8 speed cassette

ian slater

Pedelecer
Mar 31, 2024
47
0
Hi
Can anyone offer some advice please,i have bought a yose power conversion kit.The rear wheel hasn't come with a brake disc or rear sprocket.I've sorted the brake disc but unsure about cassette, the reason being is that there's a thread around 38mm -40mm and wanted to know which type of sprocket i have to buy please.Any feedback appreciated
Thank you
Ian
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,842
3,169
Telford
If you have the threaded boss, it's for a freewheel, not a cassette, in which case it's better to limit yourself to a 7-speed one because of the width. I'd recommend a DNP freewheel with 11 teeth on top gear. Most freewheels are 13 or 14 teeth, which makes the gearing a bit low for an electric bike.

These ones have a little surface rust on them, but that's nothing to worry about. As a precaution, you should pour in a bit of 3-in 1 oil before you install it. It's 11/28. 11/30 is better but harder to find.


Or you can pay more for one of these:
 
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saneagle

Esteemed Pedelecer
Oct 10, 2010
6,842
3,169
Telford
I forgot to mention that the gearing is only a problem with 26" wheels or smaller. 29" ones would be OK with 13T top gear.

To clarify the position with 8-speed ones. They're wider, so it's a bit more difficult to get the motor between the drop-outs. The worse thing, though, is that it's only wider on one side, so when you eventually get it in, the wheel won't be central to the frame, so you have to dish it. It probably already has a bit of a dish because geared hub-motors are always off-centre. The extreme dish you need for 8-speed means that the spokes have little tension the drive side, so they come loose.

I've run a few bikes with 8-speed free-wheels. It can be done. It's just a bit awkward to get it right. Some frames are better than others. A bike that started as an OEM ebike might well have an off-set frame, which would make it much easier.
 

AndyBike

Esteemed Pedelecer
Nov 8, 2020
1,395
598
As above - its a freewheel cassette you need, no a freehub cassette, which is often just referred to as a 'cassette' So make sure the description has 'freewheel' in it

Most of these though are mountainbike orientated, which has large lower speed gearing of maybe 11/12-36/38, but you can get road orientated cassettes that have a tighter range of gears, so if youre on the lower speed gear your wee legs arent spinning like a kitchen fan

Roadie cassettes have always been popular on downhill orientated bikes for this close grouping.