BBS02 motor drag- normal?

[nrgbod]

I have just fitted a new BBS02 motor to my mtb but it seems to have a lot of motor drag when pedalling without the battery connected and can't see it being much fun if I ever let the battery run out.

Can somebody please tell me if this is normal as this is my first ebike and I don't know whether they need to bed in or if it's faulty or if that's just the way they are?

TIA

Edit... Although the drag felt bad with the bike on the work stand I've just taken it for a spin round the block and couldn't really feel any drag so seems like I was panicking over nothing.

 

[brightonebikes]

I have just fitted a new BBS02 motor to my mtb but it seems to have a lot of motor drag when pedalling without the battery connected and can't see it being much fun if I ever let the battery run out.

Can somebody please tell me if this is normal as this is my first ebike and I don't know whether they need to bed in or if it's faulty or if that's just the way they are?

TIA

There should only be very minimal drag compared to a normal BB. Not really noticeable difference when riding. Is there the same resistance if you remove the chain from the chainring and rotate the cranks?
Had this issue once, but transpired to be a seized jockey wheel causing the drag, could check that they are spinning freely just in case?
You could try adding lubricant to the secondary gear?
Otherwise doesn't sound right...


Sent from here to there with computer wizardry.

 

[nrgbod]

There should only be very minimal drag compared to a normal BB. Not really noticeable difference when riding. Is there the same resistance if you remove the chain from the chainring and rotate the cranks?
Had this issue once, but transpired to be a seized jockey wheel causing the drag, could check that they are spinning freely just in case?
You could try adding lubricant to the secondary gear?
Otherwise doesn't sound right...


Sent from here to there with computer wizardry.

Even with the chain removed the drag is still there however it does seem less than it was before so maybe the ride round the block has bedded it in a bit.
If I flick the pedals hard forwards they stop almost immediately but flicking them backwards with the same force they continue rotating for about a full turn before stopping.

 

[brightonebikes]

Even with the chain removed the drag is still there however it does seem less than it was before so maybe the ride round the block has bedded it in a bit.
If I flick the pedals hard forwards they stop almost immediately but flicking them backwards with the same force they continue rotating for about a full turn before stopping.

I see. It may free up a little with use, but will always back pedal easier as it's just a freewheel ratchet opposed to moving the gear cogs.
A little mobilgrease28 or similar in the secondary drive gear (easily accessed beneath the cover behind the chainring) may help?
Hope you sort it easily and there's no big problem with the unit

Sent from here to there with computer wizardry.

 

[Fordulike]

Also, make sure that the final drive plastic cover has been screwed down properly. There's very little tolerance between the cover and chainring, most noticeable when that area gets muddy and gritty.

Don't overtighten the screws though, as the plastic cover can split around the screw area. I use a screwdriver, but only thumb and forefinger to turn it.

 

[Deleted member 4366]

Crank drive motors often have a bit of drag, but you can only tell by rotating the crank without a chain on and without the motor switched on, which is something that most people would never do, so most people are not aware of it.

 

[Woosh]

When you move the crank arms forward, you engage the one way clutch. The forward drag on the BBS01/BBS02 is very little, you should feel about 50g-100g of force on your fingers, much less compared to pushing backward a bike with a geared hub motor. Moving the cranks backward has no drag.

 

[nrgbod]

Thanks for the replies.
To quantify the amount of drag I'm seeing...with the chain off, I can rotate the crank with my little finger 50mm from the crank centre but I struggle to rotate it with my finger 25 mm from the centre.
Does this sound normal?

 

[Fordulike]

Thanks for the replies.
To quantify the amount of drag I'm seeing...with the chain off, I can rotate the crank with my little finger 50mm from the crank centre but I struggle to rotate it with my finger 25 mm from the centre.
Does this sound normal?

Yep, same on mine

Stop worrying and ride like the wind

 

[Fordulike]

Thanks for the replies.
To quantify the amount of drag I'm seeing...with the chain off, I can rotate the crank with my little finger 50mm from the crank centre but I struggle to rotate it with my finger 25 mm from the centre.
Does this sound normal?

If you take the plastic, final drive, side cover off, you will then see and understand why the chainring will never spin like you are expecting it to.

Grease on the two cogs will slow them down, just by the sticky nature of grease.
Also, the final drive cog and chainring just haven't got enough mass to keep spinning.

Add to that, slight friction in bearings, means it does what it does I'm afraid.

 

[brightonebikes]

If you take the plastic, final drive, side cover off, you will then see and understand why the chainring will never spin like you are expecting it to.

Grease on the two cogs will slow them down, just by the sticky nature of grease.
Also, the final drive cog and chainring just haven't got enough mass to keep spinning.

Add to that, slight friction in bearings, means it does what it does I'm afraid.

A mate's BBS02 750W felt stiffer than any others I've seen, a little grease on the secondary drive definitely improved it rather than increasing resistance and bogging it down further.

Sent from here to there with computer wizardry.

 

[Fordulike]

A mate's BBS02 750W felt stiffer than any others I've seen, a little grease on the secondary drive definitely improved it rather than increasing resistance and bogging it down further.

Sent from here to there with computer wizardry.

I would say mine's the opposite, as I really pack the grease in there. Either way, this is not the most free spinning of drives.

 

[nrgbod]

Thanks for the replies guys, I'll have a look inside and grease it up when I fit the new chainwheel after it arrives next week. Maybe when I see whats inside I'll have a better understanding of whats causing the drag.