PaPaSteve
1 kW
This is correct
A lesson learned from working with ZAP
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Hill Climbing Assistance
- Thread starter metanewbie
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A lesson learned from working with ZAP
metanewbie
100 W
Please share. I'm learning a lot from reading all this.
ebike4healthandfitness
100 kW
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It is, but the larger diameter tire also travels further per revolution.
metanewbie
100 W
Would a 700c or 16" wheel operate under a friction drive more efficiently or the same?
ebike4healthandfitness
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The only thing that matters is how well the roller makes contact with the tire to transfer power. You don't want the roller to slip on a steep climb.
metanewbie
100 W
This cycling blogger mentions using 3M flooring grip tape (vs what comes with the friction drive) to achieve what you are advising.
PaPaSteve
1 kW
Sprockets or gears calculations are based on working from a center axis to the gear or wheel radius.
With friction drive the roller is, in essence, pushing directly on the ground with the rubber tire acting as a transfer medium.
So roller circumference times rpm = vehicle speed
Not counting the losses due to aero drag, weight, tire efficiency, incline and mechanical friction.
With the ZAP the drive power was either on/off so it helped to have some motion before pushing the go button.
When off, the drive roller dropped away from contacting the tire so the system was extra weight but not extra motor friction.
ebike4healthandfitness
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Yes, that's why i like geared hub motors. next best thing to a direct drive in terms of simplicity
And yet with a geared hub motor the ring, planet and sun gear all share the same thermal space as the motor.
With that said, I myself am not against motor, gears and controller sharing the same space. Rather the motor, gears and controller should all be very efficient.
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Yes, but only one thing is making significant amounts of heat, not two, and nylon gears are rated for temperatures around where the stator would fail, usually a bit lower, to act as a fuse to save the stator. That's fine.
Contrast this to motors with controllers in the motor casing.. now you have lower thermal overhead for both components.
Manufacturers will do the following to countercompensate:
- do the right thing and put in two thermal sensors and downrate each individual component when it gets hot
- downrate the components full time
- leave it up to god
If we're talking about a cheap chinese thing, the engineering choice is often the latter
Same thing could be said about batteries next to motor, controller in battery ( if done wrong ), etc
metanewbie
100 W
I'm still searching. So far, the friction drive offers the most overall flexibility, despite the obvious shortcomings.
But ... is there a rear hub drive that will accept 9-speed cassettes (I use Advent 11-38) that might not be the perfect hill climber but will help me a bit?
The funny thing is I had a single-speed folding bicycle with a 250-watt geared rear hub, and it had 12-inch wheels, but I could grind up the hills and not be exhausted!
Knowing this, I'm curious if there is a kit out there that will fit what I need — a decent rear hub that accepts 9-speed cassettes with a 700c wheel. The max tire width my bicycle can handle is 32mm. Ideally, the kit will take 36 volts so that I can purchase these batteries.
Thanks!
But ... is there a rear hub drive that will accept 9-speed cassettes (I use Advent 11-38) that might not be the perfect hill climber but will help me a bit?
The funny thing is I had a single-speed folding bicycle with a 250-watt geared rear hub, and it had 12-inch wheels, but I could grind up the hills and not be exhausted!
Knowing this, I'm curious if there is a kit out there that will fit what I need — a decent rear hub that accepts 9-speed cassettes with a 700c wheel. The max tire width my bicycle can handle is 32mm. Ideally, the kit will take 36 volts so that I can purchase these batteries.
Thanks!
metanewbie
100 W
Here is an interesting recent post by the forum post/blogger who advocates the Qiroll friction drive.
metanewbie
100 W
I think I may have found a rear hub candidate, but does it accept 36-volt batteries? The manual says it might.
You want a slower winding honestly. And dual reductions instead of single..
The controller in that kit, if made for 48v, won't work with a 36v battery. Since it is a non programmable controller, it will have a fixed low voltage cutoff
Previously mentioned, this would be close to, if not the ideal motor for your hill climb, due to the very high reduction ratio, and slow speed:
Q100C CST 36V350W Rear Driving EBike Hub Motor RPM 328
It may only work with 8 speeds, but you can lockout the top gear. If you're using this motor, you won't really need it anyway.
The controller in that kit, if made for 48v, won't work with a 36v battery. Since it is a non programmable controller, it will have a fixed low voltage cutoff
Previously mentioned, this would be close to, if not the ideal motor for your hill climb, due to the very high reduction ratio, and slow speed:
Q100C CST 36V350W Rear Driving EBike Hub Motor RPM 328
It may only work with 8 speeds, but you can lockout the top gear. If you're using this motor, you won't really need it anyway.
ps when buying a bare hub motor, if you don't know how to lace, line up a shop willing to do / also have the right equipment to do it first.
This one's very low power, so regular bicycle spokes or sapim butted 13-14ga would be fine.
Of course you also want a controller and throttle/pas/ebrake cutoff switch that matches that controller in order to turn it into a 'kit'
This one's very low power, so regular bicycle spokes or sapim butted 13-14ga would be fine.
Of course you also want a controller and throttle/pas/ebrake cutoff switch that matches that controller in order to turn it into a 'kit'
metanewbie
100 W
I'll bookmark this one and find out the costs of the additional stuff. Though I have a feeling it'll cost more than a mid-drive and certainly more than the friction drive. I always appreciate your help.ps when buying a bare hub motor, if you don't know how to lace, line up a shop willing to do / also have the right equipment to do it first.
This one's very low power, so regular bicycle spokes or sapim butted 13-14ga would be fine.
Of course you also want a controller and throttle/pas/ebrake cutoff switch that matches that controller in order to turn it into a 'kit'
Lacing up a 1 cross hub motor isn't that hard to do. Check out Grin's learn tab on how to do it.
Though, I have only done one wheel, and will have to run the thing to find out how well my wheel build works.
Wheel building is kind of a relaxing thing to do.
Much, much more mellow than building a battery.
Though, I have only done one wheel, and will have to run the thing to find out how well my wheel build works.
Wheel building is kind of a relaxing thing to do.
Much, much more mellow than building a battery.
It is why it is important to buy from reputable local dealer.
Mid drives have reputation of being less reliable than hub drives, but keep in mind, mid drives usually must endure much more punishment. My mid drive takes me places hub motor couldn't even dream of and so far all is good (fingers crossed)
As per Toseven you might be right. I can't comment on reliability of their motors as Toseven practically do not exist in UK. Their rep made a brief appearance on our local e-bike forum, but quickly disappeared and was never seen again.
Yeah, it’s tricky to conceptualise. Might help to think in terms of leverage. If the wheel isn’t acting as a lever there’s no change in ratio, and therefore it’s merely a large idler.
No build thread. It is as ordinary e-bike as it can be. Cube Attention SLX + TSDZ8 + 48V 17.5Ah Samsung battery.
Yes, it has Topeak rear rack. Quite unfortunate for mtb, but it is all in one bike. Commuter, cross country, downhill, cargo etc.
The battery in the original photo was long and flat, mounted on top of the downtube, which drew my attention. But now it does not look like that! Must have been some kind of optical illusion I was seeing.
Edit: I swear what I saw was a different photo, not an illusion. Too bad I did not take a screenshot.
Edit: I swear what I saw was a different photo, not an illusion. Too bad I did not take a screenshot.
Well... sorry for disappointment
Here you have a flat battery if you are looking for one:
Great new form factor 1.4kwhr battery for full suspension bikes
Just wanted to give the forum a heads up, @metanewbie mentioned this newer company affordable ebikes, in Canada. I looked into their batteries, and saw this gem that's designed to run as a single or double battery. Combined sizes go up to 72v 20ah. 21700 - Slim Pack Batteries - 36V / 48V /...
endless-sphere.com
crunchysteve
1 W
It's probably a dissenting view, but I'm going to suggest "look to Europe." Most European countries have a 250w maximum and pedal assist only (no throttle rule) and Australia, where I live, follows this as well. My tourer/commuter has a front wheel kit because I wanted to preserve my "mullet" gearing at the rear (1x9, 11 to 46 teeth. I'm a weirdo, I know, it's microshift and I love it) If you're happy with whatever gearing fits, the rear wheel is better for traction, but I can still gravel climb with the front doing more than me and don't lose traction, even on a 2m 50%er I have to throw the bike at flatout at the bottom and nearly stopped at the top. (Might be a 30%er, we Aussies are given to beer talk, even when sober.)
Now, I know there are a lot of people here on EndlessSphere riding much higher power because the USA has been slower to restrict eBike power. This is good but also not so good. I mean a kilowatt will get people biking more, but I have a heart condition with a medical maximum BPM of 130, a 90 year old's MHR at 63 and 250w feels like me before before my NSTEMI (The "widowmaker" according to the local paramedic culture) That's at 20% pedal assist on the flat. Full power, all 250w, makes me feel like Cadel Evans on the Champs Elysee! Even with panniers on for a week away!
I live in Melbourne, Australia, and there are some nasty breath suckers between my place and the CBD. Short but nasty steep. These are the hills that I avoided before adding an e-kit to my beloved long hauler (not a surly, just what she's designed for, slow grinding the miles, well, kilometres here, but they look more impressive on paper
) I avoided these hills before my heart popped a big end.Anyway, my nearly 2am AEDT sleepless point here is, don't fear a proper e-kit. My only regret, after resisting for years, was overestimating the battery I "needed." If you're just after a hill boost, you'll get that from 250W, you'll feel at least 20 years younger most of the time on 20% to 40% boost and you'll still get that healthy, aerobic workout without being so goddamned anaerobic on the big hills. 10Ah battery at 36v is more than enough for a commuter, probably a 7.5Ah is enough, depending on how big your hills are. There's no complication after install. Just a bike computer sized speedo and battery display, a small control box on the back of my seatpost and a motor in one of the wheels. My battery, though, yeah, 7.5Ah at 36v would have been way better than the 15 I bought. For around the city, anyway.
Wheel drivers are inefficient, can be noisy, are frankly not easier to install, looking at most of the designs and they slip badly if you get caught in the rain. They look attractive because they look like there's only one thing, not a collection of bits. If you're worried about the technicality of installing a wheel kit, talk to the bike shop that does your services, buy the kit they recommend, have them fit it. I used to work audio production, have a background in electronics AND have always serviced my own bikes. I found install a challenge, a physical one, too. But that lasts a moment, then you have a purpose built bike with an electric assist, that's as easy to use as the front gears on a 3xN derailleur setup... except you've got 5 or 6 of them, or off... easier, actually. button up, button down. Want to go? Push a pedal. Want to stop, grab the brakes. As easy as riding a bike, really.
The Europeans are killing it with eBike adoption, and pedal assist is why. It's still like riding a bicycle, just with a robot giving you a "backie" (or a "dink" as we call it in Australia)
metanewbie
100 W
When it comes to mid-drives on the reliability scale: Bafang, Tongsheng, and Toseven. The main drawback to Bafang is the lack of torque sensing, though posters have said you can make it a lot smoother by 'removing speed limits from PAS modes.'
Am I accurate so far?
Am I accurate so far?
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