Crank Shorteners

[Hamish]

I have just bought a tandem to ride with my 7 year old daughter. Second hand Thorn Voyager in fantastic condition.

It is a small rather than childback with 160mm cranks. I am wondering if 160mm is too long and if so should I try using shorteners.

So questions-

- Is 160mm too long for a 7 year old of average height?

- Do shorteners work?

- If so which make - Thorn or Highpath for example?

-Do they make the whole thing a bit wide?

-Should I send the cranks for drilling instead?

I also posted this on the CTC site - appologies to those who read both!

Thanks

hamish

[ernie]

hi hamish, my daughter and i have a thorn discovery Large/Small. morag is an average sized 8 year old . we successfully traveled through laos before xmas averaging 80 km a day for 6 weeks. morags cranks are 155mm long .160mm may be a little long but i'm sure your daughter will grow into them really quickly, is she feeling any dicomfort from the cranks she is using ?what kind of distances are you hoping to cover and how often? personally i'd save myself the bother and stick with 160mm unless your daughter is complaining of pain.

[sireatalot]

The only way to be sure is to measure.
I wouldn't trust the internet for anything accurate, but this might help as a rough gauge of length:
http://www.highpath.net/highpath/cycles/shorteners.html#length
Look at how high the knees/thighs come up, it is generally easy to spot if the cranks are too long (or the saddle is too low).

[xpc316e]

My son is a rather short 10 year-old who is 4'5".  I have fitted Highpath shorteners and they are very useful.  I can easily change the crank length to suit my 5'0" partner, and keep them to fit on another bike - these two options wouldn't be possible with redrilling.