Elan +2 final drive- Kelvedon CVs v SpyderCV/Doughnud ?Cvob

[dick+2130/5]

I drive an Elan +2s 130/5 with standard twin cam engine and the 5 speed Austin Maxi derived gearbox. Currently fitted with original style doughnuts, which I think are due for replacement. I have read all I can on this forum but still unsure on which way to go.
I don't like the wind-up with the current doughnuts but feel that the cushioning must provide some protection to the drivetrain and particularly the reputedly fragile Maxi gearbox ( mine is OK so far but I drive very conservatively).
So my instincts lie with the Spyder CV + Doughnut set up, but it has the downside using the limited life doughnut. I see that Spyder claim longer doughnut life with their set up but can't understand how that is achieved.
That leaves me with the Kelvedon CV+CV,system which seems to be widely used, and recommended as reliable. No cushioning in the system however, and i wonder if the reliability reputation comes from its use in the lighter Elan with the robust Ford 4speed box ?.
If anyone has got experience, good or bad, running either Spyder or Kelvedon system on a 5 speed +2 I will be very grateful to receive your comments.
Thanks,
Dick

PS: What's the appeal of Elantrikbits kit versus Kelvedon ? Both claim to cope with droop OK
.

[shynsy]

I suspect if you drive conservatively then the cushioning effect, or lack of it, is probably not and issue.
Tim

[alanr]

Personally I don't see the Doughnuts as protecting the gearbox that much although I am sure it must help to some degree.
The Doughnuts though I believe will give more protection to the Lotus differential assembly which in standard form is just quite literally hanging from a couple of smallish rubber mountings and the driveline torque being taken up by a couple of simple tie rods and rubber bushes!
It is a very fragile arrangement even in standard Doughnut form with the diff casing being made of aluminium. The diff case ears easily break off the upper part of casing and the tie rod holes easily get ovalised.

To me if you are going to go with CV's, the Spyder arrangement of a CV outer and a Doughnut inner does seem a sensible compromise.. My take on this is that there does need to be a rubber cushion in the driveline somewhere and the Spyder setup achieves this.

The Elantrikbits CV's and the Kelvedon/Sue Miller Cv's are very similar in execution. It is said that the Elantrikbits are of better quality but against that is the much higher initial cost of the product and the shipping from the other side of the world which does make them rather expensive here in the UK.

The above is just my take on it. You pays your money and takes your choice but personally I will be sticking with Doughnuts on my +2!

Alan

[dick+2130/5]

Many thanks for you quick replies and opinions Tim and Alan R, Most helpful.
Regards,
Dick

[alan.barker]

Hi Dick,
The TTR do suffer from droop and the Elantrikbits are better Engineered thanTTR.
I fitted Elantrikbits on my Sprint 100% nice kit super. Treated metal and Steel adapter plates not Alloy. Replaceable special fixing Studs top job.
Alan

[elans3]

My experiences are with original (2 doughnuts per side),
Performance Unlimited units, (an earlier version similar to the TTR UJ-type), and I found these hard on the diff and created noise.
I swapped them out for the Spider single inner doughnut + one CV, and loved them.
Next to no wind-up, quiet, and much kinder to the diff.
I wouldn't hesitate in fitting them again to my next Elan.

[rgh0]

There is no evidence of the cushioning effect of donuts being required or being signficant. The Lotus 5 speed box was used successfully in much heavier cars such as the Elite with a 2 litre engine and no donuts. I have used Cvs in my Plus 2S 130/5 and my 4 speed Elan for around 40 years without issues with gearboxes or diff . i dont drive gently in eaither car and the Elan does multiple racing drop the clutch starts at every race meeting without issue

The one donut and one CV version I could never understand as you still have the greatest problem present which is a donut failure wrecking the rear of the chassis and suspension.

If you want a reduction in noise and vibration and some protection to driveline components then you put the rubber donuts in the propeller shaft between gearbox and diff like many modern European cars do not on the diff output shafts where they struggle to handle the much greater torque and angular deflecton.

The biggest advantage of the ElanTrikBits Cv conversion is that the captive bolt design allow a small amount of movement to align with the diff output and hub axles holes which were not drilled very accurately by Lotus as the Donut would accomodate a large fitting tolerance

just my personal opinion

cheers
Rohan