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E bike conversion

Posted: 15 Sep 2020, 6:35pm
by densmall
Can anyone recommend a front wheel motor conversion,my budget is around £500.

Re: E bike conversion

Posted: 15 Sep 2020, 6:48pm
by philg

Re: E bike conversion

Posted: 15 Sep 2020, 10:05pm
by hemo
One needs to say what the bike use and terrain may be.
Hub motors come in various winding speeds or Rpm, for fast riding on flattish terrain then go for a high wound hub. If the terrain takes in inclines then one needs a lower wound slower rpm hub.

Re: E bike conversion

Posted: 22 Sep 2020, 5:29am
by bikes4two
Hi Hemo,
Hub motors come in various winding speeds or Rpm, for fast riding on flattish terrain then go for a high wound hub. If the terrain takes in inclines then one needs a lower wound slower rpm hub


Can you expand on the above please e.g.
> what exactly is 'high wound' and 'low wound' (what figures/parameters describe this)? Maybe some typical figures might help my understanding.
> and how do you find these parameters for any particular hub motor offering

Unless I missed it, none of the listings linked to by PhilG gave such information?

Thanks.

Re: E bike conversion

Posted: 22 Sep 2020, 7:30am
by Bonzo Banana
Hub drives are normally split between geared and direct drive although I'm sure windings maybe significant between brands but I would say to a much lesser extent than geared and direct drive. The smaller geared hubs use 3 nylon/plastic planetary gears normally to slow the hub rotation and increase torque they also add a clutch that allows the wheel to freewheel when not powered with almost zero resistance. They are probably the best option for most people especially those who want to remain on the legal side as they are lower powered typically. For heavier riders or people who want more speed and not bothered about legality then direct drive may be the option. I went with direct drive as I'm a very heavy rider and the direct drive hub wheel had a max. load of 200kg where as the geared hub the manufacturer also sold was only 100kg. That could be for various reasons one of which simply was the geared hub is not capable of shifting greater weights however the fact it is geared down means the difference in torque is not that much, the direct drive hub just can spin faster. I didn't really want the option of stripping the nylon planetary gears so and took the information in the spec of a 2x load capacity. The model I choose also has a restricted road legal mode which drops power from its probable 400W sustained output to around 250-280W and where as peak power would have been up to 1000W it is now more like 700W but this is actually typical of commercial legal ebikes that can have peak output for short periods above 700W which you can get from any bike shop, the 250W is rated or nominal power which are vague terms at best, most ebikes peak well above this unless you get the very cheap end models £400 approx Halfords, Argos etc which may have sustained power of only 150-180W and only peak over 250-300W.

Re: E bike conversion

Posted: 22 Sep 2020, 7:49am
by philg
bikes4two wrote:Hi Hemo,
Hub motors come in various winding speeds or Rpm, for fast riding on flattish terrain then go for a high wound hub. If the terrain takes in inclines then one needs a lower wound slower rpm hub


Can you expand on the above please e.g.
> what exactly is 'high wound' and 'low wound' (what figures/parameters describe this)? Maybe some typical figures might help my understanding.
> and how do you find these parameters for any particular hub motor offering

Unless I missed it, none of the listings linked to by PhilG gave such information?

Thanks.

I think he's referring to the maximum rpm that the motors are designed for.
A typical hub motor here
http://www.topbikekit.com/akm100cst-cas ... _uploads=0
has 2 winding options - 201 and 328rpm allowing for different wheel sizes in differing legal speed limit locations (e.g. UK, USA etc.)

In the UK for 26-28" wheels then the lower 201rpm unit is best allowing a maximum speed just higher than our legal limit.
This has the advantage of better torque at lower speeds so its hill climbing ability will be better than the higher rpm units.

The Chinese kits such as Yose all to my knowledge and experience have the higher rpm motors fitted to cater for all markets, whilst this is not ideal in practise it is not a huge drawback though given the choice I would always specify the 201rpm unit.

HTH

Re: E bike conversion

Posted: 22 Sep 2020, 8:03am
by Bonzo Banana
philg wrote:
bikes4two wrote:Hi Hemo,
Hub motors come in various winding speeds or Rpm, for fast riding on flattish terrain then go for a high wound hub. If the terrain takes in inclines then one needs a lower wound slower rpm hub


Can you expand on the above please e.g.
> what exactly is 'high wound' and 'low wound' (what figures/parameters describe this)? Maybe some typical figures might help my understanding.
> and how do you find these parameters for any particular hub motor offering

Unless I missed it, none of the listings linked to by PhilG gave such information?

Thanks.

I think he's referring to the maximum rpm that the motors are designed for.
A typical hub motor here
http://www.topbikekit.com/akm100cst-cas ... _uploads=0
has 2 winding options - 201 and 328rpm allowing for different wheel sizes in differing legal speed limit locations (e.g. UK, USA etc.)

In the UK for 26-28" wheels then the lower 201rpm unit is best allowing a maximum speed just higher than our legal limit.
This has the advantage of better torque at lower speeds so it's hill climbing ability will be better than the higher rpm units.

The Chinese kits such as Yose all to my knowledge and experience have the higher rpm motors fitted to cater for all markets, whilst this is not ideal in practise it is not a huge drawback though given the choice I would always specify the 201rpm unit.

HTH


That's really good info I think I saw that before but assumed it was purely for wheel sizes, i.e. high rpm for 20" wheels and low rpm for larger wheels but it makes a lot of sense it also works to keep to road legal speeds with smaller wheels.

Re: E bike conversion

Posted: 22 Sep 2020, 11:26am
by hemo
Always opt for geared hub motor that is one that has an internal clutch that allows the hub to freewheel with out power in low gears, Direct drive hubs do not all ow this.
Rpm/ winding speed has been mentioned, the speed issue is neither here or there. they can be set to remain legal. What is important is one matches a particular winding to the circumstances the bike will be used for, if one encounters inclines/hills then a low wound/rpm motor is more efficient for getting up them. A high wound/rpm motor may bog down and overheat on inclines,a low wound motor will climb with ore torque at lower speed. The heavier the load and rider/bike, the more reason to have a low wound winding.

Mid drive motors are a different kettle of fish OEM ones are torque sensored so simply relies on rider input power and correct gear selection, if one has weak leg power or stamina then they are a less desirable option.

201rpm is often the best option for 26" wheels and above. If one wants to go faster pedal beyond the cut off, good if you want a nice work out but simply don't like hills. If one is using a small wheeled bike <20" then opt for 300- 328 rpm for good torque and speed, a 201rpm hub in a small wheel will equate to approx. < 12mph so might be a bit too slow.

Re: E bike conversion

Posted: 22 Sep 2020, 12:31pm
by bikes4two
Thanks for the clarification regarding was it low RPM or high RPM - there was no mention in the Woosh and Yosepower listing as to RPM but the TopBikeKit listing has a drop-down menu for RPM selection (201 or 328).

Re: E bike conversion

Posted: 22 Sep 2020, 2:18pm
by philg
bikes4two wrote:Thanks for the clarification regarding was it low RPM or high RPM - there was no mention in the Woosh and Yosepower listing as to RPM but the TopBikeKit listing has a drop-down menu for RPM selection (201 or 328).

One would hope that Whoosh, catering mainly for the UK domestic market would choose the lower option for the larger wheels.
Yose IME always use the higher option. Despite this being the less desirable option for hilly area, down here on Exmoor the rear drive kits do cope with climbs exceeding 20%, though with significant rider effort but that suits me, YMMV.

One thing to mention is that the Lishui controllers Yose now offer are 'speed' control and not the previous KT 'torque/current' control.
As an operating system I much prefer this as it needs far less/no change in PAS level during a ride - provided you can set the level at a speed you are happy with.

Unfortunately the term speed control is a misnomer, they are RPM control - it has no way of knowing the actual speed but calculates it from the wheel diameter and it's own measurement of RPM. The 5 PAS levels for the Lishui are preset at IIRC 40% 55% 70% 85% and 100% of maximum RPM. This corresponds, on a 700c wheel to speeds from approx 10mph up to 25mph and only the first 3 are within the legal UK limit - you basically have only 3 speeds to choose from.

The Swytch controller is also speed control but allows you to program each level individually and also a choice of the number, up to 9 which is overkill but very flexible - why Yose do not use the Lishui firmware that also allows this is a mystery to me, it does smack on unnecessary penny pinching.

Re: E bike conversion

Posted: 22 Sep 2020, 5:36pm
by hemo
Woosh usually use low rpm hubs, they are nice people to speak to so ask for Tony or Andy and they will give you the low down on the hubs. Yosepower now use I believe 201 rpm hubs as opposed to the 270/300 rpm ones, personally speaking the speed controllers do not give as nice a ride as current/torque controllers.

Re: E bike conversion

Posted: 27 Sep 2020, 5:53pm
by bikes4two
Well, there's a first, a posting from someone (PhilG) who prefers a speed control system over a current/torque controller!

We only have one ebike in our household - my wife's and it was 'speed control' - it was impossible for her to pedal alongside someone on a non-ebike as the speed control either left her behind or somewhere in front but never able to go at a similar speed.

I changed the system to a KT controller - what a difference and very much for the better - but each to their own :-)