Mounting Commuter Booster suggestions

*** changed title to reflect that it's a Commuter Booster friction drive, not Kepler drive (by yoyoman on 2017-07-27) **

I bought an older generation Kepler friction drive since the new gen would mount too far from the wheel on my Dahon Mu SL folding bike. It just arrived, and now I'm looking for advice on methods for mounting it on the kickstand plate. Ideas:

1) Any ideas on a stubby, solid tube about the size of a seat tube that could be drilled and mounted vertically with a bolt thru the kickstand plate into the solid tube. Then I'd use this solid tube as a fake seat tube and mount as usual. hmm, could this be 3d printed?

2) 1" x 3" block of wood that would be drilled thru the top for the bolt to mount to the kickstand plate. Then two holes would be drilled on the side for half of the original mounting system to screwed into the wood.

3) some sort of compression method where I'd put a plate under the two mounting pieces and drill a hole for a bolt to come from the bottom into the wide hole and out the kickstand plate. This seems like the easiest ...

yoyoman said:

I bought an older generation Kepler friction drive since the new gen would mount too far from the wheel on my Dahon Mu SL folding bike. It just arrived, and now I'm looking for advice on methods for mounting it on the kickstand plate.

Click to expand...

If that's like the one I have, I don't think it will operate as intended if you put it below the wheel; it's meant to kick onto the wheel from above via the motor's initial spinup, then grab the tire and dig in from there.

If so, then if you mount it below the wheel, you'll have to change the way the engagement works to either be always engaged or cable-operated to pull it onto the wheel.

This is the one I have
https://endless-sphere.com/forums/viewtopic.php?f=4&t=22026
that thread also has tips on mounting it for seatpost shims and such, if you need them.

It should work OK below the bottom bracket providing there is enough adjustment in the end stops. The torque reaction kick will work regardless of where the the drive is mounted. Keep in mind this drive wasn't designed for position you are looking to mount it in however if you can design a mount that complements the mounting position, you should be OK. I think a tube off the kick stand mount makes the most sense. Try and mimic the the geometry of have documented in this thread and you should be able to get it to work. https://endless-sphere.com/forums/viewtopic.php?f=31&t=86961

By the way, this drive is a Commuter Booster drive designed by AdrianSM. Unfortunately he no longer frequents this forum.

OK, I'm going to try a couple things. I got a dowel cut at Home Depot, so I will try a wood screw for this. I also found a coupler for a 3/4" pipe + some other cap like piece. Unfortunately, it's not flat on top, but there is a flat piece inside the cap where the nut can sit under.

The 2nd photo is something I also in the prototype lab at work. It looks like they 3D printed a pipe adapter plate. They had a steel version at Home Depot that was much larger and heavier. I wonder if I can ask them to 3D print a version for a 3/4" pipe ...

I didn't realize these motors were so heavy. I bought the motor, mount, esc all together from someone so I wasn't too picky about specs. I paid a lot for my 21lb folding bike, so I kind of want to keep everything else low in weight too ...

I proceeded with the wood dowel since it was the easiest. Commuter Booster is locked at a bad angle right now that hits the wheel, so I couldn't install it. I need to read posts about CB to figure out how to adjust the angle.

I am going to find a wider wood screw with more bite so I can worry a little less about the dowel ripping out. Since this mount has no bottom point, coming loose means falling off completely, some zipties to wrap around the mounting clamp and the kickstand plate will distribute some weight and at least keep the motor from falling onto the road.

I think a bolt&nut all the way thru, with fender washers large enough to completely overlap the whole hole in the stand mount and in the CB mount, would be a lot safer.

In my experience with wood and screws and single-point mounts for anything, simple vibration will rock the heavy (relative to wood and screw) CB back and forth enough to quickly wear the screw hole large enough to let the wood fall off of it. Or to rock teh screw loose out of it enough for the drive to spin around off the tire.

Some of the denser woods might take longer to ahve this happen, or might even not do it at all, but dowels are usually pretty light wood, and easy to deform.


Another issue is the screw head could just snap off, being slightly bent back and forth every time the drive moves around slightly (vibrations or engagement, or bumps on the road pushing the drive around via the tire).


The same issues could happen with plastic mounts.

I'll have to also figure out how to prevent the dowel or whatever I use from twisting. I'm thinking that I should glue it to some board that has rails that would surround the kickstand plate to prevent the board from twisting.

yoyoman said:

Commuter Booster is locked at a bad angle right now that hits the wheel, so I couldn't install it.

Click to expand...

I tried to adjust the bottom position of the motor, but it's already at it's lowest. Unfortunately, I still need it to be closer to vertical, and it can't go any farther.

So, now it looks like I'll have to build a small mounting board that will let me push the dowel back 1/4" to 1/2".

Hmm, or maybe I will, just for grins, try to mount that dowel at a slight angle away from the wheel by using the concave washer like things used to install v-brakes. I just want the joy of seeing everything working, and a more permanent solution can come later!

What gauge steel will not bend under the weight of a 2 pound motor? I am looking to buy a steel "angle", where one side would get bolted to the kickstand hole, and the bent portion is where one half of the CB mount would be mounted.

I also need to figure out how to prevent it from bouncing. Maybe I can zip tie the side closer to the wheel upwards to the end of the kickstand plate.