Which cassette for Trek Ebike conversion

[josaphine30]

Hi, I have a Trek EX 5.5 mountain bike and I have ordered the 500W em3ev rear wheel hub motor kit. My Trek has a 9 speed cassette on the back that is held on with a nut, it does not screw on. I need to know which cassette I will need to get for it to work on the hub motor wheel and do they sell them here in the UK? Thanks

 

[neptronix]

Hi, I have a Trek EX 5.5 mountain bike and I have ordered the 500W em3ev rear wheel hub motor kit. My Trek has a 9 speed cassette on the back that is held on with a nut, it does not screw on. I need to know which cassette I will need to get for it to work on the hub motor wheel and do they sell them here in the UK? Thanks

Ah, you missed something when you ordered from him.
You need a threaded freewheel.
He and others sell threaded freewheels by DNP that have 11 tooth gears which are excellent.
Shimano has freewheels with 13t lower gears on them as well. I know that here in America you can pick those up at local bike shops pretty easily, but not sure about the UK.

 

[josaphine30]

So I need a threaded free wheel cassette?

 

[neptronix]

So I need a threaded free wheel cassette?

Technically it's not called a cassette, it's just called a threaded freewheel.

 

[josaphine30]

Ok thank you, will another 9 speed be okay or does it have to be 6 speed? I remember hearing somewhere that 6 speed is better

 

[neptronix]

Ok thank you, will another 9 speed be okay or does it have to be 6 speed? I remember hearing somewhere that 6 speed is better

Try to replace it with however many speeds you had before, because you might end up with a a chain designed for X amount of speeds, but when you switch to another, you may have issues.

http://en.wikipedia.org/wiki/Bicycle_chain#Width

See here.

 

[Punx0r]

I would be interested if you find a source of 11-tooth threaded freewheels in the UK

 

[geeeyejo1]

I would be interested if you find a source of 11-tooth threaded freewheels in the UK

You can find an 11 tooth freewheel on Ebay - here is an 8 speed one - http://www.ebay.com/itm/DNP-Epoch-8-Speed-Freewheel-11T-Small-Cog-11-32-/230838943760?pt=Cycling_Parts_Accessories&hash=item35bf12c010
The number of gears will be irrelevant when you convert as you will likely only use your top gear - 11t is the way to go to allow you to pedal effectively above 20mph or so... You can either pick up a 8 speed gear shifter or just set your derailleur so the top gear lines up properly - you will still be able to shift - just might not line up all gears and only be able to access 7 to 8 of them on new freewheel

 

[dnmun]

you could ask paul if he has shipped the motor and if not then he can include the freewheel for you.

 

[dogman dan]

You may need to replace the chain as well. I think 9 speed chain is that narrow. Wider chain should work fine on your front chain rings, but it's possible that you may have to also replace the front derailur with one designed for the wider chain.

Part of why we recommend converting other types of bikes. Got an old steel 21 speed MTB handy? Maybe you should leave your 9 speed alone?