My 900ss needs a new front tyre which is currently a 60 profile. I want to put a Bridgestone S20, but the site gives the sizes of 60 for the 750 and 70 for the 900. There looks to be enough clearance to fit a 70. So now I'm totally confused. Any clues anyone?
If it feels okay I wouldn't worry about it, you'll have to try bloody hard to fall off the edge of the tread. I've tried a 65-profile tyre on one of my bikes that should have a 70, and I prefer the way it rolls into bends.
What he says...... And watch out for your speedo being right on the money, rather than ambitious with the 60 profile............I know, I have gone through the exercise of swapping my 60 for a 70 and researched the speedos.....(same speedo and drive gear on 750s and 900s). If the mudguard is too close, there is probably a good reason......the front mudguard sags over time, but I have got a trick how to get some clearance back, failing that I have a pair of unobtrusive mudguard risers fitted on mine. You will find it handles differently in that it won't suddenly fall over in corners and you will think that you are running out wide, but you can just push it down a bit more quite easily. AL.
Thanks guys, With the 60 profile that might explain the speedo, not that I've gone over 70 :wink:. I'll see if I can get a 70 profile to fit, otherwise I might be in touch Al for those mudguard mods
With the 60 profile my speedo was about 5 - 7mph ambitious (about 5 @ 30mph).......With the 70, I have no margin for error, reading as near as d*mmit dead on 30 @ 30mph. Mudguard mods are easy to do....one involves a blowlamp / hot air gun.......the other involves a machine shop.....but the 70 profile should fit without clearance problems, because it was a standard fitment. AL.
I can get my fingers in between the front tye and the mudguard, and if I've done my sums correctly the difference in profile is 6mm on the radius, and my fingers are thicker than that.
I have two spare front wheels, one with a 60 (worn) and one with a 70......standing next to each other I'm convinced it is more than 12mm overall difference, but as I'm no mathematican, I'll have to measure them....back soon...... AL.
I changed from a 70 to a 60 on my 907 to get some clearance from the rad after fitting showa usd forks on the bike. As much as I like the quicker steering, its nice flicking through roundabouts etc. but I'm not over keen on the feeling when dropping it round a tight corner. The 60 seems like the rims too close to the road. All in my head I know but thats how it feels. I've resolved the rad contact issue now so will be going onto a 70 profile soon.
Just stood the two wheels in-line and upright.........my 60 is worn but still quite legal............the 70 is a race scrub (so as near as dammit, new)..... ......using a decent level across the 'crowns', I reckon there is easily 20mm difference in diameter. AL.
Thanks for checking Al. I'll still give it ago as I think the extra sidewall height will give me a little more rim protection over the pot holes.
I got mine from Ghost because the DD-ers use the 70 to prevent rolling over.......I found my 60 was causing the bike to drop quite unexpectedly in slow corners (partly because it was worn) but I also noticed how close the rim comes to the road. Also watch your fork stanchion position in relation to the mudguard and bottom yoke.....if the stanchions are up too high, and you have to lift the mudguard, you might find the fork travel brings the mudguard real close to the yoke. AL.
Just a quick update. Got a Bridgestone BT021 fitted last weekend. Had the front fender clearance issue, but thanks to Arquebus and a hot air gun I've adresses the rear sag. Only casualty is a pulled thread on the fixing points on the front forks. So I've spent the weekend scrubbing the tire in. First impressions are the bike tips in to corners a lot better and feels more flickable, tends to need spme correction in slow corners but in faster ones its as steady as rock. We will have to see how it behaves in the longer term. Well worth the pain to get here.
