Have a new BMW swingarm and a Quaife reverse-box and this is my reverse-trike driveline layout.

I would ideally like to have the reverse-box and sprocket flange hard fastened together (no UJ) to reduce 'length', but would this be a disaster. Or could it be done with careful engineering and reverse box mounting?

Also, as the swingarm driveshaft-end will be subject to a little vertical movement during suspension travel, then would a CV Joint be better? BMW just use a UJ on the bike.

[img][/img]

I would have thought that it will be ok, so long as you get the UJ from the reverse box as close as possible to the swingarm pivot axis

Im assuming that the shaft in the swingarm has room to move up and down at the input end?

just need to make sure that during travel the shaft doesnt get close to the roof or floor of input area in that swingarm

[Edited on 15/7/10 by tony-devon]

That was my first concern Tony... I'd initially thought that BMW had placed the UJ at the pivot point, but turns out it's slightly more on the engine side, so I'm happier about clearance. This drawing should explain...




Also, there are two points of movement for the driveshaft in the BMW set-up. One at the UJ we're discussing and another at the bevel-box end...

What's your thoughts about hard-fastening the sprocket and reverse-box flanges together (no UJ)?

I've seen mid engined cars and large trikes done this way, the gearbox solid mounted to an independant diff in there case. They always fractured in the end and they ended up putting a tiny propshaft in.

I notice pro motive may have a setup or parts that could work for you they have introduced a reverse box with one side using a direct coupling, not solid though using a sprocket into a machined sprocket shaped cup

Cheers
David

And this is what the cup looks like, I think they are using this style of coupling differcult to tell from the other photo, a phone call would solve it

Cheers
David

[Edited on 15/7/10 by Minicooper]

Cheers David... that's quite an interesting set-up!

I think you're right about having a 'link' between all the flanges... a UJ would most-likly help prevent any misalignment problems before they started!

very interesting idea that cup setup, gives some room for error, but peronally would have liked to see some sort of cush drive setup rather than a direct steel to steel contact

surely a trike would be subject to an msva so wouldn't need reverse as its classed as a bike? or am i just being thick?

quote:

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Originally posted by ashg
surely a trike would be subject to an msva so wouldn't need reverse as its classed as a bike? or am i just being thick?

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Aaaaand... I remember trying to enter the A1 road at rush-hour in a BEC MK that I had at the time. It didn't have the luxury of a reverse gear.

Stalled the b*gger and left my nose out in the junction... by the time I'd got it going again, my chance was lost and I was being bombarded with flashing lights, horns and cars making comically exaggerated swerves around me!

Of course no-one wanted to let me out... they just wanted to vent their pent-up rage at a stranger from the safety of their little tin boxes!

Reverse is good!

Who has nicked the pictures from my reply?

Cheers
David

[Edited on 16/7/10 by Minicooper]

Wasn't me!