Building an R1 Powered Seven: Sticky tires

Building an R1 Powered Seven

A few years ago I got it in my head to build a kit car. After months of searching I came across the Locost concept. In short, quite a few amateur hobbiests around the world have built their own Lotus 7 inspired cars from scratch, following plans available on a variety of Internet sites and published in a book by Ron Champion.

I started gathering parts and finally began building the chassis in July '05. In August '10 the car was titled, licensed and is now street legal. The following blog captures the progress of the build and driving experiences after completion.

Wednesday, October 27, 2010

Sticky tires

I tried two types of Hoosier slicks on the last two Philly region autocrosses. The first set were 20.5x7-13 R35A compound tires. They are made for a 6"-8" rim, but mounted okay on my 5" rims so a I gave them a try. It was a cold day and everyone complained of poor traction. My times were competitive but traction felt worse than in previous autocrosses with street tires... could have been the due to the conditions but I wasn't impressed.
Last weekend I tried a set of 22.5x7.2-13 R25B compound tires and the grip was excellent. Since it was a warmer day and different course it's hard to compare tires, but I think I'll stick with these for autocrosses until they wear out. I contacted Hoosier tech support and they recommended 20.0/8.0X13 R25B tires, which are almost identical, just smaller diameter. Getting the car closer to the ground can only help so I'll keep an eye out for a set of these to try next.

Despite being listed as 22.5x7.2 they measure almost 10" wide and would have rubbed against both front and rear fenders, so I had to remove the fenders to run. Looked a bit strange without rear fenders, but added lightness.