Electric 2021 Q45

[bret]

I have significant joint problems, so I can't just get stronger to keep riding. I have put a motor on my folding commuter, and now I'm going to do this with my Q45. I will get more exercise if I'm not daunted by hills or headwinds, or lousy weather while commuting. If I damage my joints anymore, I stop riding.

I bought one of the returned Q45s, and while I expected a 2019, I received a 2021 model. This presents some challenges - primarily the thru-axles. There is a wide selection of motors for a quick-release or bolted axle, but as far as I know, the only choice for thru-axles comes from Grin Technologies in Canada in the form of their own-design All-Axle hub motor.

I already used one of those for my folding commuter.

I received the slow-wind motor today, with a 26" rim. On my folding bicycle, I used the PAS 24 cadence sensor, and it's also not fixed there although it is a closer fit to the bottom bracket. But it's floating and works well there, so something like that will be what I manage here. I can also start with just the throttle.

I chose the 26" rim so I can mount 2"+ tires. The Q45 is the 'adventure' model, and I fully intend to ride on gravel and nice trails. I know the bicycle is not suited for air time.

I put the rotor on the wheel and mounted it to consider the fit. The disk rotor is millimetres away from the motor cable. The torque arm means there are 6 orientations. The first one I tried seems close to what Tortue described, and I can see why he relieved the edge of the swingarm.

I also tried the position that rotated the motor cable towards the front from there and I think I like that better. I'm thinking to have it go out and curve up and then bend forward at the top. I'll screw something into the mudguard mounting threads which are just forward of the axle to fix the cable so it is pulled upwards and remains several millimetres away from that disk.

Tortue added some pictures including his cable routing below.

With my approach, the stock thru-axle will not unscrew - the cable will block the arm. But I have already replaced the front axle with one from the Robert Axle Project which has the cones to fit my training stand, and I have one for the rear as well so I can mount a trailer hitch. Those are hex driven, so there won't be any interference from the cable.

You can get one for the rear that fits if you don't want a trailer hitch, too. The Robert Axle Project thinks it's a 100mm front wheel axle - nothing odd about it.

I'm going to have to do something about the seat pan - my bones are at the edge, and one hip joint is being very painful. I may get it widened, or research other solutions.

There is a business here which can make anything for bicycles - he fabricated the battery mount for my folding commuter. I didn't see a rectangular extrusion as Tortue described from my local hardware chain (Bunning's Warehouse) and I don't have space for any serious work so I may hand it to him. He can probably widen the seat pan as well, but there's some time before I'm ready for that, so I'll try moving the seat around first.

I have foamcore board and tape. I'll design the battery mount and work out the Phaserunner mounting.

Rain and rain this week (it's winter in Perth), so I wont be on the road soon. I'll contemplate that cable route. But it seems that it can fit together well, and that's nice to know.

 

[Tortue]

Bret,
My first attempt at the battery bracket was cobbled together with aluminum sheet, rivets and angle stock. After assembly, it was obvious that I could have used 2" X 3" aluminum tube, cut down to to fit. (A few additional holes added for cable management.)

Side View

 

[Tortue]

Another view of the bottom...

 

[Tortue]

View from the top showing rivets.

 

[Tortue]

Fuzzy shot of the motor wire exit (Sorry, tremors )

 

[Tortue]

Current handmade LG/MJ1, 8p-14s 30ah battery setup in 7s series configuration. The bags are large format, padded film carriers. $20ea from Bezo's little company. The frame is 1/8" aluminum sheet and various PETG 3d printed parts. The Phaserunner is zip tied to a 3d printed shelf between the battery mounts , along with a DC buck convertor that gives me USB power for lights, gps, phones and other toys.

 

[Tortue]

I added a passive cell monitor/balancer to each pack for maintenance. I don't use BMS's. I can' find one that works worth a damn.

 

[Tortue]

A shot of the battery mount from underneath with the 3d printed gussets/strap mounts. Someday I'll powder coat the aluminum. I've traveled 96 miles on this setup, without human power. I usually charge to 56v (85% ish) and manage 50 miles between charges. A beast!

 

[Tortue]

If you haven't yet, order the handlebar mounted rheostat. I use the handlebar mounted buttons to set power presets for trip longevity, and the rheostat for top speed and cruise control limits. Endless adjustment for speed/distance.

 

[bret]

@Tortue, you mention in another thread that you added a trailer, but I don't see the hitch attachment in your pictures. Can you say what you use?

 

[Mathew Fy]

I don't know how to mention someone in a post without using the quote feature. I'd like to know that.

@bret
Try writing the person’s name after the “at”symbol (@username). I think they’ll receive an email notifying that they were mentioned.

 

[Tortue]

Hey Bret.
I added a dog trailer to my prior T-50. I drilled a hole for the hitch post through the massive dropout gusset on the T-50. Worked great.
I've given thought to having a custom thru axle milled that would accommodate the hitch post on the right side of the Q-45.
But, as the pup hates the trailer, I haven't been motivated.

 

[bret]

@Tortue I'd like to see how you fixed the torque arm for your All-Axle motor.

 

[Tortue]

Not very elegantly I'm afraid.
There's no simple (or even complicated) effective mating surfaces to be had.
My first solution that worked was sliding a piece of heavy duty hose over the torque arm and drilling a 1/4" hole, just behind the included slot, and using three quality zip ties to hold it to the swing arm.
I've since graduated to a 3D printed block that accommodates the torque arm and the "sliver" of available flat aluminum on the top of the swing arm. I'm still using the 3 zip ties. The plan is to change them out if any of them shows any wear or stress.
As you've undoubtedly found, there's no easy solution due to the narrowness of the swing arm upper flat area and the minor offset of the torque arm.
I've made drawings of a solution that should work, but would entail drilling and tapping the swing arm flat.
I've been lazy I guess

 

[bret]

Not very elegantly I'm afraid.

In the States, I can buy hose clamps that are made of steel wire instead of a metal band - one of those would fit in the short space on the top of the swingarm between the threaded mounting boss and the weld at the top of the sloped plate. I can't find those here.

Grin uses a mount that attaches to such a mounting boss for eZee motors and Bafangs and such - but the angles on this mounting mean the push-pull of the torque will tend to unscrew the single screw and then the motor will pull it's own wire harness out.

I'm thinking of spanning the threaded boss right at the axle and the next one on top of the swingarm and attaching to that. I'll think about it.

 

[bret]

@Tortue

I chose the PAS24 sensor for this, as you say you did, and I used that as well for my Tern conversion. I didn't fasten the sensor on the Tern, and I think you said you left yours floating on your Q45 as it doesn't fit over the brackets that hold the chain stay to the bottom bracket on the end of the boom.

I am waiting for some parts to try mounting my torque arm and don't have my Q45 running yet, but I started having problems with surging on my Tern, and it seems to come from the floating sensor moving around randomly (but often). I taped it in place and the surge ceased. You may find the same problem at some point - this only occurred after a year of use.

I am thinking to attach the sensor to the face of the bottom bracket/clamps with some dots of removable silicon sealer. Any comment?

 

[Tortue]

Sounds like a great idea. Did you shave off the bottom bracket tab? Mine wouldn't fit the diameter of the Cruz bottom bracket.
In addition, I taped my signal wire down with a bit of extra length to create a partial loop in order to force the Pas24 to stay in one position. I just checked it and it doesn't move more tha a few millimeters between forward and back pedaling.

 

[bret]

@Tortue I've had some time now to look at the cable exit for the All-Axle motor. The photo you provided above seems to show that you have relieved both the swing arm at the bottom and also the motor hub itself where the cable exits to gain the clearance to hold the cable away from the rotating parts (brake rotor and mount). Can you confirm this - the greyish background is exposed metal on the motor hub where you removed some material?

Thanks.

 

[Tortue]

You are correct!
I relieved approximately 1.5mm from the inner circumference of the disk rotor. Bear in mind that all rotors have different inner diameters. Since the applied forces on the rotor screws are in line with the rotation, I wouldn't hesitate to remove even more material.
I also relieved the sharp edges left by my die grinder with a wire wheel.
I used a powered wire wheel to smooth the edges of the hub motor disk receiver face.
I removed approximately 2mm from the hub motor to make a flat where the cable exits. I also opened the outer insulation sheath and flattened the wiring with a bit of hot glue to hold the shape and recovered it with vulcanizing tape.
The wiring is still uncomfortably close, but so far hasn't become an issue.

 

[bret]

@Tortue
I flipped my torque arm - the load is borne by the lobes where the arm mates to the axle - rather than the mounting screws. I am replacing the screws with m3 button-head bolts.
I used epoxy putty to make a seat to fit the swing arm cross section - it's just a bonus that it looks like my bike is held together with chewing gum.

I arranged the shoe centered on the bottom of the swing arm, wrapped the swing arm in cling wrap, and then mashed the epoxy putty in place and rotated the arm so it seated. I made sure to leave thick putty across the bottom to join the sides so it would resist splitting, and I cleaned it up a bit once it hardened. But I want it plush so it is robust, so I didn't clean it up a lot.
https://photos.app.goo.gl/DBZVAMq2E4SgfRgs8