Able to hit hub top speed with mid -drive.

[hillslayer@]

So bought a no name 1500 watt hub for the rear added a 60 t chainring to the BBSHD. The hub was listed as a 500 RPM hub no load spin up was 44 mph on 48 volts. I have never had a hub come close to that speed unless down a steep hill usually tops out around 34 mph. Today hit 45 mph on a slight downhill. Not bad for 48 volts.

 

[ebike4healthandfitness]

This is with the 5 speed freewheel right?

P.S. How many of those five gears do you normally use? Which gear do you use the most?

 

[hillslayer@]

The 14t is now flat terrain gear if you want to go 30 mph plus. Most hills are 17 t and 21t that will be in the 25 to 30 mph range . 24 and 28 for the real streep stuff or slow speed work.

 

[Chalo]

Hubs have one gear. That's their shortcoming and their strength. You pick the battery voltage, motor RPM per volt, and controller amp limit to match your wheel diameter and desired cruising speed. If you get it right, you have optimal efficiency in your most prevalent running conditions. You'll give up some top speed and climbing ability in return for being better at what you do most of the time.

Also, you will get vastly increased pedal drivetrain life rather than vastly diminished endurance as with a crank drive. And you will have redundancy, so the pedals will take you home if the motor fails, and the motor will take you home if the pedal drive fails.

Most high dollar commercial e-bikes are crank drive for a reason, and it's not a reason that works in your favor. They want you to report back to the dealer often with worn out parts and breakdowns, and they want to to replaced your busted bike with a new one as soon as possible.

How much of a sucker are you? Only you can say.

BBSHD at least has the advantage of being somewhat intercompatible and hackable, but only if you don't get one of the CANBUS versions, that trap you into their parts ecosystem.

 

[hillslayer@]

Mid-drive and a hub best of both.

 

[bengxe]

Mid-drive and a hub best of both.

Not so much best of both as all of both, including cost and weight.

 

[Chalo]

Not so much best of both as all of both, including cost and weight.

I suggest, it's actually the worst of both.

 

[hillslayer@]

If you live in the mountains it's the best of both, easily sustainable high uphill speeds without worrying about melting down your motor.

 

[ebike4healthandfitness]

In order to achieve the same hill climbing performance of a 1500w DD and a 1000w mid drive with 5 cogs he is going to need a very powerful DD motor. More than 2500w.

Also remember his bike is a fat bike (with 190mm rear spacing) so the tire diameter will be at least 29" (and probably 30") which hurts the ability of a DD hub to make power compared to the same motor built with a smaller diameter tire.

That said, with 190mm rear spacing the real estate does exist for 55mm extra stator width compared to what is seen on a typical 135mm motor.

Trouble is nobody actually makes a DD motor that makes full use of that available real estate. Not even at 170mm.

Honestly this seems like a real shame when we consider the Stealth Bomber ebike is a European Spec moped falling under the 4000 watt continuous power category yet it's 55mm wide stator Crystalyte DD hub motor is only listed at 2500 watts continuous (with 27.5" x 2.8" tire*)

Assuming that 2500 watt 55mm wide stator DD motor scaled linearly a 90mm stator width version of that motor would make 4090 watts continuous power (with 27.5" x 2.8" tire*).

*27.5" x 2.8" tire will be a smaller diameter (approximately 1") than a 26" x 4.0" fat bike tire commonly used by 170mm rear spacing fat bikes. The OP has a 190mm spacing fat bike which means he can fit an even wider and thus taller tire.

 

[hillslayer@]

To get similar ability on a hub only system you would need a qs 205 hub and battery to match which would weigh as much or more than mine. On a steep enough hill you could still cook the qs 205 hub.

 

[ebike4healthandfitness]

To get similar ability on a hub only system you would need a qs 205 hub and battery to match which would weigh as much or more than mine. On a steep enough hill you could still cook the qs 205 hub.

QS 205 is only 50mm wide stator and you already have 35mm wide stator.

I don't think 50mm wide would be enough.

P.S. I don't think DD with very wide stator neccessarily needs to weigh that much. Take for example GRIN FAT DD. It has 45mm wide stator and yet only weighs 6kg. Therefore I wouldn't expect a GRIN 90mm stator motor to weigh much different than a 10.5 kg Crystralyte 55mm stator DD. Remember that weight of 6 kg for GRIN 45mm includes various components (freehub, side covers, axle, etc.) that wouldn't be duplicated on a 90mm version....so 10.5 kg for GRIN 90mm rather than 12kg is achievable most likely.

 

[hillslayer@]

Have you looked at the price of that grin hub . I think saving close to a Grand and still outperforming it is worth a few pounds. I can't find a any specs on the motor I am using it may have a 40 mm wide stator as it measures 8 mm wider than my 135 mm drop 1500 watt hub. Only thing on it is a serial number maybe I will Google it

 

[Chalo]

If you live in the mountains it's the best of both, easily sustainable high uphill speeds without worrying about melting down your motor.

You can use two hub motors for the same benefits, but without the bike-destroying efficiency of a mid drive.

 

[ebike4healthandfitness]

You can use two hub motors for the same benefits, but without the bike-destroying efficiency of a mid drive.

A powerful front hub motor is going to be hard on a suspension fork though.

 

[hillslayer@]

Have you looked at the price of that grin hub . I think saving close to a Grand and still outperforming it is worth a few pounds. I can't find a any specs on the motor I am using it may have a 40 mm wide stator as it measures 8 mm wider than my 135 mm drop 1500 watt hub. Only thing on it is a serial number maybe I will Google it

Just checked the measurements on my motor same as a 205 on the outside, it says 48 volt 1500 watt on it wish I had opened it up. Probably just using the housing for cheaper components.

 

[hillslayer@]

You can use two hub motors for the same benefits, but without the bike-destroying efficiency of a mid drive.

I been running mid-drive motors for over 2 years never had them destroy anything never even broke a chain. With a hub combo it's only used uphill mostly making wear on the drivetrain even less.

 

[ebike4healthandfitness]

Just checked the measurements on my motor same as a 205 on the outside, it says 48 volt 1500 watt on it wish I had opened it up. Probably just using the housing for cheaper components.

My guess is that is what is happening. For example, on the Leaf bike 35mm motor the 135mm version and the 170mm version have different spacing between the outside of the spoke flanges (40mm vs. 55mm) but both use the same 35mm width stator. Originally I did think though the 170mm version had a wider stator because of the extra space but Leaf bike sales told me the fat bike motor still uses the 35mm stator.

P.S. There is a higher power version of the fat bike DD motor sold by leaf bike. It has a 42mm wide stator. However, it shares the same housing as the fat bike 35mm wide stator motor.

 

[hillslayer@]

My guess is that is what is happening. For example, on the Leaf bike 35mm motor the 135mm version and the 170mm version have different spacing between the spoke flanges (40mm vs. 55mm) but both use the same 35mm width stator. Originally I did think though the 170mm version had a wider stator because of the extra space but Leaf bike sales told me the fat bike motor still uses the 35mm stator.

That's most likely with this one also didn't seem to be heavy enough to be packing a 50 mm stator.

 

[Chalo]

I been running mid-drive motors for over 2 years never had them destroy anything never even broke a chain. With a hub combo it's only used uphill mostly making wear on the drivetrain even less.

Yeah, not everybody listens to what their bike is telling them. But you do you.