By Jim Langley
Today’s column is a simple yet important bicycle safety warning covering one critical detail about using indoor trainers. It was spurred by this Comment from a reader with the pen name “dyonchik,” who shared,
“My carbon 2010 Cannondale Synapse suffered excessive wear on the rear dropouts. After the C’dale rep found out that I used the bike on a Computrainer 1-2 times a week, he refused to warranty the frame. Even though there is nothing in the documentation or warranty about not using a trainer, the best they would offer is 20% off full retail on a new bike … essentially nothing.
“My local dealer took their side in this. This is a major LBS that sells lots of indoor trainers. The owner told me that no bike was designed to be clamped into a trainer and that anyone doing so does so at their own risk. After 20 years as a loyal C’dale customer, I am out looking for a new brand and new local bike shop to patronize.”
Origins of the indoor trainer
To back up a bit and provide some reference, bicycle trainers have been around since the dawn of cycling. It’s harder to pinpoint when the first rear-wheel-mount indoor trainers were invented, but it wasn’t that long ago; I had one in the 80s, I believe.
Trainers have always been popular for riding indoors to escape the dark or bad weather, for warming up before races and for riding in places where you couldn’t otherwise, such as in a hotel on business trips, for example.
But, today, trainers are more popular than ever because technology is rapidly changing. The many new computers, power meters and electronic and social media toys available let us compare and compete with friends riding their trainers, track our training and even virtually ride in epic places like the famous climbs of the Giro d’Italia, etc.
Carbon changes things
Something else has changed over the years: bicycles. And, that’s why “dyonchik’s” Cannondale was damaged, and why you want to pay attention to today’s warning if you are just getting into trainer riding.
What happened to bicycles is that many went from being made of rugged steel, to far lighter and more delicate materials, such as aluminum and carbon. What’s more, even the dropouts on these frames are made of aluminum or carbon. This is important to understand when it comes to using a trainer with these bikes.
How the trainer holds your bike
The modern folding rear-wheel-mount trainer with a roller that drags on the rear tire, holds the bicycle by the quick-release, the clamping mechanism that holds the rear wheel in place on the bicycle.
All trainers should come with a dedicated quick-release designed for use with the trainer. These QRs are typically made of steel. You must remove your QR and replace it with the one made for the trainer.
This is because the trainer’s quick-release holders that tighten on the QR and hold up the bicycle are shaped to fit it and are usually not designed to securely or safely grip other quick-releases. Sometimes they’ll seem to work. However, if your quick-release doesn’t fit perfectly, or worse, if any part of it is made of aluminum, the trainer’s holders will usually damage and eventually ruin that part.
Don’t assume – check and double check
When you get a new trainer, you’ll read the instructions and find the special quick-release. It would be easy to just set up the trainer, swap out the quick-release on your bike, mount your bike in the trainer and start riding. But, don’t do that.
Instead, first carefully check how the trainer’s holders are working on that quick-release they supplied. Be sure they are securely tightened onto the quick-release only. In order for the trainer not to harm your bicycle, it should only hold onto the ends of the quick-release. No part of the trainer should touch your bicycle’s frame or dropouts.
This is hard to see, so get down close to each side, shine a flashlight on the area, if needed, and make 100% certain that even under a super-hard pedaling effort — like standing to climb or sprint — the trainer’s holders couldn’t ever contact any part of the frame, stays or dropout on your frame.
Take your time. Check both sides. Push and pull sideways on the bike to make sure it’s seated in the trainer. Make sure the trainer is really tightened onto your bicycle, too. If the clearances are hard to see, try to slide a credit card between parts all around and on both sides to make sure there’s enough clearance.
If the provided quick-release doesn’t work
Some bicycles have unusually shaped stays and dropouts where even with the dedicated QR that came with the trainer, you cannot prevent the trainer’s holders from contacting the frame. If you have that issue, do not ride the trainer until you’ve fixed this issue.
Usually you can get the clearance needed by going to a different model quick-release with taller/longer end caps. Of, try adding spacers/washers to the QR to extend the ends. You only need a quick-release with a skewer (the small diameter rod that connects the ends) long enough to let the spacers fit.
Once you’re sure that your bicycle is only being held by its quick-release and nothing is touching your frame, you’re ready to enjoy your indoor rides worry-free. The only bicycle parts that will wear are most of the same ones that wear when you’re riding outdoors, plus that special rear quick-release.
To repeat, regardless of what that LBS told “dyonchik,” you can’t harm your bicycle riding it on a trainer as long as you take these precautions. Witness my teammate, who has logged 20,000 indoor miles on his Giant Advanced carbon bicycle trouble-free.
Tip: Sweat is corrosive to metal, so be sure to drape a towel over your bicycle and components or use a sweat-catcher accessory offered by most trainer companies to keep the sweat away.
Jim Langley has been a pro mechanic and cycling writer for 38 years. At RBR he’s the author of Your Home Bicycle Workshop and moderator of the technical forums on the Premium Site . Check his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter.