Series 1 or 2 SD1 alloys?
- Thread starter WarrenL
- Start date
That's a real downer. You do wonder when they grind away like that what the safety implications are. I'd be tempted to look for another and keep it as the spare if it bothers you that much.
If I had an s2 and not my s1 I'd definitely be on the look-out for those same rims.
If I had an s2 and not my s1 I'd definitely be on the look-out for those same rims.
WarrenL
Active Member
They've only taken a little bit off, but it's enough to visibly widen the bevel. To be honest, it's only really noticeable when you have all the wheels lined up together on the garage floor: I don't think anybody but me will ever know once they're on the car. However it just pisses me off and it means they won't ever get any business through me.
WarrenL
Active Member
Almost there! The front wheels are on, fitted with the existing front tyres. Unfortunately my local tyre dealer didn't have 205/75 x 14 in the workshop and we had run out of time (it being lunchtime Saturday) to get something delivered from the warehouse, so they're arriving on Monday. I couldn't resist fitting the front wheels anyway, and it provided an opportunity to take a shot showing the contrast between the old and new:
Interesting how much bigger the mags look, even though they're the same size. The black of the steel wheels makes them look smaller, and the tyres correspondingly taller.
Interesting how much bigger the mags look, even though they're the same size. The black of the steel wheels makes them look smaller, and the tyres correspondingly taller.
Hi Warren,
You're going for a bigger rolling diameter with 205/75 series (HR rated at the very least I hope?) than the original rolling diameter. My understanding has always been that with 205 width tyres, the correct aspect ratio is 70. Certainly that delivers a wheel with a rolling diameter that conforms with the gearing specs as covered within the workshop manual. My speedo agrees with the digital speed board displays that I sometimes come across, so that provides additional confirmation which is reassurring.
Ron.
You're going for a bigger rolling diameter with 205/75 series (HR rated at the very least I hope?) than the original rolling diameter. My understanding has always been that with 205 width tyres, the correct aspect ratio is 70. Certainly that delivers a wheel with a rolling diameter that conforms with the gearing specs as covered within the workshop manual. My speedo agrees with the digital speed board displays that I sometimes come across, so that provides additional confirmation which is reassurring.
Ron.
WarrenL
Active Member
Hi Ron, remember that my speedo is now driven by the Dakota Digital box. I can adjust it infinitely, so the 205/75 is a deliberate choice to raise the gearing a little more. I did notice that ghce Graeme runs 205/75, as it happens, but online tyre calculators show 205/70 to be closest to the original rolling diameter.
Chris, the lockup issue is no more! See the ZF thread.
It's a Xmas emu over at Ron's house. Here, since the Maoris ate all the moas, we have to make do with a rather stringy kiwi.
Chris, the lockup issue is no more! See the ZF thread.
It's a Xmas emu over at Ron's house. Here, since the Maoris ate all the moas, we have to make do with a rather stringy kiwi.
grifterkid
Member
Perfection! That is all there is to say... :wink:
WarrenL
Active Member
Here you go Ron. The original 185R14s are equivalent to 185/80R14. The rolling diameters are as follows:
205/70R14: 79.4 inches.
185/80R14: 80.6 inches.
205/75R14: 82.0 inches.
Rolling diameter is +/- 3-5% accurate, the local tyre guru advises me. So you can see that the original tyre size is almost bang in the middle of our two chosen options, and within that accuracy limit there's bugger all in it either way. All you can really say is that by going for the 205/75 I am, according to the official rolling diameter and not accounting for accuracy, raising my gearing by about 1.7%. If my arithmetic is correct (no guarantee of that), I drop roughly another 40rpm at 100kph (about 2100 to 2060 in fourth gear lockup). Hardly worth the effort, but better a rise in gearing than a fall, since higher gearing was the whole point of all my recent efforts. I'll recalibrate the Dakota box as required.
205/70R14: 79.4 inches.
185/80R14: 80.6 inches.
205/75R14: 82.0 inches.
Rolling diameter is +/- 3-5% accurate, the local tyre guru advises me. So you can see that the original tyre size is almost bang in the middle of our two chosen options, and within that accuracy limit there's bugger all in it either way. All you can really say is that by going for the 205/75 I am, according to the official rolling diameter and not accounting for accuracy, raising my gearing by about 1.7%. If my arithmetic is correct (no guarantee of that), I drop roughly another 40rpm at 100kph (about 2100 to 2060 in fourth gear lockup). Hardly worth the effort, but better a rise in gearing than a fall, since higher gearing was the whole point of all my recent efforts. I'll recalibrate the Dakota box as required.
Hi Warren,
Appreciate the figures.
The one big downside in running the 75 series tyres, certainly here in NSW and no doubt Australia wide, is that their speed rating is 'S' or below. That makes them illegal to use on the Rover here.
The quality also falls so that the ability to source a tyre that runs true is also diminished.
Ron.
Appreciate the figures.
The one big downside in running the 75 series tyres, certainly here in NSW and no doubt Australia wide, is that their speed rating is 'S' or below. That makes them illegal to use on the Rover here.The quality also falls so that the ability to source a tyre that runs true is also diminished.
Ron.
WarrenL
Active Member
SydneyRoverP6B said:
What makes them so, Ron? The ones coming in for me are an H-rated Goodyear. I think he said Duramax, but don't quote me on that.
Now, I wonder if I'm imagining things. During last night's test run (mixed urban/motorway, some large multi-lane roundabouts), the car seemed to me to handle rather differently. Remember, the only change so far is the fitting of the front alloys. The tyres are the very same ones as before, just transferred to the new rims, and the back wheels are thus far untouched (i.e, total crap). However, the front end seemed somewhat more direct and... different, especially through the roundabouts. More surefooted, a little less ponderous in the steering perhaps. I'm stuck for the right adjectives, but it seemed somehow improved. Is the change from steel to alloy rims enough? They're much lighter than the steel rims, that's for sure. Is the geometry subtly different, hence noticeable to the driver? Or am I simply a victim of my own wishful thinking?
WarrenL wrote,...
Hi Warren,
According to the Goodyear Australia website, the only tyres in that size available here are S-rated tyres for commercial vehicles. Goodyear may well make H-rated tyres in that size, as you have some on their way to you, but they aren't listed as being available here.
Ron.
Hi Warren,
According to the Goodyear Australia website, the only tyres in that size available here are S-rated tyres for commercial vehicles. Goodyear may well make H-rated tyres in that size, as you have some on their way to you, but they aren't listed as being available here.
Ron.
