Need help please

[faroeb]

Hello, I don't know if I am tripping or not but i feel like for the last week my bike is not running as smooth as it used to.
It kind of feels like there is a barely noticeable "bump" when pedalling once per turn. I am not sure anymore if it is normal and because I just noticed now am hyper focusing on it or not.
Is your bike running completely smooth or do you feel a bump once per turn?

Thanks in advance for any help and sorry for my poor english as it is not my first language!

[johnlvs2run]

That's a common issue with the C2 Bikeerg, see here. <-- This issue appears to be caused by the cranks coming loose due to C2's inferior crank attachment design consisting of a tiny screw on the end, and 2 small bolts held on only by pressure which eventually slide sideways and cause the thumping.

The method that works best for me is to put the screw in half way, hold the end with pliers, tap the crank to make sure it's on all the way, tighten the bolts, and then remove the screw. The screws don't help once the bolts are in, and I personally don't like how they extend the width of the crank. I use longer pliers on the end of the allen wrench to make sure the bolts are as tight as possible.

Switching to the widely used traditional tapered square spindles <-- would be far superior and would eliminate that issue. The tapered square spindles are used with cotterless cranks, which allows the use of superior cranks of different sizes and designs. Currently only C2's steel forged cranks can be used and are limited to a 170mm length.

[faroeb]

That's a common issue with the C2 Bikeerg, see here. <-- This issue appears to be caused by the cranks coming loose due to C2's inferior crank attachment design consisting of a tiny screw on the end, and 2 small bolts held on only by pressure which eventually slide sideways and cause the thumping.

The method that works best for me is to put the screw in half way, hold the end with pliers, tap the crank to make sure it's on all the way, tighten the bolts, and then remove the screw. The screws don't help once the bolts are in, and I personally don't like how they extend the width of the crank. I use longer pliers on the end of the allen wrench to make sure the bolts are as tight as possible.

Switching to the widely used traditional tapered square spindles <-- would be far superior and would eliminate that issue. The tapered square spindles are used with cotterless cranks, which allows the use of superior cranks of different sizes and designs. Currently only C2's steel forged cranks can be used and are limited to a 170mm length.

Thank you for your fast reply and help! You were correct, tightening one of the screws fixed it!

[johnlvs2run]

Thank you for your fast reply and help! You were correct, tightening one of the screws fixed it!

You're quite welcome. I'm glad you got it resolved right away.