I have broken a frame in a trainer....granted it was an old worn out frame. Some folks say that there is nothing to worry about, I am not one of those. I dont put my new bikes in one - but of course will ride the rollers on any bike.

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What if the Hokey Pokey is what it is all about?

I haven't had a problem with my frame, but can you believe I've gotten a flat when riding my trainer. Good thing I wasn't going downhill!!

I have broken two Airborne titanium frames on my trainer over the years. Both frames failed in the same spot, where the top tube met the seat tube. Each time a crack formed across the weld parallel to the top tube due to the frame flexing while I was doing high-cadence intervals. When you ride on the road, the bike can rock side to side as you pedal. Without being able to rock, my frame was flexing at a point where it wasn't designed to flex. The manufacturer replaced the frame twice under warranty, but after the second time I made sure my bike wasn't clamped too tightly into the trainer and stopped doing those workouts altogether. I haven't had a problem since, which is good since Airborne and their warranties are long gone.

To be fair, I'm a 200+ lb. rider. Lighter folks on different frame materials probably don't have the same issues.

Ive done that too! Mine was like a catastophic blow out too. I dont know what the hell happened.

The other day, I was cleaning my bike outside (which I normally clean it inside), and I noticed a crack in my top stay of my cervelo. I have about 4000 miles on this bike and I ride it on a ratio of 40:60, trainer:road.

I'm not 100% sure if it's just superficial meaning it seems there is a thick plastic cover (thicker than clear coat) over the paint/aluminum.

Your thread got me thinking, what if it's the trainer? I'd imagine there is a lot of stress in the top stay.

I've also broken an aluminum frame at the seat stay/top tube junction.
It was Bianchi and they replaced it. They didn't ask if it had been on a trainer, so I didn't tell.
I'm in the proccess of building a "b" (C-dale aluminum) bike for trianer/general use.

I really doubt that trainer forces have not been taken into consideration in frame design. I say just put it on there and ride it and don't worry about it. If you're really worried, don't go crazy with the out-of-saddle sprints and you'll be fine.

RE: the blowouts while on the trainer. To prevent keep the back tire clean. Before each trainer session I clean the tire with rubbing alcohol. It works! (from Computrainer directions)

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tri-bich

From talking with reps, trainer forces haven't been accounted for in the majority of bikes, simply because it's not a normal load, and not an intended use of the bike. Yes, they're inherently strong enough to withstand a little trainer use, but that comes from making the frame strong enough to handle normal riding use; trainer function is a byproduct. It's like Zipp 29er wheels...in most cases, it works, but it's a stress the product wasn't designed for, and you'd better lie your ass off if it breaks or you'll never see a warranty replacement.

That said, I think it's Kinetic or someone who has a new trainer that pivots to decrease some of the lateral stresses. Doesn't really solve the tensile loads on the seatstays, but it alleviates some of the problem.

Cervelo guarantees their frames with or without trainer use. I think it all depends on the company. The trainer is just a way of life when you live in the great white north.

:-)

Jodi

Cervelo also has some pretty over the top engineering. Didn't they go like 400,000 cycles in the efbe certification?

I have blown out the back *and* flattened the front. Can't explain the front. After two months of riding the training it just developed a slow leak one day and went flat over night. Very odd......

There's some German(?) magazine that reports on frame durability that regularly reports on certain frames lasting much longer than others, a few people have pointed out the discrepancy in the testing method (similar to riding a trainer with no vertical compliance at the fork) versus real world riding.

http://www.sheldonbrown.com/rinard/EFBe/frame_fatigue_test.htm

 

Incidentally, the German magazine Tour did test this whole trainer business scientifically. They put strain gauges on the seat and chainstays and the tubes and then measured the strains at different power outputs/torques on the trainer and the road.

Guess what? The strains were actually slightly higher on the road than on the trainer. IIRC, they speculated it was because you swing your bike a little from side-to-side on the road and that distributes the strain more unevenly.


-jens

All I know is this- both my tri bike and road bike frames have lifetime warranties ;-)

I had a blowout too. I wasn't even on the bike at the time. I'd just set it up to get ready for a ride, went to check my emails, then...booooom.
The morning sun came thru the window and heated up the tire. since I'd already adjsted the tension to ride, the expansion had no where to go.

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"thoughts become things, choose the good ones"

I was talking to the mechanic at my bike shop last week and I asked him what his thoughts were on putting a carbon frame on a trainer. What he said was the manufacturers are seeing this as a gray area and may not warantee the frame if you break it on a trainer. I refuse to put my QROO Seduza on the trainer simply because the first time I did it, there was a lot of creaking noises that scared the hell out of me. I won't do it again.

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"Paulo knows where to find me."

my bike builder/mechanic says no to putting your main ride on the trainer for the reasons you mentioned. put a beater bike on it.

Would a mountain bike be any better?

I've always wondered about the loads applied to the rear axle and the rear triangle when you "clamp" the bike into the trainer.
I hate watching the whole thing flex as I crank it down.
Is there anything published on the best way to mount the bike into the trainer, anyway?

would work, but then again, not everyone has a beater bike. I sold 2 bikes to get my Transition Pro (that I love love love), but can't ride in a lot of winter conditions (I have Raynaud's), so I have to trainer it... they said it should be fine, as long as I change the wheels and tires (I use a tire specifically for trainers).

Granted, I am 5'4" and weigh about 120-125 lbs in winter...but I am hoping that will change (DOWN)...they said it should be fine...I hope so..I have the ONE bike!

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Tiger for Life -- War Eagle!

My '06 QR Caliente creaks a lot when on the trainer. It bothers me, too, but I still ride the trainer with it.

Remember this?

http://forum.slowtwitch.com/...%20warranty;#1112989

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Tom Demerly
The Tri Shop.com

Cool. That was way back.. thanks for the reminder!

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