Which pedal is reverse threaded

Most pedals like our reliable Thump flat pedals require a pedal wrench, which is a long, thin tool specifically designed to fit the external spindle flats between the pedal and the crank leg fig. Even though you might already have a regular wrench that fits, a good pedal wrench is not terribly expensive and will save you from a lot of frustration and possibly some bloody knuckles. If you are upgrading to high-end pedals like our premium Trail pedals , you will most likely just need an appropriately sized hex key , which fits the spindle from the inside of the crank leg fig.

We also recommend having an adjustable torque wrench and bike grease on hand. Now you should be all set to go! First Name. Last Name. Email Address. Have an account? Sign in Email Address. Did every bike manufacturer get this wrong?!? Of course not, and the real answer blew my mind. It is not, not mind you, because of the effective unscrewing force from the non-zero friction of the ball bearings.

Instead, it is an effect that works in the opposite direction in this case : mechanical precession :. The direction of rotation of the inner part is opposite to the direction of rotation of the radial force.

I picture it like a pencil in a toilet-paper tube: crank the end of the pencil around, and there is a force that wants it to rotate on its long axis from friction with the wall of the tube. The screwing force from precession on a reverse-thread on the right pedal is much stronger than the unscrewing force from friction of ball bearings, so bike manufacturers ignore the latter. RSS feed for comments on this post.

TrackBack URI. Comment by sam — April 18, Another place where gyroscopic precession pops up is in aviation. The precession of spinning gyro-based instruments used in flight in the clouds requires the pilot to occasionally reset them to other indicators. The directional gyro for instance which is basically a steady copy of a compass will precess up to 10 degrees or more per hour. So occasionally as you are flying along you have to reset the direction to the compass heading.

Comment by Austin Blanco — April 28, The elliptical path generated by the rather insignificant space between the mated parts would only serve to allow the effects of cumulative rotation to eventually separate the parts, hence the need for left and right threaded pedals. Just my 2 cents worth…. Comment by Dave — January 22, Comment by Geert — May 30, I wrote to Huffy and they told me this is the industry standard in pedal design..

How freaking hard is it to turn the thread around on the left pedal? Comment by avemaria — April 28, Fuck that stupid ass design…. See image at top if in doubt. If pedal is difficult to thread into arm, or if the threads in the crank are damaged, there may be some repair possible by chasing them with a tap.

Taps will align damaged threads, but will not restore metal that is simply removed. If no threads are left, have a professional mechanic install a pedal bushing kit. Pedals bearing may be serviceable depending upon the manufacturer and model of pedal. Some pedals use adjustable cup type ball bearing system, and may be cleaned, greased, and adjusted.

Service tools are proprietary to each brand. Some pedal models are not intended to be serviced, and are simply ridden until the pedal wears out. Pedal bearing service is typically best left to professional mechanics.

Pedal bodies often are made with small screws and bolts. These screws hold together the cage and mounting plates. Occasionally check that these fasteners and the cleats on your riding shoes are tight.

Additionally, lubricate the pivot points on clipless type pedal systems.