Draggy ebike hub
 

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[Closed] Draggy ebike hub

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Hi,

I've just got my new ebike - a Ribble CGR AL e. It's got a mahle hub motor on it which just feels really draggy when it's not giving you extra boost, e.g. when you're going over 15.5mph or not pedalling or have the bike "switched off". None of the reviews I read of the bike before (or indeed after) I bought it comment on this. I just wondered if anyone else experienced this or if maybe it's a fault or maybe if I'm just being over sensitive. I've played with the rear brakes and it's not that.

I'm using it for a 16 mile each way commute and it's still overall sped me up by about 15% but it just takes a lot of fun out of the ride when you can't really fly down the descents.


 
Posted : 09/10/2021 8:41 am
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That's what rear hub motors do, nothing you can do about it. You will soon get used to it. If you don't trade it for a crank motor.

15% over that distance isn't very much. I guess that's why they get chipped. There's one bloke I see who maintains his speed up hill at 30mph without pedalling 🤬


 
Posted : 09/10/2021 10:19 am
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Bah. Thought so.

It's very disappointing how much less fun the bike is than I was expecting because of this.


 
Posted : 09/10/2021 10:36 am
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It's the big magnets and coiled copper in there, always draggy when not under power. That's the big drawback to hub motors...well that and the spoke breakages if it's not build well with stronger than standard spokes


 
Posted : 09/10/2021 10:37 am
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Tell me about why there are more spoke breakages?


 
Posted : 09/10/2021 10:46 am
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Do you know what sort of percentage efficiency you get with them? I've looked around online and re-read th reviews of my bike but there is nowhere that mentions this issue so far as I can see. It's far and away the worst thing about the bike imo


 
Posted : 09/10/2021 11:05 am
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Tell me about why there are more spoke breakages?

Me too, I’d expect less given shorter.


 
Posted : 09/10/2021 11:10 am
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Me too, I’d expect less given shorter.

Short spokes don't always mean a stronger wheel due to the angles involved at the hub flange - but unless your buying cheap shit from Ali Baba /eBay / it's a non issue

There is no more torque or force being applied to spokes by a hub motor than any other kind of motor.


 
Posted : 09/10/2021 11:46 am
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Is it actual hub drag you're feeling or just the result of the motor switching off when you hit the limit?

Flip the bike upside down and just spin the wheel and see how long it goes?


 
Posted : 09/10/2021 3:02 pm
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15% over that distance isn’t very much. I guess that’s why they get chipped. There’s one bloke I see who maintains his speed up hill at 30mph without pedalling

Ha, I got buzzed by a similar twunt on my road bike ride today.
Came up behind me on a hill, overtook me - I was pushing it at about 20kmph, and he must have been going nearly double without pedalling!
Then slowed down and made some disparaging comments and sped up again.
I overtook him on the next downhill though.

Is it actual hub drag you’re feeling or just the result of the motor switching off when you hit the limit?

Flip the bike upside down and just spin the wheel and see how long it goes?

I found this with a dynamo hub. Felt weirdly draggy when spun by hand, but not noticed when cycling.


 
Posted : 09/10/2021 3:11 pm
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Tell me about why there are more spoke breakages?

Massive amount of torque going through them compared to legs. We've seen lots of cheap ebike hub motor wheels with multiple broken spokes. Length is less important than quality and build


 
Posted : 09/10/2021 3:48 pm
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Thats cheapo builds not an inherent problem with hub motors. Think about the leverage with the bigger diameter hub - that reduces stress on spokes. Its no more torque than if you had a midmount motor and a stronger wheel build on the hub motor all other things being equal


 
Posted : 09/10/2021 3:56 pm
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Massive amount of torque going through them compared to legs. We’ve seen lots of cheap ebike hub motor wheels with multiple broken spokes. Length is less important than quality and build

As I said little to do with the hub. More the quality of the shit your being brought to work with.


 
Posted : 09/10/2021 5:00 pm
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Is it actual hub drag you’re feeling or just the result of the motor switching off when you hit the limit?

I'm fairly confident it's the hub. I had the same thought so I tried riding the bike with it switched off and it still feels very draggy compared to, say, my mountain bike which just had a normal rear wheel with a derailleur. My old commuter has hub gears so I'm used to a bit of drag but it's much worse than that.


 
Posted : 09/10/2021 5:20 pm
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We’ve seen lots of cheap ebike hub motor wheels with multiple broken spokes.

The bend / bad entry angle at the rim? Not the case with small hubs like the ebikemotion / Mahle but more common on the larger hub motors.


 
Posted : 10/10/2021 2:37 pm

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