Bullet proofing that axle!
The rear axle is in and ready. I’ve used this setup before and it has shown to be very strong and dependable. A 42 long x1” Azusa axle with ¾ step downs on the ends, using BMI # 400249 sprocket hubs, BMI # 400110 locking collars, modified yerf wheel hubs, stock sprocket and brake rotors. I took pics of the assembly process but for some reason the pics came out too dark to see any detail so all I got is the finished product.
I’m not real crazy about those sprocket hubs. I chose these because they were small, compact, light and had the correct bolt pattern for the yerf sprocket and rotors. When starting the assembly I discovered these hubs were bored slightly under size and need to be bored out to fit the Azusa axle. The flange was not welded square on to the center so that resulted in some run out and wobble of the sprocket and rotors. It required some filing on the mounting face and juggling with the bolt tightening sequence to get the wobble and run out down to an acceptable level. When I strip it down to paint I’ll chock these up in a lathe to true up the mounting surfaces.
The white you see is SCD40 PVC 1” pipe cut to fit between all the hubs and bearings. This pipe serves for several reasons. It is a spacer to help kit the hubs positioned where they won’t slip up and down the axle. The pipe protects the surface od the axle from nicks and dings that make it real tough to ever remove the axle and the pipes holds the bearing square with the axle . The way these bearing are shaped to fit the flangettes, the bearings can get cocked out of square while tightening the flangettes thus causing a bind on the axle. This bind creates rolling resistance and robs horsepower. The square cut ends on the PVC hold the bearing straight and aligned. Once every thing is slid on the axle, tightening on the axle end nuts squeezes everything tight together so the whole unit can be dropped into the hangers and bolted in place. The axle spins true and free.
I also made up a bracket to hold the speed sensor for the TrailTech. I use one of the brake rotors, to mount the magnetic bolt and placed the bracket to align the pickup. Last time I installed a Trailtech I used the formula in the instructions to calibrate the speed and it worked pretty well.
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