The Crank Arm Shortener from Ortho Pedal™ provides adjustable crank length for cyclists with limited knee or hip range of motion or those who struggle with knee pain and discomfort caused by longer cranks. There are four different pedal settings available, which can reduce crank length by 24mm, 41 mm, 59 mm or 76 mm. Reduced crank length or shorter cranks can be beneficial for cyclists beyond those who require it as part of rehabilitation.
Crank Arm Shortener Features and Benefits
- Manufactured in the USA from high-grade aluminum alloy into an attractive shape that easily bolts onto your existing bicycle crank.
- Handcrafted stainless steel bolts provide strength and durability
- Unlike other bolt-on products, the Crank Arm Shortener from Ortho Pedal will not mar or damage cranks
- Initially constructed as a recovery and orthopedic device but can be applied to adapt crank length easily compared with replacing an entire bicycle crank
- Crank arm length can be adjusted as range of motion increases during a recovery process
- Useful for cyclists with short inseams (under 80cm) who would benefit from turning a smaller radius to resolve or prevent knee pain.
- Pivotal for cyclists with limited lower limb range of motion due to injury or surgery
- Reduces stress on the knees and hips
- May reduce pain or discomfort
- Installs in 10 minutes
Standard: This model fits cranks from 5/8″ wide to 1-1/8″ wide. This typically applies to steel cranks and “older style” aluminum cranks.
Wide: This model fits cranks over 1-1/8″ wide to 1-3/4″ wide. This typically applies to “new style” aluminum cranks.
NOTE 1: If your pedals are an older style with flats requiring a pedal wrench for removal and installation, you will need a pedal wrench to move your pedals from your existing crank arms onto the crank arm shorteners.
NOTE 2: If you have an older style stationary exercise bike or kids bike, it may have pedals with 1/2″ axles which is smaller than standard. To connect the crank shortener to your existing crank you will need the optional 1/2 bolt (1 per side), available here.
- Standard 9/16″ pedal axle holes
- Suitable for use on regular bicycles, e-bikes, and indoor exercise bikes such as the Peloton bike
NOTE 3: The use of this product will increase the stance width of the cyclist, equivalent to the width of the crank arm on each side.
What’s in the Box?
- Set includes both left and right-side adapters and hex wrenches for installation and adjustment.
- Click here for Orthopedal installation instructions
- The Standard model weighs approximately 265 grams (per set)
- The Wide model weighs approximately 295 grams (per set)
- Reduces crank length by 24mm, 41 mm, 59 mm or 76 mm
- Standard 9/16″ pedal axle holes
Original Development and Why it Helps with Rehabilitation
The Ortho Pedal™ (Crank Arm Shortener) solves a problem many people with arthritis cope with, or people who have had knee surgery experience: the inability to ride a bicycle due to limited range of motion. The problem is solved by reducing the amount of knee bending required, which is achieved by moving the pedals closer to the crank. A smaller circle requires less motion and this can allow people with knee pain to exercise within their tolerance range of motion more effectively while providing a cardio workout! Crank arm shorteners typically fit people with range limitations down to 60 degrees of flexion and 20 degrees of extension. Many people who are planning to have Total Knee Replacement Surgery order them in advance to be ready to use when they come home after surgery. There are many other uses including physical disabilities, adolescent racers, adaptive sports participants, etc…
High quality.perfect fit.easy to install.now I am able to pedal my bike with my limited knee range of motion.
Works great so I can ride shortly after hip replacement.
Does not work well for curved crank. Set screws do not engage with crank.
Crank shortener is a quality product but price is a bit high. Installed on a pair of 170mm cranks I was able to verify that I would easily adjust to a much shorter crankset without having to disassemble the 170mm set. I ultimately bought a 152mm triple crankset made by SR Suntour for only $30 new. I was glad to be able to confirm that size would work for me before buying the new set and having to replace the bottom bracket to test it.
Product works great on my Schwinn exercise recumbent bike. No complaints!