Bridgestone V02 slick test

//Bridgestone V02 slick test

Bridgestone V02 slick test

This information is posted to help all riders around the world get the best out of these new tires and as a result be a lot safer through knowledge rather than blind experimentation. Please share the URL page link to this page to help others.

 

 

June 2nd, Thunderhill Raceway Park: ambient 90F and track temp 106F

 

2013 Aprilia RSV4R SE

Fork height +10mm, preload 6 turns in, rebound 16 clicks out, compression 8 clicks out

Shock height +4mm, preload 5 threads showing, compression 5 clicks out, rebound 8 clicks out

Electronics: sport mode, ATC (traction) 3, AWC (wheelie) 2, ALC (launch) 2, ABS 1

Tire warmers on high for 30 minutes reading 150F, 32psi hot and 26psi hot off the warmers

 

The all new V02 slicks with MotoGP carcass innovation (advanced belt construction technology) looks immediately different to the V01 in roll profile. The feel of the carcass is also completely different on the grip surface of the tire compared to the V01 in regards to flex and to me it felt slightly stiffer but more importantly slower to react to pressure/weight changes from my hand pushing on the center and sides of the tire. Always good to feel a tire before it gets mounted! This resistance indicated to me that the tire shape would not instantly deform under hard acceleration and that should equate to 2 things:- excellent drive grip and accurate corner exits.

V02 soft front and V02 medium rear.

I had R10’s on the RSV4R Factory from the last track day for chassis dial in and used them to get the geometry I was looking for at Laguna Seca. With a different track, that geometry would be wrong so with new tires and completely different circumferences may as well get a 2 for 1. The initial scrub in laps gave a very different feel indeed from the R10’s in terms of tire peak feel, turn initiation, side contact patch and side to side transitions. Geometry was close but not right, but I needed to really get to know these tires first before making any decisions on chassis changes.

The one thing that stuck out in my mind immediately was the ease in getting to the edge of the tire and the secure feeling it gave me. Normally on warm up/scrub laps I’ll explore lean angles but in this case there was no desire to do so. I went straight to my knee right away.

Tire Temps: 165F front (35psi hot) and 175F rear (26psi hot)

The tire temps gave me a hint that all was not well as Session 2 was going to be about trail braking and driving hard out of corners. I was concerned that the rear was under inflated and the front over inflated BUT that was just an educated guess. Again, no chassis changes until the tires requested that be done from wear patterns.

Session 2 was used to get more familiarization with the roll profile of the tires in turn initiation, line correction and acceleration with ever quicker lap times. My brain needed the time to recalibrate as the R10 is a much softer carcass. Entry speed rose and it was very apparent that the initiation of a turn was certainly a little more controlled than the R10, and that is something I like. The roll to the edge of the tire was very easy indeed and there was no acceleration from the profile in getting to the edge of the tire. That gives a very secure feeling for me (versus the 125 V profile tire that gets to the edge very quickly). A little more bar pressure and the turn in sped up so there’s a nice blend here between the V and more round front tires that Bridgestone offer. Bad line selection? The bike responded immediately and with calmness which inspires confidence. Drive grip? Oh my, there’s an absurd amount of drive grip between this tire and the R10 with the RSV4 ejecting from the corner into the fast sections of the track.

Tire Temps: 165F front and 190F rear

The goal of Session 3 was to explore feel on the edge of the tires. I chose Turn 2 and Turn 14 for heavy trail braking and drive grip in Turns 6, 8 and 12. Tires were again 150F when I took the warmers off and the first few laps were dedicated in focus to trail braking. As the entry speed into the corners was raised, I could feel the edge of the tire gripping the track but not overly deforming sending me off line from an excessive profile degradation. That encouraged me to enter faster and brake harder. In so doing the Aprilia held its line and didn’t over or under steer at all. I was charging Turns 2 and 14 so that gave me all the information I needed to know. Switch to corner exit – this should be fun!

Turn 6 leads into the fastest section of track so turn in and apex point are critical to get the exit defined. Careful approaches and throttle timing gave me some lessons until I had the line set and then I could get to the throttle. In turn 6 the tire slid, gripped and flew off the corner. Turn 8 no slip, turn 12 not slip. I put that down to the chassis being already loaded from earlier acceleration/apex speed and lean so the carcass is already compressed into the track. No point staying out when you are getting slides, so back into the pit.

Tire Temps: 165F front and 211F rear

 

The front tire showed the faintest of geometry tears so I added 4.5 turns of preload and set fork compression to 5 clicks out. The carcass was still effectively cold so I took 1psi out on the warmers (34psi hot) just before heading onto the track.  The rear was clearly under inflated so I brought the hot pressure up to 27.5psi off the warmers from 26.

The good thing about slicks is you can see the rubber ball size (should be 2-3mm) and rubber aggregation on the edge of the tire. Classic visual that the tire is too hot with the rubber stringing itself together and lots of rubber balls 3-5mm in diameter.

 

With the revised tire pressure and fork settings, I went back out on the track, tires again at 150F off the warmers. The front felt stiff, non-compliant and introduced chatter on heavy trail braking which removed confidence. Change geometry, not settings! The front tire couldn’t care less and gripped the same as before and wear improved with the faint geometry tear gone. The rear was initially frightening out of Turn 6 as there was no slip at all and the bike drove so hard at Turn 7 that I couldn’t get my timing right for that corner. Yes, I’m glad I’m in Sport mode……..

Tire Temps: 175F front and 188F rear

So, reset fork settings to get the plushness and feel back in the forks and raise the front by 3mm to reset geometry. Drive grip was mind boggling to me so the math in the rear end and shock settings aligned to hot pressures is dead on for now. I’m new to this Aprilia and calibration is taking me a while with this level of power in getting my brain comfortable with acceleration and speed over distance to trust where I am in time and space. Once that gets settled down I can move back to peripheral vision and start relaxing again.

June 9th, Sears Point/Sonoma Raceway

 

2013 Aprilia RSV4R SE

Fork height +10mm, preload 6 turns in, rebound 16 clicks out, compression 8 clicks out

Shock height +4mm, preload 5 threads showing, compression 5 clicks out, rebound 8 clicks out

Electronics: sport mode, ATC (traction) 3, AWC (wheelie) 2, ALC (launch) 2, ABS 1

Tire warmers on high for 30 minutes reading 150F.

 

As I work in the mornings providing suspension tuning support to all riders, I did not get out until 2pm. The track temps were in the 110-118F range so tire pressure started a higher at 35psi front and 28psi rear off the warmers.  Of note was the normal afternoon breeze did not appear so track temps soared in the afternoon to 118F which understandably created a lot of hot tears from pressure being too low.

There was a lot of traffic through each of the three sessions but a healthy pace was held throughout all 3 sessions.  Here’s the tires at the end of the day after 50+ miles of track time.

Note the front and rear tire rubber balls are too large so even more hot pressure was needed. You’ll also see a band of wear in the rear tire on both sides validating that pressure was too low. I would have gone to 29.5 hot to reassess carcass temps that hit 205F.

 

Thunderhill 5 mile course June 14/15 with Zoom Zoom

2013 Aprilia RSV4R SE

Fork height +10mm, preload 6 turns in, rebound 16 clicks out, compression 8 clicks out

Shock height +4mm, preload 5 threads showing, compression 5 clicks out, rebound 8 clicks out

Electronics: sport mode, ATC (traction) 3, AWC (wheelie) 2, ALC (launch) 2, ABS 1

Tire warmers on high for 30 minutes reading 150F.

 

It was an unusually cold morning with cloud cover and wind, so tire pressures were set at 33psi front and 27psi rear on the warmers after 30 minutes. The first session was understandably slow with many riders learning the new West Course configuration even after watching the video I recorded and donated to Thunderhill of the layout, reference points a week beforehand.

Many riders didn’t realize that the new course would have a profound effect on tire wear (better described as surface finish) so there were all kinds of questions regarding the 1000 grit finish they were seeing. There’s a new appreciation for different track surface mixes/aggregates and how that effects the tire. For those that ride Nola for example in New Orleans, it is the same surface finish.

 

 

Tire wear after session 1:

The front tire especially on the left side showed a very clear hot tear even with the low lap pace  so it is evident that the tire has to have a slightly higher pressure than you would expect for slower laps/colder track temps. Please bear that in mind. In this case 1-1.5psi would be added.

The rear tire was very very smooth to the touch and visually. The starting tire pressure was again a little too low as you can see a rough band of wear on the left side/middle of the image. Hot tire pressure was increased 1.5psi.

 

 

 

Having changed tire pressure, faster laps were run in the second session so here’s the result of the pressure changes:

As you can see from the images, the front tire cleaned up pretty quickly but there was very little change in the wear pattern on the rear tire. Another .5psi hot was added on the warmers.

 

After these hot pressure changes, the track temps and ambient temp remained stable for the rest of the day with a very slight increase at the end of the day.

No chassis nor suspension changes were needed.

 

Sunday June 15th.

A much warmer start to the day and noticeably higher track temperatures by 9am. Staring pressures off the warmers were 34psi front and 28 psi rear. It was fine for the front and rear initially. However during the second session the pace was noticeably higher and the rear carcass reached 207F and did not wear well.

It is quite obvious to see the tear in the left side of the tire from the pressure being too low, even though the surface wear remains very smooth. Another 1psi was added on the warmers to take it to 29psi hot.

That seemed to really stabilize the rear tire carcass temps and keep it at 180-185F for the rest of the day.

 

By the end of the day, the tire wear was pristine:

There’s still some slightly dark discoloration on the surface of the tire – that’s the residue of the earlier hot tear. Overall the left side healed up very well indeed. The front doesn’t look like it has been used at all…..

 

Summary

attachmentThis was taken at the end of the day on Sunday 6/15 by Dito of GotBluemilk.com while I was working with Marcus Zarra. After 4 days on the V02’s there was no hesitation getting the bike onto the Bickle knee pucks quickly. Phenomenal edge feel.

 

 

In previous tests with the V01 slicks I’ve managed to get about 150 miles on average out of the medium compound rear. with solid A pace track riding and some fast lap times. With the V02, I’ve doubled that distance. How’s that for an ROI?The drive grip lasts and lasts……

There are still depth holes there for all to see on the left side of the rear tire, so I could go even further but with perhaps .4mm left, I can feel that the grip level is starting to go especially on high speed hard acceleration corners.

The V02 is a stunning tire in many ways over the V01 for a 1000cc superbike (only as  a 200 series) and the drive grip takes some getting used to especially in regards to recalibrating throttle to eye to speed. Once that calibration is set, your lap times will decrease BUT as with any race tire you MUST keep an eye on carcass temps and make sure you have the right hot pressures.

Next up is the V02 soft rear tire. That will be another two weeks or so before I’m back at the track and able to test.

By | 2018-01-27T18:45:41+00:00 January 4th, 2018|Categories: Tires|0 Comments

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