Hyena
10 GW
Bolted to a bike and drag raced against your BPM commuter.full-throttle said:
What ? you asked!
GNG, 1000W 48V BB-drive, $400
- Thread starter spinningmagnets
- Start date
What ? you asked!
full-throttle
1 MW
:lol:Hyena said:
Patience :wink:
This is all I had the time for
[youtube]AVZJk6JRzrM[/youtube]
adrian_sm
1 MW
Now I suspect the idler is to help take up that run out.
bzhwindtalker
100 kW
I may get one of those if the real world tests are good (waiting for the reports to fire up the credit card)
(waiting for the reports to fire up the credit card)
Since the stock driven 44T chainring has five arms, it may be a simple job to drill 5 holes in them at a 130-BCD pattern to attach a larger chainring. Vuelta has these at 48T-60T (if your frame/chainstays/ground-clearance will allow a larger chainring). There are also 48T-50T in a 5-arm 110-BCD chainring. http://www.vueltausa.com/se-chain-ring-130mm-38-60t-1.html
edit: the stock chainring that drives the chain from the BB back to the rear wheel is a 38T, perhaps it may be useful to put the 44T in that spot, and then attach a 60T to the 38T that you now place in the motor-driven position. This would lower the pedal-cadence some, and still keep the top-speed near stock. This would make the secondary drive ratio 12T / 60T = 5:1, the overall reduction would then be 5.7:1 X 5.0:1 = 28.5:1 ...The original ratio is 21.1:1, the 155 pedal cadence should then come down to somewhere around 110?...
edit: the stock chainring that drives the chain from the BB back to the rear wheel is a 38T, perhaps it may be useful to put the 44T in that spot, and then attach a 60T to the 38T that you now place in the motor-driven position. This would lower the pedal-cadence some, and still keep the top-speed near stock. This would make the secondary drive ratio 12T / 60T = 5:1, the overall reduction would then be 5.7:1 X 5.0:1 = 28.5:1 ...The original ratio is 21.1:1, the 155 pedal cadence should then come down to somewhere around 110?...
full-throttle
1 MW
The video was shot with a 27mm eq lens, so very close to the motor. It's a little noisier than a geared hub, much less than a RC though.Whiplash said:
@ cyclebutt: Got your pm. You've got to enable yours.
kfong
100 kW
Looking good so far, how solid is this setup on the bike? Is the structure strong enough for the loads without twisting? I might get one based on the field reports.
Craigh85
10 W
That's my kit arrived today pulled it out the box all looks well, can't fault their service, good communication, quick delivery item looks as described. Let's see how the actual product holds up, will start fitting to my big hit tonight. Hopefully have some feedback soon.
Cyclebutt
100 W
Any suggestions for a drive chain brand/quality to go with this kit? I've had issues with the Sram 850 and someone suggested a Shimano HS. I'm going to order a wide range 7 spd cassette (11-34 higher??) for this thing. Suggestions for a derailleur would also be welcomed.
"Any suggestions for a drive chain brand/quality to go with this kit?"
Wippermann is the gold standard, if you think you need it.
http://www.youtube.com/watch?v=RGjcD8xEu8o
If you are running 8 or fewer cogs in back, use 8 speed chain. If you run an internal hub, you can run heavy duty, bushed, single speed chain for best life. Again, Wippermann is the best. I run cheap SRAM PC850, and replace it every 3-4K miles. Cheaper per mile than Wippermann. I am only running 350-500 watts through my chain, 1000-1200 watts, instantaneous peak, per my CycleAnalyst. Get a chain checker to keep track of wear with your particular setup, and replace chains before they get too bad.
Wippermann is the gold standard, if you think you need it.
http://www.youtube.com/watch?v=RGjcD8xEu8o
If you are running 8 or fewer cogs in back, use 8 speed chain. If you run an internal hub, you can run heavy duty, bushed, single speed chain for best life. Again, Wippermann is the best. I run cheap SRAM PC850, and replace it every 3-4K miles. Cheaper per mile than Wippermann. I am only running 350-500 watts through my chain, 1000-1200 watts, instantaneous peak, per my CycleAnalyst. Get a chain checker to keep track of wear with your particular setup, and replace chains before they get too bad.
full-throttle
1 MW
Miles,Miles said:
Am I reading this right - 628W rating @ 2,000RPM with the centre distance of 76mm? 628 is not much.. Or is it derived from 3Nm input?
Would you be able to re run the calculator with HTD 450-5M-15 and centre distance 92~95mm (actual adjustment range on the drive)
It spins so much better without the idler
76mm was the minimum centre distance..... I set the torque to 3Nm to arrive at the recommended 15mm belt width. You can increase the speed for more power throughput. 3Nm isn't the maximum, there's headroom for shock loads. Also bear in mind that it's a rating for industrial use.
Ok, I'll run it with 450mm belt.
Ok, I'll run it with 450mm belt.
full-throttle
1 MW
Thanks!
redstone02
100 W
- Joined
- Aug 1, 2012
- Messages
- 102
Please help me understand what the data is saying. Are your calculations without the idler?Miles said:
With centers @ 92-95mm = 450mm lenght belt w/o idler?
If so, what are your thoughts on belt wear and rachetting?
Thanks,
Red
I would think that the somewhat excessive idler wrap on the primary drive belt would be helpful on a slow off-road steep ascent, but...my interest in this kit would lean more towards a street commuter (a mix of fast flat roads, and a few fairly steep paved hills), and I believe in this application the extra idler/pulley/belt wrap would prove to be unnecessary.
edit: perhaps a small amount of "slop" on the bottom of the belt would still be helpful for run-out. The idler shouldn't be too difficult to modify.
edit: perhaps a small amount of "slop" on the bottom of the belt would still be helpful for run-out. The idler shouldn't be too difficult to modify.
redstone02
100 W
- Joined
- Aug 1, 2012
- Messages
- 102
Miles said:
Thank you. I am not looking to "amp up" the controller, just wanting a reasonably fast commuter (flat, w/o any hills) that is efficient.
Removing the idler, I guess the pulley run-out would stress the belt.
Looking at credit card now for a purchase.
Hillhater
100 TW
spinningmagnets said:
The Engineer in me screams .."fix the freekin runout " !! :x
I agree! but the appeal of this kit over other similar kits is the affordable price. I can see getting a local machine shop to slightly bore out the central hole in the primary pulley with a new hole that is perfectly concentric, and then bush it back to the original size with something bronze, so...I guess it would depend on the price of local machine shop work vs having an idler keeping tension.
I'm also curious about this drives performance at 36V because of the stock high-RPM pedal cadence...vs swapping in a larger 52T-60T chainring on the drive unit (compared to the stock 44T), while running it at 44V.
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