Is it possible to change the lengths of bike cranks? ive had debilitating arthritis since I was five and whilst I was younger I enjoyed riding a bike. Unfortunately due to degradation of my hip and lower back joints I am unable to use bikes with long cranks as my hips and back don't allow for the upwards movement.

There is some rotation and upward movement within my hips and back still - I'm able to climb stairs just about for instance.

As I say, would it be possible to adjust the crank length? Would this need to be specialist or would my local second hand dealer be able to do this?

Any help would be greatly appreciated!

Thanks
Yes, you can change the length of the crank arms. If you are going to replace crank set, you need to make sure it is compatible with your frame. There are a number of different interfaces between the cranks and the bottom bracket.

Some common sizes are (many cranks will have the size stamped on the back of one or both of the arms):


165 mm
170 mm
175 mm


The size is the distance from the center of where the crank attaches to the bottom bracket to the center of the pedal axle.

If that is enough, you can just swap your crank set for different one. If not there are companies selling specialized shorter cranks or crank shortening devices 

Lastly, kids bicycles have much shorter cranks, maybe it would be possible to use some of them on an adult bicycle.