2500M: 15" wheels?

[Renaldo]

Guys, forgive my ignorance on this, but I have the opportunity to buy some very nice 15" x 5" wheels for my 2500M (American Racing Silverstone mags).

My car currently has 14" t-slots.

Should the 15" wheels fit? (without any fouling against the fenders?)

Ron

[Dollyman1850]

bit narrow??
N.

[TA14]

Yes, plus what's the offset? Should be close to zero for an M. (Can't remember whether it's +/- 2mm ET)

Usually easiest to go for 16" and fit 205/55/16s.

[Slow M]

I believe the T-slots are 6J (6" wide), with zero offset. Going to a 5J/15 will reduce the contact patch. I agree with going to 16" diameter, as the performance tire options will continue to disappear, for 15" and smaller diameters.

Best,
B.

[Renaldo]

Thanks guys. Again, forgive my ignorance, but could you get out the chalkboard and help me understand the repercussions of a reduced contact area? I assume it means that handling is negatively affected? Less grip in particular?

Despite not being the ideal size, these wheels look drop-dead gorgeous. I gather they were a dealer option on the original TR250 (TR5 in UK)!

The fellow selling them had them on his TR250 and they're in very nice shape.

I'll try to post some pictures...

By the way, I'm assuming by going to a larger diameter wheel, my speedo would need recalibrating?

Ron

[phillpot]

Renaldo said:

I'm assuming by going to a larger diameter wheel, my speedo would need recalibrating?

Depends on profile of tyre (and probably wasn't too accurate before )


If you "play around" on a website such as this you can soon sort out what you need to retain a near as damn it diameter/circumference.


May not be so easy to actually find that size tyre in a decent Brand, speed rating etc.


Probably wouldn't want to go any bigger than a 185 on a 5" rim

Edited by phillpot on Saturday 29th November 20:16

[Slow M]

Renaldo said:

Thanks guys. Again, forgive my ignorance, but could you get out the chalkboard and help me understand the repercussions of a reduced contact area? I assume it means that handling is negatively affected? Less grip in particular?

Despite not being the ideal size, these wheels look drop-dead gorgeous. I gather they were a dealer option on the original TR250 (TR5 in UK)!

The fellow selling them had them on his TR250 and they're in very nice shape.

I'll try to post some pictures...

By the way, I'm assuming by going to a larger diameter wheel, my speedo would need recalibrating?

Ron

Right, reduced contact patch equates to less available mechanical grip. The thing is, the compound, and tread block design also play into abailable grip, and there are just no decent tires being made, in the right size, for the 14" T-slots.
http://www.tirerack.com/tires/TireSearchResults.js...
http://www.tirerack.com/tires/TireSearchResults.js...
If you give it a couple of years more, they won't have anything available, for 15s, either.

I just had a look at what Coker have available, in a 14", and it's pretty grim.
https://www.cokertire.com/tires.html#cat=brands&am... Redline,Raised White Letter,Redline&tire_brand=BF Goodrich,Coker Classic,Michelin&tire_rim_diameter=14&tire_type=Radial
ignore the 50 section BFG, I can't exclude it, from the selection set.

I'd go with something closer to a 215/55/16, mounted on 6"/6.5" wheels with a slightly deeper backspace, and keep the T-slots in a safe place. Another choice, is that you could talk to a custom wheel maker, and ask if they could cut up the T-slots, and use the centers on a 16" modular wheel, drilling them, and bolting spun inner and outer halves onto them.

It's too bad, that these cars look better, with a lot of curved rubber filling the wheel arches. None the less, they are sports cars, and it seems silly, to ask them to dance in climbing boots, or play tennis with ski boots on.

Best,
B.

[Renaldo]

I hadn't been keeping up with this, but I agree it's amazing how smaller-size tires are disappearing.

I guess it's not surprising when the smallest subcompact cars available now, seem to using 15" & 16" wheels.

The standard size tire on the 2015 Nissan Micra, which is a tiny car, is 15" and that's on the absolute base model.

An eye-opener...

[madsvlund]

Forget 16", that area is allso going down, for my M rear's (9.5x16) are there onle a few in 245 remaining (perhaps due to the porsche crow) and for the semi slics do toyo make a 255 and Kumho a 265, but only in hard compounds.

The US market seem's to use 16" a bit more, but importing tyres seem a bit odd.

For the space under a M, with the right ET can the rear arches take 8" / 225 tyres without any issues, if the seatbelt bracket is removed, can 265's on 10" go under. For the front is things a bit more tight, mainly due to the large scrub radius on the car (will make the wheel travel forward and backward when turning) and depending on ridehight is the bonnet an issue as well. 205's is the limit, and 195's do actually fit better.

I'm on 215's front now, but will modify the upepr wishbone (once more) to eliminate the adjustabel top balljoint, and replace it with a lower joint from a triumph stag, to gain 15mm more ET on the front's so I can increase from 7,5" to 8,5" and still be MOT'able

[Slow M]

madsvlund said:

. . . The US market seem's to use 16" a bit more, but importing tyres seem a bit odd. . .

Mads, The OP is in Canada. It's the same market. Also, adding much more rubber to the rear, than to the front, will mainly screw up the handling balance, on a car that can't be throttle steered. I would keep front and rear the same.

catfishdb said:

Sitting in the loading bay at work.

Arthur

catfishdb said:

They are Compomotives. Correct off-set. No spacers required. Tire fitted is 215/45 17". Rides a little stiff. Corners flat.

Arthur

Could do something similar, to Arthur's car, too, although I understand why you like the ARs.

Best,
B.

[TA14]

Slow M said:

I'd go with something closer to a 215/55/16, mounted on 6"/6.5" wheels with a slightly deeper backspace

I wouldn't want to go less than 7" for a 215.

[Slow M]

Always a good idea to look into tire manufacturer's recommendation for rim width.

Some mfgr's spec 6" plus.

Best,
B.

[Renaldo]

Guys, I realize much of this is personal taste, but please post some pictures of some larger diameter wheels 16 that you think look good on the M series.

I'm very interested to see some of your suggestions/ideas, before I move in that direction.

You've got me thinking about moving to a 16" alloy of some sort. (but man those 15" AR Silverstones look good!)

Ron

[Slow M]

Simmons:



Panasport:


Compomotive:




CCW (I'd ask for the center to be sandwiched, or behind the shells, and painted gold):


Jongbloed:


Ronal:


These J.A. Pearce Magna are nice, but I've no idea if they will be available in 16":


Best,
B.

[bluezeeland]

Alltho in the post above Bernard is showcasing some rather tasty wheels, he touched upon something else earlier, namely you should go to far off the original (if your car is more or less original(ish), which excludes Mads car, as it is heavily modified, suspension/upright, brakes and steering) (not judging here, just an assessment )

I am a fan of Tslots on an M series, they look best in my view, plus mine are shod with 185/80/14 HR Michelins , which is as per original size and are performing very well !

......and cost a small fortune !

Frank

[catfishdb]

Each to their own. Early on in my build I was thinking of using the T-slots but blacking out the entire centre section and just leaving the polished rim. Something like Fuchs on early 911s. I have seen the Panasport wheels on a few classic TVRs and think they look correct for the period. I was also thinking of using them as I was having minimal luck finding a decent range of 14" tires.
I am thrilled with my Compomotives. You will notice a slightly heavier steering feel at low speeds and the shorter sidewall makes the ride a little harsh for some.

Arthur

[Renaldo]

Arthur, I sent you PM. I'm looking at a set of Konig Rewinds which I can get for a good price locally. Look very much like Minilites or Panasports.

They're 16 X 7, with 0 offset.

Wondering if they're would be any fitment issues, whether 0 offset is okay, and what size tires might be a good choice...

Ron

[catfishdb]

Hey Renaldo,

I will check my Compomotives to see what rim width they are. If memory serves me correctly they are 7" with a 0 or very small offset.

I have absolutely no issues with the 215 17" 45 tires rubbing. The suspension arms are original, only the ride height has been lowered slightly.

Arthur

[Renaldo]

Guys, I asked John Wadman about the offset issue.

He told me, according to his notes, the original wheels had a 4mm negative offset.

I guess it's important not to stray too far from that. A few mm is ok though, as I understand it...

Ron

[TA14]

Slow M said:

Always a good idea to look into tire manufacturer's recommendation for rim width.

Some mfgr's spec 6" plus.

Yes, but most if not all suggest a 7" rim for a 215 is best, saying that the tyre will fit on a rim as small as 6". When buying new wheels I'd want the idea rim width not the least that you can get away with.