Hill Climbing Assistance

metanewbie

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I'm about 155 pounds, but I carry a lot of stuff roundtrip to work, and I'm surrounded by steep hills.

I am considering a friction drive like the QiROLL because I only need something for hill climbing, and I prefer not to have a bunch of extra 'ebike weight' just for hill climbing assistance. I'm in decent shape, but at the end of the day, hill climbing is not fun.

I have two bicycles, and I was hoping to have something to swap to either. However, my primary ride is the hybrid.

I've attached three images showing my commute of 10 to 12 miles and my two bicycles.

Any advice is appreciated!

Please let me know if I posted to the wrong category here.
 

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Pretty gnarly.

That little bike would climb like a billy goat with a little geared motor on a ton of volts. By little, i mean 4-6lbs. That's all thanks to the torque advantage of the small wheel. You can expect ~2 times the torque per lb of motor in those dinkers.

For the bike with much taller wheels, you probably want a big geared motor or mid drive, both would be around 10lbs.

Either of these solutions wouldn't have all the downsides of a friction drive. Both would have substantially more power, which you need.
 
Pretty gnarly.

That little bike would climb like a billy goat with a little geared motor on a ton of volts. By little, i mean 4-6lbs. That's all thanks to the torque advantage of the small wheel. You can expect ~2 times the torque per lb of motor in those dinkers.

For the bike with much taller wheels, you probably want a big geared motor or mid drive, both would be around 10lbs.

Either of these solutions wouldn't have all the downsides of a friction drive. Both would have substantially more power, which you need.
Interesting!

I was looking at this or this and considering it as well for the sake of simplicity. The fewer devices/cables, etc., the better.
 
The complexity exists with either of those, it's just a matter of how it's designed physically.
Designs that hide complexity tend to be more difficult to service, sometimes aren't serviceable at all because they only have 1 parts supplier. And ebike companies go out of business all the time.

DIY kits popular on this forum don't look clean but you have available to you modular, repleaceable, documented, and supported components, which matters.

I wouldn't get either of those.

GMAC or it's not regenerative generating braking brother will slay that hill, takes an hour to overheat in this condition. It's 9lbs.

1729810734912.png

You'd probably get away with a smaller motor, the Shengyi SX2. The motor is 7lbs.

1729810809760.png

Thermals are not modeled on this motor but i imagine time to overheat is generous also.

Lesser powered motors would most likely melt up that hill. Your bike with the smaller wheels will perform a similar feat on a smaller motor than the Shengyi if weight matters.
 
The complexity exists with either of those, it's just a matter of how it's designed physically.
Designs that hide complexity tend to be more difficult to service, sometimes aren't serviceable at all because they only have 1 parts supplier. And ebike companies go out of business all the time.

DIY kits popular on this forum don't look clean but you have available to you modular, repleaceable, documented, and supported components, which matters.

I wouldn't get either of those.

GMAC or it's not regenerative generating braking brother will slay that hill, takes an hour to overheat in this condition. It's 9lbs.

View attachment 361129

You'd probably get away with a smaller motor, the Shengyi SX2. The motor is 7lbs.

View attachment 361130

Thermals are not modeled on this motor but i imagine time to overheat is generous also.

Lesser powered motors would most likely melt up that hill. Your bike with the smaller wheels will perform a similar feat on a smaller motor than the Shengyi if weight matters.
That's really useful information! It tells me I'm better off e-converting the small folder first as a 'hill climbing commuter.'
 
Yeah, how big are the wheels on that thing & does it have a standard 135mm QR rear axle?
 
16 inches? that's really small.

Something to think about is that the ride of the 700c wheeled bike will be a LOT smoother.

As speed goes up, a smaller wheeled bike starts feeling progressively rickety & you find yourself wanting suspension to overcome That. The 700c bike will start feeling rickety at a much faster speed.

You may find that on an ebike, comfort trumps weight since the motor more than makes up for the weight.
 
16 inches? that's really small.

Something to think about is that the ride of the 700c wheeled bike will be a LOT smoother.

As speed goes up, a smaller wheeled bike starts feeling progressively rickety & you find yourself wanting suspension to overcome That. The 700c bike will start feeling rickety at a much faster speed.

You may find that on an ebike, comfort trumps weight since the motor more than makes up for the weight.
So, would you focus on converting the 700c first?
 
I'm about 155 pounds, but I carry a lot of stuff roundtrip to work, and I'm surrounded by steep hills.
That's really useful information! It tells me I'm better off e-converting the small folder first as a 'hill climbing commuter.'
What does a lot of stuff look like and how do you currently carry it?

Since you are 155 lb, then you also have the option of a TSDZ2B mid drive. Since you pedal a lot already, the torque sensing pedal assist will work great, and you can take advantage of the gearing you already have (I believe 52T is available) on the smaller bike. Hard to tell what the chainring to chain stay clearance looks like on the larger bike without a better angled photo. You could run 250W, 500W or 750W.
This guy is using 500W. He passes some riders on a few steep spots, so you can see what it would look like to pass your current self. Sound level is reasonable, especially compared to a friction drive.
 
So, would you focus on converting the 700c first?

Yep, too bad the folder isn't a 20" wheeled bike; it'd have better NVH at speed. :)
 
What does a lot of stuff look like and how do you currently carry it?

Since you are 155 lb, then you also have the option of a TSDZ2B mid drive. Since you pedal a lot already, the torque sensing pedal assist will work great, and you can take advantage of the gearing you already have (I believe 52T is available) on the smaller bike. Hard to tell what the chainring to chain stay clearance looks like on the larger bike without a better angled photo. You could run 250W, 500W or 750W.
This guy is using 500W. He passes some riders on a few steep spots, so you can see what it would look like to pass your current self. Sound level is reasonable, especially compared to a friction drive.
Ideally, I'd like to have one motor (or hub) and a battery, and that's it—as simple as possible. I don't care about throttle, display, etc. I just want something that helps me with the hills. I'd rather be non-electric on flat roads and downhill, and I don't mind going slow and steady.

Can I set up a mid-drive with just two parts?

Can I get a small bottle battery for it?
 
Save the bikes you love and just buy a gently used bike to convert. From my experience, after a few years of hiding in a garage great bikes go cheap. Then convert that.
And if you go that route check out Grin (ebikes.ca). You could build a great direct-drive with regen braking and torque sensing. Grin does cost more for us diy'ers, but the bike you make will leave you smiling.
My work bike is this Trek 700. It has a bbs02 mid-drive, and takes me home after a hard day's work.

PXL_20231012_190339524.jpg
 
I just want something that'll give me a 10 to 20% boost up the hills. That's why the QiRoll, on paper, looks appealing — swappable between bicycles and can be physically engaged/disengaged for specific case uses. But what I'm reading here is that nothing is reliable without adding expensive e-stuff with wires, bulk, and weight.
 
Ideally, I'd like to have one motor (or hub) and a battery, and that's it—as simple as possible. I don't care about throttle, display, etc. I just want something that helps me with the hills. I'd rather be non-electric on flat roads and downhill, and I don't mind going slow and steady.

Can I set up a mid-drive with just two parts?

Can I get a small bottle battery for it?
Well a motor and battery are fewer components than a hub motor, controller, and battery, plus with the little mid drive can be kept in its most efficient range through gearing, not bike speed, rather than attempting to ride fast enough to keep a hub in its efficient range.
 
Well a motor and battery are fewer components than a hub motor, controller, and battery, plus with the little mid drive can be kept in its most efficient range through gearing, not bike speed, rather than attempting to ride fast enough to keep a hub in its efficient range.
I see what you mean. The problem I had with the Bafang mid-drive was that it always had to be on; otherwise, there was too much resistance, and the cadence sensor setup felt worse than the hub system.
 
A few learned lessons from trying a ZAP bicycle friction drive motor kit . . .
Friction drive motor systems wears the tire out quicker.
Keeping the tire pressure in the correct range is important.
Wet weather effects performance significantly.
When the battery dies the motor does disengage and it's just extra weight, not extra resistance too.
 
A few learned lessons from trying a ZAP bicycle friction drive motor kit . . .
Friction drive motor systems wears the tire out quicker.
Keeping the tire pressure in the correct range is important.
Wet weather effects performance significantly.
When the battery dies, the motor does disengage, and it's just extra weight, not extra resistance, too.
Google searched. It's an interesting design. The lead-acid battery, due to its bulk and weight, was probably its biggest hurdle, as with many older-style lighting systems. Thanks for warnings.
 
I haven’t read many complaints about the tsdz2b about pedaling drag, unless it has bad bearings.
It looks like one of the most appealing options. It won't be so easily swappable. I'd have to find a small-sized bottle battery for it.
 
Wow that's a low price. I guess the catch is they have no idea of the capacity?
They've never sold me any dead or used-up junk yet, but at this price and with a BMS, it's not a bad risk to take and find out.
 
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