big wheels

classic2cv · Post by **classic2cv** » Sat May 12, 2007 9:01 pm

what are the biggest wheels that i can fit to my TZD estate without modding my rear aches ? (much)

Ian_Fearn · Post by **Ian_Fearn** » Sat May 12, 2007 9:04 pm

I think part of it depends how good your rear arm bearings are!

Pretty sure Billy put some 15's on his estate.

Wonder what a BX would look like on a set of 20 inch chrome spinners....
Mr Chidlow, can you do me a photoshop?

tim leech · Post by **tim leech** » Sat May 12, 2007 9:46 pm

You can fit 17" wheels as long as the arm bearing are good, but you cant do more than a 205 tyre? But it will ride like the spheres have gone!

Philip Chidlow · Post by **Philip Chidlow** » Sat May 12, 2007 10:24 pm

Ian_Fearn wrote:
Wonder what a BX would look like on a set of 20 inch chrome spinners....
Mr Chidlow, can you do me a photoshop?

Give me a while. I am Photoshopping like mad at the moment - it's what I do... but for Gawd's sake I need a break

classic2cv · Post by **classic2cv** » Sun May 13, 2007 1:22 am

i might have the option of 15's on my estate. (195 tyres)

Kitch · Post by **Kitch** » Sun May 13, 2007 1:31 am

BX 16v alloys go on, but its a very tight squeeze. The fill the rear arches out to say the least!

I imagine 15's would go with a 195/50 setup though, as the overall RR isn't much different to the 16v alloys due to the huge boyancy aid tyres they come with!

DLM · Post by **DLM** » Tue May 15, 2007 1:39 pm

My personal view, whether relevant or not: there's a world of difference between what are the biggest that can be persuaded to fit and what will make a sensible choice for the car.

Also factoring in the effects of the non-design-spec wheels is at best an inexact science. I work from first principles and if adding in something that will cause larger moments (and more potential for mechanical wear and tear) I'd consider it very carefully. First-principle Physics can tell you quite a lot.

You might find yourself changing rear arms more often , and with more difficulty (as if anyone needed that), though you'll get the warniong signs much sooner. I've also seen recently what can happen when standard-fit 185 alloys are fitted but care is neglected when tightening the lengthier wheelbolts & a hub thread gets stripped as a consequence. There's greater scope for that sort of thing the more non-standard you get...

classic2cv · Post by **classic2cv** » Tue May 15, 2007 3:37 pm

Yes I can agree with you totally

I only asked to find out if I could fit a set of 15” alloy wheels to my TZD estate

But I noticed that the gap between the rear wheel arch and tyre is quite close as standard and I didn’t want to modify the body visibly

And as you say more grip means more wear and tear on the running gear

kiwi · Post by **kiwi** » Tue May 15, 2007 8:49 pm

I had a set of 15 inch tyres I was going to fir to the Rear of My BX and the overwhelming advice from two Tyre fitters was DO NOT!

Sensible advice I guess.

Mike P · Post by **Mike P** » Wed May 16, 2007 8:44 am

I ran a Bx16v with 17" x 7" wheels on it, with 205/40/17 tyres in it. Offset was 15mm.

Front strut clearance was fine, just had to cable tie the handbrake cable to stop it rubbing. Rear inner arches were trimmed by 5mm to
flush them with the arch extensions on the 16v.

Looked something like this

:

Mike P.

Cornishbx16v · Post by **Cornishbx16v** » Wed May 16, 2007 12:04 pm

i also ran 17's on my 16v, same offset as mikes! (et15) and has only to file some of the fibreglass on the rear of the side skrt to get them to fit without rubbing (only when in low)

kiwi · Post by **kiwi** » Wed May 16, 2007 12:29 pm

Dont forget the speedo error your going to create as you pass one of the many fixed camera sites in the uk

Post by **docchevron** » Wed May 16, 2007 1:15 pm

Well, kinda, as long as the rolling circumference of the tyre is the same the speedo wont be affected.

Mike P · Post by **Mike P** » Wed May 16, 2007 3:10 pm

Using tyresave.co.uk tyre size calculator, the difference between a 195/60/14 tyre on a 16v to a 205/40/17 is + 1.02% on the diameter.

If I can do my maths right, that equates to a +0.817% increase on the circumference, so if I was doing 100mph on the speedo I would actually be doing still less than 101mph, more to worry about at that speed than percentages

Mike P.

jeremy · Post by **jeremy** » Wed May 16, 2007 4:27 pm

Isn't it a bit over 3%?

The circumference if the wheel is its diameter x pi - and pi approximates to 22/7 (or in rough terms a bit over 3) - so if the diameter is 1.02% greater - the circumference will be 1.02 x pi (or a bit over 3) = 3+%