Well I think you have answered your own question really.
You have previously owned the car,really know the car and all it’s foibles, done lots of miles in it, know how it drives on doughnuts, and have previously been happy on rotoflex doughnuts. So therefore if I were you I would keep your money in your pocket and retain the doughnuts!
No brainer to my way of thinking!
Alan…(Note:- One ‘L’ only, thank you.)
CVs is my advice. Fit and forget. As others have said, you can get a sudden catastrophic fail with a Rotoflex joint despite regularly checking it. Take no chances with your safety, especially in a fibreglass car that has zero side impact protection.
Yours looks like a 130/5 which will have the diff brace as standard. So was mine, I fitted CVs and drove spiritedly. I didn’t put new frustacones in (the diff flexible top mount) and I didn’t have any problems. The originality thing is out of the window anyway because you have a Spyder chassis.
I’ve posted on the subject of donuts v. cvjs a number of times since I converted my +2S over 20 years ago, but I’ll post again here for the benefit of the present topic.
I’ve had the car now for 39 years, and have raced and hillclimbed it for the last 16 years. The present 1860 engine has been dyno’d at 169 bhp
Donuts never lasted very long, 20k miles at best before starting to crack and come apart. The last catastrophic failure (in heavy traffic ) broke off the complete brake caliper from the suspension leg casting. No drive, no brakes, no handbrake, and a very red face !
I fitted CVJs supplied by Spyder. That was over 20 years ago, and they’re still perfect.
Imho the “drive cushion design” is a salesman’s turnaround put out by a clever ACBC to hide the real reason for the donuts. They were cheap.
[quote]
Imho the “drive cushion design” is a salesman’s turnaround put out by a clever ACBC to hide the real reason for the donuts. They were cheap.
[/quote ]
Nowadays a CV joint conversion isn’t that much more expensive than 4 x donuts. Given that the donuts have a much shorter life the CV joint seems to be the obvious way to go - Its the way I went last time I was faced with the choice.
One thing I don’t think Colin would have liked is the increased unsprung weight but I guess there are always trade offs.
Just my two penneth
I don’t think it’s fair to say that doughnuts were fitted just because they were cheap. They were the best things available to do the job at the time. Universal joints as were commonly available at the time had their disadvantages - they are called universal joints and not constant velocity joints for a good reason. UJ’s were probably OK for the race track at that time but not so good for long term on road use. I know jags had UJ’s but the track width is much longer on a jag compared to a Lotus.
If the car had been designed to use CV’s from the outset perhaps other changes might have been considered as well - eg strengthening the diff housing mounting ears but who knows? These days if it works it works if it doesn’t work it doesn’t work.
Exactly. Chapman and his team were well aware of u-joint and sliding splines limitations. If u-joints were used the rear struts could not have allowed nearly as much bump or droop travel.
Chapman used U-joints combined with rubber donuts, without sliding splines on the Lotus 23 in 1962. The 23 had less suspension travel than the Elan.
The Datsun 510 (Nissan Bluebird for the rest of the world) used sliding spline u-joints on a semi-trailing arm rear suspension. Only about 5" of total suspension travel and one was lucky to have a set last 35-40,000 miles.
This was a great thread with some very helpful information! I am working through this same rear drive dilemma. My car can now move under power for the first time, after two years of restoration. The rotoflex are toast and I will not be driving it except for some brief tests in front of my home. I’ve spent hours reviewing almost every supplier. In the end, I chose Elantrikbits, down under, to make up my CV conversion kit. (Sue Miller was a close second and somewhat less expensive) However, I was impressed with the offerings from Elantrikbits. Their machine shop capabilities, overall quality, product design, and customer service appear excellent. My kit has been ordered, and is being manufactured as we speak.
Once received, I’ll post some picts of the kit as unboxed, and add some technical details as I install it on my 71 Plus 2, -currently with some very tired looking donuts, see photo. I am looking forward to the installation and a smoother acceleration.
That explains a lot of things that you guys have been going to the cake shop to get doughnuts for your car. I hope you haven’t been eating the leftovers of the doughnuts your car previously had fitted.
To all you pussycats complaining about the dangers of driving cars fitted with doughnuts living on the edge is all part of the authentic Lotus experience so stop whingeing.
If you think that’s bad then try driving one of those things with the engine in the wrong position at the limit (the make of which I can never remember). Then you’d really have something to complain about.
I’ve just re-read the thread. Certainly some strong, helpful views for and against CV/ rotorflex couplings have been expressed, but I can’t say there has been any whingeing, as you describe.
But I suppose that is just a matter of opinion.
Malcolm
After a catastrophic failure of the doughnuts in the S4 about 30 years ago I fitted Spyder CVs with the retention of one of the doughnuts. A half hearted solution ( doughnut still require all the usual maintenance and changing)and have since replaced for Col’s Elantrikbits CV. A marvel of engineering.
I have not seen a car with secondary throttle bodies still intact in decades, mine it has been near 40 years.
Having owned my +2 since '76, the donuts were a constant issue requiring frequent checks.
I have the non failsafe driveshafts. An eventual failure of a donut whilst pulling away from a roundabout in heavy traffic, one burst. The driveshaft smashed the diff housing and bent the diff mounts and A frame.
I now run on Spyder CVs which are easy to fit. Only issue I have had is that one joint boot split.
I have only heard good reports regarding the Sue Miller CV kits.
Would I go back? Never.
Also I’m sure the quality of modern donuts are not as good as the originals
Slightly off topic but I am thinking of Elantrikbits CV for my S4 Elan.
Has anyone checked the position on import duty to UK?
I have attempted to locate the Commodity Code but it does take some searching on the Gov website. Did not find a similar description of shafts with 2 cv joints but similar items seemed to suggest 0% import duty for items from Australia.
Any contributions would be helpful and hints on dealing with customs and duties on arrival.
Thanks
Graham
Good point Graham B
Hi Graham
If it’s of any interest, I paid an additional £158 in customs and import fees on top of the price of the Elantrikbits CV drives when I bought them in 2020
I paid £135 in customs fees, that was in August '21.
If you do place an order Col will provide you with an Australia Post tracking reference. This will tell you when it arrives in the UK (in my case Coventry airport), and its progress etc. At some stage it will say something like “with local carrier”. This was Parcelforce and I found that if you enter the AusPost tracking reference into the Parcelforce system it converts it to their own tracking number, so you will know when it’s at your local depot.
At some stage Parcelforce will send out a letter saying that there is £X amount to be paid. I went to the local depot and paid and collected, but I think you can also pay over the phone and they will deliver.
It is a bit of a palaver TBH, but if you keep on top of the tracking it should all be OK.
If you are on holiday in Australia you can collect, put in your Flight Luggage.
Fly back home with and pay no Customs.
They weigh 11.5kgs. So if travelling light you can still stay below the 25kgs flight allowance.
Alan
Illegal. I found a code 87 08 50 99 05 that describes a CV joint, sort of, and the duty is 2% then you have to pay VAT of 20% on top. If you go through the “Nothing to declare” section, better hope you don’t get searched…
P.S. Allowance on personal imports is £390 if arriving on a non private transport such as a normal commercial airline. Don’t think the elantrikbits shafts are that cheap. Any more than that and you are supposed to pay VAT and import duty per https://www.gov.uk/bringing-goods-into-uk-personal-use/arriving-in-Great-Britain.
The disadvanatge of the Elantrikbits Cv shafts is that the cost when delivered in the UK or Europe or the USA is maybe higher than local competitors depending on the shipment methods and taxes imposed after the tax free export from Australia.
The advantage is you are dealing with the actually manufacturer not a retailer and Col can answer any question you have and stands by his product.
Yes I am biased as I worked with Col many many years ago to make the first CV conversion he worked on for my Elan. This is still running after over 40 years and around 40k race miles with no maintenance and I started with used VW Cvs from a wrecker back then which are still running good today!
There are many reputable options to choose from so do your sums and assess the quality as best you can and make your choice. All I can say is any of them are better than having a failed donut tear up your chassis which happended on both my Elan and Plus 2 before I did CV conversions.
cheers
Rohan
Delivered to Hotel in Sydney, super contact with Col.
Will be fitting to my Sprint sometime in Feb here in France.
Alan
