Does direct drive trainer damage frame?

Discuss light weight issues concerning road bikes & parts.
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biwa
Posts: 31
Joined: Fri Sep 21, 2018 8:39 pm

by biwa

To save time during the week, I train indoor using a Elite Drivo with one of my two Ti road bikes (only ones I have). I also ride both bikes outdoor on weekends.

I'm not a heavy rider, ~66kg, and pretty much all my trainer rides are intervals. I wonder if the clamping/force on the frame by the trainer will affect the frame (e.g. the chain/seat stays) adversely over time?

Ravnsnaes
Posts: 90
Joined: Thu Dec 22, 2005 2:48 pm
Location: Denmark

by Ravnsnaes

The short answer is NO, using a direct drive trainer will not damage your frame. But in some instances, using an indoor trainer could void your frame warranty.

by Weenie


cunn1n9
Posts: 104
Joined: Sat Jan 15, 2011 1:24 am

by cunn1n9

The short answer is YES it can. I have had it happen to me in a Kickr.

If you stand up you can create a motion whereby the bike if not fixed by the rear dropouts would naturally rock side to side. This is most exacerbated at low cadence and high torque. If you do this the motion is restricted by the bike being fixed at the dropouts however the force is still present and is applied as a twisting force that will break down the carbon dropout if done enough. Mine did this however I had it fixed by a very skilled carbon repair person.

I since sold the Kickr and would only ever use an old frame I didnt care about in a Kickr or use an alloy frame.

If you just sit and pedal at a optimal cadence so as to do create the side to side motion you will probably never have a problem.

kgibbo1868
Posts: 155
Joined: Thu Jun 21, 2012 6:36 pm

by kgibbo1868

I would say if you don't clamp the frame tight enough you can have some issues. I had my bike come out of my Kickr sprinting (1200W) and my hanger bent a bit. I think it could have done more damage, but I was lucky and now I clamp the frame a bit tighter and am careful not to rock side to side while sprinting.
Pain is my friend!

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ergott
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Location: Islip, NY
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by ergott

cunn1n9 wrote:
Thu Sep 27, 2018 12:12 am
The short answer is YES it can. I have had it happen to me in a Kickr.
What frame?

TobinHatesYou
Posts: 1867
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

I routinely do 1200-1300W 1s and 1100W 5s, 900W 15s power on an aluminum alloy road bike attached to a CycleOps Hammer. It has shown no signs of fatigue and a carbon composite bike should be less susceptible to fatigue than an alloy bike.

mattr
Posts: 3817
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

There have been a few reported failures on here, and other forums that i've seen. Probably less than 20 in the last 3 or 4 years.
*Usually* very lightweight frames and very rigid trainers. But not really a big enough sample to draw any meaningful conclusion.

Quite a few manufacturers have caveats in their manuals and exclusions in warranty documents as well.

You've got to decide if you think it will be an issue.
Quite a basic run through of the loads will show that they are significantly different to those you see on the road, not necassarily bigger, just not the same. Which may or may not be a problem. Depending on what margins there are on the frame design.

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silvalis
Posts: 472
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

cunn1n9 wrote:
Thu Sep 27, 2018 12:12 am
The short answer is YES it can. I have had it happen to me in a Kickr.

If you stand up you can create a motion whereby the bike if not fixed by the rear dropouts would naturally rock side to side. This is most exacerbated at low cadence and high torque. If you do this the motion is restricted by the bike being fixed at the dropouts however the force is still present and is applied as a twisting force that will break down the carbon dropout if done enough. Mine did this however I had it fixed by a very skilled carbon repair person.

I since sold the Kickr and would only ever use an old frame I didnt care about in a Kickr or use an alloy frame.

If you just sit and pedal at a optimal cadence so as to do create the side to side motion you will probably never have a problem.
Sounds like you need a trainer rocker plate (eg, a rockit board/DIY)
Chasse patate

mattr
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Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

Or a Neo.

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silvalis
Posts: 472
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

Or that fancy bike treadmill
Chasse patate

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corky
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Joined: Thu Jul 06, 2006 5:53 pm
Location: The Surrey Hills

by corky

*cough* rollers *cough*

mattr
Posts: 3817
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

full effort/1000+ watts on rollers?

No thanks.

eric01
Posts: 546
Joined: Mon Feb 06, 2006 1:06 am

by eric01

Get a beater bike off of eBay and use it dedicated for the trainer. Weight, aero and component quality doesn’t matter on a trainer


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AX Lightness Vial Evo, Carl Strong Titanium

biwa
Posts: 31
Joined: Fri Sep 21, 2018 8:39 pm

by biwa

So it seems like as long as you don't rock it left and right on the trainer and keep the whole thing relatively stationary laterally, then you should be fine..

by Weenie


TobinHatesYou
Posts: 1867
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Sometimes in sprints I make my trainer rock and even bounce the whole system. Before I added foam gym flooring, my whole set-up would walk itself forward about half a foot in 15s sprints. Frame is still fine. If you do none of these things, you’re especially fine...

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