Suzuki SV650 Riders Forum banner

1 - 20 of 85 Posts

·
Registered
Joined
·
603 Posts
Discussion Starter #1
Hello All, I have a quick question. I believe most of you guys are running the 70 series profile due to the availability and extra contact patch of the tire while leaned over?... My question is did you guys drop the front 10mm to compensate for the higher sidewall of the 70 tire, so it'll flicks into turns just as quick as a 60 series tire, any adverse effects?

Thanks.
 

·
Registered
Joined
·
190 Posts
I left my suspension the same and the feeling is excellent, maybe even better. (Maybe it wasn't correct before?)

I love the way it handles now.
 

·
Registered
Joined
·
799 Posts
Hello All, I have a quick question. I believe most of you guys are running the 70 series profile due to the availability and extra contact patch of the tire while leaned over?... My question is did you guys drop the front 10mm to compensate for the higher sidewall of the 70 tire, so it'll flicks into turns just as quick as a 60 series tire, any adverse effects?

Thanks.
you have to measure tires and compare. numbers mean nothing, it does not mean 70 is higher. two tires marked same but different brand or just model don't have to be same.
 

·
Registered
Joined
·
282 Posts
I went from the stock Dunlops to Bridgestone BT-016's with a 120/70 front. I tried it at NJMP Thunderbolt without changing the rake and it was ridiculously slow to lean over, I really had to muscle it.

Then I raised the forks 11mm (I was shooting for 12 since that's what 10% of 120mm is) and rode Summit Point Shenandoah and VIR Patriot. The steering was way better. I don't know how I could have gotten the bike leaned from side to side in the esses at Patriot with all that extra rake and trail. Even with the forks raised 11mm, it still seemed a tad slow/hard to lean in that section.
 

·
Registered
Joined
·
603 Posts
Discussion Starter #5
Thanks for the input fellas...I'll keep it in mind when adj is needed.

Forbin - would you do 70 again for the next tire? I'm thinking bt-016 too, and they offer it in 60 size. How do you like the tire?
 

·
Registered
Joined
·
328 Posts
I will keep 70 series tires on my SV from now on. I raised the forks 12mm to compensate in the height difference and it handles great.
 

·
Registered
Joined
·
282 Posts
Ran a 54.43 at Patriot on them my second day at that track. I hear the best lap there is about 46 or 48 seconds. Wasn't recording my times and Shenandoah. I haven't tried any other tires on my bike under dry conditions so I can't really compare, but they seem to grip nicely and slide smoothly with pretty decent feedback when they do.

Third gear, coming out of the last right-hander before the uphill back straight (running clockwise), I had it leaned over on my knee with the throttle nearly pinned at 8-9k RPM (stock gearing) and it stepped out just a little. Again, these are pretty much the only tires I've had on the bike. Suspension is also completely stock. (5'7, 135 lb rider w/o gear)

I wouldn't even consider using a 120/60. The 70 is an industry standard for a reason.
 

·
Registered
Joined
·
603 Posts
Discussion Starter #10
Hmm - you give up contact patch for quicker steering or does it just match your riding style better?
 

·
Registered
Joined
·
799 Posts
contact patch is dependent on tire profile, not number stamped on it.
you have slow and quick turning 60 tire.
just like you have same brand and same model tire in different compounds they also different in construction.
like I said, number means nothing.
 

·
Registered
Joined
·
282 Posts
I wouldn't even consider using a 120/60. The 70 is an industry standard for a reason.
not in racing.
I have never used anything other than 60.
Out of curiosity I looked up the race tires currently offered by the big 4 and found these sizes for front tires:

Bridgestone Superbike (slick): 120/600 and 125/600 (tire diameter listed instead of sidewall ratio, equivalent to a 70 and 67, respectively)
Bridgestone BT-003 (DOT race): 120/70
Michelin Power Race (DOT race): 110/70 (only 1 compound), 120/60 (only 1 compound), and 120/70
Pirelli Diablo Superbike (slick): 120/70 and 120/75
Pirelli Diablo Supercorsa (DOT race): 110/70 and 120/70
Dunlop Sportmax GP-A (DOT race?): 120/70
Dunlop Qualifier (street?): 110/70, 120/60, and 120/70

You're right, tire profile has a lot to do with the size of the contact patch, but it seems to me that a taller tire would give the tire manufacturers a lot more room to work with in optimizing the profile.
 

·
Registered
Joined
·
2,383 Posts
If I have a choice, I choose the 70 series front because that will give me a bit more ride height to compensate for the shorter gsxr fork that I have on my bike.
 

·
Registered
Joined
·
799 Posts
new power one I believe has 3 or 4 different tires (race dot ones), plus street version.
the thing is I don't think they use numbers for measurements. remember old dunlop (208?) 180 tire, it measured at 188. than you have michelin power race 180 measuring at 175.
that is 13mm difference in width on tires marked with same numbers.
than you go to slicks which are whole another story.
basically I don't really care what it say on tire. if I change tire and worry about geometry I measure it. but mostly I just put it on and go ride. than I adjust everything by feel I get from bike.
 

·
Registered
Joined
·
603 Posts
Discussion Starter #15
not in racing.
I have never used anything other than 60.
I guess you like the 60 for turning speed?
I have to think about this now...I may go 60. I like the way the bike steers with the 60.
 

·
Registered
Joined
·
799 Posts
you still missing point. 60 can be V shaped or round shaped. one turns good other does not. 16.5 slick is stamped 60 but has widest contact patch leaned over. 17 slick is same diameter but shorter sidewall and more round.
forget about numbers.
 

·
Registered
Joined
·
282 Posts
TYRES
Front
Pirelli Slick 120/75-R420 (16,5”)

Rear
Pirelli slick 190/65-R420 (16,5”)

Source: http://www.ducati.com/racing/09/sbk/bike/index.jhtml
Where have you seen R420's with a 60 aspect?

I guess you like the 60 for turning speed?
I have to think about this now...I may go 60. I like the way the bike steers with the 60.
Provided the tire profile is similar, all you would need to do to maintain rake and trail when going to a 70 aspect tire is raise the forks ~12mm. Lift both ends of the bike, loosen the upper and lower triple clamp bolts and the clip-on bolts, then just slide the forks up and tighten all of the bolts back up to spec.
 

·
Premium Member
Joined
·
228 Posts
Btw, you only have to raise the forks 6mm to account for the difference between a 120/60 and 120/70. It's a difference in radius, not diameter.

Of course, the 6mm is theoretical; the tires should be physically measured to find the actual amount.
 

·
Registered
Joined
·
282 Posts
Btw, you only have to raise the forks 6mm to account for the difference between a 120/60 and 120/70. It's a difference in radius, not diameter.

Of course, the 6mm is theoretical; the tires should be physically measured to find the actual amount.
That's incorrect. It's still 12mm. Theoretical of course, as you said.

Multiplying the aspect ratio by the width gives you the sidewall height, not double the sidewall height.
 
1 - 20 of 85 Posts
Top