SRM crank swap

talenthound said:

Anyone ever swapped out a set of cranks on a SRM? Is this something that can be done at home or must it all go back to SRM for installation?

I've done it a number of times. All you need is the right size Torx head socket and a torque wrench. IIRC, the spec is 15 Nm, but you might want to double-check that to be sure. I can say that if you torque them to spec, you don't have to use Loctite (which some people recommend), whereas if you don't torque them to spec, they can come loose.

talenthound said:

Anyone ever swapped out a set of cranks on a SRM? Is this something that can be done at home or must it all go back to SRM for installation?

I assume you mean the square taper version with the three torx screws. The first time you do this it's hard. This is because they put loctite in the interface between the crank arm and the powermeter body. If it does not come out easily what they told me to do was to suspend the powermeter body between two blocks of wood (with as much support as possible for the powermeter body) and gently tap the crankarm part that juts out with a rubber mallet. The first time I did this I had to increase the strike force with each unsuccessful attempt and actually emailed them to verify I was doing it right, the successful attempt was pretty hard - YMMV. After this I never used loctite, never have the arm slip, always use a torque wrench and the crank arm pops right out when I need to change arms.

Woofer said:

I assume you mean the square taper version with the three torx screws. The first time you do this it's hard. This is because they put loctite in the interface between the crank arm and the powermeter body. If it does not come out easily what they told me to do was to suspend the powermeter body between two blocks of wood and gently tap the crankarm part that juts out with a rubber mallet. The first time I did this I had to increase the strike force with each unsuccessful attempt and actually emailed them to verify I was doing it right, the successful attempt was pretty hard - YMMV. After this I never used loctite, never have the arm slip, always use a torque wrench and the crank arm pops right out when I need to change arms.

Actually it is for a Cannondale's Hollogram proprietary bb and cranks. A splined bb interface if I'm not mistaken. I can't find any pics of how the SRM spider attaches to the crank arms to verify it is the same as other SRM's.

talenthound said:

Actually it is for a Cannondale's Hollogram proprietary bb and cranks. A splined bb interface if I'm not mistaken. I can't find any pics of how the SRM spider attaches to the crank arms to verify it is the same as other SRM's.

Ah, I will have to plead ignorance on this point.

If I get stuck, I usually contact SRM or the dealer I bought my SRM from and they are very helpful, once they start responding. 🙂

When you figure this out, post a picture. I'd just like to know for future reference.

Woofer said:

Ah, I will have to plead ignorance on this point.

If I get stuck, I usually contact SRM or the dealer I bought my SRM from and they are very helpful, once they start responding. 🙂

When you figure this out, post a picture. I'd just like to know for future reference.

Will do, thanks for replying.