Cassette speed limitations / kit requirements

[Morinr]

Hello guys,

Been looking in the market for a few weeks and am looking for a kit that will allow many speeds on my rear cassette, or keep my wide range with 3 ring front crank. I currently have a 29er with disks and 24 speed... I am looking to add an ebike kit and convert it to a commuter.

I was looking at the Magic Pie 4 as I like the clean look of internal controller. I was hoping I could get more than just a 6 speed cassette on the back. Anybody have any experience with this? If not what are the teeth ranges and I  think you wont be using as many gears with a Ebike less of the middle range I guess.

I also want to be able to control the power and set limits for myself as well as others ie son who I don't want getting hurt. Are there any other items that we can use for a Magic Pie besides the Cycle Analyst? It is just expensive I was hoping to spend less than $50 on this display. Or if anybody has a used for sale I am very interested. Also can the cycle analyst change limits on the fly, ie I get home from work with only limit speed, can I change it to 20km and give to my son to go? Or does it need the usb connection to change every time?

Thanks,
morinr

[Bikemad]

I have an old style seven speed 34T-14T threaded freewheel on mine (modern cassettes will not fit):



If your dropouts are wide enough you should be able to fit an eight speed threaded freewheel with a couple of spacer washers on the axle to provide the required clearance between the sprocket and the frame.

The Cycle Analyst can be programmed during the ride as it does not alter the internal controller settings.

Alternatively, you should be able to use a simple speed reducer to quickly switch between unlimited and adjustable throttle settings.

If you use a small preset trimpot and a key switch instead of the potentiometer and toggle switch shown it would prevent you son from overriding the speed restriction.

Alan
 

[Morinr]

Thanks for the information, very interesting and solid solution. My rear drop outs are the "standard" 135mm. What would the max gears on the rear be? And if so it has to be a free wheel? If so where could I pick one up cheap? Preferably the 7 speed similar to yours.

When adding the rear cassette... I need to buy a threaded free wheel? Or what fits with these.... don't want to waste time and money on the wrong cassette.

Sorry if they are not called cassettes if are free wheel... not too up on the bike terminology.

Do you know if there are cheaper products that can also display speed/ PAS level battery level etc? I want some information but shelling out the 150+ for one just is tooooo much on top of a kit that is already 450 bucks.

Thanks again

[Bikemad]

You must use a threaded freewheel and not the splined cassette:



The most gears I've seen fitted has been 27 using a nine speed freewheel on the rear:


If you have a steel frame it can easily be stretched slightly to accommodate the wider gear and spacer washer/s, but I wouldn't recommend stretching an aluminium frame as it can result in frame failure over time.

This is the seven speed freewheel I have fitted to mine. You should be able to adjust your dérailleur end stop screws to set the travel limits for the seven speed unit, but if the gears do not work correctly with your indexed gear changer, you might have to fit a seven speed changer mechanism to correctly match the spacing of the sprockets on the freewheel.

If you want to keep all eight speeds on the rear, I would suggest the DNP Epoch 8 speed freewheel as the 11T sprocket will produce a much higher top gear so you won't have to pedal as fast trying to keep up with the motor.

I am not aware of anything cheap and compatible regarding the display unit, has anyone else come across something suitable?

Alan