Shorter Crank Arms??

markshaw77

Hi All

I'll start with a quick sob story (bear with me!)...back in August, I ordered a new bike ( ) - a Specialized Sirrus Comp - via the C2W scheme. Unfortunately, 3 days later, I slipped while out with the kids and badly tore the cartilage in my right knee ( ). I have had surgery to repair it, so am currently in v. light rehab after 6 weeks of limited weight bearing and flexion.

This week, I got back on the bike (mounted on the turbo) and started to turn the pedals again with virtually no resistance, but my knee is still sore at the top of the pedalstroke - the point where it is most bent.

I have already lifted the saddle to the point where I can barely reach the bottom of the stroke, but I was wondering if there was anything else I could do to limit the flexion in my knee.

Is it possible to get some shorter crank arms to further shorten the "rise and fall" of the stroke?

If so, what do I need to look out for and where can I get some?

it would only be a short term measure, so if it is going to cost a fortune, I will probably work on some stretches etc before trying the bike again, but if I can do this cheaply/easily I would like to give it a go.

Thanks in advance for any advice....

redvee

I guess you've got a 170mm chainset on the bike, shimano used to/may still do a 165mm chainset but only in the higher end stuff. Another option is to try Highpath Engineering.

cjcp

markshaw77 wrote:

I have already lifted the saddle to the point where I can barely reach the bottom of the stroke,

I wouldn't have thought this will do your knee any good; you risk over extending the leg. I also wouldn't have thought that 5mm less of length in the crank arm will remedy the problem. I'd check with a physio.

roger_merriman

i'd 2nd the physio you really don't want to risk your knee.

markshaw77

Thanks guys

@CJCP - extension is really not a problem at all, but I agree with you that only 5mm difference in the crank length is not going to make much difference

I found a variety of crank shorteners on the internet which are typically used for kids riding tandem bikes with adults, but to get any meaningful reduction in length, I am looking at £60+ a piece so probably not worth it for now.

I was given the green light by my consultant, so I'm not too worried, but I am due at the physio next week, so will probably just hold off until then

Still, the urge to ride my shiny new bike after having it sit there beaming at me for 3 months is getting pretty unbearable, so we will see how strong my patience is!!
:twisted: :twisted: :twisted:

greg66_tri_v2.0

Jeez, that sounds bad, but how badly did you tear your cartlidge and now invasive was the op?

I did my right one when I was 20. I waited 18 months for an op and it took almost as long to regain full motion in it - tendons and ligaments shorten if not exercised and take a while to lengthen.

I did the left one with a twist whilst skiing when I was in my mid 20s. I got back to England on the Sunday, had an op on the Thursday, was riding a bike (ok - swinging the knee out and pelvis up) the following Monday and skiing bumps 7 days after that (although that's better than it sounds; contrary to popular myth skiing bumps properly doesn't hammer your knees that much).

The point is that with the second one I had the second ski trip booked and no insurance to cover it if I cancelled, so I had to get it back to working in a short time frame.

I guess if it's a really bad tear then things are going to be different. But as a rule of thumb I'd say doing most things to mobilise it are going to hurt to begin with. The thing I was told was to do as much as I thought I could: if it was too much the whole knee would swell like a balloon (which it didn't). Just remember little and often is better than a lot without a break, and punctuate with rest, ice and elevation.

Good luck.

markshaw77

Thanks for the advice and best wishes G66

Sadly things took a bit of a turn for the worse over the weekend when the cartilage tore again :twisted: :twisted: :twisted:
Not as bad as before, but not good!!

I originally had a couple of small tears as a teenager which healed with rest (as directed by consultant), but this time I went for the full monty!!

I had a "displaced bucket handle" tear on the medial side and the displaced "loop" got wedged underneath my thigh bone which locked my knee at about 30 degrees short of straight :shock: :shock:

I had an arthroscopy (keyhole) and then pushed the loop back and stitched it in place to heal - hence the 6 weeks limited weight bearing and flexion to avoid pulling the stitches out. They didn't want to remove it as it was such a large tear (about 2/3 of the circumference of the cartilage) that I would have been pretty much guaranteed arthritis in later years.

But, having done this again over the weekend, I am back to see the consultant on Thursday to figure out whether it is more rest or more surgery. Just what I need ahead of Xmas :x :x :x

BTW, how long before my shiny new bike begins to rust in my garage?!?
Anyone volunteer to ride it for me :?: :?: :?:

cjcp

Unlucky mate. Hope you make a quick receovery.