R1200ST/RT alternative tyre sizes

[Anonymous]

#4265

Has anyone tried on an R1200ST/RT/R a 120/60-17 size front tyre instead of the normal 120/70-17 size? I know there is potential for rim damage as their is less profile to protect the rim on large bumps, but have seen others do this on sports/touring bikes, and liked the effect on handling.

[Anonymous]

#17607

My R1100S came with a 120/60/17 fitted when I bought it . It was brand new and fitted by the bike shop prior to me purchasing. The bike had a nasty habbit of wanting to throw it's self on the ground in downhill tightish corners going round east cape. Also the tyre casing showed early signs of failure when I replaced it with the correct size.Once fitted with the correct tyre the bike was much nicer to ride with consistent turn in.If your aim is to make the bike a bit faster to turn in then dropping the front 2 mm will make a huge difference equally you can lift the rear 3mm On the R1100S this equates to shifting from a 48/52 front to rear weight bias to 52 /48 front to rear weight bias.The "extra " weight on the front gives much better feel and precision

[Anonymous]

#17608

P.S. the 120/60/17  over the standard would equate to  12mm drop on the front  which is a significant change and would probably mess with ABS if you have it. Another trick is to change the Paralever link whick lifts the back - I am looking at making an adjustable one

[Anonymous]

#17609

Hi BillyBMThanks for the response. Yes, I calculated the difference in size and it was substantive. Although I also measured the difference in height on a 120/60 on the front of the Ducati sitting next to the 1200 and the difference was only 4mm or so when measured from the edge of the tread to the centre.

[Anonymous]

#17610

The 4mm is just the difference in the shape of the tyre, the “sidewall” will be shorter. So the measurement from the rim to the road is what you should check and be aware that different rims can vary this measurement by a couple of mm as well.Small changes can make a heap of difference to the feel of a front end. Bear in mind also that with a  Telelever front end if you drop the tyre  diameter the telelever becomes more horizontal and provides less dive and then less feel when braking. Reducing the height of the front shock  2mm  drops the front of the bike 3.5mm and gives slightly more dive- which translates to a bit more feel with the brakes plus more feel in corners from the increased weight on the front. 

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