While the “riding on a trainer will damage your carbon frame” myth has been officially busted, indoor riding can still pose a threat to your bike in two ways: wheel strain and sweat corrosion.
We’ve put together an exhaustive list of common trouble spots reported by riders who train regularly on Zwift. Also included are “indoor only” maintenance tips so you can enjoy every Zwift session without being interrupted by a mechanical!
Wheel Strain
Skewer
Your rear skewer handles more stress in a stationary setup than it will on the road. This can lead to a bent or flexing quick-release axle if you use an aluminum or titanium quick-release rear skewer, which can lead to your frame disconnecting from the trainer – which can severely damage your frame. This is why trainers typically ship with a sturdy steel skewer you can easily swap out. (Obviously, this isn’t an issue with thru-axle bikes.)
Solution: always use a steel skewer on your rear wheel when using a trainer.
A note on sprinting: keep in mind that, without a rocker plate, your indoor out of the saddle sprint technique will have to be different from your outdoor. Outdoor sprinting typically involves keeping your body fairly upright while the top of the bike moves side to side. Indoor sprinting requires the bike to stay fairly stationary, so your pedal and body motion will be more “up and down.” Here’s a video from Shane Miller discussing this topic >
Back Tires
“Wheel-on” trainers allow you to keep your rear tire on your bike and provide resistance by pressing a roller against your rear tire. These are the most common trainers used today due to their low cost and ease of use, but they will wear out your rear tire much more quickly than outdoor riding.
Solutions:
- Use a trainer tire: these tires are made to be used only on indoor trainers, so the rubber is grippier and the tread is smooth. They are usually brightly-colored so you don’t accidentally use them outside.
- Use a spare wheel: many cyclists have a spare wheel lying around–use it as a dedicated trainer wheel (with a trainer tire or an old tire you don’t mind wearing down).
- Don’t change anything: this was my approach in my first indoor season, and I was happy with it. My Gatorskin tire was rather worn at the end of the outdoor season anyway, so I kept it on all winter and put a new tire on when I started riding outside again.
Top-Rated Trainer Tires
Another thing to keep in mind with your tires is that it’s not good for them to have constant pressure in one small area, which is exactly what the resistance roller does when your back tire isn’t spinning.
Solution: disengage the resistance roller to prevent the creation of flat spots on your tire if you leave your bike on the trainer between rides.
Front Wheel Spokes
Out of the saddle riding (even if not sprinting) is going to put significant load through a handful of spokes, leading to uneven fatigue.
Solution: Rotating your front wheel 1/4 turn before each workout or once a week will even the fatigue.
Sweat Corrosion
No serious cyclist can avoid sweating on their bike, but we must understand that sweat eats metal. Of course, it’s important to have a good fan or two to reduce sweating and encourage drying as much as possible. But even then, you will sweat, and this can cause major damage to your bike. Here are the key problem areas to keep in mind:
Handlebars
We’ve heard many stories of cyclists snapping their aluminum handlebars because they were corroded from sweat. Aluminum handlebars are typically anodized to prevent this corrosion, but scratches or flaws in the anodized surface can lead to bar-weakening corrosion.
The challenge is that you can’t see handlebar corrosion since it is covered by your bar tape. And the danger, obviously, is that a handlebar failure outdoors may be catastrophic.
Solutions:
- Ride with gloves and/or a towel over your handlebars. Both of these will soak up much of the sweat that would otherwise make its way onto your bars.
- Change your bar tape at least once a year, and be sure to check for corrosion each time you do so.
- Apply Boeshield T-9 to your clean bars to prevent corrosion.
- Use carbon instead of aluminum handlebars. It won’t corrode!
Headset/Top Tube
The headset and top tube are directly in your sweat “splash zone,” and these are two parts you definitely want to keep in tip-top shape. Sweat will corrode your headset bolts and any exposed aluminum, and can even damage your paint.
Solution: get a sweat net. They’re cheap, and work great! We use Blackburn Sweat Nets which you can find on Amazon for ~$15.
Downtube and Bottom Bracket
Thanks to gravity, sweat on your downtube will find its way to your bottle cage bolts and eventually your bottom bracket. Both of these are problem areas – the bottle cage bolts can corrode when sweat bridges the gap to your carbon frame (see “More on Sweat” below). Your bottom bracket’s metal parts (and the cables which may run beneath it) can also corrode from accumulated sweat.
Solution: a sweat net (see above) should keep sweat from your downtube as well, but check to make sure it is staying clean. If it isn’t be sure to wipe it down after each session.
Seatpost
If sweat gets on your aluminum seatpost it will quickly move down to the seat tube and create corrosion/seizing problems at the top of your seat tube.
Solutions
- Apply grease or anti-seize compound to your seat post and clean it regularly
- Use a carbon seat post
ANT+ Dongle
We’ve heard more than one story from Zwifters who had their ANT+ dongle in a place where it was catching drips of sweat. This is a death sentence for anything electronic!
Solution: relocate the dongle, or place it inside a plastic bag or plastic wrap.
More on Sweat
Carbon and aluminum lie on opposite ends of the galvanic scale, which means connecting them with an electrolyte (such as your salty sweat) effectively creates a battery which will greatly speed up aluminum’s corrosion. So pay attention to where your sweat falls, and make sure you don’t let it stay on your bike for long.
Additionally, if you spot any corrosion, don’t wait for the part to fail. Replacing your handlebars now is much cheaper than fixing a broken collarbone later.
What About You?
Have you had any problems with indoor training damaging your bike? Got suggestions for other Zwifters? Share below!
Having learned this the hard way, I cant emphasize the danger of sweat corrosion enough. Zwift is amazing, but if you dont regularly inspect your bike and protect it with a towel and fan you are taking a big risk. Under the bar tape is a big danger zone. I hit a mild bump on a downhill during mt mitchell ride that fractured my handlebars due to this. I managed to stay upright, but almost killed myself because i sweated all over everything indoors.
wow! I hope you got a good picture at least!! 🙂
I ruined my first carbon bike with sweat, I didn’t realize that one of the adjusters on the downtube had rusted, I went to tune my bike and snapped it off. Dumb.
Great Article Eric – thanks. It definitely goes in the ‘things I din’t know I didn’t know’ category!
Titanium frame under my butt…no sweat issues 😁
Thanks! Just ordered a frame to build up that will be Zwift only. And I have both alloy and carbon bars available…so I guess I’ll rock the carbon.
Would love an article about how often to lube a chain (when only used indoors) and any other bike maintenance I wouldn’t have thought of that we should be doing.
I wipe down my aluminum bike after each ride with an all natural cleaner (it smells like vinegar). Is that an acceptable choice or is it too acidic? What is the best option?
Great tips!
I’m starting to use more and more towels to catch the sweaty waterfall all over my bike.
I could be wrong but I think my bottom bracket (it is a bit older) now needs to be replaced due to slight alignment issues with my direct-drive trainer. Be careful everyone.
Worth saying that the quick release that comes with the Wahoo Kickr18 is really flimsy and bends on sprinting. I’ve replaced mine with a much heavier one.
Yup. Actually linked to a post about that above!
Check your bottom bracket, too. The bearings on the left side of my BB were completely corroded after just a few months of indoor cycling, even though I wiped it down after every session. Now I have a small towel there to catch any sweat.
I always lay a towel across the handlebars and grip them through it.
I can’t comprehend sweating that much 🤯 must be able to smell that bike and rider from across the street 😂🤢
Hi, broke my handlebar during a sprint 4 months ago 🙁 Completely “corroded”…
Hey Eric. How often do you clean your sweat net? I grab old beach towels and drape over my bike – mostly because i have enough and don’t have to wash dailY
but the Net is better since it covers more area, so long as I don’t have to be doing laundry everyday
Rarely, actually! Maybe every few months? It doesn’t seem to get too funky.
Gross. Just take it off after a week of riding, put it into your washbasin filled with water and see all the sweat come out of it.
I basically wash my towels, one I put over handlebar and the other over top tube, at least once a week, before rest day, so they are dry the following day.
As a former mechanic I am so thankful for this article existing! Saw a lot of sweat damage first hand. Also worth noting, damaged paint on an aluminum frame can corrode. Recently I snapped a chainstay on my frame while throwing down some watts. On closer inspection, the frame had corroded around where an old zip tie had removed some paint. Lessons learned the hard way
😫 get you bikes clean 😜 cleaning tissues are the key 🦠😷
Yes!! Some of the routes on Zwift have such sudden ramp changes, i.e -5% to +10% multiple times over a short distance that the necessary gear changes to maintain a smooth spin are tearing my drivechain up. Dust in the Wind for example. I’ve never confronted courses like this in the real world and I will avoid these in the future
I had a brake cable guide on the bottom of the top tube pop off. Had a good look and there was caked sweat galore around and under it.
I have found putting a cleat screw in the hole where you tighten the headset keeps out the sweat. Just make sure to put a good coat of grease where the screw makes contact with the headset.
Or wrap your stem in Saran Wrap! Waterproof.
I had a broken carbon seatstay repaired (something heavy fell over onto my bike) and it held up perfect to a year of outdoor riding. It broke in the same spot at the repair my first ride on the direct drive trainer. Not saying a new carbon frame would suffer the same fate but without question the trainer puts added stress on frame members. I’ve since been using a cheaper older carbon bike without issue.
I’ve got my retired road bike that I use on my trainer, dubbed “my bitch”
The seatstay on my Focus Izalco Max Disc cracked after 4 perfect months on my Wahoo Kickr. Focus flatly and repeatedly refused to accept a warranty claim and kept saying “our bikes can’t be used in turbo trainers”. I explained a few times that the Kickr is a direct drive trainer, attaching the bike the same way that it does with a wheel (which they had to have known already). Again, they refused and nearly ignored my asks for help. The warranty they kept pointing me to explicitly says it prohobits “clamp type turbo trainers”, which I can understand given… Read more »
I use my old Cannondae CAAD9 as my indoor trainer bike. My answer to the sweat problem is to cover all sensitive areas with silicone. Provides a nice waterproof seal. I use a piece of plastic duct taped to the non-drive side of my frame to serve as a “sweat shield” for my bottom bracket. Works great. Now my only issue is my corroding shoes during the summer months; after each ride it’s like I went swimming in them.
Talking of sweat getting everywhere, what about training mats? Obvious they are an essential both to protect the floor underneath and also noise dampening, but how (and how often) should they be cleaned? Especially when using a heavy static bike / current times (ie. something which is in place for an extended period of time)? I give mine a wipe after each use with the towel that’s about to go into the wash, especially if there’s pooling sweat, though I’m sure it also absorbs plenty. Almost like these should be considered a disposable item, but they aren’t cheap especially the… Read more »
i was thinking of ankle bands, Like sweat bands for the ankles to stop the soaking of my shoes on the trainer. IDK…
Also clean your HR monitor sensor connections regularly as it tend to corrode and cause the sensor to disconnect from the belt
Don’t zwift with tape on your handlebars, it’s the number one reason they corrode. The tape is a sponge and it holds the salty sweat near the bars for hours after you are done allowing the galvanic corrosion to take place. If you don’t have tape on the bars, most of the sweat will drip down or evaporate and while the salts may stay behind they cannot do nearly as much damage without the moisture present. Even stuff like lizard skins will cause trouble, even though it’s non-porous sweat will wick underneath the tape due to capillary action and you… Read more »
…. toss the towel in the laundry! I don’t have an unlimited supply of towels 🙂
I’ve had two head tube bearings go. Aluminium Bearing within the carbon frame of my look695. Totally seized and requiring a drill to get it free! Both times expensive, and should have learnt the first time. Yes, I use a sweat net. Now making sure I Vaseline the top tube and move the bars left and right every day, before and after training…plus a wipe down.
Stop the handlebar problem by first wrapping the bars with pvc electric tape. Then put your bar tape of choice over it. Save your headset by wrapping part of an old T shirt around it. Aluminum seat posts can be coated with a shmear of anti corrosion grease. It’s not rocket science.
My chain broke tonight while Zwifting and it scratched part of my trainer where the Wahoo decal is. I feel so bad about it. Thinking of replacing the decal.
Has anyone damaged a rear hub on a wheel-on trainer? I hub is making noises after only 5500 on these wheels.
Ohhh, I wished I saw this earlier. Failed handlebar after 4.5 yrs Zwifting, almost flew off the bike. I should have TLC’ed the bar tape. I mostly MTB IRL, Zwift is a fun means to stay in shape with a road bike permanently attached to a Kikr. I considered it as a training appliance, dead wrong on that Sir 🙂
I ride on Rollers while Zwifting, is there any stress on the bike or other things to watch out for using rollers?
Rollers don’t stress your bike at all. The only thing to watch out for is you don’t fall off and bang your frame, like I’ve done… multiple times. 😆
All the more reason to get an MP1 platform!!
Helps to eliminate pressure points that cause damage.
question… when I stand during a workout even when I’m in big gear in front and small in back my bike feels like it’s going to fall apart… I have a saris 3 smart trainer and use my specialized ruby as my training bike…