15 inch wheels

[SRF]

Quite often I have seen 15 inch alloy wheels advertised,  They are supposed to be the same PCD as my vitesse.  It is my intention to replace my wheels with alloys soon.  Has anyone any experience of these bigger wheels, the increase in size would help with the  vitesse low gearing.

[Clive]

They are MGF wheels.
However, you will need low profile tyres, and so will make little difference to the gearing.

I have had them on a spitfire (but the profile was too low really for the rear suspension, OK with rotoflex though) and on my toledo. No issues to report. However, clearance may well be tighter on a vitesse, especially at the front. Tyre choice will be very important.

If you want longer gearing I suggest a 3.63 diff  ;) and overdrive is pretty vital.....

[Deleted User]

Call me careful, but I suggest you think long and hard before moving to 15" wheels.

The tyre diameter equivalent to 155/80R13 is 195/50R15. If your car is lowered at all, then this size will be too wide, causing fouling on both the front scuttle and the rear arches. Common wisdom on this forum suggests 175/70R13, 175/65R13 and 185/60R13 are "ideal" options. I have also seen 175/65R14 used (once), but it was a standard ride height car.

HTH

[garyf]

I've recently fitted some 13" X 5.5J Alloys on my Vitesse, I've got 175/70 Tyres and have slight rubbing on the front bulkhead on the nearside when reversing on lock :-/, overall though I'm happy with the way they look, ride and steer, I was expecting much heavier steering but it's only slightly heavier when turning at low speed.

The Triumph Swing Axle rear Suspension on Heralds & the earlier Vitesse's is just not designed for low profilie tyres with the large Camber changes?

Personally I don't like the look of the Herald/Vitesse or Spitfire/GT6 with 15" wheels, they just don't look right in my opinion, 14" with 175/65 tyres look ok though.

If you want quieter cruising and better economy a diff change, overdrive or even both is the way to go, the Ford Sierra 5 speed gearboxes are another option, although it won't be cheap ??)      

[uksnatcher]

The exaggerated look of 15" wheels and low profile tyres fill the arches and give a sort of bad-ass image to the car but 13" wheels with more sidewall will make the car handle sooooo much better.

(reformed 15" owner now wont go back......13" all the way....there are some REALLY nice 13" alloy/steel wheels out there...Revolution, Cosmic, Turbo, Alleycat, Weller, Minilite.....to name few )

:)

[Tim Bancroft]

Totaly agree with the last two postings-stay 13'' and use 175/70 13 rubber!

[MrSpeedy]

Just to mix it up a bit, I had 195/45 R15 on my old Sprintfire and it sat a treat imo. Never really had any huge problems with the swing arm rear end either

[SRF]

Thanks for this very valuable information, 15" wheels don't seem to be a good idea. My next plan is to change the diff.  Again some 3.63 ones are advertised around the £100 mark, so with the cost of a rebuild it becomes rather expensive.  I have managed to get the innards of a 3.63 diff and I wondered if it was a practical to change the gears in my diff.  I am not sure if this is a job I can do or whether an expert would carry out such a conversion. Again any advice is gratefully received.  

[Nick Jones]

If you are starting with a 3.89 diff then it should be possible to swap the 3.63 parts in.  Fairly skilled job though and some special tools very helpful.

Nick

[Clive]

Diff building needs somebody who knows what they are doing. And even to look at the innards and see if they are OK to use...........some are worn and will be dreadfully noisy no matter what.