Questions re fitting a 7-speed Shimano cassette on a Bafang CST 250w 160mm motor

[jonathan75]

I've put the cassette on and unfortunately there's about 7mm of play where the cassette is just flopping on and off the side of the motor. I've had a look and the spacers will cost a fortune, like £15 or something, and the tools another £15 for a torque wrench and the cassette-lockring-tightening-tool. Unless I do some kind of 'hack' and just wrap oh I don't know, a length of thick wire or coathanger around the bottom of the cassette, and just grease and do up the lockring until it's as tight as my hands can make it. Cost £0.

Be grateful for any thoughts.

 

[Deleted member 4366]

You don't need a torque wrench. All you really need is the cassette removal tool. The chain whip is useful for removing a cassette, though you can use an old chain instead.

http://pages.ebay.com/link/?nav=item.view&id=191267332337&alt=web

 

[Nealh]

Although cheap I didn't have a chain whip to hand when I needed one so had a look in my box of car tools (from my days of diy car maintenance) and used an oil filter chain gripper which also has a hex end for a spanner or socket spanner, it is now in with my bike tools. A tool I haven't used for over twenty years now recycled for another use.

 

[jonathan75]

Thanks both. Do you think some coat hanger and superglue/epoxy (possibly with narrow wire woven between) could make a reasonable spacer ring? The mtb boards are all about pvc plumbing pipe but I think the motor might melt that.

 

[Deleted member 4366]

From memory, there's no significant flange at the inboard end, so you need a metsl spacer of the correct diameter otherwise it will rub on the motor when freewheeling.

Your problem seems a bit unusual because I've used a 7 speed freewheel before on that motor and it fitted perfectly. Are you sure that you don't have a nine speed with the two loose gears missing?

 

[jonathan75]

The flange is about 3-4mm so pretty tight so I'd have to construct something quite carefully

 

[jonathan75]

Perhaps my local plumbing supplies place will cut me off some copper pipe

 

[jonathan75]

Done