[HP17]

I considered a 180/60 for the reasons mentioned but in the end I thought it would be safer to have the extra tire of the 190, for a couple reasons, especially on track.

While the 180 would probably be ok, I don't want that in the back of my mind.

 

[TheRanchFireblade]

Do you have rear shock height adjustment? Chain length altered or changed? Sprockets swapped?

 

[johnbkk]

Many people do not realize this BUT the number on the side of a tire doesn't always mean what you think.

For example...

Pirelli Diablo Supercorsa SPV3 (DOT track day tire) 200/60 is 670 mm in diameter - can be used on the street AND track
Pirelli Diablo Superbike slick 200/60 is 662 mm in diameter
Pirelli Diablo Superbike slick 200/65 is 672 mm in diameter
Michelin Power Cup 2 (DOT track day tire) 200/55 is 665 mm in diameter - can be used on the street AND track
Michelin Power Performance slick 200/55 is 660 mm in diameter
Michelin Power Performance slick 200/60 is 675 mm in diameter

There is a 6.5 mm difference in rear ride height between the Pirelli and Michelin 200/60 slick results in VERY different handling characteristics not to mention the tire profile.

This is why it is VERY important to pick a tire that fits your needs and stick to it.

This is great info, I'm just wondering where you got the tire measurements?
Thanks.

 

[roadracerx]

Do you have rear shock height adjustment? Chain length altered or changed? Sprockets swapped?

Already on it dude

This is great info, I'm just wondering where you got the tire measurements?
Thanks.

I have gathered this info over the years. I have a small business setting up track motorcycles and tires are a big part of that equation.

I considered a 180/60 for the reasons mentioned but in the end I thought it would be safer to have the extra tire of the 190, for a couple reasons, especially on track.

While the 180 would probably be ok, I don't want that in the back of my mind.

I get what you are saying but in reality this isn't really any issue. Tires don't always measure what the side wall states, for example, the new 190/60 PIrelli Diablo Superbike slick actually measures 200 mm wide.

 

[HP17]

Got to take the CBR out the other day with the fresh Pirellis. Initial findings are good although I did not have full confidence in the tires, but some of that was just due to the conditions not being ideal. I can say though that the rear tire hooks up much better than the OEM S21 did. The bike feels really nice exiting corners. Not getting the feeling that the bike wants to run wide anymore either.

Roadracer (or others) do you see anything from the front tire wear. Some guy out in the mountains thought it looked like I had a compression problem but I'm not seeing it.

Right now my suspension settings have front sag at 38mm, rear sag at 30mm (rider sag). Damping is all just a touch softer than stock due to shitty roads. I'm thinking maybe I need a little more damping now that I am going to be leaning the bike over more on good tires. Especially for my track day at Chuckwalla on the 9th. Interested to hear others opinions. Oh and FYI I weigh 160 lb.s without gear.

 

[jehanzeb]

@jehanzeb the 180 will work on a 6" rim but the profile will be slightly different but will work just fine. I am just exploring ideas to give you a bike that handles well with a tire diameter close to oem but have not made a determination yet.

Sounds good thanks! I prefer a 180 actually. Hopefully there are some sticky vendors for that size.

 

[roadracerx]

@HP17 front tire looks fine and you don't really see issues with compression on tire wear anyway....you see spring tear, too little or too much rebound and you see cold and hot tear. Be careful what some schmoe on the roadside says to you. Rider sag of 38 mm front and 30 mm rear is in the ball park. What is your bike sag? What cold pressures are you running?

 

[Timmy1]

I’m loving the Pirelli Diablo Rosso 2s at the moment. There are 190/50 rear and 120/70 on the front. Turn in is sweet as and it doesn’t run wide at all.

 

[jehanzeb]

@jehanzeb the 180 will work on a 6" rim but the profile will be slightly different but will work just fine. I am just exploring ideas to give you a bike that handles well with a tire diameter close to oem but have not made a determination yet.

I am leaning more towards the 180/60 at this point now.
For a high hp bike, it may not be enough contact patch but to be honest I am not going 100% on it either.
Do you know the diameters of any 180/60 tires ?

 

[roadracerx]

The Pirelli TD, DOT and Superbike slick in size 180/60 are all 656 mm in diameter.

 

[HP17]

So my track day went well with the new Pirellis, although to be honest I'm still not really happy with how the CBR is feeling in the corners. It feels slow to turn in, like it takes a lot of bar pressure. Mid turn it feels like I am having to keep pressure on the bars to hold a given lean angle. I tried letting go of the bars mid turn and the bike wants to stand up. I don't like that and want it to keep a lean with no bar pressure. Corner exit was good. Lots of traction driving out of corners. Much better than the factory S21's.

Some of what I was feeling may have been due to the fact that I was riding two bikes, my DRZ and the CBR. The DRZ turns in effortlessly, holds a lean with no input on the bars, etc. While it was fun to ride two bikes next time I might just focus on one or the other.

 

[roadracerx]

@HP17 what size and model of Pirellis did you go with?

 

[HP17]

@HP17 what size and model of Pirellis did you go with?

Diablo rosso corsa 2. 190/55 rear 120/70 front.

 

[roadracerx]

where is the fork ride height and what other changes have you made to the bike please?

 

[HP17]

Fork ride height is at stock level, which has the fork caps just a mm above the top of the triple clamps. Bike is all stock. Suspension settings going into the event had the rear preload around 30mm, front preload around 33mm. Dampers all a touch softer than stock settings (felt better for bumpy SD roads).

After having the handling issues I described here, I went to Paradigm racing and had AJ help me to double check the sag numbers, and adjust the damping settings. He dialed in more front sag, and said the front and rear rebound was too slow. He adjusted it accordingly, but after going back out, the bike did not feel much better. It's possible I am the issue, not the bike, but it really did not feel right to me...

 

[roadracerx]

@HP17 yes I had mentioned to you before that you needed 40 mm rider sag front and 30 mm rear. This is not preload, as you mentioned. Preload is HOW you adjust the tension on the springs to get bike and rider sag. Do you know how to measure bike and rider sag? If not I can direct you, if you do I would like to know where your bike and rider sag are currently WITH gear. Sounds like the trackside tuner made changes in the direction I already suggested.

 

[HP17]

@HP17 yes I had mentioned to you before that you needed 40 mm rider sag front and 30 mm rear. This is not preload, as you mentioned. Preload is HOW you adjust the tension on the springs to get bike and rider sag. Do you know how to measure bike and rider sag? If not I can direct you, if you do I would like to know where your bike and rider sag are currently WITH gear. Sounds like the trackside tuner made changes in the direction I already suggested.

Yes yes sorry I meant sag not preload. And yes I had targeted 40mm up front with myself on the bike, with gear, but either my friend measured incorrectly or AJ at Paradigm measured incorrectly. Our measurement at the rear of 30mm agreed with AJ's measurement. I do know how to measure bike and rider sag, although I see why you would be skeptical lol.

I'll need to check the front again to see where I'm at with gear. After he adjusted the front I asked AJ if we should remeasure but he said "I don't need to, I have it where I want it". We left the rear preload alone.

 

[jehanzeb]

So my track day went well with the new Pirellis, although to be honest I'm still not really happy with how the CBR is feeling in the corners. It feels slow to turn in, like it takes a lot of bar pressure.

Thanks for the feedback after your trackday!
I am feeling the same way on the turn in. Requires a lot of input to initiate a turn.
I am thinking a 180/60 might be the cure but have not mounted it yet.
Will post when mounted and tried.

 

[HP17]

Thanks for the feedback after your trackday!
I am feeling the same way on the turn in. Requires a lot of input to initiate a turn.
I am thinking a 180/60 might be the cure but have not mounted it yet.
Will post when mounted and tried.

Yea no problem! Interesting you are having a similar feeling. I will say though, I went for a street ride through the local twisties the other day, and the bike felt a lot better. Easier to turn, held a line well. Only change I made was putting the tire pressures back up to street levels (about 34 f and rear).

I think most of what I was feeling at the track was in my head, and due to going hot off the supermoto to the supersport (never done that before). Contributing factors were probably the wind (20mph+) and maybe too low front tire pressure. Attached are some pics of the tires for reference.

Front looks good to me

Looks like a hot or cold tear on the rear. Not sure which but leaning hot.

 

[roadracerx]

@HP17 Too low front pressure will FOR SURE give you the feeling the bike is hard to turn! Tear on rear is HOT caused by too little air in the tire.

Hot tear is caused by underinflation; the contact patch is too large on the ground which in turn cause it to overheat. When the whole of a tyre over heats, the surface gets hot and is melted off very quickly and is pitched away due to the centrifugal force created when the tire spins.