26r Revolution wheels PCD question

[Emma-Knight]

What PCD and what rim dimensions do 26r Revolution wheels have?

Anna

[trw99]

Anna

I think I am right in saying there were two wheel sizes, one five and a half inches, the later one six inches. Though they looked like Revolution wheels, they were specially made for Lotus out of magnesium. I am happy to be corrected mind you!

Two points of reference were:
http://www.lotuselan.net/uploads/26r_parts08.pdf

and the attached.

Tim

[trw99]

Duplicate post deleted

[elj221c]

Can't help with PCD but the original wheels have four drive pins bolted to the wheels instead of five studs pushed into the hub. These require a different hub which also have coarser KO thread to suite the alloy spinners.
I believe TTR will provide replicas to suite standard KO hubs as well as the original style so they should be able to give you the PCD.

Roy
'65 S2

[Emma-Knight]

Thank you. So I'll ask TTR.

Anna

[SADLOTUS]

I've just measured my TTR 26R replica wheels from centre to centre of the bolts.
I made it 70mm - which makes a pcd of 99.
using:
http://www.gomog.com/allmorgan/wheeloffset.html

BUT. If i'm 1mm out (quite likely) the pcd is 100.

100 seems more popular among more modern cars.

http://www.carlsalter.com/wheel_fitments_by_pcd.html

What did TTR say?

BTW. I considered using a different wheel as a spare as I only have four TTR wheels - they are SO expensive!- and looked at maybe a Revolution wheel or similar. Reading through the net it seems the weight/stress/force of the wheel must be taken by the centre hole of the wheel and not the lugs or the wheelstuds. These findings were all cars with bolt on wheels. I wonder how this all applies to spin on wheels?
Opinions please. Scientific or otherwise

[GrUmPyBoDgEr]

We've had a similar sort of discussion on the wheel location argument a couple of years ago.
The Lotus concept of utilising 4 or 5 pegs & the conical central fixing puts both of those features in conflict with each other.
The old Rudge type spline knock-on's used the splines for drive & a cone for tightening the wheel. both of those features were fairly "slack" in their fit & complemented one another; sort of!

The Lotus pegs are a tight fit (relatively) & the cone on the pressed steel wheels is also an immovable feature also for location or what you might call "centralising"
In my opinion both of these features will fight each other in the race to win the location stakes.
Most likely the central cone will lose the race due to the forces applied to it by the high spinner/knock-on tightening torque causing it to deform & comply with the centralising force provided by the pegs.

The "Two Gates" alloy wheels fitted to my S4 alleviate this compromise by having a steel fully floating central adapter ring with the cone machined into it .
The wheel locates on the 5 pegs & the central adapter ring floats on the flat surface on the front face of the wheel when the spinner is tightened.
Here there is no conflict; the spinner holds the wheel onto the axle & the pegs provide the location for drive/braking.

Back to Anna's original question; although I don't have the answer.
Revolution did make knock on wheels for the Elan & maybe even for the 26R's also in their day.

Cheers
John

Amended to add a photo of my Elan fitted with the wheels described where the floating conical adapter which fits between the wheel & spinner can just be seen.

[Galwaylotus]

I've just measured my TTR 26R replica wheels from centre to centre of the bolts.
I made it 70mm - which makes a pcd of 99.
using:
http://www.gomog.com/allmorgan/wheeloffset.html

Am I missing something? Why not just measure the diameter directly as shown in your sketch?

[SADLOTUS]

Mr Galway

There's an effing great big spinner in the way, it was raining, the dog's having a dump in the neighbour's garden and I'm late for work.

..... also, more truthfully, until I looked it up, I thought that measurement was the pcd

P

[Elan45]

At the time of original manufacture, Lotus, as was the rest of UK was still on the Imperial system of measure. The pins bolted into 26R wheels are on a 4 inch PCD. Tim is correct about there being two types of 26R wheels. The 5-1/2" wide ones have no cut-outs between the "spokes", while the later S2 ones are 6 in wide and have cut-outs between the "spokes" and do look a bit like Revolution wheels, but they are not.

I have known Elan owners who have bought 26R wheels, thinking they were the same 3-3/4 in PCD as standard Elan hubs, hoping to bolt them on. Today I believe that TT has copies in the style that will bolt on to which ever bolt pattern you wish to use.

Roger

[Galwaylotus]

Mr Galway

There's an effing great big spinner in the way, it was raining, the dog's having a dump in the neighbour's garden and I'm late for work.

..... also, more truthfully, until I looked it up, I thought that measurement was the pcd

P

Ahhh! That explains it.

[Emma-Knight]

In our Garage, there is a set of four old (Revolution or 26R?) very lightweight alloy 5 or 5 1/2 x 13 in wheels with PCD around 4 in or ca. 100 mm. The PO had one S1 and one S2 26r style racer which were broken up in the early seventies. If anybody is interested, I can check them for dimensions and condition. (They did look straight and had no curb dents)

Anna

[elansprint71]

Opinions please. Scientific or otherwise

Your circle is not round.

Well; you did ask.