Specialized Rockhopper with Bafang 8FUN

[Scott_J]

Howdy!

I'm trying to fit an 8FUN to a Rockhopper and there are two wee problems that I hope someone could please help me with?

The Motor fits through the bottom bracket frame ok, but falls short when tightening up the bolts. Is there a thick washer that would fit?
Also, the motor seems to hang a little low. has anyone else had this problem?
It's on my girlfriend's bike and I don't want it booming out and catching on a rock or log etc. whilst out on our gravel path jaunts.

A bit OTT, but she has a habit of smashing rear mechs and suchlike!

Pics attached and thanks in advance!

 

[peter.c]

Some kits supply a spacer, if not pack out with washers i have used a 8mm nut as a spacer if the gap is large
[Is the motor against the bottom bracket or is it fouling the chain stay ]

 

[Nealh]

I have bought Black nylon spacers the correct size on ebay for my build some years ago.

 

[mr_ed]

Yep I bought black anodised aluminium spacers off eBay. Measure the depth you need.

 

[jimriley]

I video I watched prior to my install used a bit of rolled up inner tube between the motor and the frame, motor pushed hard up against the frame tube when tightened up. It's worth getting the USB cable and phone app to tweak your settings too. Mine came.with a 46t front cog, swapped it for a 42, much better on hilly trails.

 

[Scott_J]

Some kits supply a spacer, if not pack out with washers i have used a 8mm nut as a spacer if the gap is large
[Is the motor against the bottom bracket or is it fouling the chain stay ]

The motor sits flush against the bottom bracket and the chainring is 2mm away from the chainstay.

 

[Scott_J]

Yep I bought black anodised aluminium spacers off eBay. Measure the depth you need.

Nealh and mr_ed, do you have a link to the eBay post by any chance?

 

[Scott_J]

I video I watched prior to my install used a bit of rolled up inner tube between the motor and the frame, motor pushed hard up against the frame tube when tightened up. It's worth getting the USB cable and phone app to tweak your settings too. Mine came.with a 46t front cog, swapped it for a 42, much better on hilly trails.

Thanks for the info everyone. Sorry to ask, but where do you get the phone app from?

 

[Nealh]

https://www.ebay.co.uk/itm/401879787794?var=671719739321

 

[peter.c]

Download from android app store on google play just put bafang in the search
Look for this one speeed app bafang bbs01/2 /hd

 

[jimriley]

Thanks for the info everyone. Sorry to ask, but where do you get the phone app from?

Don't be sorry, don't ask never know
It's called Speeed, 3 "e"s. For Android phones.

 

[Scott_J]

I managed to get the spacers, but I now can't fit the final cap on!

Will it be OK to ride without this attached?

 

[mr_ed]

It’ll probably be ok. You could locktite the thread, or put a paint mark across the thread and the nut so you can see if it moves.

I had the same on mine but I sawed and filed the bottom bracket tube down a few MM to give myself some extra threads showing. That was a pig of a job to keep the faces parallel.

I did mine up with a torque wrench and the proper socket and it hasn’t come loose at all.

 

[Scott_J]

It’ll probably be ok. You could locktite the thread, or put a paint mark across the thread and the nut so you can see if it moves.

I had the same on mine but I sawed and filed the bottom bracket tube down a few MM to give myself some extra threads showing. That was a pig of a job to keep the faces parallel.

I did mine up with a torque wrench and the proper socket and it hasn’t come loose at all.

I'll try the paint mark, that seems like a good idea.

Filing the BB!!! Jeez, you're brave!

 

[AndyBike]

You could ask a bike shop to dress the BB faces. they have a tool for that due to press in and more modern BB's.

 

[mr_ed]

You could ask a bike shop to dress the BB faces. they have a tool for that due to press in and more modern BB's.

yes that would be the sensible answer! Whenever I’ve mentioned my ebike conversion in the local bike shops they’ve looked at me like I’m insane and acted like they want nothing to do with it!

yes it was brave to cut down the bottom bracket, but it solved the problem. Took about 3 hours to get it right. I think i must’ve watched too much Allen Millyard on YouTube. He’s always hacksawing engines up and welding them together to add more cylinders!

 

[peter.c]

Thats why they only want to sell you a overpriced mass produced ebike that they are not allowed to repair but have to send it back or replace the whole motor
Looking at your picture will the pedal arm clear the chainstay ?

 

[Scott_J]

Thats why they only want to sell you a overpriced mass produced ebike that they are not allowed to repair but have to send it back or replace the whole motor
Looking at your picture will the pedal arm clear the chainstay ?

Sorry for the late reply...

I used spacers from an old set of V-brakes (see pic) Sweet!

Yes, the crank clears the chainstay, but the chainring is 1mm from touching it!

Anyhow, it is clearing, but the chain alignment is too much of a crossover to reach the lower gears.
Not too much of a worry for now, but I've fitted brake sensors and the motor has stopped working altogether!

I haven't fitted the throttle because I want the Missus to use her legs a bit!
Will this cause the motor to cut out?

Thanks!

 

[peter.c]

Try a 42t bling ring lekkie or a cheaper copy will help correct the chain offset
Lots of people do not fit a throttle , unplug the brake sensors one at a time see if the fault clears they cause a few headaches

 

[Scott_J]

Try a 42t bling ring lekkie or a cheaper copy will help correct the chain offset
Lots of people do not fit a throttle , unplug the brake sensors one at a time see if the fault clears they cause a few headaches

I've tried unplugging and reattaching the sensors to no avail.
I'm currently running a 42.
The bike came with a 36, so I may just go back to that.

Thanks Peter.