Tyre desert

[chrishewett]

Having messed with the suspension I had hoped to fit new tyres this week and see if there was any improvement.
I am having trouble finding any tyre 175/70 with a speed rating H.
The Falken FK-07U I ordered are no longer available in that rating.
I really don't want to spend a fortune as I am not sure they won't be chewed up.
Has anyone bought any of this size recently?
Chris

[Hamish Coutts]

Chris,

175/70s?

That was the size I was going to fit until I talked to the depot manager of ATS in Leith, Edinburgh. After pouring over his books he said that I should be fitting 185/60*13 as this had the same rolling diameter as the original 165*13s. (I wanted something a wee bitty beefier than 165s). I ended up with Uniroyals @ about 50 squids each. So far they are fab, much better than the 165s (admittedly they were 1970s Goodyears) and the car sticks to the road like the proverbial sh1t to a wet blanket.

I have no rubbing problems and the balance (both wheel and car) is good.

My gearing is about right as the sat nav is only about 3mph ahead of the speedo at 70mph. I have a 3.55 dif fitted. So at 70mph the engine is pulling about 3,800(ish) revs. Good for touring but not so good for sprints. Then again you could fit a different diff for that!

Hamish.

[Hamish Coutts]

Chris,

Forgot to say that ATS also list Michelins in 185/60 but they could only find 3! They said that more would be available later. (they had an offer on Michelins that made them cheaper - think about 20% discount if you bought 4 or more)

Have you got a local ATS depot? May be worth a try.

Hamish.

[chrishewett]

Hamish,
Havn't I read that 185 rub on the rear springs? Mine are standard.
Chris

[pmallinson]

Gents

So very much has been written before about tyre choice sizes and the like that I think everyone must has been totally confused SO all I offer is a GREAT supplier of tyres of nearly any size and any brand TO YOUR DOOR their prices are VERY keen and if you buy 4 tyres delivery is FREE

Who are they I hear you cry: P

Try MyTyres at http://www.mytyres.co.uk/start.html

See the attached run on 175/70/13 H rated 21 different tyres from 19.00 to 53.50 GBP !!! I actually fitted the UniRoyal Rallye 680 to my +2 and so far I'm VERY happy with them 4 off all for 144 GBP delivered (they have gone up a tad now but not much) and it cost me 25 Euro to have the 4 fitted inc Balance !!

They supply to nearly every country and are dead reliable in my experience over the past 10 -12 years and maybe 20 sets of tyres over that period.

OK so you now have to have them fitted but in my experience about 5 - 7 quid for fitting including balancing and this still makes them cheaper than your local tyre shop !!

Cheers and good luck let me know how you get on

[Hamish Coutts]

Chris,

You may have a point there. I have the smaller diameter Spyder springs fitted and I can get my finger between the rear tyre side wall and the spring seat. Therefore there are no rubbing problems.

The front is standard with no rubbing problems either.

Car groud clearance is about 6" and I have +2S alloys fitted.

Regards,

Hamish.

[msd1107]

Hamish,

185/60-13 is NOT the same tire rev/mile as 165-13.

185/60-13 is 956 rev/mile (21.7 in dia). 165-13 is 887 (23.4 in), an 11.4% difference. I made the same mistake many years ago when my 185/70-13 tires (893 rev/mile, 23.2 in) became unavailable. I also have the 3.55, but the difference in revs is quite noticable. So much so that I asked my mechanic if my tach calibration was wacky! (incidentally, 155-13 is 912 (22.8 in), 145-13 is 939 (22.1 in), 175/70-13 is 917, 22.6 inch and so on.)

I have a spreadsheet with all the tire sizes and their corresponding rev/mile figures as reported by the tire manufacturers sorted by both wheel size and rev/mile. To my knowledge, there is no equivalent in the industry.

You can request a copy from me (david_harralson at hotmail.com). I would be more than pleased to send you a copy. Lotus owners need all the help they can get to keep their cars running optimally.

David
1968 36/7988

[theelanman]

I got goodyear NCT3's
full set for ?100 and theyre 175/13 70....I think they may be a 't' rating though.....

[schroeder]

Chris

I have 185/70x13 fitted on +2 alloys with standard springs. They are close but do not rub. I have heard that you can gain a little more clearance with the help of a hammer to the spring perch.

Stu

[chrishewett]

I am a bit worried about trying 185 tyres as if they rub it would be an expensive experiment. I have located some yokohamas, 175/70, at more than I wanted to pay and will have them fitted next week.
Will it never end? The season of fun is nearly upon us and I am still not ready!
Chris

[schroeder]

Chris

I understand the concern, regarding wheel arch rubs. I have no such problem.

It should be fairly easy to check the amount of clearance you have and determine if you have at least 5 mm per side.

If you go down this route, remember to check all four wheels/tyres as the body shells are rarely if ever aligned on the chassis. Also need to check the front through full steering path and of course allow for suspension compression.

I plan to get mine out of storage later today and will measure my clearance.

Stu

[schroeder]

OK so not so easy to measure the clearance. But here's what I have found. All measurements approximate.

With 185/70x13 the tyres extend outward beyond the inner arch lip at the rear and beyond the outer arch edge from vertical centerline forwards on the front.

On front wheels clearance from tyre to bodywork toward the bumper on horizontal centerline is 1.5 inches. Clearance from tyre to bodywork towards the door on horizontal centerline in 2.0 inches.

Both front and rear clearance between tyre and bodywork on vertical centerline is 2.25 inches.

Suspension is stock springs with koni shocks rear and gas filled (SPAX I Think) front.

There is insufficient compression available in the suspension for the tyres to make contact with the arch. I've been using this set up for road and the occasional track day for 3 years without and rubbing of arches or stock rear spring perches.

Only problem was debris that was thrown up which left a small crack in the front arch lip. Guess the wider tyre makes this more likely, but could occur with skinny tyres too.

Stu

[chrishewett]

Thanks Stu, I will get the tape measure out tomorrow and see how that equates to my car.
Chris