‘75 B-210 wheel and tire sizing

[JayDilla]

I’ve recently acquired a set of SSR MK2’s. They’re 13x7 et5 and et15 . Hopeing they fit? From what I’ve got on here I shouldn’t have any issues just hoping they give the look I’m going for and dont hit anything in the inner fender walls ie, the lead springs. I was aware finding 13” tires in the states  would be a pain but didn’t expect it to be this hard. As of right now I am debating between 2 sizes. BfGoodrich’s 205/60r13’s and KUMHO’s 185/70r13’s. Originally was hoping to get a low profile look but realizing now that isn’t very likely. Any thoughts and tips on this would be much appreciated! Thanks

[datzenmike]

Too late now. The golden rules are.....

 

Know what will fit your car before you get a hard on.

Never make your car fit the rims... make the rims fit the car.

Hope.... is overrated.

 

You are going to have to take your spare out and make some measurements on it and make some measurements of the space around the tire on the car, front and back so you know what will fit without rubbing the fenders or the suspension. Go online and there are dozens of wheel back space/off set calculators that will compare what you have to what you would like. This should be done before you spend money on any tires. Too late for the rims. They'll either fit or they won't. 

 

 

[JayDilla]

Haha yes definitely my loss and stupidity if it doesn’t work out. Pretty new to all of this and realizing there’s much to learn . Happy to finally have joined the forums and get any help I can. I’ve seen a lot of mixed opinions on here however as to what fits and what doesn’t . Your definitely right on just checking myself and knowing exactly what’ll fit. As for making the car fit to the wheels I’m not interested in going that route. Prefer to do things correctly and not screw the ergonomics of the car up. I will be test fitting them soon and will update. 

[datzenmike]

You may luck out but check what you need before adding tires to the pile.

[JayDilla]

Yeah I’m going to get them mounted before I buy anything else forsure. I need special lugs for the MK2’s aswell (shank lugs) but I’m going to try mounting them with normal acorn style just to see how it fits at ride height before going further. 

[Dguy210]

I currently run 280zx 15 inch +12 rims on my 74 4dr B210. I have an excel sheet I designed and empirically tested to determine max wheel size for 13, 14, 15 inch wheels.

Note: I have 280zx front struts and rolled rims, so I would suggest a slightly more conservative approach than the max sizes if you are running stock equipment. Basic rule is keep total tire diameter under 24 inches and you should be fine. Max front with trimming inner edge of fender is 23.9 inches and may still rub a bit at full lock for the rear it is 24.7 and may rub when fully loaded.

 

For 13 inch wheels with stock struts:
The 2 bolded choices 185/70 and 175/70 are safe sizes and are the most common when I last searched (granted 2011), sizes are ordered by price for tires of that size so are out of date but should still be reasonable.

The 2 choices listed in italics and strikethrough are only suitable for rear tires under special circumstances: avoid.

Total Height (in)     Height From Rim Wheel Size Height Aspect mm in 13 23.2 185 70 129.5 5.1 13 22.8 155 80 124.0 4.9 13 22.6 175 70 122.5 4.8 13 22.1 165 70 115.5 4.5 13 21.7 185 60 111.0 4.4 13 19.9 175 50 87.5 3.4 13 22.2 195 60 117.0 4.6 13 21.5 215 50 107.5 4.2 13 22.7 205 60 123.0 4.8 13 21.4 165 65 107.3 4.2 13 24.0 175 80 140.0 5.5 13 24.7 185 80 148.0 5.8 13 21.0 225 45 101.3 4.0 13 21.3 235 45 105.8 4.2 13 21.9 225 50 112.5 4.4 13 21.0 255 40 102.0 4.0

 

Also, I would suggest checking out this prior thread:

 

 

Edited February 19, 2019 by Dguy210

[JayDilla]

Wow man! That’s super helpful! Thank you. Hoping to get them mounted today and take a look at ride height fitment! Will upload some pics when I do 

[JayDilla]

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[JayDilla]

Turns out they’re gonna damn near be perfect! I’m pumped!!

[Tom1200]

Is this car your daily driver? If it isn't then your tire choices have some options you likely have not considered. 185/60-13s are widely available in R compound tires. While they can be pricey new, buying take offs (used) from a place like John Berget Racing Tires ($250-$300 per set) makes for a good deal.

 

As for the size go with no wider than 185s, with a standard or near standard motor the narrow tires (read lighter by as much as 4lbs per tire) will noticeably help the acceleration. Additionally the car will have a nimble feel.

[JayDilla]

Yeah I’ve actually found quite a few more tire sizes aswell and ended up going with 175/50r/13s . I am going to look into some used R tires now that you brought that to my attention tho. Thankfully this is no longer my daily as I live in Seattle and she gets pretty nippy while driving hah. Good point on not wanting wider than 185 though. It’s daily stock as far as the motor goes and I definitely wouldn’t meant to lose any of the massive 68 horses pullin her down the road?

[datzenmike]

Too close to call and the car is on stands.

[JayDilla]

1 hour ago, datzenmike said:

Too close to call and the car is on stands.

Shit really? Well I’m too invested at this point hah... I know once the car is lowered to ride height the wheels will be creeping towards the fenders a bit more but I can’t see the gap between the suspension in the front and rear getting much smaller or am I incorrect about that? 

[datzenmike]

The rear is a solid axle so the car will just come straight down on them but the fronts will swing outward slightly as the lower control arms swing up to level. X your fingers.

 

You can 'roll' the fender lips for more clearance but this is poor form as  the fold strengthens them. I'm not a fan.

 

I had a brand new '76 2 door in the day. A very fun car.

[JayDilla]

44 minutes ago, datzenmike said:

The rear is a solid axle so the car will just come straight down on them but the fronts will swing outward slightly as the lower control arms swing up to level. X your fingers.

 

You can 'roll' the fender lips for more clearance but this is poor form as  the fold strengthens them. I'm not a fan.

 

I had a brand new '76 2 door in the day. A very fun car.

Ahh ok cool , my biggest concern was clearing the suspension and seems I’m good on that end. I personally like the flared look so a bit of wheel poke won’t kill me. I can’t see it rubbing at its current ride height and with the tires I went with since I found some 13s with a low sidewall and there will be a bit of stretch. I was aware that the front once lowered will push the wheels out a bit . I’d prefer to roll the fenders than rock spacers behind the wheel. And yes rolling the fenders takes from the structural integrity but I believe there are ways to do it properly. And later down the road I wouldn’t mind going real agressive with the offset on the wheels and having huge over fenders. Always been a fan of the bosozuku style in Japan. But also want my car to perform decently too.         

 

And rad! The two doors are sweet aswell. Personally feel they’re a bit short in the chassis for my eyes . Even the 4door looks frumpy from certain angles at its current ride height. Been researching different ways to go about lowering the car both front and rear a bit just trying to avoid cutting the front springs as I’ve seen you criticize this highly on here in different threads. You mentioned there’s a way to go about it where you use slip ties or something. Allowing adjustable height and dampening which would be ideal or even better I’d go for the 280zx strut conversion allowing better front brakes and adjustable coil overs . However I’ve read most 13” wheels won’t allow the brakes to fit so I’m trying to get the specs on that fitment to see if the MK2’s will clear the 280zx caliper and it possibly being able to shave down the calipers to fit. Appreciate all the help man?

[datzenmike]

Spacers behind the wheels will move the rim even farther out.

 

Imagine if the strut tube continued down on that (I believe most Datsuns are 10 degree angle) past hub with the wheel on it and touched the ground. The center line of the tire should be almost at the same place. Perhaps slightly outside of this. This is called a positive scrub radius. When steering, the wheel (almost) stands still and rotates. Now imagine you add 10 feet of wheel spacers and move the wheel all the way out there. Now when you turn the wheel it doesn't rotate, it moves in a 10 foot arc. Obviously increased scrub radius increases steering effort. Yes this is exaggerated for effect. Moving the tire outward increases it's (not your) leverage on your steering. When driving with too much positive scrub radius any imbalance in traction or braking will assert itself strongly as feedback in the steering. If one wheel drops off the pavement it will pull harder to that side and the same with hitting a deep puddle on one side. A little can provide a better feel for the road, some feedback. Too much and you'll be wrestling with the steering. You can go to wider rims as long as the center line remains in the same place. 

 

How much is too much? I have no idea. Try to keep it as close to factory as possible.

[JayDilla]

1 hour ago, datzenmike said:

Spacers behind the wheels will move the rim even farther out.

 

Imagine if the strut tube continued down on that (I believe most Datsuns are 10 degree angle) past hub with the wheel on it and touched the ground. The center line of the tire should be almost at the same place. Perhaps slightly outside of this. This is called a positive scrub radius. When steering, the wheel (almost) stands still and rotates. Now imagine you add 10 feet of wheel spacers and move the wheel all the way out there. Now when you turn the wheel it doesn't rotate, it moves in a 10 foot arc. Obviously increased scrub radius increases steering effort. Yes this is exaggerated for effect. Moving the tire outward increases it's (not your) leverage on your steering. When driving with too much positive scrub radius any imbalance in traction or braking will assert itself strongly as feedback in the steering. If one wheel drops off the pavement it will pull harder to that side and the same with hitting a deep puddle on one side. A little can provide a better feel for the road, some feedback. Too much and you'll be wrestling with the steering. You can go to wider rims as long as the center line remains in the same place. 

 

How much is too much? I have no idea. Try to keep it as close to factory as possible.

Yeah I am aware that spacers would have this effect . How they’re mounting currently it seems as tho the scrub radius should be fairly close to stock possibly a bit increased. Was just saying I’d prefer to have the fenders rolled then have issue with my wheels hitting the suspension. Which would require spacers at that point. However I do appreciate the detailed explanation on scrub radius. That all makes a lot more sense and possibly running spacers in the future could benefit my handling a bit as long as I do go too far with increasing the scrub radius. Cause parallel parking is already a bitch with no power steering haha. Not to I want to have to fight the wheel more when going over dips or uneven roads. 

[datzenmike]

Well it does have benefits. The car sends more input to the driver though the steering wheel. Like everything... too much may be TOO much.

[JayDilla]

19 minutes ago, datzenmike said:

Well it does have benefits. The car sends more input to the driver though the steering wheel. Like everything... too much may be TOO much.

Yes I’ll definitely keep this in mind. Before I increase scrub radius and steering input needed to turn I’d like to get my steering and front suspension dialed in a bit better. I’ve got a lot of wheel play and going 60 on the freeway gets pretty damn sketchy. Was thinking I needed to get my steering box looked at or tighten it a bit but after reading some stuff on here it sounds like I should lift the car and check some of the control arms and idle arm first and replace any nasty old bushings and this usually fixes most peoples issues. If you know a good place to find most these parts that’d be helpful too! I know eBay seems to have quite a bit and I found another website MOOG suspension that seems to have parts for front suspension aswell.

 

(also had a question if it was just me or was everyone unable to access this forum yesterday? Does it tend to go down at times?)

[Dguy210]

2 hours ago, JayDilla said:

Yes I’ll definitely keep this in mind. Before I increase scrub radius and steering input needed to turn I’d like to get my steering and front suspension dialed in a bit better. I’ve got a lot of wheel play and going 60 on the freeway gets pretty damn sketchy. Was thinking I needed to get my steering box looked at or tighten it a bit but after reading some stuff on here it sounds like I should lift the car and check some of the control arms and idle arm first and replace any nasty old bushings and this usually fixes most peoples issues. If you know a good place to find most these parts that’d be helpful too! I know eBay seems to have quite a bit and I found another website MOOG suspension that seems to have parts for front suspension aswell.

 

(also had a question if it was just me or was everyone unable to access this forum yesterday? Does it tend to go down at times?)

 

Replace the ball joints, Idler arms, and any kind of movable joint on the front suspension, Rockauto should have most of the parts. This makes a huge difference in the feeling of looseness in the steering wheel. I'd repack your front bearings too while you had everything apart anyways but that's just me.

 

The steering box can be adjusted to have some of the backlash taken out (same as 510 steering box, I'm sure someone has a tutorial around here somewhere or see Datsun1200 site).

 

Front suspension on a B210 is very very similar to a 510 so any suspension hop-up parts for the 510 will usually work. 

 

Go to the 280zx struts, they really make a big difference in braking and will let you run larger wheels as they do pull in the strut about a 1/2 inch per side I believe. The caliper can be shaved to run some 13 inch rims, results might vary.

 

Always remember to readjust alignment, even if with a tape measure, on your wheels after any suspension adjustments.

Edited February 23, 2019 by Dguy210

[Tom1200]

I was outin the garage porting a cylinder head over the weekend so I'm just getting to this.

 

First, while lowering the car will help the handling it's not always the best thing for daily use. When I had my B210 I had a set of Enkei wheels with 185/60-13s, some Koni dampers/shocks and a set of Addco sway bars. For the brakes I used Repco Metal Master pads on the front, can't remember what brakes shoes a I used. The car used 80hp A14.  Overall the car was fun to drive. 

 

While I use the ubquitous 280ZX strut on my 1200 race car, they are rather heavy and for a low powered street car not really needed. Also note the 280ZX calipers due need to be milled to fit under a 13" wheel. 

 

Check Datsun1200.com it has good info on upgrading the brakes on the stock strut replacement.

[Dguy210]

1 hour ago, Tom1200 said:

I was outin the garage porting a cylinder head over the weekend so I'm just getting to this.

 

First, while lowering the car will help the handling it's not always the best thing for daily use. When I had my B210 I had a set of Enkei wheels with 185/60-13s, some Koni dampers/shocks and a set of Addco sway bars. For the brakes I used Repco Metal Master pads on the front, can't remember what brakes shoes a I used. The car used 80hp A14.  Overall the car was fun to drive. 

 

While I use the ubquitous 280ZX strut on my 1200 race car, they are rather heavy and for a low powered street car not really needed. Also note the 280ZX calipers due need to be milled to fit under a 13" wheel. 

 

Check Datsun1200.com it has good info on upgrading the brakes on the stock strut replacement.

 

For a 1200 the mklotz brake upgrade is much better than the 280zx for front weight, overall costs and ease of finding parts, but not a lot of options for a B210 except swapping to hard to find 1200 stuff and then upgrading.

 

For practical purposes I would argue the 280ZX strut is probably the best overall upgrade for his B210 that won't be super expensive, difficult, or hard to find.

Edited February 26, 2019 by Dguy210

[datzenmike]

About adjusting the steering box...

 

Almost exclusively the most wear will be in the position it is driven in most which is straight ahead with less to each side. If you remove all the 'slop' in the center you are likely to have tight steering on turns. Now this could affect getting the wheel centered after a turn, it may jam and if not it will accelerate the wear to the sides and stress the box unnecessarily. 

 

If you adjust the box do it with the wheels off the ground and spin the steering wheel quickly lock to lock to check for any tight spots. When it does show signs, back your adjustment off slightly and check again. Don't forget to set the lock nut to hold the gear lash setting and check one more time. Most boxes take GL-4 but check your FSM for this.

 

Additional slop may be worn or less than perfectly adjusted  pre-load on the wheel bearings. Poor front end alignment can also cause you to see/saw the wheel when steering. Yes the idler arm bushings is another good one and of course the ball joints..

[JayDilla]

11 hours ago, datzenmike said:

About adjusting the steering box...

 

Almost exclusively the most wear will be in the position it is driven in most which is straight ahead with less to each side. If you remove all the 'slop' in the center you are likely to have tight steering on turns. Now this could affect getting the wheel centered after a turn, it may jam and if not it will accelerate the wear to the sides and stress the box unnecessarily. 

 

If you adjust the box do it with the wheels off the ground and spin the steering wheel quickly lock to lock to check for any tight spots. When it does show signs, back your adjustment off slightly and check again. Don't forget to set the lock nut to hold the gear lash setting and check one more time. Most boxes take GL-4 but check your FSM for this.

 

Additional slop may be worn or less than perfectly adjusted  pre-load on the wheel bearings bearings. Poor front end alignment can also cause you to see/saw the wheel when steering. Yes the idler arm bushings is another good one and of course the ball joints..

Yeah definitely don’t want to have my steering lock up on me. Going to order up / replace all the front suspension parts needed and upgrade where possible . Struts ect.. but thankfully all the us b-210’s came with the more beefy suspension already. Whatever I can’t replcae I plan on cleaning up and refinishing . If I’m still unhappy with the wheel play I will look into adjusting the steering box. 

 

 

On another note. My tires and special Mk2 shank lugs should be arriving this week! Aswell as wheel locks to keep em safe! Can’t wait to get em mounted ? will upload photos later this week! Thanks for all the helpful tips guys. 

 

As far as replacement front end suspension parts . Any brands I should get ? RockAuto seems to offer quite a few different options in most the parts

[Tom1200]

The KYBs from rockauto will work fine. I've actually used them on my race coupe.

 

Better would be get a set of Koni inserts, Classic Garage has them for $120 each. Couple that with some Koni Classics for the rear $100 each, you'll have to take some measurements as the B210 specific ones aren't available anymore. Check Datsun1200.com as the site has shock measurements and possible substitutes listed. $450 for dampers is a lot for a stockish car but it's worth it. Good shocks/dampers are one of the best upgrades you can do for any car.

 

Again the KYBs will work fine but I'd spring for the Koni dampers. 

 

Now as for your steering slop check the idler arm bushings these are the first things to wear out. Have someone move the steering wheel back and forth slowly, watch the idler arm in relation the the steering links. Obviously you can check the ball joints but I will tell you the ball joints have been on my race car for 25 years and they are still fine. 

 

On the 280ZX struts; they are popular for a reason. Being off a 3000lb car the components last forever. The only down side is the weight.