Can a 1000w mid drive do hills, or does it always needs MTB gearing to get high Nm?

indianajo

Well-Known Member
Get your face out of the book long enough to put your butt on both types, then get back with me.
Don't need to waste time on a $4000 bosch bike. Nearest one for sale is in pancake flat Indianapolis, or maybe flat Chicagoland. Or take a $$$$ trip to Colorado to climb the nearest real mountain. I've climbed 15% grades twice weekly with 100 lb groceries & spares & 80 lb of bike at 8 mph with a $350 ebikeling 1300 W geared hub. No pedaling required. I'll admit, the "500 w" replacement bafang geared hub drive has been a disappointment, but not the fault of the category. Cheap *** uber jump specification motor I bought for $35 will assist up the hills if I pedal hard @ 2 mph. Looking for a replacement Mac 12t "1000 w" that was even more powerful than the ebikeling.
I don't need another 2 wheel toy, I've got 23 acres of downed locust & cherry trees to cut up & haul to the sinkhole. A 4 wheel trailer for my Ford 1520 tractor is the next big purchase.
 
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EMGX

Well-Known Member
FWIW, I put a 500w tsdz2 mid drive on a 20" folding bike and had to be careful on steep inclines to not wheelie in low gear and that was with a much less powerful, torque sensing only set up. A 1000w mid drive might be hard to handle and potentially dangerous on a short wheelbase 20" bike.
Check out this video of the Luna 20" folder with BBS02, other video reviews also mention that it can buck you off.
 

duggie

Member
Region
United Kingdom
EMGX..........that is just fantastic, just right for me. However, my hill is about twice as steep. So we'll see. But we're getting there. Thanks
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Don't need to waste time on a $4000 bosch bike. Nearest one for sale is in pancake flat Indianapolis, or maybe flat Chicagoland. Or take a $$$$ trip to Colorado to climb the nearest real mountain. I've climbed 15% grades twice weekly with 100 lb groceries & spares & 80 lb of bike at 8 mph with a $350 ebikeling 1300 W geared hub. No pedaling required. I'll admit, the "500 w" replacement bafang geared hub drive has been a disappointment, but not the fault of the category. Cheap *** uber jump specification motor I bought for $35 will assist up the hills if I pedal hard @ 2 mph. Looking for a replacement Mac 12t "1000 w" that was even more powerful than the ebikeling.
I don't need another 2 wheel toy, I've got 23 acres of downed locust & cherry trees to cut up & haul to the sinkhole. A 4 wheel trailer for my Ford 1520 tractor is the next big purchase.
Not sure of your point? This is what I was responding to:

"This fantasy persists all over electricbikereview forum. Mid drives have usually a 46 tooth sprocket or so. They have some internal gearing, but the quoted torque is at the drive chain ring. For a mid drive to get torque multiplication "through the gears in the back", the largest rear sprocket has to be bigger than the front. The stock bafang 1000w chainring is 46 tooth. https://bafangusadirect.com/collect...bafang-1000w-bbshd-mid-drive-ebike-motor-kit# That means to get any torque multiplication from the chain & sprockets you would need a 48 tooth rear sprocket. So Duggie's statement about mountain bikes "with extra massive cogs in the back" is correct.There are bafang accessory "bling ring"s available in 32 or 28 tooth. The only other "chain ring"s listed are 40 tooth, 42 tooth, and 44 tooth."

You don't need a 4000 dollar bosch bike to see that all else being equal, the mid drive will easily out climb a geared hub.
 
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duggie

Member
Region
United Kingdom
Well, thank you AHicks. I'm a mechanical engineer, but there was just some 'maybe' smoke and mirrors I maybe didn't know of. It's gears, just gears, like it always has been, block and tackle. Gos bless you all. I see the way now. My 'customized' ebike will be life changing for me. Thank you, thank you thank you all...........that darn bloody great hill....no more. Thank you
 

tomjasz

Well-Known Member
Again, the most commonly used chainring is a 42T on the BBSxx series motors. Larger cogs on BBS01B and BBS02B make proper shifting VERY IMPORTANT. The 01 and 02 are much more easily overheated. I built a ZIZZO folder with a 250W BBS01B and it wasn’t my cuppa. I’m suggesting the OP ought to by a decent MTB . Here a place like Bikesdirect have some ok lower end mountain bikes .
 

duggie

Member
Region
United Kingdom
tomjasz.......Thanks for that info. I've gone ahead and purchased a mid drive and hope it will arrive today. I'll give it a test ride and post how it goes.

I also ordered it with a 40T chainring. You say that larger cogs are very important for proper shifting. Please can you explain your reasoning? I'm aware I will need much respect always for the bike so as to avoid any potential danger, so I am interested in your reasoning.
 

tomjasz

Well-Known Member
40T chainring
IF you ordered ab BBSxx series Bafang motor and a Lekkie 40T kit, you're good, BUT if you ordered an after-market 40T from another source it will NOT have an offset and you may have a bad chain line that limits the available gears. You may lose the very sprockets you want for hill climbing.

This information assumes you bought a Bafang BBSxx series motor.
Not sure of your point? This is what I was responding to:

This fantasy persists all over electricbikereview forum. Mid drives have usually a 46 tooth sprocket or so. They have some internal gearing, but the quoted torque is at the drive chain ring. For a mid drive to get torque multiplication "through the gears in the back", the largest rear sprocket has to be bigger than the front. The stock bafang 1000w chainring is 46 tooth. https://bafangusadirect.com/collect...bafang-1000w-bbshd-mid-drive-ebike-motor-kit# That means to get any torque multiplication from the chain & sprockets you would need a 48 tooth rear sprocket. So Duggie's statement about mountain bikes "with extra massive cogs in the back" is correct.There are bafang accessory "bling ring"s available in 32 or 28 tooth. The only other "chain ring"s listed are 40 tooth, 42 tooth, and 44 tooth.

You don't need a 4000 dollar bosch bike to see that all else being equal, the mid drive will easily out climb a geared hub.
Careful here AL please see the above. Many resellers now break down the kits and offer alternatives to the OEM 46T for the BBSHD. I did notice many BBS01 and BBS02 resellers no long offer an OEM 42T. In my experience another Bafang and reseller F-up!
Well Joe has it not quite right. He has zero experience with BAFANG mid drives. A 42T chainring with a 14T-32T freewheel/cassette is a veritable mountain goat. To go smaller on the front and still maintain a chain line only a Lekkie 40T kit, about $150USD will maintain a decent chainline. A 36T front will have no offset. I sold and supported 100s of BBSHD kits and personally had 3 different frames with 3 BBSHD motors.

What make model and year of bike are you converting?
The BBSHD is very popular with pedicabs. Again it’s a beast of burden.
All the best!

Tom
I warned posters earlier in the thread...
 

duggie

Member
Region
United Kingdom
Thanks, yes, it is a BBSxx. I'll look to see if it is a Lekkie; I guess it's branded on it.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
@tomjasz-
My thinking was in more generic terms, regarding @indianajo's comment "This fantasy persists all over electricbikereview forum."

Lets take 3 500w bikes. In an attempt to keep things as equal as possible, one is a geared hub, one is a Bosch, and the last is a BBS02. Of those 3 plain vanilla generic bikes, which can be expected to be the better climber?

I could be wrong, but I shouldn't have to change much in the way of gearing to see my point.....that either of the mid drives will easily out climb 500w geared hub motor. You don't need a 4000 Bosch equipped to make that point.... -Al
 

tomjasz

Well-Known Member
The point was your description
There are bafang accessory "bling ring"s available in 32 or 28 tooth. The only other "chain ring"s listed are 40 tooth,
28, 32, and 40T will all change the chain line and users will lose gears. Thus my comment.

Otherwise we both agree. Especially regarding joes frequent mid drive malarkey.
 

retiredNH

Well-Known Member
Region
USA
I wouldn't be too quick to change gearing. Last year, when I bought my ebike, at first I thought the low wasn't low enough for my local hills. After two weeks of riding, I was no longer even using the lowest gear to climb the hills.

Just relax and get used to the bike before jumping to mods...
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
The point was your description

28, 32, and 40T will all change the chain line and users will lose gears. Thus my comment.

Otherwise we both agree. Especially regarding joes frequent mid drive malarkey.
I screwed up, was quoting what indianajo had said in that paragraph. Forgot to put it in quotes, so my bad..... I can see that without them that was pretty confusing. Now edited/fixed. -Al
 

duggie

Member
Region
United Kingdom
Well.......the brilliant news is that from the little test I have just done, I will now be able to get up that blasted steep hill.

However, I do lose 1 and 2. But it pulled so well in three I may be ok with that for the time being, and later I'll see what I can do. I may have to change the crank cog, and/or I may change the cassette. I don't want to strain the motor.

So it seems I got there in the end, with all your help, and got what I needed. I'm very happy. It will make a big difference for me.

It's been a bit of a gruelling day. So, the question is......do I have a few beers? You know the answer. Cheers. Doug
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
What did you end up going with?

Regarding keeping an eye on motor strain, most bikes have a real time watt meter. That will tell you exactly how much strain you are putting on the motor at any given time.
 

duggie

Member
Region
United Kingdom
AHicks.........Bafang mid drive kit, 1000w 52 v. It is powerful, and normally I would have gone for less, but I have a very specific need for it. My journeys will only be a mile, off road, and I don't want to go faster than 5 mph. But I have to climb a very steep hill, and I'm getting older. Only a bicycle will fit this path. Occassionally, I'll go with gf to a cycle path on our little tours, so I can use it then; she has same bike but with much less power, so they do need to be folding. It's ideal for my needs.

Gf is good with stuff like control panel, so she'll get good and hopefully be able to show me the watt meter, as that would be a helpful readout, thanks.
 

retiredNH

Well-Known Member
Region
USA
I wouldn't worry about straining the motor, and changing the chainring won't really affect the motor much anyway. From the POV of the motor (so to speak) it's how fast you go up the hill, not how fast the chainring is turning that matters, at least over a much broader range of outputs than a human.
 

duggie

Member
Region
United Kingdom
EMGX, your video, true., Thanks. Everyone, thankyou. I tested the bike, it is fantastic. The HILLL, no worry. I came here a green horn a couple of months ago and you have clued me up. Thanks, it will change my life. The bafang..............jesus!!!!!!!!!!!! Practice necessary..........but it does do it, and it can gentle off on a hill standing start (with the thumb throttle, gentle, take time), with practice. Incredible. Thank you all very much. it feels like an Oscars speech: thanks to indianajoe (I do have 1 &2, just needed adjustment), AHicks and all the crew, my producer, and financiers, co-star, mother, father, family and friends, and my long term girlfriend......God bless you all, thankl you