Lotus S3 Rim measurements

[Darcy]

Hi, I'm a new S3 owner and I want to replace the steel wheels with some aftermarket rims.  Can someone tell me the offset on the stock steel wheels from 1970? 

Ground clearance under the oil pan seems really minimal, but I don't want to change the handling, so I think I will stick with stock 13" diameter rims. 

 

Thanks

[11Budlite]

According to the Tony Weale book, the correct negative offset for S3 wheels up to 6" wide is 3/4" or 19mm. The negative offset could have been an error because doing a Google search shows offsets of positive 15 - 25. You might want to measure your wheels to determine what you have. 

 

This guide shows offsets of positive 15-25 as well: https://www.vtowheels.com/cars/lotus-7-1957-1973

[San Augustine]

The original steel wheels came off the Ford Cortina which were 13x5.5 with ford pcd 4.25  or 108mm. 
 

Lotus had offered optional Lotus brand alloy wheels similar to the Dunlop D1 in 1970. They were also used on the S4. Specs on these were 13x5.5 4.25 pcd. These are very rare today, however, John Brown Wheels in the UK makes replicas of the D1 in the correct pcd and an offset of 16mm which are probably better quality than any 56 year old wheels you could find today. I found a set of original Lotus Brand alloys for my S4 on this site. They are still in the box and need to be refinished. If I find they aren’t true I would have been better off to go with the modern replicas. I got one of my Lotus brand wheels out this morning and got an offset of 15 which +/- 1mm close enough to 16mm. 

 

Tires 165 80 13 or 185 70 13.  

The only 165 80 13 tires that I am aware of is Pirelli and can be bought from Lucas tires. - Considering how light these cars are this would be my choice. 

 

https://lucasclassictires.com/tires/165vr13-pirelli-cinturato-cn36/

 

185 70 13 is more common and less expensive. 
 

Here is a link to an original S3 with the Lotus Brand wheels 
 

https://www.gpsevens.co.uk/portfolio-item/lotus-super-7-s3-holbay-s-1969-the-only-factory-built-lotus-s3-in-existence-5949

 

 

The John Brown D1 replicas

https://johnbrownwheels.com/product/55-x-13-d1-4x108-5513D14108

 

Revolution wheels would also be period correct. 
https://revolutionwheels.com/product/rvb940-4-17561mbhr-wip/

 Pricey 

 

John Brown makes a copy at half the price. 

 

https://johnbrownwheels.com/product/6-x-13-revolite-4x108-6013RL4108

 

I followed the auction and I think you got a very good deal on an amazing original car. Enjoy!

 

 

 

Edited 12 hours ago by San Augustine
Clarity

[Carz01]

@San Augustinethanks for the detailed post about the wheels. I find it interesting that the wheels on the gpsevens car have a triangular relief where your wheels have a trapezoid shape which is what I have. I’m also running the Pirelli 185/13 tires on my S4. Great wheels! 

[San Augustine]

@Carz01You are absolutely right! I just noticed it myself. I checked some other pictures and I think that the Lotus Holby on the GP,sevens site has different wheels. I found this to confirm the Brand Lotus wheels on a Lotus S3 twin cam from the Tony Weale book p. 223 and they are not triangular as well this advert from about 1970. And also this pic from of the Lotus Seven twin cam from the Earles Court motor show of 1969.

Edit - at the bottom of this page Link explains the difference between Dunlop wheels and Brand Lotus. Both were offered for the S3. 

http://www.lotus7register.co.uk/ser3pix.htm

 

Dunlop light alloy wheel 

 

 

2 hours ago, Carz01 said:

@San Augustinethanks for the detailed post about the wheels. I find it interesting that the wheels on the gpsevens car have a triangular relief where your wheels have a trapezoid shape which is what I have. I’m also running the Pirelli 185/13 tires on my S4. Great wheels! 

 

Edited 4 hours ago by San Augustine

[San Augustine]

The Dunlop wheels are more attractive in my opinion. @Darcy get the John Brown wheels and Lotus badges for the center cap! 

[San Augustine]

@Carz01 Love to see some pics of your 7s.

[Darcy]

Thanks to you all for such great information.  During the auction I had a lot of questions, because I didn't have time to thoroughly research Sevens.  I knew I was going to get one, but when this one popped up a few hours away, with this history, I decided it was the one. 

 

I think I am going to put aside the wheels and original (!) tires for a special day, when it is time to show the car as it was originally sold. 

The John Brown D1 replicas are very attractive and a very reasonable price.  I think we have a winner.

 

I am picking up the car on Saturday. After I get it home I will be taking many more photos of it to document the condition as purchased.  The auction pictures were nice, but not nearly detailed enough for my records.  

 

Since the car was not plated for 40 years, it will take some time to understand what it needs.  I have the time to make it right and it is not going to be a trailer queen.