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There has been a lot of talk in numerous threads about what wheel and tyre combinations people are going for, so it seemed sensible to extract it out into a separate thread for ease of reference
I suppose i should kick off....
I have tried MGC wire wheels (5.5 x 15) with std MGC tyres fitted (165 SR 15) but i had issues where they hit the bulkhead.
I recessed my bulkheads but i was still getting some scrub at the end of each lock so i've now decided to go for either 175 65 15's or 165 65 15's, still on 5.5 x 15 wire wheels.
Once i've decided, these should be bought and tested in the next few days, so fingers crossed that they solve my clearance issues!
Edit: i ended up with 165 65 15's, although i'm tempted to put 175's on the back next time.
And i thought it worth while reposting this post from Mister Towed as it has been really really useful!
Mister Towed wrote:
SR refers to the speed rating, not the size of the tyre. 165 SR 15's are 80 series aspect ratio: that means that the side wall height is 80% of the width of the tyre 165mm x 0.8 = 132mm. You need to multiply that by 2 and add it to the diameter of the wheel to calculate a total wheel and tyre height. Or you could just paste this link into your browser...
It's quite a useful tool for checking how different sized wheels and tyres compare to the standard Herald/Vitesse 155/80/13's.
175/65/15's are a common size and add only 5% to the diameter of the standard tyres so fitment shouldn't be a problem. The bonus is you get much more modern tyres (so you can actually stop!) at half the price of classics. Try this link -
It'd be interesting to hear from anyone who's already fitted their wheels and tyres to see what's possible.
Pictures would be good, too, as the fit of the wheels/tyres in the arches can make or break the looks of a car - just look at a Banham 550 on 13" rims to see what I mean.
I'm kind of settled on 175mm wide (to give better grip whle not stiffening up the steering too much) and I have a set of MGB 14's, the only decision left is the tyre wall profile: will 80's foul the bulkhead; or will 70's look a bit small?
Hi Dave I was interested to read that you hae resessed your Bulheads, I am going to have to perform this operation,any chance of a Pic to see what I'm in for.
Cheers John
Back in the summer I bought a lovely set of second hand MGC chrome wires off ebay. They are 5.5 x 15" and came with almost new 185 x 70 SR15 tyres.
Having also bought the long splined hubs and fitted them, it was clear that we needed to modify the bulkhead as others have said before. However having cut back the sheet metal until it is flush with the chassis outriggers over the past few days, I now find that when turning the front wheels on reasonable lock the tyres are actually toughing the chassis itself!
Since I cannot really modify the chassis, I guess the choices are either change to a lower profile tyre with all that expense, or limit the lock on the steering rack.
Has anybody out there found a safe and cost effective way of limiting steering lock please? I would love to hear your solutions.
I know that Gary had done that on 66? and i'd also be interested to see how it was done, as i was only able to recess my bulkheads so far due to my lowered battery tray getting in the way, so at extreme lock i still get a bit of rub
But by limiting the lock i'll be fine and i'll still have more than enough left.
Hi I have a picture of the O/S Bulkhead on No.66 Looks like a large persuader job to me! Good Luck
Yes, I seem to remember Gary saying he'd modified the bulkheads on '66 with a hammer in order to fit the 15" rims with tall tyres.
It shouldn't be too difficult to fabricate a stop of some kind to limit the steering travel instead, after all, the Herald/Vitesse has far more lock than you really need.
Thanks for the pic. jw52. We have already cut the bulkhead, hammered the front plate backwards, then folded the sections together & welded them up. It looks pretty much like your photo of 66, but the tyre is rubbing on the section of chassis coming out from the centre rail towards the side outrigger - directly beneath the battery or the pedals depending on which side you are viewing.
I was hoping that somebody out there may have already tried to fabricate some sort of split collar that could be clamped around the ends of the steering rack bar to limit it's travel either end. It sounds simple............... As always, it would be easier to copy someone who has successfully done the job rather than re-inventing it.
Any suggestions as to how you managed with 66 Gary?
I was hoping that somebody out there may have already tried to fabricate some sort of split collar that could be clamped around the ends of the steering rack bar to limit it's travel either end. It sounds simple............... As always, it would be easier to copy someone who has successfully done the job rather than re-inventing it.
Any suggestions as to how you managed with 66 Gary?
I've not yet bought them myself but their helpful tech dept told me...
"The kit comes with two pairs of bushes to suit to two different racks fitted to Mini's, one pair are 22mm ID and the other pair 28mm ID they are both 37mm OD." and they are 12mm thick.
If you Google 'steering limiter' you'll also find a number of parts for Ford cars but I struggled to find any specs.
Hi, as most builders are replacing outriggers etc. during chassis restoration is possible to weld the front outrigger further back to enable more clearance to be obtained? If standard suspension bushes are used any clearance when stationary will reduce when driven especially under braking. T
yres will also change shape and and size also thus reducing clearance.
Hi, as most builders are replacing outriggers etc. during chassis restoration is possible to weld the front outrigger further back to enable more clearance to be obtained? If standard suspension bushes are used any clearance when stationary will reduce when driven especially under braking. T
yres will also change shape and and size also thus reducing clearance.
I'd considered doing this myself because it does look possible. I decided not to though as it would introduce too many unknowns for my liking, affecting things like the cockpit length, the seat to pedals relationship and requiring the gearbox tunnel to be cut down. It would probably also require the front of the body to be cut back and the bonnet lengthening to compensate, which could adversely affect the looks imho.
I may end up clearancing my bulkhead eventually, but I'm hoping to get away with fitting tyres that don't foul in the first place. The 155/80/14's fitted to two of my old mgb wires look the part and have the same sidewall height as the 175/70/14's that I keep coming back to. Once I've refurbished and fitted my bulkhead back on the chassis I'll bolt up the old 155's and see whether they fit. Here's hoping...
Thanks very much to Petrux, Mr Towed & Davecymru for all the help and suggestions.
I have measured the 13/60 Herald steering rack, the shaft is 20.6mm and the rack end opening is 42.3mm. Speaking with KAD Engineering, their kit has both 22mm and 28mm i/d spacers, both with 37mm o/d that will slide inside the pocket of the rack? Not sure how that's going to work, the pocket is 16.8mm deep. They come with cable ties to secure them instead of jubilee clips, kinder on the rubber gaiters I guess.
For under a tenner it seems a good value kit and I can't find anything else on the net that seems more relevant so one is on it's way here. I will report back on this thread when i've messed around with it a bit.
Like Gary, I do like the tall period look of '66' and hope to keep the 185 x 70 x 15's I have already, It just mean's losing around 3/4 of a turn on the lock each way from dead centre. With the Herald's famous taxi turning circle it shouldn't be too much of a problem I hope. Can't be as bad as the L200 double cab pickup I used to drive, that was an absolute nightmare in multi story carparks.
As for moving the outriggers to give more tyre space, I think it is probably a non-starter with the DVLA inspection ahead. I understand from talking to Gary in the past that they won't allow any chassis modifications, so you could then end up having to go the SVA route.
I have to report that the steering lock limiters were not a success. They were too loose on the shaft for safety even after some adjustment with a hacksaw, so I have abandoned this approach. The instructions clearly state that they should be a tight fit at the end of the rack, or they could slide and possibly jam the steering travel.
Back to the drawing board with tyre sizes. I see Davecymru has 165/65/15's, and still experiences some scrubbing at full lock. Is this on the chassis rail or the bulkhead?
Has anybody out there actually fitted a tyre on a 15" front wheel that does not touch the chassis under the pedals / battery box?
I would be grateful to know of practical results, other wise I think the solution will be trial fitting some scrap tyres from the local garage until I find a combination that works.
Our bulkheads are already modified and don't seem to be the problem.
Hi Paul have you considered drilling the steering limiter and rack across the diameter and fitting a sprung rolled split pin ebay[190539899878] the hole would need to be a snug fit.
Just a thought, but would eliminate the sideways force. I don't think a small hole would weaken the rack.
I have 185/55/15 on mine I have managed to sort it out with height adjustable shocks and a small recess in the bulkhead.
This is a problem with the 15's ...I never really cured the red cars full lock issues ...we were going to weld steering stops onto the spindles but the car went to Germany before we dealt with it.
I think tyre sizes may be the easy option.....
Also , once the car has been inspected ...it wouldn't be an issue if you were to 'repair' the outrigger and the replacement section ended up just back a little from the original ....or got bent a bit in the process of your restoration or that repair patch ended up just a bit shallow... ...
Cheers guy's, what a fantastic response in just a few hours. This is a brilliant resource for all of us builders.
I am a bit nervous about drilling the rack, so will play conservative and fit the biggest tyres that won't foul the chassis on my 15" wires.
To sum up so far using the excellent tyre size calculator program:
The original wheels were 155/80/13 with overall diameter 57.82 cm - ok.
Davecymru has fitted 165/65/15 with overall diameter 59.55 cm - ok.
JW52 has fitted 185/55/15 with overall diameter 58.45 cm - ok.
I have fitted 185/70/15 with overall diameter 64.00 cm - PROBLEM!!!
So the magic overall diameter lies somewhere between 59.55 and 64.00 cm.
Could I ask JW52 how many mm clearance you have between the tread and the chassis rail when they are at their closest point of the steering lock?
Does anybody else have a wheel tyre combination that adds up on the tyre size program to give an overall diameter greater than 59.55mm -AND STILL CLEARS THE CHASSIS ? Don't worry about the bulkhead, we can all fix that.
Thanks again, this must help others out there to avoid costly mistakes buying the wrong size tyres.
I've bolted up my 165/80/14's (61.96cm) on the front and reported back that they cleared ok with a few mm to spare.
That was after putting it on full lock one way, finding they cleared then assuming it would be the same both sides. Now I've tried full lock the other way I've found that the nearside wheel just fouls the chassis rail. This is probably down to the different wear on the old tyres and I've yet to try them with the bulkhead fitted, which is still a work in progress...
Now, my old tyres are worn smooth across most of their surface which probably knocks about 10 -15mm off the original diameter of 61.96cm. So, they're actually about 60.5 to 61cm.
Based on that assumption I'm probably going to fit 175/70/14's giving 60.06cm and hopefully no fouling issues. If Trevor's car was anything to go by they'll still look pretty good. He used 165/70/14's (58.66cm) and got the stance I'm looking for.
Thanks Mr Towed, great information. Just what I was looking for!
Having Googled 'new car tyre tread depth', it looks like for a normal road car the consensus is 8mm. So if yours are actually fully smooth, we can take 16mm off the original diameter of 61.96 cm. This seems to suggest that 60.36 cm. will just touch, if only because of the odd distortions in the chassis over time.
Looks like your proposed 175/70/14's at 60.06 cm. would be a perfect size.
For the 15" wheels, the safe choices seem to be coming out at:
175/60/15 - overall diameter - 59.10 cm.
165/65/15 - overall diameter - 59.55 cm.
185/60/15 - overall diameter - 60.30 cm.
As Mr. Towed has suggested the 175/65/15 at overall diameter of 60.85 cm. could well be a good fit, but the numbers suggest that with full new treads might possibly just touch on full lock.
Any more contributions to the discussion out there please? Its good to share !!
