Protecting Crank Arms

When you’re spending hard earned cash on a bike, it’s understandable that you want it to remain in the best possible condition for a long time. Protecting crank arms using clear tape is a sure way to keep your cranks looking better for longer.

Protecting Crank Arms Using Clear Tape

Everyone has a different name for clear tape – helitape, surface guard, clear film, clear bra – but regardless of its name, it’s really useful stuff. I have used the 3M Scotchgard Paint Protection Film for the last two years and it’s worked great for me.

My example is the Truvativ Descendant cranks. While I’m confident that the cranks themselves will be strong enough for a rider like myself, I’m not convinced that their finish will remain in tact for very long, especially after the finish of my Truvativ Holzfeller cranks has begun to wear significantly after only 5 days on the bike.

Truvativ and Shimano cranks are notorious for their finish wearing off because of the convex face on their outer surface – those of you with “polished” (worn) Shimano Saint cranks take note!

The solution? Clear tape your cranks! Clear taping your cranks will minimise the wear and tear that your cranks are subject to. Even if you’re not interested in the aesthetics of your bike, it should help to keep the resale value of your cranks that little bit higher once you’re done with them.

How to Protect Crank Arms with Clear Tape

Here’s a quick walk through of how I clear taped my Truvativ Descendant cranks:

1. Measure the amount of clear tape that you need for each crank.
   • For those with Descendants, I found that 45x130mm (around 1.75×5.1 in) worked perfectly.
2. Cut the clear tape and backing. Make sure you use either a sharp pair of scissors or a sharp utility knife to make the cuts.
3. Fill a container with some warm water and a little detergent. One or two drops is enough.
4. Clean the crank surface, ideally with an isopropyl alcohol.
5. Heat the crank and tape if possible. A hair dryer is perfect, just don’t overheat the tape. You just want to make it pliable.
6. Wet the crank surface, then peel the backing paper off of the film.
7. Apply the film to the crank, taking your time to make sure that everything lines up. Thanks to the detergent mix you have plenty of time, so use it.
8. When the film is in the right place, push the bubbles out. Work from the inside out – I “sealed” the entire length of the crank first and then pushed the bubbles outwards towards the side of the crank, wrapping the tape over the edge of the cranks as I went.
9. If there’s a lot of water on the cranks at this stage and they are unbearable to work with, use the hair dryer again. Make sure not to get too close though otherwise you will melt the tape.
10. Push out any leftover air bubbles, otherwise find a needle and pop them as best you can.

It’s quite a simple job, it just takes patience and some preparation to do it well and easily. I’d say if you haven’t taped anything before to give yourself an hour to get the job done.

So there you have it, protecting crank arms from pedal rub is that easy!

Protecting Carbon Cranks Using Crank Boots

For anyone with carbon cranks, I recommend picking up a pair of RaceFace Carbon Crank Boots to protect with bad pedal strikes. These are an inexpensive investment in protecting carbon cranks when you consider the cost of high end cranksets.

The rubber crank boots simply slip over the end of the cranks and are held on by the pedal axle. It’s worth noting that pedals with an oversized inboard bearing won’t work with crank boots out of the box, you will need to enlarge the hole in the the crank boot. There are also crank boots for aluminium cranksets, but unless you are notorious with striking your pedals I personally wouldn’t bother.

So there you have it, protecting crank arms is cheap and easy – perfect for a rainy day while you’re waiting for other bike parts to arrive on a new bike build.