Hello, First time posting. Are there any hard fast rules for picking stoker crank length?
What info should one use. The stocker has never ridden much. We have just gotten her on a single with 172.5mm cranks. I could not say if she is a spinner. Thanks
A consideration on a tandem is what the stoker's preferred cadence is relative to the captain's. A shorter crank will tend to increase the preferred cadence and can be used in cases where the stoker would otherwise prefer to spin at a lower rate if both were using the same length cranks. Conversely a longer crank for the stoker can be used if they would otherwise prefer to spin faster.
But small differences in crank length aren't usually too critical. My single bikes have lengths of 170, 172.5, and 175 while our tandem is 165. I hardly notice the difference when switching back and forth.
Crank length is a matter of preference for the most part. Everyone is different and really it's hard to notice a difference. There are general rules people follow, but like all general rules, they apply the average rider. I use 165 cranks on my track bike and 172.5 on my road and tandem. I'm a former track sprinter and like to spin on the road and like my cadence over 100 as much as possible. My wife with a 30" inseam has 172.5 on the tandem and 170's on her road bike, however, she likes to pedal closer to 70. The easiest thing to do when we're riding together is use a little bigger gear for me to help slow things down on the straights and a little smaller on hills then she would like and we're both happy. Really, whatever the bike comes with will most likely work and I wouldn't put much more thought into it than that.
As for the amount of information out there... Try not to let it bother you. Get the best that you can afford and go out and have fun.
Last edited by buster110; 05-12-11 at 08:45 AM.
Reason: I suck at proof reading
650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport, Trek TX700,
For some people crank length is not that important. I agree that if the captain likes a higher cadence than the stoker then it is a good idea to have the stoker use shorter cranks than the captain. This will help the stoker and captain sync their cadences.
Some people do have problems with cranks that are too long. This is sometimes the case with people that have limited flexibility in their hips. Other physical issues also can cause problems. Any equipment changes that makes my stoker more comfortable on long rides seems like a good idea to me.
I suggest starting with inexpensive or stock cranks just in case you want to change later. Actually that is pretty good advice for buying a starter tandem. Hopefully both of you will love it and it will be your first tandem on which you can learn all sorts of things you want changed on your next tandem!
Your tandem will probably come with cranks and they will probably be 175mm front and 170mm rear. If your stoker rides 172.5mm on a single, she will probably be happy with 170mm (I'll be surprised if she can tell the difference). Make sure you are happy with fit all round. It's possible to change cranks later, but a full set of cranks is pretty expensive and relatively hard to find, especially in odd lengths, so best to test ride as much as you can.