Cage tyre sizes

Is it practical to fit:

235 55 R17
to
225 45 R17 rims

Will they differ much and how when fitted. The arch clearance on the Aero
is minimal

 

That won't be the rim size. That's the existing tyre size. They're
probably 7x17 rims. Yeh, those tyres should fit on there easily. But
that's not going to be your big problem...

Obviously, 10mm difference in width...

That'll be tight, then. 225/45 is a nominal 101.25mm sidewall, 235/55 is
a nominal 129.25mm sidewall. That's a big ol' difference. I'd be
surprised if it didn't rub.

It's also going to affect the gearing & speedo significantly - it's a
damn near 9% difference in circumference.

 

8.83% increase in diameter - 5.6cm difference.

(63.4cm vs 69.0cm)

That's a fairly large change.

You can play about with sizes here:

http://www.etyres.co.uk/tyre-size-calculator.htm

 

7" is a bit narrow for 225 tyres.
You would be better with an 8" or 8.5" rim for 235 tyres.
Why do you want to do it?

 

Thanks both. I shall pass.
Complicated business this Snow Tyre thing.
Pete F came up with a link to supplied steel rims with tyres but 16" is the
largest.

Then again I realise a slightly narrower but higher profile 16" tyre would
be a similar rolling radius. But would the wheel clear the caliper on an
Aero...

Complicated.

 

I'm trying to fit snow tyres not change rims IYSWIM

 

Have you considered snow socks for if it gets really bad? - cheaper and
probably more convenient than changing tyres.

 

Yeah but a winter front tyre change is for the even more terminally lazy

 

Putting winter tyres on just the front wheels is just fine, so long as
you don't mind reversing into the scenery.

 

I use 16 inch winters on my 9-5 Aero and it's fine. I suspect you'll
have the same calipers but those at www.uksaabs.co.uk will know for sure.

 

I'm not Finnish FFS I just can't be arsed losing traction (FWD) on the short
trip to office

 

Then you want narrow, high-profile tyres.
Whatever is the narrowest tyre that will fit your rim.

 

^ this.

A wider tyre will spread the load over a greater surface area,
resulting in less traction on a snowy or icy surface, not more
traction.

 

I swopped the almost slick front tyres on one of my Evo Vs for the
winter rear tyres on my other Evo V because I was slithering all over
the place on the Autobahn on the way to Austria last year. That gave
both cars proper winter tyres up front and Yokahama trackday/legal
tyres on the rear. It really didn't feel unsafe at all, in fact I was
glad the car had some kind of grip and wasn't trying to spin all over
the place on the slush.

--
Lozzo
Versys 650 Inter-Continental Hyperbolistic Missile , CBR600F-W racebike
in the making, TS250C, RD400F (somewhere)
BMW E46 318iSE (it's a car, not one of those 2-wheeled pieces of shite
they churn out)

 

This has been argued lots of time, and has an element of truth _if_
you're driving on snow and ice all the time, but fitting too narrow
tyres will completely **** up everything else about the drive and
handling, so shouldn't really be regarded as a good thing.

No, all you need to do is consult your car's manual, or if not then a
main dealer, or a tyre fitting place, and see what size winter tyres
are recommended.

Simples.

 

Yeah, I had to buy a complete ew set of 17" alloys for the R36 winter
jobbies. Summer ones are 18", so they're slightly higher profile, but
not by much.

That was the issue on mine. Huge front brakes would not allow a 16"
rim to fit. I even got a tyre centre to try one for me.

I had originally planned to use the 15" steel ones off the Volvo,
which have the same bolt pattern and much higher profile tyres within
<5% difference, which is broadly the accepted limit, but they were
right out, obviously.

 

Yes, it is.

Bollocks. Quite a lot of folk do just that over here.