The compression cap is there to preload the crank To butt up against the bearings lightly (i.e. compress it all together) so they are in the correct position on the spindle. At this point you skipped a step where you should check for side to side play and only tighten the cap to the point that there is none. Then torque the bolts up. If you do up the cap tighter than is required to remove play, it'll push the arm up against the bearings too hard and your crank will not spin freely, resulting in bearings wearing out faster. It only needs to be done up to "4 in lbf", which is pretty much lightly finger tight with thumb and index finger, i.e. don't tighten as hard as in this video!

Good video - one thing for anyone watching, do not clamp your carbon frame…. It has a good chance of cracking under pressure. Always clamp  the work stand to the seat post!

This was better at explaining the process than a lot of professional videos.

I had play in the crank after regreasing the BB. With this video I worked out that it was as I'd put that little bolt pin you mention the wrong way round.  Daft as you can see the different hole sizes when you look at them.  Swopped it the right way round, reinstalled the dust cap then tightened the bolts in the order you explain and now zero wobble.  Many thanks, 9 years after you posted this!

I wasn't sure if a clip was holding in the drive side or not.10 year old tutorial is more informative than a Google search that directs me to an ai answer trying to sell me a new crankset.

Mate, thank you for the video. I have been trying to figure out this over past few days with no joy. And while looking and pulling things apart I actually threw away the plastic locating thingy from left crank arm. (Luckily I put it in recycling rather than the bin, so was easy to find again).  With your vid I was able to get done really quickly. Thanks again

The special tool I was able to go without. Because you explained that it shouldn't be too tight I was able to tap it around with a flat blade screwdriver and mallet on the knurled outer edge without damaging it. And did it up the same way.

Watching this six years later, and still useful.. so thank you.

I just put on a 4iii crank arm power meter, you're I used your video, you saved me the money at the bike store.  Only tool I had to buy was the bottom bracket tool that had the cap tightener on it, I needed one anyway so it wasn't a big deal 😎.

This video is Golden and concise. Thank you!!!
I'm here because i just bought a used bike, and while swapping out for a personal seat, the darn 'wedge piece' seatpost clamp fell into the frame and got wedged by the water cage hole. Need to take the bottom bracket out to fish it out...

Just got my first power meter. Very excited.

Just want to thank you for this video.  I built up a frame that, years later, broke - and couldn't remember the process of taking the GRX crankset I put on there back off.

Best and simplest instruction I’ve seen. Thanks. Now need to do it myself 😊

Thanks for posting, excellent tutorial. Tip: If you're replacing the crank like I did remove the pedals before you remove the crank, a lot easier when pedals still attach to it.

Thanks bro! I was able to change my crank with no issues. I didn’t have the special crank tool.. I used the butter knife trick and it worked for me. Salute!

I usually put my bike in the stand clamp on the seat post not the the frame

The cap is to preload the bearings. Once preloaded you tighten down the crankarm with the pinch bolts. In theory you then can even remove the cap. Same principle as ahead headset...

Thanks for this.  Was changing my bottom bracket and really wanted to ensure I was doing everything in the right order without ruining anything.

"what really holds the crank arm on is that cap.."
So, in other words, don't tighten down the non-drive side crank, and then spin the cap in/on. No wonder why my left crank was loosening up! Thank you! - AB in Santa Barbara, California and Sabah, Borneo

Thank you Clint. Fantastic. Just changed out some 175mm SLX cranks to 165mm on my Scott Spark

Marvellous, to the point, concise and points out the important things to consider. Thank you.