open their brake calipers on the climbs to avoid rubbing and close them again afterwards."

I was a little bit, "really?" as I don't ride the latest wheels.