# Carbon frame stress and trainers



## hikertoo (Jul 7, 2010)

Makes me think twice about using a trainer with my carbon frame....
http://www.kurtkinetic.com/faq.php

From their website
*Has Kinetic done any type of testing on trainers and bike frame stress.*
We are aware that most bicycle manufacturers will not warranty bicycles damaged by side to side torque from riding on a trainer. Our solution is the rock n roll bike trainer http://www.youtube.com/watch?v=GQz_u0Vc8Os . When riding the rock n roll bike trainer the top plate moves with the bicycle – thus eliminating any stress on the rear stays or bottom bracket of the frame.
It is our understanding that bicycle frame failure from riding indoors is rather rare, but of course it is in your best interest to follow your bicycle manufacture’s advice.


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## Mel Erickson (Feb 3, 2004)

hikertoo said:


> Makes me think twice about using a trainer with my carbon frame....
> http://www.kurtkinetic.com/faq.php
> 
> From their website
> ...


They are trying to sell their trainers. It's tough to differentiate one brand from another. It's called marketing. Don't put too much stock in it and don't worry.


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## Cooper1960 (Oct 14, 2010)

What a timely post, I was wondering the same thing tonight as I was on the trainer. I have a Kurt trainer and I leave my Trek 2200 on it. When I stand and peddle in the big ring the bike moves two inches side to side looking at the bottom bracket. I know it's not all flex at the bottom bracket itself but that's the only visual point of reference I got.

I think if you're just spinning at a high cadence a carbon frame would be OK, but when you're really torquing the peddles I think it puts a lot of stress on the frame. And I expect others to say the bikes are made for that, or that the frame stress on the road is actually the same or greater than on a trainer. I can't prove either argument, but from what I see I am not going to put my carbon frames on the trainer.


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## PJ352 (Dec 5, 2007)

Mel Erickson said:


> They are trying to sell their trainers. It's tough to differentiate one brand from another. It's called marketing. Don't put too much stock in it and don't worry.


That was my initial opinion as well, then out of curiosity I went to the Specialized FAQ section and found that they don't share our views:

Quote:
Specialized Carbon frames safe on indoor trainer?
Published 10/06/2009 06:20 AM | Updated 01/04/2011 03:17 PM 
I have heard pros and cons on this. What is the truth? If i use a sturdy steel skewer with an indoor trainer am I:

1. voiding the warranty? or

2. at risk of damaging the bike? Is there a certain trainer that you recommend? 

Thanks!

Specs answer:
High performance carbon road bikes are a really bad idea on indoor trainers. The fixing of the rear chainstays in one place and the biting of the clamp creates all kinds of twisting forces from odd angles, that can, over time, be really bad for a lightweight frame.

Our bikes withstand some amazing torture tests in the lab. However we really can't recommend it. Have we heard of people doing it? Yes. But we have also heard of people breaking their bikes, and being quite upset when their warranty claim is denied.

What I do for my own winter training is I have an old "winter rat" bike that does double duty as my awful weather ride, and that lives on the trainer in the winter.
End quote.

In light of this I would suggest that members check with their bike manufacturer for clarification.


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## TWB8s (Sep 18, 2003)

Rollers.


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## calle_betis (Jun 30, 2006)

Frankly, I would look at the warranty from the bike company. I keep my aluminum framed bike in the trainer and my CF bike on the rollers.


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## pdh777 (Oct 7, 2005)

Thanks for the info - I'll be taking my Look off the trainer now - and using my steel bikes from now on.


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## Don4 (Jul 29, 2010)

*From the Felt FAQ on their website:*

*I have heard that you should not put a carbon stay bike on a trainer - is this true?*

The loads a trainer puts on a bike are quite different from those which the bike is designed to withstand on the road, particularly when it comes to tensile forces in the seat stay— which try to pull the dropout out of the seatstay . However, Felt has been selling bikes with alloy dropouts bonded into carbon seat stays for four years now . Some of these bikes have been used in trainers , and we have not encountered problems . Even so , we recommend avoiding out-of-the-saddle efforts while riding trainers . However, riding on rollers loads the frame in a similar way to riding the road and should not damage your bike' s seat stays or dropouts .


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## nm_biker (Jan 3, 2011)

bottom line: its not great for your bike, but not that bad either if done appropriatley. that means to not get out of the saddle and make sure that your bike is securly and properly attached to the trainer. carbon is stronger than steel in terms of torsional strength. kurt is trying to sell those bouncy trainers. anyone try one? been wondering how the ride. i 've also been curious about the new lemonde 'wheel-less' trainer. looks like specialized avoided the question about the warranty and basically told you to buy another bike just for your trainer. nonsense.


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## PJ352 (Dec 5, 2007)

nm_biker said:


> bottom line: its not great for your bike, but not that bad either if done appropriatley. that means to not get out of the saddle and make sure that your bike is securly and properly attached to the trainer. carbon is stronger than steel in terms of torsional strength. kurt is trying to sell those bouncy trainers. anyone try one? been wondering how the ride. i 've also been curious about the new lemonde 'wheel-less' trainer. *looks like specialized avoided the question about the warranty *and basically told you to buy another bike just for your trainer. nonsense.


IMO you're reading what you want into both Felt's and Specs statements, but that aside, I don't agree that Spec avoided any question. What's unclear about the following statement?

"...we have also heard of people breaking their bikes, and being quite upset *when their warranty claim is denied*."

Seems pretty clear to me.


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## krisdrum (Oct 29, 2007)

All this stuff is laywer driven CYA language. Every single pro team uses trainers for team warm-ups. Granted, they get free bikes and such, but you never see any of them on rollers. Just some food for thought.


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## nm_biker (Jan 3, 2011)

PJ352 said:


> "...we have also heard of people breaking their bikes, and being quite upset *when their warranty claim is denied*."
> 
> Seems pretty clear to me.


uggggggh...you got me! :blush2:

thanks for calling me out bro! 

truth is, if you break your bike in the trainer you are doing something wrong or you are too FAT. is it possible yes OF COURSE! but the truth is you would probably crack your aluminum frame under the same circumstances. the real answer is rollers, but some people, myself included, prefer a trainer and have neither the funds nor the space to house another steed.

and if it works for these specialized, then why not yours?


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## psycleridr (Jul 21, 2005)

When is the last time you saw a pro standing up and really putting high torque while "warming up"? A warm is is an easy ride to get the HR and blood moving not an anearobic workout. Like Felt said .... avoid out of the saddle efforts and you will be ok. If you are standing up and cranking a high gear for intervals you might want to think twice about it


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## dot (Mar 4, 2004)

buy some rollers and don't strain your brain.


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## mymilkexpired (Apr 21, 2004)

TWB8s said:


> Rollers.


Indeed... This is the only way I run my carbon frame.


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## Lou3000 (Aug 25, 2010)

This from the Slowtwitch forums



> In response to your question I phoned (just now) the following companies to clear this up:
> 
> Felt: Trainer use does not void normal warranties. Bicycles are covered under normal use warranty for trainer use.
> I spoke with Scott at Felt.
> ...


So, Specialized's no trainer policy would not be the norm. I have a feeling unless you are just being a moron and trying to be Mark Cavendish, you are probably not going to break your bike.


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## kbwh (May 28, 2010)

Standing up and hammering while on the trainer has always felt unnatural to me, so I refrain from doing it. I rather do like Fabian: Gear up and glide away sitting.


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## mymilkexpired (Apr 21, 2004)

Its nice that someone took a minute to collect an answer from a support agent but often times reality rarely mirrors what has been said in the past. 

I do agree with other posts regarding your STYLE of riding. In either case, I'd still pass. Get your arse out in the cold weather and HTFU or get some rollers.


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## PJ352 (Dec 5, 2007)

nm_biker said:


> ...and if it works for these specialized, then why not yours?


Because if they break their bikes Specialized gives them a new one... FREE!


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## PJ352 (Dec 5, 2007)

Lou3000 said:


> So, *Specialized's no trainer policy would not be the norm*. I have a feeling unless you are just being a moron and trying to be Mark Cavendish, you are probably not going to break your bike.


Based on your list, that would appear to be the case, but there are more brands NOT listed than listed, so IMO you may be jumping to a premature conclusion.

As far as the odds of breaking a bike is concerned, I agree with those offering that it's a CYA move and to temper ones riding style on a trainer, but IF the bike breaks, that CYA language allows for an out by the manufacturer. 

Everyone has to weight the risks/ benefits, but I for one am going to take the opportunity to shop for a steel bike. It's not that I _want_ another bike, but... you know... just to be safe.


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## den bakker (Nov 13, 2004)

anyone actually know one that has broken a frame in the trainer or seen a broken frame from trainer use?


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## serious (May 2, 2006)

I have an Opus bike on the trainer (with CF seat and chain stays) and I train really hard on it, with plenty of out-of-saddle riding, but no crazy out-of-saddle efforts.

Frankly, any explosive out-of-saddle efforts on the trainer cause major slippage, so they are a bit frustrating anyway.


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## looigi (Nov 24, 2010)

nm_biker said:


> and if it works for these specialized, then why not yours?


These guys warm up on them, but don't necessarily train hard on them? And if they break them, Specialized is off the hook, cuz these guys get free bikes from Trek now...


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## frdfandc (Nov 27, 2007)

den bakker said:


> anyone actually know one that has broken a frame in the trainer or seen a broken frame from trainer use?




I've personally never seen a bike, carbon/steel/ti/aluminum, with any type of frame break from use on a trainer in the 3 years I've been working at a LBS.

However, I have seen frame damage on a couple of alloy bikes due to improper mounting in the trainer, due to the use of an improper sized skewer. Some skewers have a big blocky style QR, instead of a nice rounded one.

These QR skewers are great for trainer use.











These not so much.











Not saying a frame can break on a trainer, but then again, a frame can break when its being ridden outside.


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## 2Slo4U (Feb 12, 2005)

PJ352 said:


> That was my initial opinion as well, then out of curiosity I went to the Specialized FAQ section and found that they don't share our views:
> 
> Quote:
> Specialized Carbon frames safe on indoor trainer?
> ...



Interesting....I wonder how the warranty conversation would've went when the person trained by Specialized, in a Specialized shop put my Specialized Roubaix on a trainer to do their high tech Specialized Body Geometry fit and it imploded? I spun on that trainer for 90 minutes or so, he never once said "Ummmm, this might void your warranty!"


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## PJ352 (Dec 5, 2007)

2Slo4U said:


> Interesting....I wonder how the warranty conversation would've went when the person trained by Specialized, in a Specialized shop put my Specialized Roubaix on a trainer to do their high tech Specialized Body Geometry fit and it imploded? I spun on that trainer for 90 minutes or so,* he never once said "Ummmm, this might void your warranty!*"


Maybe..

1. The rep would tell him he doesn't check their FAQ section often enough and the LBS needs to pay for your new bike. 

Or

2. The rep would tell him that you apparently don't check their FAQ section often enough and shouldn't have let him use your bike on the trainer, so you're SOL. 

Or

3. Because they know the type of spinning done during their BG FIT there's no cause for concern. 

I choose #3.


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## Cinelli 82220 (Dec 2, 2010)

I use a junk steel frame on the trainer and don't worry about it.


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## zakyma (Jan 25, 2010)

For trek.FAQ they said it is ok to use the cf bikes on trainners but I use emotion rollers because it is better.


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## dot (Mar 4, 2004)

frdfandc said:


> These not so much.


looks like typical shimano skewer. I've been using them (Deore/LX/XT QRs) for 6 years on my minoura RDA with several bikes. Half of the frames got broken  but definitely not from trainer use.


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## ZoSoSwiM (Mar 7, 2008)

On the road you don't notice your frame flexing from side to side as your pedal. Hell if you were able to see your frame flex as your sprint to a sign or up a hill you'd likely be scared to ever ride it again. The only reason you notice it so much on the trainer is because it's locked in. If riding a trainer kills my bike I don't think I'd be very safe with it on the road. Let alone sprinting at 1200 watts.


Just use the correct skewers, don't under/over clamp it, and don't tip over. If you're really worried don't stand and sprint.


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## Jwiffle (Mar 18, 2005)

nm_biker said:


> kurt is trying to sell those bouncy trainers. anyone try one? been wondering how the ride.


I have one and like it a lot. I didn't get it because it was less likely to hurt my carbon Cannondale Synapse, but because I liked the idea of the rocking giving a slightly more realistic feel and making you use your abs a little more than traditional trainers.

Oh, and the inside Cannondale Rep for our shop was clear that trainer use would never void a C'dale warranty on their carbon bikes (or alloy, either for that matter), as I happened to ask one day after I had read that Felt post on their site a couple years ago. And I'm fairly certain that trainer use won't void a Giant, either. I think it's fewer companies that would actually deny a claim based on trainer use.


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## calle_betis (Jun 30, 2006)

Lou3000 said:


> This from the Slowtwitch forums
> 
> 
> 
> So, Specialized's no trainer policy would not be the norm. I have a feeling unless you are just being a moron and trying to be Mark Cavendish, you are probably not going to break your bike.


'm not sure 6 bike companies make the "norm" with there being hundreds of bike companies, but the_* trend *_is apparently that it may be OK with some companies. I'll stick with putting my aluminum rain bike on the trainer and my CF bike on the rollers.


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## reyesjames (Jul 20, 2007)

Any body looking for e motion rollers? Made by inside ride


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## Tommy Walker (Aug 14, 2009)

Great info on this thread, thanks all.


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