Going back to Rotoflex

[KyleK]

I am currently in the market for and Elan. I am looking for an S1 or S2 and want the car to be as original in specification as possible. Many Elans I have seen are close and only have wheel upgrades and CV joint driveshafts. Going back to original steel whels is easy, but can a CV joint conversion be easily returned to Rotoflex?

[Frank Howard]

If the PO kept the original axles, the answer is yes. And while you're at it, you can also trade in your daily driver for an Edsel.

[CBUEB1771]

can a CV joint conversion be easily returned to Rotoflex?

Frank is correct in that going back to Rotoflex couplings is not difficult. Look carefully at the output shafts from the differential. Some CV axle conversions have a replacement output shaft that accepts the CV joint directly and therefore will not bolt to the Rotoflex. In this case you will need to get the original output shafts. You might also want to consider the later Rotoflex system that has pins on the inboard and outboard shafts and rings on the intermediate shafts which limit how far things flail if a Rotoflex joint comes apart. Not original to an S1 or S2 but a very subtle change and very advisable. I think the lotuselan.net home page wall paper shows this arrangement. Also keep in mind that current replacement Rotoflex joints may have suspect rubber and bonding to the stiffening plates and bolt tubes.

Hey, fourth gear! This makes me think I should put my +2 back together.

[cabc26b]

Hi Kyle,

Nice to hear that your looking at an elan. To franks points yes you can but why, that said. IMO the best of both worlds is the UJ and sliding spline setup . If you spec it using the donut stars ( 3-bolt ) on the output and hub its simple to swap the middle section between sliding spline and rotoflex/donuts ,BTW some consider the UJ/splined set up a factory option and so "original" I don't run the donuts - here are but a few of the reasons -
The quality of the donuts available is not as good as it use to be which is a bitter pill to swallow give the cost of $600 per set- this makes the maintenance routines a constant, if you don't check then you risk failure ( i use to get about 38-45 hours runtime on donuts for a vintage sports racer that used the donut/uj combo using the heavy-duty 3.78 bolt circle) , if they fail the event is never pleasant and the flailing half-shaft will cost you as it bends metal and punches holes in fiberglass. The more horsepower the engine makes the less MTBF you can expect and at some point its a crapshoot.

I can make up a nice kit of parts for and s1/s2 donut drive if you really want one

George

[richard sprint]

I received opinion during the week that the Rotoflex gives a far smoother ride and is their preferred option for normal road use so long as one is easy on standing starts what is the general consences?

Smoother ride?
How many miles before they break up?
Could original suspect fitting have caused them to break up?

[Jolly Jumper]

I received opinion during the week that the Rotoflex gives a far smoother ride (...)

Definitely yes, the ride is much smoother with the Rotoflex. I have two Elans and on both cars I changed the Rotefle to soild driveshafts (one with Mick Millers, the other one with the Tony Thompson Kit) and on both cars I could then feel the severe vibrations coming from the rear wheels. So I changed the weak steel wheels to Minilites and now it is just about okay.

Fact is the Rotoflex cushion the driveline and make for smooth drive. However, as said above, the rubber used in the Roteflexs sold today degrades quickly and the Roteflexes are prone to breaking. The other thing which makes the solid driveshafts an option is that there is no surging effect when going on or off the throttle.

I would say they add precision and take away smoothness. If your steel wheels are weak, the solid driveshafts will exaggerate the vibration.

@ KyleK: If you actually want to use (i.e. drive) an early Elan, go for minilite wheels and solid driveshafts. In any case both parts are easy to replace, so there is no need making it the main criteria. Far more important to find an early car with original spec interior (Texture, Steering Wheels, Dashboard, Gauges), + original roof, colour, etc.

[richard sprint]

Thank's Jollyjumper

My feeling is to fit the rotoflexes and see how long they last - I might only do about 5k miles per annum. Are they supplied with a perimeter metal band? or when seen so fitted is this just for ease of installation?

[mikealdren]

Richard,
the band is to hold them for installation. It holds them so that the bolt holes align with the shafts. Take them off and the rubber pushes out the bolt holes to a wider diameter. You can use Jubilee clips if you ever have to take them off and on again.

When you install them, jack up the suspension to make sure that the shafts are lined up so the bolts go straight through or you'll struggle for hours!

Mike

[KyleK]

Thanks for all the advice. I am well aware of the benefits of CV and U joint drive lines. My issue is really trying to keep things original. For example, and I'm sure to open a can of worms with this, I won't consider a car, no matter how nice, if it has a Spyder chassis. Not because I think Spyder chassis are bad, but because I want my Lotus to be as original as possible despite its deficiencies. The Spyder Chassis is better, but it is not a Lotus chassis. The CV joint/U joint drivelines are better, but not the way Lotus built them. It is that simple.

As far as reliability issues with rotoflex. I race a Type 61 FF and a Type 69 with 250hp BDA. Both use rotoflex coupling, and I have never had a failure.

My Lotus are stored inside a heated "Barn" with a lift and while I drive my Lotus all the time, mileage is somewhat limited, so overuse, environmental conditions and inspection are not issues.

I don't mind the wind up hop in the Plus 2, so I don't think I would mind it in the Elan.

After seeing responses I will take away from this that:

1. Going back to original is not hard, so I shouldn't rule out a car because of the conversion.
2. If a nice car comes along with non-Rotoflex drive line maybe I should keep it that way.

In the mean time I'll keep looking for a nice Elan S1 or S2, or Cortina, or Elite, or Europa, or Esprit, or Type 72D, or.... well you get the picture.

[memnon]

Hi,

You've had the advice on how easy it is to swap. So here's my attempts to extrapolate Lotus thinking through to today.

The modern rotoflexes are not to the same spec as original, the rubber contains less toxic compounds and doesn't perform as well. The lifetime of these seems to be much less than the original items. The price now is much more than it was when the cars came out of the factory. I think Lotus now would not be fitting these items given their price and lack of longevity if an Elan were still a production car.

It is known that Lotus did try a solid shaft, I couldn't say to what design though!

You'll make the choice, I have gone for reliablity and an Elan so many of the reasons not to have one. Best of luck whatever you decide

[alexblack13]

Why not go half n half. Spyders solution still uses a rotoflex each side.This gives the smoothness with much longer rotoflex coupling life span.
Best of both worlds....

You do still get a bit of the dreaded surge but it's controllable.

have a look on spyders web...

Alex Black...

[elansprint71]

Why do folks keep saying that rubber couplings give a "smoother ride"? What sort of modern car has rubber couplings? Are modern cars "not smooth"?
The Rotoflex Metalastic coupling was the cheapest solution at the time, that is why it was used; today CV joints are cheaper, that is what Lotus (and everyone else) use today.

Forget going back to the Edsel, why not an Ox-cart with solid wooden wheels? Now they WERE smooth.

[Elanintheforest]

The BMW Z4 is a great modern car?.and the Honda 2000?.and the RX8?.even the MX5. They?re the latest and the best, why not upgrade to those? You?ll need lots of airbags, safety cages and air con, and a bigger engine to drag it all around but hey, that?s progress.

I?ll stick to ORIGINAL as well. I?m not going back to anything, just enjoying an old sports car because of what it is, not somebody elses idea of an ?upgraded? hybrid .I?ve got a modern car, why would I want a semi-modern one as well?

How about a turbo-diesel in a GP Bugatti? Probably develops more power, it?s a hell of a lot cheaper, and it?s what everyone uses today???..

And the Bugatti has brake drums for goodness sakes....upgrade to Ford Focus ones, with nice nice low profile tyres....a vast improvement.

Originality vs upgrades is such a non-controversial subject, eh??
Mark

[robcall]

I deliberated this one long and hard.I've never had a problem with rotoflexes in the past and 20 years later I'm told the rubber quality is now an issue.To go for a solid driveshaft conversion I'd also have to remove the pegs from the drive shafts-going even less original
I had a long conversation with Steve Taylor from The Elan Factory.
His opinion is unless your doing grand prix traffic light starts the good quality donuts should be fine.Look for ones with the silver paint dot.

as an aside-didn't the early Elans have a narrower driveshaft diameter measured to the boltholes

[paddy]

as an aside-didn't the early Elans have a narrower driveshaft diameter measured to the boltholes

Slightly larger: elan-f14/elan-drive-shaft-coupling-pcd-for-t17430.html

Paddy