When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
81 FB original wheel offset And original tire size?
Inset backset offset tomaato tomarto….
Anyone know the inset/offset/backset of the original wheels on a 81FB with drums on the back? Can we confirm it was 20mm, and that the tires were 185/70 R13?
Nothing in the FSM. Found these dims on this forum but want to double check. The Kid has sold me his share in our FB (so he can buy a GS300) and I can finally get rid of the poke and stretch he insisted putting on the FB. But first, need to do some tire math.
The go-to aftermarket wheel size is 15x7 w/ 20et. No spacers needed with that rim size.
This is my first time dealing with this so checking my assumptions/nomenclature.
- 20et = 20mm offset?
- Doesnt our weird bolt pattern require an adapter in order to open up wheel choices…. which in effect works as a spacer?
Feel free to lay some wisdom on this newbie.
Well, if you WANT to use non-RX-7 bolt circles then that is your choice. I am a stubborn, sometimes-purist, and only use 4x110 or 4x114.3 rims on my FB.
*I converted my S/GS to GSL-SE brakes so now everything is 114.3.
15x7 20et is the go-to for first gen guys. Yes, you can get an adapter and put any wheel on that you want, but then you need a slide rule and 2 years of calculus to figure out the proper fit.
The Panasports and other popular 1st gen rims all come in that size because it just plain works and looks good. 205/50 R15 fit great and are extremely close to OE 13" diameter, so your speedo still reads right. But they will rub the front sway bar "slightly". You'll never feel it, but you'll see a rub spot on the sway bar. 195 width won't rub, but it's 10mm narrower so pick what you like. My Summer tires are 195 on front and 225 on back, both on 15x7's. My winter tires are 205/50r15 all around.
Yes et means offset. I don't know what et stands for. But it means offset.
Last edited by Maxwedge; Dec 21, 2022 at 06:07 PM.
Well, if you WANT to use non-RX-7 bolt circles then that is your choice. I am a stubborn, sometimes-purist, and only use 4x110 or 4x114.3 rims on my FB.
*I converted my S/GS to GSL-SE brakes so now everything is 114.3.
15x7 20et is the go-to for first gen guys. Yes, you can get an adapter and put any wheel on that you want, but then you need a slide rule and 2 years of calculus to figure out the proper fit.
The Panasports and other popular 1st gen rims all come in that size because it just plain works and looks good. 205/50 R15 fit great and are extremely close to OE 13" diameter, so your speedo still reads right. But they will rub the front sway bar "slightly". You'll never feel it, but you'll see a rub spot on the sway bar. 195 width won't rub, but it's 10mm narrower so pick what you like. My Summer tires are 195 on front and 225 on back, both on 15x7's. My winter tires are 205/50r15 all around.
Yes et means offset. I don't know what et stands for. But it means offset.
With you on the purist thing. With the FB my son and I share I have had to walk a careful line... give him enough input so he got hooked into the car but not enough that he ruined it. I would rather keep it as close to original as poss, but still he snuck in red/blue/silver Racing Beat oil lines and those pokey/stretchy wheels.
Any experience or knowledge with VTO wheels? They appear to offer copies of the Panasports at a lower price, and have an actual functioning website.
And if I went Panasport, best place to source them? Spent the last hour searching, but hard as most suppliers go by car make and model rather than by size and offset. And as a Brit I was starting to get post traumatic flashes with all the mentions of Triumphs and MGs.
"I converted my S/GS to GSL-SE brakes so now everything is 114.3."
Talking of which just got back from the OReillys auto parts store that opened up last week in my neighborhood. Manager saw me pull up and greeted me with a 'Where did you find that RX7?'. Kind of dismissed him as a general knowledge kinda guy who just liked old cars until he asked if I had switched the rear axle to a GSL yet. Turns out he has owned three FBs in his time. Very happy to have found him.
