Road Cycling - I'm worried about mounting a CF bike to a trainer

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




SHIM_105
10-13-11, 07:20 PM
Ive got a Minoura Mag trainer and a Bianchi infinito but I'm a little worried about mounting the bike to the trainer. The bike moves around on the road but in the trainer I'm concerned about all that torque going into a frame that's not going to move. Would there not be to much load on the chain stays?


BestSportEver
10-13-11, 07:24 PM
No.

Besides from my experience sprinting on a New Specialiezed Tarmac SL4 in a trainer, have you never seen the lines of pro cyclist warming up before the time trials on their $10k bikes mounted in trainers?

SHIM_105
10-13-11, 07:29 PM
No.

Besides from my experience sprinting on a New Specialiezed Tarmac SL4 in a trainer, have you never seen the lines of pro cyclist warming up before the time trials on their $10k bikes mounted in trainers?

I have seen, yes. But I always assumed at the pro level they had expendable bikes so to speak. I also have a steel framed bike but rarely ride it. As far as the Bianchi, do I just change out the skewer?


ColinL
10-13-11, 08:43 PM
It is best to use a steel skewer on the trainer. You probably can use aluminum if you don't weigh too much. If you have some other material, I wouldn't try it.

jwible
10-13-11, 08:50 PM
It'll be fine. use an old skewer so you don't tear up a good one in the attachment points on the trainer. I've sprinted on the trainer plenty of times. No prob.

grwoolf
10-13-11, 09:59 PM
You are probably less likely to hurt a carbon bike in a trainer vs. alum/steel/ti. One nice property of carbon is that it doesn't have the same tendency to fatigue/crack from repeated stress cycles (unlike welded metals). If you were superman-strong, maybe you could cause a catostrophic carbon event. Have fun trying, I think you'll get tired before the bike explodes.

Digitalfiend
10-13-11, 11:34 PM
I'd generally say there is nothing to really worry about, partly due to the properties of CF. With that said, I still went ahead and bought a Kurt Kinetic Rock and Roll trainer (which is really nice btw) to allow some lateral and vertical compliance. The bike frame is still likely being flexed to some degree, but I'm not going to worry about it. Lifetime warranty on the frame anyhow... :)

rangerdavid
10-14-11, 06:22 AM
I agree your bike will be fine, as stated above, just swap out the skewer for an old one and ride the snowy days away.

ahsposo
10-14-11, 06:26 AM
If you're planning on riding that CF bike on a trainer in a confined space I'd think twice. Exploding CF is far worse in a confined space. All those little fibers are like deadly needles.

Vetboy
10-14-11, 06:52 AM
I'd generally say there is nothing to really worry about, partly due to the properties of CF. With that said, I still went ahead and bought a Kurt Kinetic Rock and Roll trainer (which is really nice btw) to allow some lateral and vertical compliance. The bike frame is still likely being flexed to some degree, but I'm not going to worry about it. Lifetime warranty on the frame anyhow... :)

OP, I think you'll be fine - I've been using a Look in my trainer for many years. Just a word of warning though - I believe some manufacturers recommend against using their carbon frames on a trainer so lifetime warranty may not apply - read the fine print.

Joe

Digitalfiend
10-14-11, 06:55 AM
If you're planning on riding that CF bike on a trainer in a confined space I'd think twice. Exploding CF is far worse in a confined space. All those little fibers are like deadly needles.

Good point, I highly recommend a flak jacket while training indoors on CF...

StanSeven
10-14-11, 06:57 AM
OP, I think you'll be fine - I've been using a Look in my trainer for many years. Just a word of warning though - I believe some manufacturers recommend against using their carbon frames on a trainer so lifetime warranty may not apply - read the fine print.

Joe

That's another rumor that isn't true. Try and find that statement anywhere.

lowspoke
10-14-11, 10:05 AM
That's another rumor that isn't true. Try and find that statement anywhere.

From the warranty page for Seven Cycles at http://www.sevencycles.com/warranty.php


The entire Diamas and Elium model lines are optimized for normal road riding conditions, and not designed for fixed stationary trainers. Use of a stationary trainer with any clamping mechanism will void the frame’s warranty.

nhluhr
10-14-11, 11:13 AM
Use rollers instead. You can add resistance fans or use small diameter rollers and you get to work on balance and spin at the same time (without any worry of breaking your frame or hurting your warranty).

hhnngg1
10-14-11, 11:16 AM
No risk whatsoever. Slap the bike on and ride with abandon.

I've been riding a Cervelo which lives on the trainer 95% of the year, and I ride it a lot - to the point that my sweat totallly destroyed the ultegra brakes due to corrosion and I had to replace the whole thing and get the whole headset redone.

The frame is totally fine.

Psimet2001
10-14-11, 11:24 AM
It's a trainer.

Would you want to ride a bike that would fail on a trainer?

Are trainer manufacturers in the business of destroying frames?

It's hearing questions like this that makes me sad for the loss of common sense in our current culture.

SHIM_105
10-14-11, 01:54 PM
It's a trainer.

Would you want to ride a bike that would fail on a trainer?

Are trainer manufacturers in the business of destroying frames?

It's hearing questions like this that makes me sad for the loss of common sense in our current culture.

There are many items designed with good intention that fail in practical use. I just like to be as informed as much as I can.

nhluhr
10-14-11, 01:59 PM
It's hearing questions like this that makes me sad for the loss of common sense in our current culture.You wouldn't think a fork-mount roof rack would damage a bicycle but people have reported breaking dropouts. I for one applaud the OP for asking instead of just assuming. Obviously somebody (Seven Cycles) thinks it's a problem and it is absolutely indisputable that the forces will be different.

merlinextraligh
10-14-11, 02:12 PM
There are many items designed with good intention that fail in practical use. I just like to be as informed as much as I can.

Dude, think about it.

The forces a frame is subjected to on the road, such as hitting potholes at 40 mph, are som much higher than the static load on a trainer.

abstractform20
10-14-11, 02:14 PM
just make sure to keep the trainer away from open light. unless you like wearing down your carbon faster.

merlinextraligh
10-14-11, 02:22 PM
You wouldn't think a fork-mount roof rack would damage a bicycle but people have reported breaking dropouts.

I seriously question whether anyone has ever broken a dropout on a properly secured fork mounted roof rack.

I can see it happening from operator error. ( such as not screwing down the QR enough to account for the lawyer tabs before closing it)

I bent a steel front drop out once, when I didn't strap the back of the bike down, and the bike swung around, pulling half way out of the fork mount, and only staying attched by one drop out, again operator error.

I'm not riding a bike on the road with a dropout that can't handle the force of the wind on the bike when the bike is properly secured to the rack, and not subject to an inappropriate amount of closing pressure (i.e. not too loose, or grossly too tight.)

The forces placed on the drop out turning and braking at 50 miles an hour down a twisty descent, let alone hitting bumps at that speed, with my 200lbs on the bike, have to be orders of magnitude higher than on a properly secured roof rack.

nhluhr
10-14-11, 02:26 PM
I seriously question whether anyone has ever broken a dropout on a properly secured fork mounted roof rack.

I can see it happening from operator error. ( such as not screwing down the QR enough to account for the lawyer tabs before closing it)

I bent a steel front drop out once, when I didn't strap the back of the bike down, and the bike swung around, pulling half way out of the fork mount, and only staying attched by one drop out, again operator error.

I'm not riding a bike on the road with a dropout that can't handle the force of the wind on the bike when the bike is properly secured to the rack, and not subject to an inappropriate amount of closing pressure (i.e. not too loose, or grossly too tight.)

The forces placed on the drop out turning and braking at 50 miles an hour down a twisty descent, let alone hitting bumps at that speed, with my 200lbs on the bike, have to be orders of magnitude higher than on a properly secured roof rack.I guess you'll have to take this with a grain of salt:
Fork mounts are an accident waiting to happen. Too much stress on fork dropouts. It's not BUMPS you idiots (I never said that) it's CROSSWINDS. I have personally lost a bike off a fork mount carrier in a strong winter crosswind, and I've seen a $8K TT bike blown off a fork mount carrier by crosswinds before the Sandy Hook TT at the Jersey shore a few years ago.

Scratches on your bike caused by carriers that grab the down tube? Not on the ones I had. They rocked:

http://bicyclespleasanton.com/images/library/site/thule_crtem_07_p.jpgwhich was immediately followed by:
The fork mounts themselves do not fail. They put so much stress on the fork dropouts that the fork dropouts fail, the bike then flies off the rack. That's the problem, not the rack itself failing, the rack putting too much strain on the fork dropout which can't handle the torque focused on it by crosswinds.

merlinextraligh
10-14-11, 02:53 PM
I'm not buying it. I'd like to see the pics of the drop outs still in the rack, with the bike blown off.

The torsional forces on the drop outs cornering, and braking at 50 mph with a 200lb rider on it have to greatly exceed some wind on the frame.

Also I've driven thousands of miles at 80+ mph with bikes on roof racks without incident, and you routinely see people driving down the interstate with roof racks at high speeds without issue.

hhnngg1
10-14-11, 03:29 PM
In defense of Mr. Obvious, the trainer CAN (but not commonly) potentially do more damage to your bike than on the road.

I'm a heavy sweater, and even with a bike thong, I managed to do over $400 of damage to my Cervelo in a 14 month period where the bike was on the trainer pretty much the whole time and not outdoors due to sweat dripping off through the thong and severely corroding the headset and components (they actually didn't look bad at all, but when I took the bike off the trainer, to my horror the brakes wouldn't move and the front headset was frozen stiff!) In contrast, I rode this bike purely outdoors for 2 years before that and it was as good as new throughout that entire period. I would never be able to do this much damage to that bike outdoors outside of a crash. So there are definitely some not-so-obvious risks involved for some.

garciawork
10-14-11, 06:46 PM
I'd generally say there is nothing to really worry about, partly due to the properties of CF. With that said, I still went ahead and bought a Kurt Kinetic Rock and Roll trainer (which is really nice btw) to allow some lateral and vertical compliance. The bike frame is still likely being flexed to some degree, but I'm not going to worry about it. Lifetime warranty on the frame anyhow... :)

I wasn't really worried about it, but I went with a Rock n Roll as well. Now I'm NOT worried at all, and the thing is amazing! Peace of mind and an awesome trainer.

Psimet2001
10-14-11, 08:06 PM
There are many items designed with good intention that fail in practical use. I just like to be as informed as much as I can.

Maybe for new items, but trainers have been around a long, long time. I've personally had at least one around at all times since probably 1987. Haven't lost a bike yet. Guess I COULD be doing it wrong though..... :rolleyes:

jdon
10-14-11, 09:05 PM
My LBS had two aluminum cross bikes with CF stays returned due to broken stays at the dropouts. It was more a matter the resin connecting dissimilar materials but both broke in trainers. The manufacturer replaced both frames no questions asked. So, depending on the frame, trainers can cause damage.

roadiejorge
10-14-11, 11:03 PM
Bikes can be damaged on trainers but that's the exception not the norm. Educate yourself on how to mount your bike properly and you'll be fine, in the 20 years I've used one I have had no issues whatsoever.