Morris Minor Owners Club

Apologies in advance as I guess wheel questions come so often but as I can't find the answer I'm going to have to ask it.

Here goes

Has anybody fitted 5.5 x 15 inch wheels with 185/65 x15 tyres to their moggy. Using an online calculator this is the closest replacement for the 165/80 x 14 tyre that I have on there at the moment. What I would like to fit is the Minilite wheel but I need to know what offset I would need so as not to foul the inner wheel arch. There is some room for the wheel to come out from the hub and not stick out beyond the wheel arch about - 35mm.

Has anybody gone down this route ? I need a wheel that will help with cornering as the engine as been rebuilt, tweaked and put in front of a close ration healey gear box and I'm quite keen on keeping it all together and not under steer into the nearest hedge.

By the way there is also the disc brake conversion from Bull Motif fitted.

Once I get a chance I'll post some pics of the pick-up complete with custom tipping rear load area.

Wryka

i can't help too much, other than that i've got 5.5x14 minilites on mine. with 185 tyres. and they're ok on the rear, but the tyre rubbed the top trunnion at the front. so i fitted a thin spacer to allow for that. the outer edge of the tyre comes just in line with the edge of the wings.

that is all, of course, dependant on wheel offset. and i'm not sure what the offset is on my wheels! i've got to take them off this afternoon, so i'll try and measure it for you!

right, i measured my minilite, and measured a standard minor wheel too while i was at it.

minilite: overall width 189mm. distance from mounting flange to rear edge 116mm.
offset = 116 - (189/2) = +21.5mm

minor wheel: overall width 133mm. distance from mounting flange to rear edge 92mm.
offset = 92 - (133/2) = +25.5mm

i fitted a 1/4 inch spacer which will effectively reduce the offset by 6.3mm. so my front wheels, with 185 tyres, just clear the top trun, and just sit in line with the wing edge, have an effective offset of 15.2mm.

that's a big change from 25.5 to 15.2, but i've had that setup for 3 years now and the handling is fine, and steering is only a little heavy when parking.

of course, this all depends on the tyre size due to the 'scrub radius'. which is the distance between the king pin pivoting axis and the centreline of the tyre on the ground. if this radius is 0 then the tyre will be at its easiest to turn (steering weight) as you're dragging equal amounts of rubber both sides. i've never sat down and worked out what the scrub radius is of a standard minor, or of mine for that matter. so i cant tell you how they differ with the addition of minor wheels.

scrub radius is affected by king pin inclination (angle of the pivoting axis from vertical), wheel offset, and tyre radius. you wont really be changing king pin inclination, only wheel size and offset. so if you want to keep the scrub radius the same as the minor. for the same tyres size, you need the same offset wheel. but if the tyres are slightly smaller in radius, then the scrub radius will be the same as a minor if you have a smaller offset of wheel.

phew. turns out i did learn something at uni afterall

Cheers for that Chris

I've been talking to a wheel and tyre supplier about the same thing and we came up with

5.5 x 15 wheel and a ET15 offset with a 185/65x15 tyre which looks as though its the same as your uni powered calcs.

All I need to do is choose a suitable tyre make a nd put the order in on Monday.

This time next week I will have the new shoes for the moggy.

Thanks for your help Chris - I maybe back for more !

Wayne

glad to help!

show us some pics when you've got them on. i've got 14's on my 4 door, and they're ok. but i'd love 15's for my 2 door once it's on the road!

apparently yokohama tyres are pretty good if you can afford them!

If you want to avoid understeering into the nearest hedge - put some negative camber on the front wheels....