Space saver spare wheel

[dezelsky]

Will soon go on a long European trip in my 1947 400. It is an early car, with the spare wheel inside the boot. This takes up quite a lot of valuable space for a long trip, and is heavy, so I am thinking to carry a modern space saver spare wheel instead. Has anyone else done this? I think the PCD on early Bristols is 112mm - the same as many Mercedes cars, so I am thinking it won't be too difficult to pick up a space saver wheel. But will it be suitable in terms of overall diameter and offset?
Any thoughts on this appreciated.

[dezelsky]

Adding to the above, my 400 currently runs on Blockley 185/VR16 radial tyres, which according to Blockley have an overall diameter of 696mm.

[dwomby]

Can't answer your questions but you should also check that hub bore is correct diameter for your car and that the lug nut shape where they snug up tight to the wheel is a match.

David

[David C]

Early 400 wheels are probably not much wider than a space saver wheel at 4". I think I have a couple of spares.
You may be better off just carrying a spare tyre and leave the wheel at home.

[Geoff Dowdle]

Dezelsky,
The photos of your 400/112 that I have, show it has larger than standard 400 wheels and oversize tyres at 185/80 x 16 . Possibly the rims are 4.5 inch or wider.
If they are 401 - 406 rims of 4.5 inch wide, your tyres at 185 x 16 are too wide for the rim .

All 400s originally had 3.5 inch by 16 rims with 5.50 x 16 Cross Ply tyres which were very narrow.
A space saver rim might only be 3.5 to 4 inches wide which might not be much of a reduction if any to an original 400 rim and tyre.

I have two later 400s with the spare wheel on the boot lid & the alloy cover .
Modern 175/80 x 16 tyres will not fit under this cover , so I have an old style 5.50 cross ply tyres fitted to the spares .
In nearly 40 years of 400 motoring and well over 100,000 miles have never needed to use a spare wheel as the 4 road wheels
have always had good quality tubes & tyres fitted and inflated to the correct pressure. But of course one still needs to have a spare wheel,

Geoff

[dezelsky]

Thank you Geoff and others for your comments. You are probably right that there won't be a major space saving, and I feel uncomfortable driving without a spare, although likewise I have never had a puncture on this car and run with good quality inner-tubes.

You are right that my 400 runs on 4.5 wheels. I am not sure I agree with the comment that "185 x 16 are too wide for the rim". Blockley specify min wheel width of 4" for these tyres, and the overall diameter is similar to the original cross-plys (±690mm). Yes, they are wider than the very narrow original cross plys on 3.5" rims, but I have run these, and similar size Pirelli Cinuratos before that, for many thousands of continental miles over 25 years without issue. Road holding is excellent and ride quality is very good, with no adverse effect on steering. They also fill the wheel arches and look correct IMHO (see photos). The Longstone web-site also has a good review for 400 tyres and recommend various 5.50/16 or 6.00/16 options.

Maybe I should just carry a 3.5" original wheel with smaller tyre as a spare for emergency use only, but as far as I know there aren't any much narrower radial tyres with correct overall radius.

[David C]

145/90 16 seems to be a common size for space saver tyres. I imagine they would fit on an original 400 wheel.

[Geoff Dowdle]

Dezelsky,
I have run 185 x 16 Pirelli on 4.5 inch wide 401 rims on my 400 but find
fitting a 175 taxi tyres, the steering is lighter especially at parking speed .

Some years ago I looked at the Longstone website and they did not know that 400s had 3.5 inch wheels fitted.
But at that time they happily recommended tyres for the 400.

Most tyre manufacturers recommend a 5inch - 6 inch rim for 185 x 16 tyres

The smallest width radial tyre in 16 inch that I know of is a 165/80 x 16 Avon which would be ideal for a 3.5 inch 400 rim or a 4 inch AC Ace rim .

A space saver wheel and tyre might be the easiest way to save some space in your boot. Do you have original 400 rims ?

Geoff

[dezelsky]

Unfortunately I don’t have any of the original 3.5” wheels.

I found a space saver wheel on eBay which on the face of it seemed to be ideal. From a Jaguar XJ with an 18” rim, 112 pcd, fitted with 135/80 profile Pirelli space saver tyre. The total diameter close to current wheels, and quite a lot less bulky and light. Unfortunately the pcd dimensions are slightly out - perhaps only 2mm between centres, but enough so that it won’t go on. Back to the drawing board.