Need help on adding a throttle to an REI Co-op 1.1 bike

[gromike]

Well, power up your bike, hit the throttle, and see which way the wheel turns. If it turns backwards power down and plug the learning wires together. Power up and if the wheel turns smoothly the right way, power down and unplug the learning wires. If it doesn't turn right, repeat.
That's my experience, YMMV.

 

[Bob.A]

Time for an update. I had to return that controller as something failed and it would keep the light on as long as the battery was connected. I ordered another controller and that one seems to be behaving itself. I also ordered a 1 to 5 cable and that is what I am also using on this one. It has connections for the light and two brake inputs and a throttle and display. All seem to be working fine so I started to pull the old parts off the bike and put the new ones on.

The multi input cable was a bit bigger than the opening that the old cables went through so I had to break out my old pneumatic filer and open the hole up a bit. Since its an aluminum frame I'm not too worried about corrosion, but I'll do my best to seal it up.

I tried to mount the pas sensor on the inside of the locking ring which mostly worked, the magnetic pickup slightly bent, but when the magnet ring is on and the pedal is back on it is too tight to turn. Any idea of an alternate way to mount it?

I need to order an extension for the 9 pin motor connector. The one on the controller is just too short, but hopefully I'll have this done soon. Thanks for lookin.

 

[Bob.A]

Going back and forth with this, I think the only thing that will work is another crankset and a new BB. I measured the bike and its a 100mm BB and the chainring is 48t. There is no way to reuse the crank, it is a 2 piece affair, with the chainring sitting on an extended spline from the BB. I found some fairly inexpensive parts on Amazon that I think will work ok, and they should get here in a week or so.

This is the original torque sensing bb with the splined end:

 

[Bob.A]

Parts came in the other day. I was able to mount the new BB after I figured out which side is which and didnt cross thread it. The Pas sensor fit fine along with the new crank and arms.

It seems like this bike has quite a bit more wiring to deal with now. I had to buy an extension cable for the motor wire, the long wire off the Pas sensor, the 1 to 5 cable, you name it. The controller itself could probably fit inside the frame but I havent even tried to stuff the wiring in first yet.

I also looked at the brake levers and could not figure out how I was going to mount the switches and the magnets. The brakes are Tektro hydraulic so there was no swap of levers happening. But Google is your friend so I searched and found this:

It just so happens that I got myself a belated holiday present in the form of a Bambu Labs P1S printer. If you are new to 3d printing, Bambu is what you want. These machines are appliances, you set them up and just start printing stuff. The picture came from printables website so I downloaded the two parts and printed them last night while watching TV. It was late so I pulled them off this morning. I checked the fit and they should work great. I may have to reprint them in black so they match the hardware. but that is easy enough to do.

Total cost for this project so far is about 180 in parts. I didn't think it would have been this expensive, but if it allows her to keep riding the bike, its fine. I still think something like a Townie or Day6 with a mid drive would be a better bike or even putting a mid drive in this frame and swapping the rear wheel out would have been less of a hassle, but you work with what you have.

 

[Bob.A]

This will be the last post for posterity unless somebody has a question or two. Bike is finished. With all the extra wiring, there was no way I was going to stuff the controller back in the frame even though it was pretty much the same size as the original. With the new 1 to 5 cable, motor extension, PAS wire and power lines there was a bunch of wiring to stuff in and it just couldn't fit. So I opted to mount it in a box I 3d printed, hung off a thin strip of aluminum bar stock on two screws that conveniently were there for the taking.

3d printed the parts for the brake magnets which seem to work fine even though the magnet seems a but far away .

I had some black abs sheet kicking around from another project so I decided to enclose the opening and give it a bit more of a factory look. I also cut a small piece to cover up the opening and used some double stick tape to hold it down.

I made a cardboard template of the opening and cut two pieces on the bandsaw and used some stainless screws to hold either side on. Not perfect but it encloses the space and hides the messiness.

So I started this out thinking "how hard can it be?" The answer was much harder than it should have been. Between waiting on parts, having to send back the first controller for a different one, ordering more parts as I went along just to find I still needed something else like the motor extension cable. it took probably 3x as long as I originally estimated and came in about the same amount over what I thought I could do it for. Here is the parts list for anybody interested.

Controller with display 66
Pas sensor 23
1 to 5 cable 20
Throttle: freebie
Hydraulic brake sensors 20 + a 3d print
Motor extension cable 10
Different front light from the parts bin
Crank and bottom bracket 35
3d electrical box print and ABS no cost or nominal and was already on hand
Stainless screws (2 trips to the store) 9
Total spent on parts 188

No idea of total hours but probably somewhere between 12-15 if can guess accurately enough.

But it is done. I took it out for a very short ride two days ago and my face almost froze off. Been in the 20's since Sunday in SE VA and we are not used to it. I got the bike up to about 16 but have since upped the amps limit to 15 from a default of 11 so it may go a bit faster but I'm not going to try it out. She weighs a lot less than me so that should also factor in too.

Thanks for the help and following along.

 

[harryS]

I tried to mount the pas sensor on the inside of the locking ring which mostly worked, the magnetic pickup slightly bent, but when the magnet ring is on and the pedal is back on it is too tight to turn. Any idea of an alternate way to mount it?

View attachment 188169

Missed your earlier post. I recently had a similar issue where the pedal arm would rub against the PAS disk and press it against the sensor (same type of bracket). I ground off a lot of metal off the inside of the pedal arm to prevent that. Probably could have slipped some aluminum shims from a pop can into the square taper hole too, but that old Harbor Fright grinder still is a work horse.

Is this a 36V bike? How many amps is the controller. Should expect 18-20 mph on 36V on 500W, but who goes that fast. I know people who do, but I don't.

Congrats on a successfull controller swap!
.

 

[Bob.A]

Missed your earlier post. I recently had a similar issue where the pedal arm would rub against the PAS disk and press it against the sensor (same type of bracket). I ground off a lot of metal off the inside of the pedal arm to prevent that. Probably could have slipped some aluminum shims from a pop can into the square taper hole too, but that old Harbor Fright grinder still is a work horse.

Is this a 36V bike? How many amps is the controller. Should expect 18-20 mph on 36V on 500W, but who goes that fast. I know people who do, but I don't.

Congrats on a successfull controller swap!

Thanks. Its 36v but I think only a 250 or 350w motor. There may have been some other way to make that pas sensor fit and work involving removing metal, but I was probably in the how much more to I really want to F with this project mode. The new crank and BB did fix the issue in a very neat manner and I was trying to avoid giving it back to her looking very DIY.

In hindsight I might have saved a few bucks finding a package that had all the parts rather than having to get the extra cables and bits. But it still would have been somewhat north of 100. Some of the parts bought did get returned which was much easier dealing with Amazon then some other vendor. Fingers crossed that she doesn't have any problems with the new electronics since I now own all the issues that come with the upgrade.

 

[harryS]

In my case, I had been having problems with the Pedal Assist stopping because the magnet disks were slipping, They were rubbing on the sensor. After a few hundred miles, the friction caused the plastic splines to break and the disk to slip. I didn't see the issue til I had broken two disks,

A better fix would have been to remove the PAS sensor, and flatten the bracket to get more room, but that would have required more finesse. Easier to grind,