Yose Power Rear 48v freewheel question

[Klang180]

So after much deliberation and great advice from people on here I bit the bullet and went and got the Yose Power 48v rear hub kit.

I am looking forward to it arriving but whilst I do I am turning my attention to the Freewheel i will need to purchase as my donor bike has a cassette. My donor bike is a 9 speed but i see 9 speed freewheels are hard to come by and those that you can buy are non-shimano. So my question is do I go with a non Shimano 9 speed or a Shimano 8 speed and will both of these fit on the Yose Power?

I am very familiar with bikes and do my own servicing but I have never dealt with freewheels as they are somewhat "old hat". I am happy to run my 9 speed setup as an 8 speed using the H/L limiters to prevent any issues but will the YH even take an 8 speed let alone a 9 speed? Would I be better off going all the way down to a 7 speed in this case?

Anyway, thanks again to all those who helped me get this far for my first (of many?) ebike conversion.

 

[vfr400]

The import thing is the stack-height of the gears. You need it to be as low as possible to get the wheel on the centre-line of your frame without having a large off-set in the rim.

Some frames have a bit of an off-set built in, but many are symmetrical, so I'm assuming the latter.

When you fit a DNP 7-speed freewheel, you need a bit of an off-set (dish) to the rim relative to the centre of the hub spoke flanges. That results in a slightly different spoke tension from one side to the other. An 8-speed DNP freewheel is a bit wider, so you need more off-set, which results in a much bigger difference in spoke tension between the two sides. The difference in spoke tension goes up exponentially as the off-set increases, so a little off-set is OK, but a big one isn't.

You can mitigate the off-set by stretching your frame a bit and adding washers to the axle on the other side. That's a really good solution for rim brakes, but if you have a disc, you need to add spacers to either the disc or caliper to get them to line up properly. Despite what people say, who have never done it, it's OK to stretch an aluminium or steel frame. There will be no long-term or other failures.

Regarding 9 and 10 speed gears, I can't say because I never tried them. The spacing of 9-speed is less than 7 and 8 speed, so it might be OK. Also 10-speed spacing is less than 9-speed, but someone needs to confirm the spacing on those DNP ones.

The most important thing for an electric bike is that you get 11 or 12 teeth on the top gear to avoid running out of pedal speed., otherwise you need to change your chainwheel to 50T or above.

 

[Klang180]

The import thing is the stack-height of the gears. You need it to be as low as possible to get the wheel on the centre-line of your frame without having a large off-set in the rim.

Some frames have a bit of an off-set built in, but many are symmetrical, so I'm assuming the latter.

When you fit a DNP 7-speed freewheel, you need a bit of an off-set (dish) to the rim relative to the centre of the hub spoke flanges. That results in a slightly different spoke tension from one side to the other. An 8-speed DNP freewheel is a bit wider, so you need more off-set, which results in a much bigger difference in spoke tension between the two sides. The difference in spoke tension goes up exponentially as the off-set increases, so a little off-set is OK, but a big one isn't.

You can mitigate the off-set by stretching your frame a bit and adding washers to the axle on the other side. That's a really good solution for rim brakes, but if you have a disc, you need to add spacers to either the disc or caliper to get them to line up properly. Despite what people say, who have never done it, it's OK to stretch an aluminium or steel frame. There will be no long-term or other failures.

Regarding 9 and 10 speed gears, I can't say because I never tried them. The spacing of 9-speed is less than 7 and 8 speed, so it might be OK. Also 10-speed spacing is less than 9-speed, but someone needs to confirm the spacing on those DNP ones.

The most important thing for an electric bike is that you get 11 or 12 teeth on the top gear to avoid running out of pedal speed., otherwise you need to change your chainwheel to 50T or above.

That was very helpful indeed. Assuming my frame is symmetrical (not at home at the moment) and given that I have rim brakes it sounds like the washer method would work well for me. Silly question but how do i know where the offset is so to speak, do I just sit it in the frame and see if it is central or is there a more precise means to do so? Should i ask Yose Power what dish they have set it up on in order to know where the spacers should go and which freewheel to get? They say compatible for 6-9 speeds but it seems like you are inferring there is an ideal that it is designed for?

Good advice on the gear teeth, I have 11T -34T on there right now and I would not like to go stray too far from that. I see I can get 11-32 Shimano freewheels so i guess that will do as the granny wheel on my triple ring up front never gets used anyway!

Thanks again vfr you've been so helpful from the get go!

 

[vfr400]

When you put the motor wheel with the freewheel in the frame with the bike inverted, you can look from behind and see whether the rim is in the centre of the frame. You can put a straight edge on the rim and see where it points to where the frame narrows at the seat-tube/bottom bracket area. A few mm doesn't matter.

 

[Klang180]

When you put the motor wheel with the freewheel in the frame with the bike inverted, you can look from behind and see whether the rim is in the centre of the frame. You can put a straight edge on the rim and see where it points to where the frame narrows at the seat-tube/bottom bracket area. A few mm doesn't matter.

Thanks, that is very clear. Thanks so much.

 

[Klang180]

I see the DNP freewheels are 36mm wide in 7 speed and 40mm wide in 8 or 9 speed. I'm not sure which would be better for the yose hub do you or anyone else know? Does it really make a difference? Got a 9 speed shifter so feel like a 9 makes most sense but I actually don't care about more gears in between the top and bottom as long as the top is 11t.

 

[chris_n]

I see the DNP freewheels are 36mm wide in 7 speed and 40mm wide in 8 or 9 speed. I'm not sure which would be better for the yose hub do you or anyone else know? Does it really make a difference? Got a 9 speed shifter so feel like a 9 makes most sense but I actually don't care about more gears in between the top and bottom as long as the top is 11t.

Bear in mind the spacing between the sprockets varies depending on the number of gears. 7 speed is 5mm centre to centre, 8 speed is 4.8 and 9 is 4.34 so you will have problems indexing correctly.
The DNP freewheel is much wider than a standard Shimano or Sram (I know that is to cater for the 11 tooth sprocket) with a Shimano coming in at 31.9 for 7 speed (HG) and 36.8 for a Sram 8 speed frewheel.
All measurements courtesy of Sheldon Brown https://www.sheldonbrown.com/cribsheet-spacing.html

 

[Klang180]

Bear in mind the spacing between the sprockets varies depending on the number of gears. 7 speed is 5mm centre to centre, 8 speed is 4.8 and 9 is 4.34 so you will have problems indexing correctly.
The DNP freewheel is much wider than a standard Shimano or Sram (I know that is to cater for the 11 tooth sprocket) with a Shimano coming in at 31.9 for 7 speed (HG) and 36.8 for a Sram 8 speed frewheel.
All measurements courtesy of Sheldon Brown https://www.sheldonbrown.com/cribsheet-spacing.html

Thanks very much for this. I'm wondering whether this hub motor is was such a good idea now as it seems I'm going to need to a new freewheel, chain and shifter too and by the looks of it I'd be losing teeth at the top end in order to accommodate a more standard size. Starting to wish I'd gone mid drive but surely it can't just be people getting 7 speed bikes to fit these kits on as that bike would either be very bad or very old.

 

[vfr400]

The 8 speed is too wide. You can use it, but you have to stretch or spring the frame and use washers on the axle. If the 9-speed is the same width, you'd have to do the same.

 

[Klang180]

The 8 speed is too wide. You can use it, but you have to stretch or spring the frame and use washers on the axle. If the 9-speed is the same width, you'd have to do the same.

Thanks that's really helpful. So the choice is get the 9 speed with 11t and stretch the frame or get a shimano 7 speed and put up with only 13t. It's not ideal either way.

 

[Klang180]

Thanks that's really helpful. So the choice is get the 9 speed with 11t and stretch the frame or get a shimano 7 speed and put up with only 13t. It's not ideal either way.

Or get the 11t 7 speed and perhaps stretch the frame and get new shifters. I'm erring towards that option.

 

[vfr400]

The DNP 7-speed has 11T top gear and doesn't require the frame stretched.

 

[Klang180]

The DNP 7-speed has 11T top gear and doesn't require the frame stretched.

That's the one then. I'll have to see how the shifters and derailleur work on that but I think the latter will be fine and the former a cheap fix.

 

[Ten98]

I made the mistake of getting the freewheel kit when my existing gears were an 8-speed Shimano cassette.

I ended up getting an 8-speed "Tranzmission" freewheel on Amazon for about £15, it fits perfect. Nothing fancy.

It doesn't have to be Shimano, and it doesn't even have to match the same ratios as as are already on the bike really.

The one I got is designed for road bikes I think, so it's a fairly high ratio gear set, but this is a benefit really since the motor provides a lot of power. I find myself using gear 3 on even the very steepest hills, gear 1, even though it's quite a lot smaller than my old gear 1, is totally unneccesary!

They do have a 9-speed as well which might suit your project a bit better? IDK.

Tranzmission 13-32 - 9 Speed Freewheel : Amazon.co.uk: Sports & Outdoors

Shop Tranzmission 13-32 - 9 Speed Freewheel. Free delivery and returns on all eligible orders.

www.amazon.co.uk

 

[vfr400]

I made the mistake of getting the freewheel kit when my existing gears were an 8-speed Shimano cassette.

I ended up getting an 8-speed "Tranzmission" freewheel on Amazon for about £15, it fits perfect. Nothing fancy.

It doesn't have to be Shimano, and it doesn't even have to match the same ratios as as are already on the bike really.

The one I got is designed for road bikes I think, so it's a fairly high ratio gear set, but this is a benefit really since the motor provides a lot of power. I find myself using gear 3 on even the very steepest hills, gear 1, even though it's quite a lot smaller than my old gear 1, is totally unneccesary!

They do have a 9-speed as well which might suit your project a bit better? IDK.

Tranzmission 13-32 - 9 Speed Freewheel : Amazon.co.uk: Sports & Outdoors

Shop Tranzmission 13-32 - 9 Speed Freewheel. Free delivery and returns on all eligible orders.

www.amazon.co.uk

How did you get your wheel central? Did you dish it? If so, how far? Is your wheel central?

 

[Klang180]

I made the mistake of getting the freewheel kit when my existing gears were an 8-speed Shimano cassette.

I ended up getting an 8-speed "Tranzmission" freewheel on Amazon for about £15, it fits perfect. Nothing fancy.

It doesn't have to be Shimano, and it doesn't even have to match the same ratios as as are already on the bike really.

The one I got is designed for road bikes I think, so it's a fairly high ratio gear set, but this is a benefit really since the motor provides a lot of power. I find myself using gear 3 on even the very steepest hills, gear 1, even though it's quite a lot smaller than my old gear 1, is totally unneccesary!

They do have a 9-speed as well which might suit your project a bit better? IDK.

Tranzmission 13-32 - 9 Speed Freewheel : Amazon.co.uk: Sports & Outdoors

Shop Tranzmission 13-32 - 9 Speed Freewheel. Free delivery and returns on all eligible orders.

www.amazon.co.uk

Thanks for the info that's interesting. I actually went for a dnp 7 speed as it had the 11t small ring and with only a 44t up front a 13t would have topped out at 21mph rather than the 25-6 it will with the 11t.

I will let you know if it's a decent quality item but thanks for the benefit of your experience.

 

[Charliefox]

So after much deliberation and great advice from people on here I bit the bullet and went and got the Yose Power 48v rear hub kit.

I am looking forward to it arriving but whilst I do I am turning my attention to the Freewheel i will need to purchase as my donor bike has a cassette. My donor bike is a 9 speed but i see 9 speed freewheels are hard to come by and those that you can buy are non-shimano. So my question is do I go with a non Shimano 9 speed or a Shimano 8 speed and will both of these fit on the Yose Power?

I am very familiar with bikes and do my own servicing but I have never dealt with freewheels as they are somewhat "old hat". I am happy to run my 9 speed setup as an 8 speed using the H/L limiters to prevent any issues but will the YH even take an 8 speed let alone a 9 speed? Would I be better off going all the way down to a 7 speed in this case?

Anyway, thanks again to all those who helped me get this far for my first (of many?) ebike conversion.

Not sure if we are talking about a bike with triple front rings....so a 24 speed. I electrified 24spd MTB and I rarely need to change to the largest rear cog as I can always go down a front ring. You would be travelling so slowly by then that the rear hub motor would not be that effective anyway. If only a single front ring then 8 speed rear cluster would be a bit limiting on steep trails but fine on normal road hills. I would try an 8 speed shimano screw on and see how it goes. Cheap as chips anyway and also 8 speed chains.