Got long legs and can’t seem to use all your power with standard 180mm (or shorter) crank arms? Order a set of Zinn custom extra long cranks and get that extra power you’re looking for. It only makes sense that your cranks should be proportional to your legs, not a length designed for somebody a lot shorter than you! Our extra-long cranks are available with a maximum length of 220mm and are specifically beefed up for bigger riders. You won’t believe the difference they make!

Custom Extra Short Cranks

Or, got short legs and have trouble getting your legs around with your standard 165mm or 170mm crank arms? Order a set of Zinn custom extra short cranks and get that extra comfort, efficiency and smooth spin you’re looking for. It only makes sense that your cranks should be proportional to your legs, not a length designed for somebody a lot taller than you! Our extra-short cranks are available with a minimum length of 130mm. You won’t believe the difference they make!

Proportional Crank Length

No other conclusion makes sense to me. Muscles and joints work most effectively when operating in a certain range of motion. Short riders should not be required to force their muscles through a greater range of motion than the person with an 80cm inseam riding a 172.5mm crank. And on the other end, 7-foot basketball players do not bend their legs any less when they jump than shorter players. So why should they use minimal knee bend and operate their muscles only through a tiny part of their range when they ride a bike?Your legs turning the cranks is what propels you along on your bike, it’s your motor. Proper crank length is crucial to achieve maximum efficiency in your “motor”. Therefore, crank length is one of the most important aspects of bike fit. It’s not enough to just scale the frame geometry to fit a rider. Crank length must also be adjusted, and Zinn Cycles is one of the only manufacturers in the world that makes cranks outside of the standard 170 – 180mm range.

What length?

Here is an interesting report and study on crank length by Dr. Martin: http://bicyclecranklength.blogspot.com/

Your ideal crank length is in the range of 21% – 21.6% of your leg length. Start by measuring your inseam with your feet 2″ apart. Be sure to measure all the way to the pubic bone. Convert your inseam measurement to millimeters and multiply by .216 and also by .21. This will give you a range of crank length that is appropriate for you.

Once you begin riding your custom cranks, your legs will be pedaling at a more natural range of motion. This allows you to use your leg muscles to their full potential. After a short adjustment period, the new crank length will begin to feel more natural. The vast majority of our customers have reported increased power, easier and faster climbing, decreased times on local rides, less fatigue, less joint pain, and overall performance increases when they went to the proportional length crank.

Check out our newest cranks,  the long awaited Zinn-tegrated custom cranks are here! Zinn-tegrated custom cranks are designed with an integrated spindle and external bearings, and compete in stiffness to any high end crank in the industry. Lighter and stronger than our square taper model and available in sizes 190mm to 215mm, the Zinn-tegrated custom cranks are the most high performance crank for the big and tall rider available. These are 100% handmade in the USA with American materials. The custom machined finish is unique and beautiful and shows the high quality craftsmanship that is put into every single crankset. Currently available in 130BCD doubles and 110BCD compacts.

These are custom made products. There may be a lead time. We usually have stock of many sizes, but not always. If an item you order is out of stock, we will notify you of the estimated turnaround time. Email us for availability information.