Wanted Spiderless square taper cranks?

[grey-beard]

Great choice bbshd so 48v? my advice is to fit the motor to the frame before thinking of cranks and get measuring. I don't know what gearing your thinking of but essentially you don't need many gears! Get it right one is all the motor needs however peddling becomes impossible then! I'd personally recommend leaving derailleur gears behind for longevity of chains sprockets etc. Your now dumping torque a moped could only ever dream of from zero rpm through a bicycle gear train.....it doesn't last! The issues you'll have will be chainline using the standard chainring at 46 tooth,clearance to chainstay and then equalisation of tread.

I've been using this motor for a few years now on various bikes, it is good. I'm using a 42 tooth lekkie copy chainring at the moment, but was considering the genuine 40tooth. I find that it's the battery that lets these motors down, performance wise, so if you have cheap batteries, as I do, which can only really pump out about 20 Amps, then your limiting what the motor can do. But in reality the Motor is happiest and most efficient when it's spinning fast, faster than our legs can go, so a smaller chain ring or bigger cog is the way to go. I only really use 4 gears, so the 10 speed I have is overkill, I really should go 7 speed, which would be more robust and involve less double shifting.
I'm only going through 2 chains a year and a cassette has lasted well so far.

 

[Mickeyspinn]

I've been using this motor for a few years now on various bikes, it is good. I'm using a 42 tooth lekkie copy chainring at the moment, but was considering the genuine 40tooth. I find that it's the battery that lets these motors down, performance wise, so if you have cheap batteries, as I do, which can only really pump out about 20 Amps, then your limiting what the motor can do. But in reality the Motor is happiest and most efficient when it's spinning fast, faster than our legs can go, so a smaller chain ring or bigger cog is the way to go. I only really use 4 gears, so the 10 speed I have is overkill, I really should go 7 speed, which would be more robust and involve less double shifting.
I'm only going through 2 chains a year and a cassette has lasted well so far.

Batteries are key....it is worth spending the money on batteries with decent capacity cells anything below 3200 mah is a little pointless.
Although I prefer a middrive the only down side compared to a hubmotor...is your gear is the motors gear! It's all about a happy balance of not using too many amps and killing the battery and having a gear you can pull too. Go with biggest cog more chain wrap will help chains and battery charge last, it's fine balance to find the right gear ....when the motor is the happiest it's screaming away but not drawing high amps.....but.....your chain surface speed will be twice a normal high pedal cadence! You could try knocking a cassette to bits just for say the best 3 or 4 cogs out off an 8 speed and just set your indexing with the derailleur hi low set screws.
I think 48v is just on the verge of bike gearings limit my 52v I've had to play with so much to get chains to give 750 miles,with derailleurs and cassettes it's was daft 2-300 miles max! If they didn't wear out they'd snap.....quick links first to break.
I still run the standard 46 chainring as I like the speed and there's not much in the way of hills near me...plus it enables me to add a little bit of pedal power at speed. I found best ratio as a single speed was 46 25 but pointless to pedal with over 20mph that gear made a battery charge last however 46 22 I found gives me a better cruise speed for not that much loss of range.

 

[grey-beard]

Batteries are key....it is worth spending the money on batteries with decent capacity cells anything below 3200 mah is a little pointless.
Although I prefer a middrive the only down side compared to a hubmotor...is your gear is the motors gear! It's all about a happy balance of not using too many amps and killing the battery and having a gear you can pull too. Go with biggest cog more chain wrap will help chains and battery charge last, it's fine balance to find the right gear ....when the motor is the happiest it's screaming away but not drawing high amps.....but.....your chain surface speed will be twice a normal high pedal cadence! You could try knocking a cassette to bits just for say the best 3 or 4 cogs out off an 8 speed and just set your indexing with the derailleur hi low set screws.
I think 48v is just on the verge of bike gearings limit my 52v I've had to play with so much to get chains to give 750 miles,with derailleurs and cassettes it's was daft 2-300 miles max! If they didn't wear out they'd snap.....quick links first to break.
I still run the standard 46 chainring as I like the speed and there's not much in the way of hills near me...plus it enables me to add a little bit of pedal power at speed. I found best ratio as a single speed was 46 25 but pointless to pedal with over 20mph that gear made a battery charge last however 46 22 I found gives me a better cruise speed for not that much loss of range.

What's your setup with the BBSHD? Got any pictures of your bike?

 

[Mickeyspinn]

I built the wheel ...can't remember exactly but a little bit of playing around with centreing the hub went on..pretty sure spoke lengths were within 1 to 1.5mm of each other.BB shell had I think around 4-5 mm machined off on drive side and a tiny bit of clearancing off the back of the main gear housing. Ended up with a chainline around 50-51 mm and equalised tread with old style road cranks that are about as flat as you can get. LHD crank needed 1 mm at the most on the inside off to clear motor.
So in all lots of headscratching trying to find 1/2 mm here and there but so worth it as it doesn't feel like trying to peddle a hog side saddle!
I wouldn't mind trying a smaller chainring for the extra acceleration but then that'd put me back to square one of poor chainline and cranks unequal tread! I've toyed with idea of making my own chainring carrier and finding either a proper 1/8 steel ring or go up a size to 420 chain. Maybe one day!
What's your current setup?

 

[grey-beard]

The bike's an on one bootzipper rigid 29er. SRAM GX 10 speed 11-36. I'm using a 42 tooth fake Chinese lekkie bling ring, although I do have a genuine 46 tooth too, quality seems the same. A 2 mm spacer behind the motor on the drive side so the chainring clears the chain stay, just, this bike was intended for tiny modern chainrings. Chain line is almost spot on, crank spacing isn't. Those are specialized strongarms, they've made it worse than the standard type, very wide and offset.
I could try the lekkie buzz bars, but I would like the 40tooth setup too, but all in that's about £350. So not now. I'll jus keep trying different cranks.

 

[Mickeyspinn]

It's tricky fiddle isn't it each frame will have slightly different clearances around chainstays How much is oneside off?
I presume it's drive side...what's your current total tread width?

 

[grey-beard]

I haven't bothered measuring, it's sooo wide, drive side is about an inch further out than the other.
I don't mind the width and I could improve it a tiny bit by removing the spacer from the drive side bottom bracket and adding a spacer behind the chain ring, to keep the clearance. But really a straight crank arm on the drive side would be the answer. All fun and games really.