Exciting! Can you point me in the direction of where technical details live? Curious about q-factor and symmetry between cranks.
PaulD's lightweight mid drive development
- Thread starter PaulD
- Start date
PaulD
1 kW
Q-factor is about 180mm for a 73mm BB. Q-factor for a 68mm BB is about 175mm. Offset is 3mm towards the driveside. If you use an extra pedal washer or two on the non-drive side that would be pretty close to symmetrical. More info is here: Mid drive kit — Revel Propulsion Ebike Mid Drive Conversion Kits
Interesting!
I noticed on the website you mention a lower Q factor pedal or bb or something..
I was wondering if the Q factor improved, if so by how much.
The lightest.bike mid drive can go all the way down to 122mm x 68mm bottom bracket and has even pedal spacing. So basically, the same spacing on a 7 speed mountain bike.
I don't expect it to be as good as lightest, because of how the drive mechanism is set up here. But i'm looking for something better than a BBS02.
I noticed on the website you mention a lower Q factor pedal or bb or something..
I was wondering if the Q factor improved, if so by how much.
The lightest.bike mid drive can go all the way down to 122mm x 68mm bottom bracket and has even pedal spacing. So basically, the same spacing on a 7 speed mountain bike.
I don't expect it to be as good as lightest, because of how the drive mechanism is set up here. But i'm looking for something better than a BBS02.
Oh wow, the total Q factor on a regular mountain bike is 170mm, so 180mm with 3mm of offset is great!
Two Q's:
- What's the price of a kit w/o battery, and will it operate on either 48v or 52v batteries?
- Any additional hot rod capability in it, or is the ~650w the thermal stasis point? or will your lawyer not allow you to comment..
Two Q's:
- What's the price of a kit w/o battery, and will it operate on either 48v or 52v batteries?
- Any additional hot rod capability in it, or is the ~650w the thermal stasis point? or will your lawyer not allow you to comment..
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PaulD
1 kW
122mm must be the BB spindle length, not the q-factor. Even pure road bikes have 150mm+ q-factor. You need to add the offset from the crank arms.
At this time, the numbers I mentioned above are the only option. This is limited by the torque sensing BB.
PaulD
1 kW
- I'll have an update with new pricing in the next few months. And only 36V batteries are compatible. Higher voltages result in motor and crank speeds that are too high.- What's the price of a kit w/o battery, and will it operate on either 48v or 52v batteries?
- Any additional hot rod capability in it, or is the ~650w the thermal stasis point? or will your lawyer not allow you to comment..
- No hot rodding allowed
There isn't much thermal overhead, and with a small battery more power is just going to drain your pack too quickly. This kit is intended to add minimal weight and that means it intended for small batteries. I am even considering reducing the peak power a bit to move this more inline with the latest generation of lightweight EMTB motors. Although 650W is nice with a fully loaded cargo bike. I have about 3000 miles (between my wife and I) on a kit on a 80lb Yuba long tail, usually with a kid on the back. This kit is aimed more at people who don't mind pedaling. There is no longer a throttle option. If you want a kit that converts your bike into a lightweight motorcycle, there are lots of options out there.
What a bummer. I actually pedal a ton, but i need more power because there's mountains to climb and couple mile 35mph sprints across roads with traffic that have no bike lane to do. I also have very high rolling resistance tires due to a goathead protection layer necessitated by the locale ( high desert ) . These two factors combined mean i need 1200w of power, and another 300w at the leg ( doable for short periods of time )
Non compatibility with 48v batteries is a bummer because the largest and most common batteries come in that voltage. I like a light motor and a huge battery.
Anyway, good luck.
Non compatibility with 48v batteries is a bummer because the largest and most common batteries come in that voltage. I like a light motor and a huge battery.
Anyway, good luck.
The q-factor specs are impressive. I also like the commitment to weight. A bump to 48v would upset the balance, you think? Will this me batch be a v4 with new features/improvements or another v3 batch?- I'll have an update with new pricing in the next few months. And only 36V batteries are compatible. Higher voltages result in motor and crank speeds that are too high.
- No hot rodding allowed
This kit is aimed more at people who don't mind pedaling. There is no longer a throttle option. If you want a kit that converts your bike into a lightweight motorcycle, there are lots of options out there.
I wonder about crank lengths as well. I prefer shorter cranks, 155mm, will that be an option or will it be compatible with off the shelf cranks?
PaulD
1 kW
Going to 48V would increase the crank/motor speed by 33%. That is more than it is designed for. V4 will be very similar to V3.
Off the shelf low offset JIS square taper ebike cranks are compatible. Miranda makes 155mm i believe.
PaulD
1 kW
Just a heads up that I have a new batch of kits available. Minimal changes with this batch. Mostly just improvements on our in house testing on the Erider torque sensors to weed out any faulty ones. Some of them have an issue that only creeps up after 10-15 minutes of riding, so we now have a test bench that runs them for 15 minutes and ensures there isn't significant drift in the torque readings.
Since we are not producing more batteries (for insurance reasons), batteries are only available with kits now.
www.revelpropulsion.com
Since we are not producing more batteries (for insurance reasons), batteries are only available with kits now.
E bike Mid Drive motor and battery — Revel Propulsion Ebike Mid Drive Conversion Kits
Ebike Mid drive motor and battery electric bike bicycle conversion kit lightweight lightest bafang torque sensing sensor field oriented control lithium ion Energon Cube Sempu T4 #25 chainring sprocket
www.revelpropulsion.com
