Large Motorbike Project

[Mouse]

The Big Bike Project
Had this project planned for just over a year and had most major parts sitting on the floor waiting for my attention but have been hung up on a few things like the transmission, a reasonably long term illness and of course being self employed Covid ate my project budget.

SPECS:
Mitsubishi Outlander Rear Motor
BMW K100 Gearbox and final drive +rear wheel
BMW i3 battery modules
Toyota Gen3 Inverter also working as charger
Custom built aluminium frame

I know this is going to be a real heavy weight but as my current ride is a VW 1900cc TDi motorcycle with car gearbox weighing in at just under 400kg I know what I'm letting myself in for.

The main technical stalling point for a long time was motor reduction for driving the prop shaft to he rear wheel. The original idea was to have a dedicated 2:1 reduction to the bike prop shaft and avoid having the original gearbox But I was unsuccessful finding anyone who would make me a hardened shaft. So after much deliberation I decided to use the original bike gearbox and just leave it in the appropriate gear all the time. The only disadvantage is that this adds about 6" to an already long vehicle. The major upshot is all the specialist parts like splines are off the shelf items making it very cost effective over having a hard to replace custom part made and hardened.

The coupling between the motor and gearbox is the first part made for the project. Made from a BMW bike clutch plate and a Suzuki Jimny clutch plate bolted together with a aluminium spacer. All fabricated in the garden shed workshop. Total cost about £50-£60 especially as the BMW clutch plate was obtained from a dealer who sold me one with worn out friction plates out of the bin and the slug of ally was an off-cut I spotted in the local scrapyard ally bin.

Motor clutch plate Part No
BLUEPRINT ADK83106
https://www.ebay.co.uk/itm/264257628857 This link will probably go stale at some point

Motor and donor clutch plates.

Ally spacer turned to take the Suzuki Jimny clutch.

Ally spacer turned to take the Suzuki Jimny clutch.

Home made indexing wheel attached to lathe for marking out the PDC.
It's more effective than you'd think

PCD marked on spacer, The same was done to both clutch plates.

Tapping all 12 M6 holes took forever, 6 holes per clutch plate.

All shiny and new

Mocking up the clutch plates to fit. The sheet metal is hardened so difficult to drill and file to the right size.

The finished thing ready to fit

In place and looking the part.

I'll probably make up a spindle to go through both splines to make sure they are absolutely concentric before bolting up permanently.

The next construction job is to make bracketry to mount the gearbox on the motor and get both splines concentric. Then this will be considered a single unit to build the chassis and battery box around. I've done this sort shaft coupling alignment with previous diesel powered motorbike projects where I've fitted small diesel engines to the BMW motorbike gearboxes giving me a head start when planning such a thing.

[Jack Bauer]

I'm not a motorbike guy but I loved your videos on the diesel bike. This should be brilliant.

[MattsAwesomeStuff]

Always a big supporter of well documented projects. Keep at it

[Mouse]

I'm not a motorbike guy but I loved your videos on the diesel bike. This should be brilliant.

Thanks, I need a bit of encouragement these days.
Hopefully I'll say something outrageous on the charging section sometime soon.

Always a big supporter of well documented projects. Keep at it

I tend to take waaaaay too many photos when I'm in a creative mood so I think your corner is covered.

[Mouse]

A long needed update, The motor - gearbox adapter plate construction.
Two bits of 10mm ally from the local scrap yard make up the 20mm gap needed between the original clutch bell housing and the electric motor.
Picture heavy because getting the alignment was a tricky process that needs to be right or the coupling will fail prematurely.

A large hole is needed for the shaft coupling I decided a hole saw from Screwfix was easier than trying to trepanning one out on the lathe or chain drill and shape a large hole.

It was easier than expected. Luckly my pillar drill has a very low gear something like 220 rpm.

Two plates. One for the gearbox and one for the motor. The intention is to fix each plate to its respective part then pin them and weld once alignment has been made.

Mocked up in position.

Drilling and then reaming out to 7.00mm for the existing alignment pin on the motor.

7.00mm alignment pin in place.

Then expanding one of the motor mount holes to 11.00mm with a reamer so a ground pin can be put through. That way when it is dissembled and reassembled it will always be in the same.

To align the bell-housing adapter plate 6mm taper pins are used by drilling and reaming out the hole with a taper reamer.

The taper pins used.

[Mouse]

Continuing...

This is how I aligned the motor and gearbox.
The BMW K100 gearbox has a push rod hole through the main in[put shaft. On closer inspection this is a very accurately machined 10mm hole so a length of ground 10mm steel fits almost perfectly with no perceptible play. The motor output shaft conveniently has a counter sunk hole in it's end. I assume as part of the manufacturing process and thus concentric to the shaft and motor armature. Alignment is achieved by turning a similar angled point on the ground shaft and placing it through the gearbox input shaft until it seats in the end of the motor shaft. The two mounting plates not yet being joined allow movement until the point is firmly seated in the countersunk hole. At this point the two shafts are in alignment and the two plates are carfully clamped so they can not move. Once clamped two taper pins are fitted to the plates so they can be removed, machined + shaped and reassembled for welding whilst retaining alignment.

Ground shaft for making the alignment rod. Surprisingly cheap for a one-use tool.

Countersunk hole in motor shaft.

Alignment rod in place through gearbox input shaft. There is no perceptible play between them.

This is how the alignment shaft will seat in the motor shaft. There is no perceptible play between them.

Everything in place ready for the alignment rod to be inserted. The two plates are free to slide about until the pointed alignment shaft is securely seated in the counter sunk motor shaft hole. A mallet was used to knock the alignment shaft to ensure it was firmly seated in position. This process was repeated several times using scribed marker lines to be sure it was done properly.

Once in alignment the two plates are carefully clamped before anything was moved so the taper pins can be fitted.

Then the drilled and taper reamed holes were made.

Taper pins fitted to lock the plates in position so they can be removed, machined and retain alignment.

CAD Cardboard Aided Design
CAD template made by rubbing over the motor flange and some cardboard to generate an imprint of the holes and flange edges. Works surprisingly well.

Template used to mark which bolt and bolt head clearance holes need to me made. Now the taper pins are fitted the plates can be separated for
machining and reassembled without returning to the actual motor and gearbox.

[Mouse]

Finishing and welding the adapter plate.

Mounting nut head clearance holes hole. Cut on pillar drill.

Checking the mounting nuts fit

Checking the socket fits and there is good clearance because some sockets are fatter than others.

Profile cut out on a band saw. A very slow process as there is 20mm of ally to cut through.
Temporary clamps made from some M8 bolts and a couple of spacers so the two parts are machined together.

Motor bolt holes checked out for clearance.

Bell housing fitted to check it all goes together before welding.

My mediocre ally welding. This is probably the best weld of the whole part
A continuous weld was made around the outside and inside of the two plates.
The two parts were firmly clamped together and many tack welds made before the seam welding was done to minimise warping and distortion.

The completed power unit. Motor, Coupling, reduction gear, Swingarm / Suspension + rear wheel

The completed power unit. Motor, Coupling, reduction gear, Swingarm / Suspension + rear wheel

The whole thing is much neater looking than I expected it to be.
Even though it's bigger than I wanted it's still very compact for what it is.

Next task is to mock up the location of the major parts like front wheel, inverter, contactor box, charger, seat etc and start planning the chassis and battery box which will need to be watertight.

[MattsAwesomeStuff]

Bravo. Well done.

One thing I might be concerned about, is what happens if your weld seam shatters?

Maybe you'd want some bolts or some plug welds through the face just in case?

[Gregski]

well sure, if you're all into that precision stuff... ha jk brilliant build

[Mouse]

well sure, if you're all into that precision stuff...

The rest is probably going to be a bit more of a lashup. But not as bad as my ratbike projects
I just wanted to be sure the shafts were in alignment so did the best can do in the home workshop. I've also seen engine / gearbox combos fail in other peoples projects when they are misaligned and the coupling or clutch fail because of it.

Bravo. Well done.

Thanks The project has been stalled for over a year and I've just kicked myself right up the arse to get it progressing again. .

One thing I might be concerned about, is what happens if your weld seam shatters?

Not sure why the weld would fail. I put a V between the plates before welding so it's relatively chonky. I am however very inexperienced with Ally welding so will take any advice.

[Romale]

what happened to this project?

[Mouse]

what happened to this project?

I've had a few personal issues that have prevented progress.
It's still sitting in the project room just as I left it.
Hopefully I can get going on this project sometime soon.

[Romale]

I've had a few personal issues that have prevented progress.
It's still sitting in the project room just as I left it.
Hopefully I can get going on this project sometime soon.

I have achieved excellent results with the Honda ima inverter + O.I. board v3. if anything, I can tell you.

[Romale]

it's just very small and fits a motorcycle perfectly. at the same time, it manages to carry a large car

[Mouse]

I have achieved excellent results with the Honda ima inverter + O.I. board v3. if anything, I can tell you.

Thanks,
I'll probably pester you at some point about that as I've got a couple of IMA inverters.

[Romale]

I've got a couple of IMA inverters.

update! I tested an ima inverter from 250 volts and it didn't burn out, up to 250 amps of battery current! this is a great power for such a small inverter