Changed 350 back to 250 yosepower

[it is i footpump]

Hi all have kudos ebike 26” mtb fitted with 36v 350w rear moter, kt lcd 4 ,kt 17amp controller.
My previous 250 moter failed so purchased 350 yose, found using thumb throttle 15mph old setup. 18 mph with 350w moter as it revs higher.
Found using level 5 assist the controller would get very very hot, in fact one controller failed, so rarely used the bike in case it let me down miles from home.

recently while perusing yosepower site found they had a rear 36v 250 rear moter kit ,freewheel 26” ,described as non waterproof ,£155 throttle only kit.
So i ordered sunday night ,arrived tuesday from wigan if i recall.

I was pleased to find that the moter wheel 250w. Married up to my existing 17amp controller, so just swapped over 350,to 250.

not used it for any long journeys but all seems to be ok,as the 250 revs slower i can use the gears more so than with the 350.
With the 350 i did not think it was as good on hills as the 250 (with original kt 15amp controller). Also i lost about 5 miles in range going from 250 -350.

i normally. Use assist mode 4 or 5 battery is 17ah yosepower, do not know what range is .?

compared to my ktm bosch 50nm bike it does feel less nippy but is nice if i just want to poddle about as its speed sensor not ts

 

[saneagle]

That's helpful information, thanks. Some of the original Kudos motors were very slow. The stepthrough one had a 180 rpm motor , so it was pretty good on hills, but only good for 15mph on the flat. The Yose ratings of 250w and 350w are meaningless. Both motors will produce the same power with the same controller. The motor's maximum rpm makes a difference to how well they climb. The slower the motor, the better it climbs. The Chinese tend to mark 20 mph stuff as 350w and 15 mph stuff 250w, so I'd say that the Yose 250w kit is optimised for 15 mph. It's a shame, they don't let you mix and match parts because the 250w motor with the 350w controller would be good for a lot of people who want that extra help up hills and are not bothered by speed.

 

[Cadence]

The Chinese tend to mark 20 mph stuff as 350w and 15 mph stuff 250w, so I'd say that the Yose 250w kit is optimised for 15 mph. It's a shame, they don't let you mix and match parts because the 250w motor with the 350w controller would be good for a lot of people who want that extra help up hills and are not bothered by speed.

I can confirm that from my recent experience. My two bikes have Yose kits fitted, which are the more recent ones with C500 displays.
The 250w rear cassette kit as supplied had a JYT brand 15A controller and C500 display with a fixed 15mph top speed and "walk assist" only throttle. I've substitued a Lishui 18A controller and another C500 display (bought separately from Yose) which enabled top speed and throttle settings. The extra amps have resulted in even better hillclimbing than before and achievable top speed is now 18mph.

My other bike has a 350w rear freewheel kit fitted and with the supplied Lishui 18A controller can achieve a top speed of about 23mph - not that I want to go that fast very often. It is not as good as the "enhanced" 250w at climbing hills however, which I put down to the difference in motor RPM, as you suggest. I definately have to start a long climb at some speed with the 350w or the motor feels as if it is slowing too much. The controller and motor have never got hot yet, but it's something I watch carefully.
Overall I'm happy with them both, but the 250w is on a 28" wheel hybrid and the 350w is on a 26" wheel rigid MTB. I really wish it was the other way around, but you can't have everything!

 

[Nealh]

The 15a Kt's suffer from thermal cut outs (mosfets get to hot and temporary short out) this occurs in high PAS and going to slow up inclines , I found the answer was to swap the 6 mosfets controllers (so6) for a the S09 version .

 

[saneagle]

I can confirm that from my recent experience. My two bikes have Yose kits fitted, which are the more recent ones with C500 displays.
The 250w rear cassette kit as supplied had a JYT brand 15A controller and C500 display with a fixed 15mph top speed and "walk assist" only throttle. I've substitued a Lishui 18A controller and another C500 display (bought separately from Yose) which enabled top speed and throttle settings. The extra amps have resulted in even better hillclimbing than before and achievable top speed is now 18mph.

My other bike has a 350w rear freewheel kit fitted and with the supplied Lishui 18A controller can achieve a top speed of about 23mph - not that I want to go that fast very often. It is not as good as the "enhanced" 250w at climbing hills however, which I put down to the difference in motor RPM, as you suggest. I definately have to start a long climb at some speed with the 350w or the motor feels as if it is slowing too much. The controller and motor have never got hot yet, but it's something I watch carefully.
Overall I'm happy with them both, but the 250w is on a 28" wheel hybrid and the 350w is on a 26" wheel rigid MTB. I really wish it was the other way around, but you can't have everything!

It's possible that you got the slower motor in the 250w kit because of the 28" wheel. They often match motor RPM to wheel size, like 201 rmp for 700c and 29" wheels, 250 rpm for 26" ones and 328 rpm for 20" ones. We need info from others to get the complete picture for definite.

 

[Wayners]

I've bought the 250w yose power in march 2023 and I fiddled in the hidden menu following YouTube video.
Increased the max speed to 30mph ( never going to get that) and i get 17.5mph in the real world with a full battery.
I think the 350w will get a little past 20mph but not so good on hills.

I thought the difference was geared 250w Vs direct drive 350w. Same motor though?

 

[saneagle]

I've bought the 250w yose power in march 2023 and I fiddled in the hidden menu following YouTube video.
Increased the max speed to 30mph ( never going to get that) and i get 17.5mph in the real world with a full battery.
I think the 350w will get a little past 20mph but not so good on hills.

I thought the difference was geared 250w Vs direct drive 350w. Same motor though?

Most likely the number of turns in the windings. The lower the number, the higher the speed. I'm pretty sure that's what the Bafang codes are. Code 8 = 8 turns per coil, and code 11, 11 turns.

 

[Slightlypedantic]

My Yose Power 250W rear hub motor in 700c wheel is marked:

"Yose" with logo and 250W.
AKM21123095065 = serial no?
95RX.RC250-3628 = (see below)

I think this is a rebranded Aikema 95RX - it looks identical.

Presumably
"RC250" means Rear hub, Cassette, 250W?
and
"3628" means 36V, 28"?

Is anyone able to say if that is correct?

I'd be interested to know what speed it is. Anyone?

I know the motor has 18 coils but don't know how many turns on each but it looks more than 8. (Reduction ratio appears to be 14:1.) Does the serial number hold this clue? E.g. does "11230" mean 11 turns per coil and 230rpm?

 

[saneagle]

My Yose Power 250W rear hub motor in 700c wheel is marked:

"Yose" with logo and 250W.
AKM21123095065 = serial no?
95RX.RC250-3628 = (see below)

I think this is a rebranded Aikema 95RX - it looks identical.

Presumably
"RC250" means Rear hub, Cassette, 250W?
and
"3628" means 36V, 28"?

Is anyone able to say if that is correct?

I'd be interested to know what speed it is. Anyone?

I know the motor has 18 coils but don't know how many turns on each but it looks more than 8. (Reduction ratio appears to be 14:1.) Does the serial number hold this clue? E.g. does "11230" mean 11 turns per coil and 230rpm?

think the speed is given by the 28, meaning 28" wheel. It would be interesting to see what markings are on a motor for a 26" kit, and see whether it has the same speed.

 

[Wayners]

My front 250w hub. 26 Inch wheel. 17.5mph

 

[saneagle]

Do I understand that right: The one marked 26 does 17.5 mph in a 26" wheel and the one marked 28 does 17.mph in a 28" wheel. That means the 26 must be around 201 rpm and the 28 185 rpm. Are you both talking about wheel in the air speed with a fully-charged battery?

 

[Wayners]

17.5mph going down the road with a 26inch wheel and 2.00 tyres.
I was struggling for 17mph on way home today as battery not 100%

In the air speed 18.5mph although battery at 80% Ish at the moment. I'll charge tomorrow when I get home

 

[saneagle]

Need exact battery voltage and no-load speed to get meaningful info.

 

[Cadence]

This is my 26" wheel 350w Yose rear freewheel hub:-



With the supplied Lishui 18A contoller I have been able to just touch 23.5mph on the flat with the power tailing off.

This is my 28" wheel 250w Yose rear cassette hub:-



With the supplied JYT 15A controller it was restricted to 15.5mph. However, on fitting a Lishui 18A controller and different C500 display from Yose I am able to get the speed up to 18mph on the flat - but no higher (even if I set the max speed in the display to 23.5mph).

Quite what this says about the markings I'm not sure, but the 250w motor is a better hill climber so I suspect it has lower reduction gears. The end part of the numbers I assume refers to spoke count and wheel size (3626 and 3628) although it could be voltage and wheel size.
These motors are listed on Aikema's website, but unhelpfully they don't state windings or reduction ratios.

The 95RX. RC 250w :-
aikema HUB MOTOR

And the 95RS.R 350w (despite only being listed as a 250W !) :-
aikema HUB MOTOR

It's obvious that R means rear and RC means rear cassette, but what the RX and RS denote is beyond me. Maybe X is "extra torque" and S is "standard". Confused? you will be!

 

[saneagle]

This is my 26" wheel 350w Yose rear freewheel hub:-

View attachment 53397

With the supplied Lishui 18A contoller I have been able to just touch 23.5mph on the flat with the power tailing off.

This is my 28" wheel 250w Yose rear cassette hub:-

View attachment 53398

With the supplied JYT 15A controller it was restricted to 15.5mph. However, on fitting a Lishui 18A controller and different C500 display from Yose I am able to get the speed up to 18mph on the flat - but no higher (even if I set the max speed in the display to 23.5mph).

Quite what this says about the markings I'm not sure, but the 250w motor is a better hill climber so I suspect it has lower reduction gears. The end part of the numbers I assume refers to spoke count and wheel size (3626 and 3628) although it could be voltage and wheel size.
These motors are listed on Aikema's website, but unhelpfully they don't state windings or reduction ratios.

The 95RX. RC 250w :-
aikema HUB MOTOR

And the 95RS.R 350w (despite only being listed as a 250W !) :-
aikema HUB MOTOR

It's obvious that R means rear and RC means rear cassette, but what the RX and RS denote is beyond me. Maybe X is "extra torque" and S is "standard". Confused? you will be!

we need the no-load wheel in the air speed and the exact battery voltage at the time.

 

[Cadence]

A bit late getting back with this, but I've not had chance to test both motors earlier.
So, using the same battery at 39.8V level, the Yosepower AKM95RS 350w rear freewheel in a 28" wheel reaches a no-load top speed of 23.8mph.
The Yosepower AKM95RX 250w rear cassette in a 26" wheel reaches 19.4mph.
Both on a stand and using the throttle.
They are both paired with a Lishui 18A controller and C500 displays set to max speed(which is 24.8mph). There could obviously be discrepancies in accuracy between the two displays, but if so probably not much.
Other than the obvious fact that the 350w motor is faster I'm not sure what this tells us.
The 350w looks slightly larger in size, but hard to measure properly. Although Aikema list 95RS and 95RX motors on their website, none of them quite match up. In particular, the 95RS is only listed at 250W, not 350w.
Yosepower claim 58Nm for the 250w when paired with a 15A controller and 48Nm for the 350w with an 18A controller. That suggests to me that the 250w is lower geared than the 350w? It certainly seems to climb better than the 350w when they both use 18A controllers. On the other hand, the 350w definitely accelerates more quickly. The 350w sounds as if it is spinning faster at max speed, so maybe that is 270rpm and the 250W is 201rpm? Or perhaps it's due to the different wheel sizes? Or both? Or all three? Dunno!

 

[saneagle]

A bit late getting back with this, but I've not had chance to test both motors earlier.
So, using the same battery at 39.8V level, the Yosepower AKM95RS 350w rear freewheel in a 28" wheel reaches a no-load top speed of 23.8mph.
The Yosepower AKM95RX 250w rear cassette in a 26" wheel reaches 19.4mph.
Both on a stand and using the throttle.
They are both paired with a Lishui 18A controller and C500 displays set to max speed(which is 24.8mph). There could obviously be discrepancies in accuracy between the two displays, but if so probably not much.
Other than the obvious fact that the 350w motor is faster I'm not sure what this tells us.
The 350w looks slightly larger in size, but hard to measure properly. Although Aikema list 95RS and 95RX motors on their website, none of them quite match up. In particular, the 95RS is only listed at 250W, not 350w.
Yosepower claim 58Nm for the 250w when paired with a 15A controller and 48Nm for the 350w with an 18A controller. That suggests to me that the 250w is lower geared than the 350w? It certainly seems to climb better than the 350w when they both use 18A controllers. On the other hand, the 350w definitely accelerates more quickly. The 350w sounds as if it is spinning faster at max speed, so maybe that is 270rpm and the 250W is 201rpm? Or perhaps it's due to the different wheel sizes? Or both? Or all three? Dunno!

That's good info. It helps a lot. When you compensate for the wheel size, there's about 10% difference in motor speed. That might be measurement error, which you could determine with a normal cheapo cycle computer that shows cadence to get the wheel rpm. Using the same device on each wheel would eliminate any difference due to meaurement.

If you average the size-compensated speeds, by adding 5% to one and subtracting from the other, you get a motor speed of 275 rpm at 39.8V, which would be 249 rpm at 36v. Without the averaging, the speeds would be about 236 and 260 rpm at 36v.

The 26" wheel has an 8% torque advantage over the 700C one when using the same motor and controller due to the size of the wheel, so yes it has lower gearing, but that's not in the motor.

According to my calculations, the front motor is about 5mm wider than the rear one, so that could make a difference.

Considering everything, I think you're right that the 95RX makes more torque and runs a bit slower than the 95RS. I suspect that the difference is in the windings, but it's not a lot. Say it's 10% difference, then you add the 8% difference from the wheel size, which is 18% overall. That's the difference you can feel.

 

[Cadence]

Thanks for the response. I am grateful for your time and knowledge.
This is relevant to me now because I'm swinging backwards and forwards over what front hub motor to get for my wife's 26" wheeler (in a separate thread).
I was sold on a 36V 350W AKM100H at 201rpm (12:1 gears), but based on what you say above I should perhaps be looking around 270rpm to achieve a top speed of around 18mph but with good hill climbing ability? Problem is I can't find one at 260rpm.
My thoughts now turn to a 250W XF07 at 270rpm (4.4:1)?
Or perhaps TBK-100AD 36v 250W at 280rpm (12:1)? Interesting comment in the description
"The TBK-100AD and AKM-100SX motor manufacturer is different". So it's a clone?
I really should stop letting these things nag away at me, While typing this an old song with the words "the more I find out, the less I know" was running through my head. I just had to google it to find the singer. Johnny Nash - I would never have remembered that!

 

[saneagle]

Thanks for the response. I am grateful for your time and knowledge.
This is relevant to me now because I'm swinging backwards and forwards over what front hub motor to get for my wife's 26" wheeler (in a separate thread).
I was sold on a 36V 350W AKM100H at 201rpm (12:1 gears), but based on what you say above I should perhaps be looking around 270rpm to achieve a top speed of around 18mph but with good hill climbing ability? Problem is I can't find one at 260rpm.
My thoughts now turn to a 250W XF07 at 270rpm (4.4:1)?
Or perhaps TBK-100AD 36v 250W at 280rpm (12:1)? Interesting comment in the description
"The TBK-100AD and AKM-100SX motor manufacturer is different". So it's a clone?
I really should stop letting these things nag away at me, While typing this an old song with the words "the more I find out, the less I know" was running through my head. I just had to google it to find the singer. Johnny Nash - I would never have remembered that!

Personally, I found the XF07 a bit weak. I talked to the MXUS sales people about it, who told me there were different versions for different markets. Some have weak magnets and thinner wire in the windings. I believed it at the time, but I'm not sure now.

Most motors are in the range 250 to 270 rpm. I can't see there being a big difference between them. You can always compensate by using higher current of voltage. If you want more climbing ability and speed, the solution is to step up to 48v. Any 260 rpm 36v motor becomes a 338 rpm one at 48v and you get 30% more torque with the same current (15A). In that case a slightly slower wind would be better. A 36v with about 230 to 250 rpm would be ideal. A 201 rpm one would give 30% more torque and the same speed as what you already have, so that would be the best choice for legal speeds.

Once you move up to 48v, 36v seems very lame.

 

[Cadence]

Problem is, with two other bikes, I want to keep a standard battery between all of them ( 36v 13Ah Hailong H1). Shame about the XF07, although I notice Woosh use it in their kits. I had read somewhere else that the XF07 was a bit weak (it may have been you! ).
Other than taking a punt on that TBK-100AD I now feel a bit stuck, unless......
BMSbattery list Q100H 36v. 350w in 260rpm. " Reduction Ratio 12:6"
or Q100 36v. 250-350w in 260rpm "Rated speed 8.1 Reduction Ratio 16" (no colon but assume 1:6?).
More confusion!
Edit - I think I've worked it out The Q100 description should read something like "reduction ratio for 325rpm is 8:2. Reduction ratio for 201 rpm is 12:6. " Perhaps someone in the Orient has fat fingers like me. Lord knows what the 260rpm version is though - 12:6 at a guess.