'lightest.bike' 1.7kg 1000w mid drive
- Thread starter Grantmac
- Start date
Q: Bikee is delivering the parts needed for dual-chainring with external PAS?
Yes. I have them.
Q: The necessary firmware update can now be done via the app?
I'm told this is the case but haven't attempted it yet.
Q: The final solution for dual-chainring ended up being simple cadence-based PAS?
Yeah, i received a sensor that looks very similar to what's pictured. It easily spins and seems to have no torque sensing ability.
Q: Will external torque sensing be supported or not? Is this being worked on?
No idea. I'm primarily interested in using the throttle, so haven't investigated. It's a good question though.
The dual chainring configuration is definitely a compromise where you can exceed the fitment capabilities of every other mid drive but lose a few % efficiency/power ( because of added chain/gear friction ) and torque sensing PAS in the process.
Yes. I have them.
Q: The necessary firmware update can now be done via the app?
I'm told this is the case but haven't attempted it yet.
Q: The final solution for dual-chainring ended up being simple cadence-based PAS?
Yeah, i received a sensor that looks very similar to what's pictured. It easily spins and seems to have no torque sensing ability.
Q: Will external torque sensing be supported or not? Is this being worked on?
No idea. I'm primarily interested in using the throttle, so haven't investigated. It's a good question though.
The dual chainring configuration is definitely a compromise where you can exceed the fitment capabilities of every other mid drive but lose a few % efficiency/power ( because of added chain/gear friction ) and torque sensing PAS in the process.
Last edited:
I played with mounting the lightest on the maxarya today. Mounting it on the front BB is ends up looking funky no matter if i use the inframe mount or medium mount. We also have the chainring on the opposite side as usual, so that complicates things.
The middle BB really seems like the way to go. It keeps the drive side where bikee intended. The inframe or mid mount will work, and it looks good.
I can fit as small as 20T or as big as 62T, maybe even bigger with this inframe mount, so i think it's possible to adjust the gearing to have a 37mph top speed. Ebikes.ca sim says on a semi recumbent, we need 1000w to do 36mph.. so this should easily be within the capabilities of the motor.
More on This later!
The middle BB really seems like the way to go. It keeps the drive side where bikee intended. The inframe or mid mount will work, and it looks good.
I can fit as small as 20T or as big as 62T, maybe even bigger with this inframe mount, so i think it's possible to adjust the gearing to have a 37mph top speed. Ebikes.ca sim says on a semi recumbent, we need 1000w to do 36mph.. so this should easily be within the capabilities of the motor.
A couple notes. from fitting on a 68mm BB recumbent with two bottom brackets.
To make the freewheel work, you are going to have to install the chainring either on the front drive pedal or middle bottom bracket.
In my case, this creates a problem. The freewheeling crankset uses 104MM BCD ( 32T lowest ) whereas my original sprocket is 22T, this would force me to run a larger sprocket size on the front, which i'd like to avoid to minimize added chain friction.
The bicycle uses a long yih freewheel, so i'm thinking that it can just take a normal bicycle freewheel, yeah?
If that's the case then i could put a 22T BMX chainwheel on, and cut this pedal down to a nub to function as a gear holder... and keep the original ratios.
To make the freewheel work, you are going to have to install the chainring either on the front drive pedal or middle bottom bracket.
In my case, this creates a problem. The freewheeling crankset uses 104MM BCD ( 32T lowest ) whereas my original sprocket is 22T, this would force me to run a larger sprocket size on the front, which i'd like to avoid to minimize added chain friction.
The bicycle uses a long yih freewheel, so i'm thinking that it can just take a normal bicycle freewheel, yeah?
If that's the case then i could put a 22T BMX chainwheel on, and cut this pedal down to a nub to function as a gear holder... and keep the original ratios.
Some notes on the wobble of the cranks that come with the kit...
The problem is in the machining of the square taper crank itself.
Without using the included spacers, the amount of wobble motion is 3-4mm; probably bad enough to make chain tensioners and derailleurs angry.
With the correct amount of spacers - just enough to notice a good amount of tension as you're bolting down the crank, we get 1-2mm of motion, which isn't too bad.
You could get some generic ebike kit cranks and replace these stock units if you like. It looks like standard threading here.
The problem is in the machining of the square taper crank itself.
Without using the included spacers, the amount of wobble motion is 3-4mm; probably bad enough to make chain tensioners and derailleurs angry.
With the correct amount of spacers - just enough to notice a good amount of tension as you're bolting down the crank, we get 1-2mm of motion, which isn't too bad.
You could get some generic ebike kit cranks and replace these stock units if you like. It looks like standard threading here.
Chalo
100 TW
+1 haha
Is it really a problem in practice? with the spacers, would it work on a regular upright bike even if it's iffy?
Luckily we are using bike parts across the board, so..
Freewheel crank - $56 shipped
Surely other makers of this exist which produce ones that fit square or ISIS tapers.
I think it will be allright on my bike even if not ideal.
Luckily we are using bike parts across the board, so..
Freewheel crank - $56 shipped
Surely other makers of this exist which produce ones that fit square or ISIS tapers.
I think it will be allright on my bike even if not ideal.
bedesign
10 mW
Chainwheel wobble
-------------------------------
I have also been struggling with this chain wheel wobble and found a
(patient demanding) solution that brought it down to less than 0.5mm.
It is caused by the crank arms outer threads not
being parallel with the square hole.
First, fixating in a vise helps -
Correction can be made by manually grinding the square hole surfaces
to 50% of their axial depths, just until the eloxation layer is removed
at the inner and outer and top and bottom opposite sides.
After that, an additional fine improvement can be found by simply turning
the axle 90° and mounting at all the 4 possible corners.
As I realise this method description is not very precise,
I could make a sketch when someone asks.
(with a critical application like this, the machining of the
hole should perhaps have been made after the eloxation)?
Fix for rrrr grrr and other motor? noice
----------------------------------------
It looks like the torque sensor arm was developed/tested
with a ≥ 9 geared bike with chain widths from 5 to 6.5 mm.
A 6 to 8 geared chain width of 7.45 to 7.8 mm will touch the sensor
arm and grind it, depending on ev. chims are used or not.
- and now over to Chalo for an even dryer comment
There's about 0.5mm of radial motion in my spline to cog interface. It was otherwise very tight. Tolerances are similar to what i've seen with splines like these.
Luckily we are not doing regen here, so that 0.5mm of motion isn't so much back and forth, and there are tons of little splines to take the load in unison. I think it'll be allright.
Luckily we are not doing regen here, so that 0.5mm of motion isn't so much back and forth, and there are tons of little splines to take the load in unison. I think it'll be allright.
Last edited:
bedesign
10 mW
My pinion gear is a solid fit, no play at all -
have you checked the seger position?
On my side..
I have a $15 170mm threaded crankset, a 22T ACS freewheel, and BMX freewheel puller on order.
Fingers crossed that this is the last round of buying parts
I have a $15 170mm threaded crankset, a 22T ACS freewheel, and BMX freewheel puller on order.
Fingers crossed that this is the last round of buying parts
Another option for freewheeling cranks... white industries makes an ebike specific freewheel.. expensive but should be very strong.
White ENO front freewheel mod.
White ENO front freewheel mod.
I have now innstalled my 1000w high torque kit on my bike.
I am quite impressed of this motor so far. It is very pulls very strongly and the torque sensing is very nice too. I have not ridden it very much yet but I really like it.
The noise level is not bad, and the pitch doesn't annoy me.
It's much better noise vise than my cyc x1 stealth gen 1 that was on my old bike. Torque sensing is also better.
And the power at pedal assist is somewhat better because torque is better at low rpm. But trotteling at higher rpm the stealth is more powerful.
I saw in the Facebook group a comment that changes have been done with the latest batch of motors to improve noise. I don't know if this is true but I am satisfied with mine.
I am quite impressed of this motor so far. It is very pulls very strongly and the torque sensing is very nice too. I have not ridden it very much yet but I really like it.
The noise level is not bad, and the pitch doesn't annoy me.
It's much better noise vise than my cyc x1 stealth gen 1 that was on my old bike. Torque sensing is also better.
And the power at pedal assist is somewhat better because torque is better at low rpm. But trotteling at higher rpm the stealth is more powerful.
I saw in the Facebook group a comment that changes have been done with the latest batch of motors to improve noise. I don't know if this is true but I am satisfied with mine.
I wish we got some communication on that here, thanks for passing it on.
How's the cranks? do they have wobble like ours?
Last edited:
