Mounting the 35A Controller Upgrade

[RiderDan]

If anyone's wondering how to install the 35A controller upgrade, there's a very simple solution using part of the stock mounting bracket.  Go to the hardware store and look for some generic stainless steel u-bolts.  What you're looking for specifically is the bar that the u-bolt inserts into.  The u-bolt itself can be tossed.  The ones I purchased are 2121xB with an inside diameter of 1-1/8".  Google search 2121xB and you'll find a ton.  You need two of them (make sure they have the bars!), four 8-32 1.75" long machine screws, and four 8-32 nylock nuts.

The mounting tabs of the controller are flimsy so we can't bolt directly to it without reinforcement, thus, the u-bolt bars.  Use the stock clamp from the original controller, put the 8-32 1.75" screws through the holes and place around the frame.  Now, insert the bar from the u-bolt on first!  This is what provides the reinforcement.  You'll want to insert a thin piece of rubber between the bar and the frame to prevent damage to the frame.  Next, mount the controller then the nylock nuts.  Tighten the nuts equally on both sides.  Done.

I wish I took pictures during the install to show the steps, but it's simple enough to figure out.  Just make sure you put the bar between the controller and the frame as that is what's providing the mounting reinforcement needed.  Attached are pics of the finished mount.

[Altema]

Excellent solution, and solves the problem of the mounting tabs on the controller being thin. Those concerned about marring the paint can always put a piece of weather stripping where the hardware contacts the frame.

[mwolff]

What model is that on?  I just installed the controller on my Radrunner Plus, placing it under the crankset where the original was.  The new controller is much bigger and I had to modify the wiring cable placement, and use a zip tie to fully secure it all........in a jury rig way, fugly.  Tomorrow I'll see if mounting on seat tube with the u-bolt as you did will work on my bike.

[RiderDan]

What model is that on?  I just installed the controller on my Radrunner Plus, placing it under the crankset where the original was.  The new controller is much bigger and I had to modify the wiring cable placement, and use a zip tie to fully secure it all........in a jury rig way, fugly.  Tomorrow I'll see if mounting on seat tube with the u-bolt as you did will work on my bike.

Sorry, I should have made that clear.  My installation is on a RadRover5 where the stock controller is installed on the seat tube.  I could re-use part of the stock mounting bracket  instead of using the actual u-bolt to go around the frame.  I just used the crossbar that came with the u-bolt to add reinforcement for the new controller, which has very soft metal.  For you, you might need the actual u-bolt sitting around the seat tube, in which case, you'll have to make sure you spec out the bolt diameter to fit around the frame as well as thin enough to slot through the holes on the controller.