Morning all, just thought I would test the combined brain power of the massif!

I'm currently building a reverse trike 3 wheeler project based on BMW R1100 & need to make up a sort of propshaft to transfer drive from the gearbox at the front to the swing arm at the rear, both of which have pre-manufactured splines. When I say "sort of" propshaft that's because it isn't transferring between 2 fixed points like a normal car prop would be, the front is a fixed point, a male spline, but the rear is a "floating" u/j with a female spline. The front end isn't a problem, I can run the existing short prop/driveshaft from the original bike thro' a bearing & then down the centre tunnel to another secure bearing where it will take drive to the floating u/j - which will then be effectively fixed by the rear bearing

For this one I have a way to manufacture a one-off to join the 2 halves, but I will likely later offer this as a kit & a better, more production like fix would be the preferred option - I haven't been able to find any existing readily available driveshafts which match the spline size. Output shafts from the gearbox appear to be about as common SH as rocking horse poo & I dread to imagine what one would cost from BMW & would still need modification to do what I want then .....

Hence I need to make driveshafts with a male spline. The existing female is 16 splines with an ID of 20mm, obviously I am aware there are various different tooth profiles etc etc - manufacturing techniques have come a long way since I was at college 40 odd years or so ago, so is there now a way of producing a male spline at a competitive price or am I stuck with a bespoke specialist manufacturer who will no doubt want to charge a fortune for the privilege?

Failing a cheap way to manufacture a male spline to match the existing, can someone recommend a good specialist in driveshafts - I think probably driveshafts rather than propshafts as what I want doesn't need u/j's or anything, I already have those

Any info or suggestions welcomed

You could try Bingham engineering , noble sq, Basildon, Bill Bingham has been hobbing gears and splines for years, very competitive on small batches/one off's. we have been using them for 20 years or so.
He can also advise on heat treatment/ Hardening, all the gears he did for us were heat treated.

[Edited on 30/10/18 by clive7883]

I needed a drive shaft for my VW 002 + MX5 frankenbox the biggest issue I ran into was the need for it to be hardened.
A 20mm bit of mild steel is going to struggle to take the final drive from an R1100 - though I might not have understood correctly.

You might find something here - though not hardened https://splineshop.com/spline-adapters/

Machining the splines, if you have a milling machine and indexing head, is probably the easy part but how do you propose to harden it, (according to the Internet its not that difficult) but unless you have done it before, how confident are you it was done properly so the shafts lasts?

I thought for this sort of application you needed to broach splines not mill them?

(I'm no engineer)

Hi

I can personally recommend these people, really excellent (bespoke) drivetrain components at sensible prices..

Linky - Berrisfords

I've had driveshafts and diff output shafts from them.

It was over 10 years ago now,but I had my drive shafts splined and hardened.i can't remember the exact cost but I know it can't have been all that expensive or I'd have cut and shut and sleeved my own out of the Nissan and ford ones i had.
From memory I had my donor nissan drive shafts turned down at the hub end to fit in Sierra hubs,splined to suit and hardened again for circa £300 the pair.
I know he had an ar#e of a job doing it too as the Nissan shafts were so hard from the start.
I guess what I'm trying to say is you might be pleasantly surprised at the cost if you go to a decent engineering shed,and not the motorsport suppliers.
Still know the place if you want to try him but it's up wrexham way.

Hardening is a pain. I have an old machinist make mine for very reasonable price. No need for hardening as the material used has similar rockwell values to the hardened shafts