Hi all,
I have a problem with my propshaft i think, i have really bad vibritions at high speeds so i took a look at the front and rear propshafts and noticed that the front prop is stretched to its limit almost 2", dont know if that have to do with the vibrations or not but it is not ok any way, so i was thinking of adding a rubber coupling or hardy coupling to gain 1" in length but dont know if it is possible when you have a four bolt english couplings at each end. I was thinking about somthing like this: http://www.novaracing.co.uk/ProductPropshaftMountingKits.html
Any one done that before or have any ideas?

Thanks / Christian

give us a picture of your setup, might be easier to understand

Of course, this is what i mean with the propshaft fully stretched.

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And this is the reversebox with the english four bolt pattern flange. (didnīt have pic of the engine side)


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And i would like the rubber coupling between the prop adapter at the engine and the prop to get the prop less stretched and of course smother gear changes.

Personally i've never seen a prop that looks like that before!

Regardless, i'm having the same problem on my car at the moment and suspect it is because i do not have enough of my splined section inside the gearbox. I would suspect that if your prop is extendable and has a splined piece also, that it could be because not enough of it is inside.

I actually have an english bolt pattern spacer for sale at the moment (30mm) if that would be enough?

Aha, I was actually thinking about contact you about that, just wanted to see if anyone have an idea on that rubber thing first. I thought that maybe it would spare my gearbox and stop making a big bang every time I changed gear.

Can't comment on the rubber thing but your gearbox shouldn't be making a bang.

I think most people will be running a solid prop straight into the gearbox and to the diff.
That's how mine is and no 'banging' changing gear...

Sorry, forgot to tell it is a BEC. And all motorcycle gearboxes have a large play in the gearbox and have rubber coupling in the rear wheel to prevent the clunking and also the chain will make it a bit smother when changing gear.