greasymonkey

This is when I miss working on cars with a group of guys standing around making comments while I bust my knuckles on a bolt that won't move! Turns out the bolts are 5/6 20, which is the correct spec for a 1990 Caterham with seat belts not harnesses.

Well, as it turns out, none of these things are true. Neither the assembly guide, nor the photos of your setup. My car was built for 3 point belts, but the builder/po decided to install 4 point harnesses instead. So, he drilled a hole for the inside harness, and re-used the outside seatbelt mounting point. The rollbar has a bolt behind the seatbelt mount that, might be 5/16, and it might be 3/8. I have a set of those amazon thread sizers, but they're absolutely useless in this situation. I bought some cheap rando hardware store bolts to figure out fit. Since I live near nothing, just waiting for them to show up. Oh the joy of old kit cars built by people that think they're engineers.

I just noticed I'm missing both bolts that hold the standard roll bar hoop to the mounts behind the seats. I'm looking to buy replacement bolts, spring washers, and flat washers. I want to make sure I understand correctly, with 4pt harness, I should get 7/16" UNF x 1" screws, NOT the 5/16" UNF x 1" screws that would be used if I had standard seat belts. The Assembly Guide says the following, which, is confusing. (note: I have 4 pt harnesses installed) "6.11 Standard Roll bar This is best fitted after any work required in the boot and before fitment of the boot cover. The roll bar attaches on top of the seat bulkhead and inside the rear of the boot. a) 5/16”UNF x 1” set screws and spring washers are used into the seat bulkhead, tighten to 20-25 lbft. The rear legs locate into the chassis brackets in the boot and are secured using 5/16”UNF x 2” bolts, washers either side and nylocs, again tighten to 20- 251bft. b) Fastening of the forward ends is dependent on the type of seat belts being fitted. Static three point lap and diagonal belt: The rollbar is secured using the same bolt as used by the top seat belt mount. The roilbar is fitted underneath one of the thinner seatbelt spacer bushes. The seatbelt bolts are tightened to 40-45 lbft. Static four point harness: The rolibar is secured at the front by 7/16” UNF x 1” set screws and spring washers. Tighten to 20-25 lbft." Thanks!

I have a 1990 Super Seven, and after discussing with Caterham, sounds like the current S3 windshield is the same as what I currently have. My glass took a major rock hit, and I'm wondering if there is a supplier for the glass and necessary gasket. Otherwise I'll just purchase the complete windshield and surround. Thanks!

Thanks, appreciate the info. Mine is a 1990 Super Seven. I’ll get to measuring tomorrow. I think they’ll fit.

I did the math on the tire sizes - 185/60 in both 13 and 14”, and both have the same sidewall height, the only difference is the circumference is an inch smaller. I’m going to look into the 195/60r14 for fit.

Yeah, I was thinking 13" as well for the same reason. What size rims should I look for in 13"?

Ah, thanks! I currently have 185/60r14, and meant to ask whether 195/60r14 would fit on the car. So, thank you for your help! I wasn't finding much in 185/60.

Sorry, should have added that I just drive the car on the street, and while a track day isn't out of the question in the future, for now, decent handling street tires are my priority.

My 1990 Super Seven has 14" Panasports, and given the few 14" tire choices, wondering if I should switch to smaller 13" wheels, or go up to 15's. The car is fairly new to me, and came with a set of fairly old Bridgestones. I feel that 15" wheels and tires might add more weight, given I have a Lotus TwinCam and not a more modern engine, I'd rather not give up HP pushing extra weight (I'm already too much weight! ) Thanks for any advice/opinions.