Tyre clearance 195 45 r15 to 195 50 r15

[miles.gray]

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I have a 40th anniversary Supersport R with Avon zv3 tryes  which I want to upgrade but replacements are only really 195 50 r15 either avon zzs or toyo 888 has anyone done this? If they foul the wings stays then it seems I either use tyres that aren't as good or buy new wheels!  As ever, any words of wisdom gratefully received.

[huwp]

You can still get CR500 tyres in 195 45 R15. They are quite expensive though.

 

Replacing the wing stays would be cheaper than new wheels - even if you have to replace the cycle wings.

[miles.gray]

Thanks.  What would I replace the wing stays with?  I'm presuming they're the biggest available as the wheels are 15 inch.  Also where do you get the cr500s from?  As they've stopped making them I'm presuming they're all now getting a bit old.  I can't find any on tinterweb and they seem very rare to come up on here.

[huwp]

Miles, I can't answer the question about wing-stays. Best you speak to CC or Redline.

 

Avon still make the CR500. You can buy direct. I suspect the likes of CC, BMTR or Demon Tweeks can supply.

[JNC]

I am afraid you remove the cycle wings and bend the stays ! Then reglue them 

[miles.gray]

Thanks both.  What a palava!  Who'd have thought.  Now considering smaller wheels but this will mean lower ground clearance so now thinking of a dry sump kit... this is going to get expensive.  

[john aston]

My guy bent the stays the tiny bit needed in ten mins with wings in situ.

[SM25T]

Look at Toyo T1R. They are a different shape to CR500 and when I changed over due to the crazy cost of CR500 I had more clearance from the side wall to the stay. You can get them on line in 45 or 50 profile. 50 are cheaper.

[Gsk 275]

I have the same issues and thinking of fitting Uni Royal rainsports, they seem to get good reports and 195/45 R15 are available. 

[JNC]

Unfortunately I bent one of mine and although it worked fine with the wing in situ I have now got star cracks  ! 

[miles.gray]

Thanks all.  I went over to see fellow club member Chris near York and bought 4 gorgeous Compomotive CXRs with 175 55 r13 on the front and 205 55 r13 CR500s on the back.  We "measured" ( by offering up a couple of planks of wood ) the clearance under the sump, then changed the wheels over and re-measured.  The sump was indeed lower by approx 1cm  ( 2.0L wet sump Duratec SupersportR ).  Although I'm no racing driver, the lower ride height was immediately apparent, as was the brisker acceleration but the increase in grip was just astounding.  The ride was also transformed.  Far less jiggly - presumably the combination of bigger sidewalls and considerably lighter wheel & tyre combo.  I knew the tyres would make a difference but wasn't prepared for the amount of difference.  I am now more nervous about grounding it out so will be saving for a dry sump and chatting to other club members about fettling the ride height.  Now though, I'll be able to "just" buy ZZSs albeit 185 55 r13 and 215 55 r13.  Also need to re-calibrate the speedo, find some centre caps and no doubt a pile of other things...  Have to say, Chris near York, lovely chap, lovely R400, great coffee and now I'm jealous of the Stack dash!

[aerobod - near CYYC]

195/50-15" tyres may fit without adjusting the stays. Here is my R400D with that size of tyre, no rubbing, although I have to tilt the wheel a bit to fit the tyre under the wing when changing it:

[miles.gray]

Just to complete the thread, I took the plunge and bought four ZZS tyres and put them on.  No problems with the clearance, they're tight but there's a few mm clearance.  Have 20psi in them at the moment but might experiment with a little less.  Roll on the summer!

[John Vine]

I've just replaced my 195/45R15 CR500 front tyres with 195/50R15 ZZSs.  I was expecting to have to do a little wing-stay surgery, but in fact the tyres (just) fit.

JV