Bridgestone V01 test, Broadford Raceway, Victoria

//Bridgestone V01 test, Broadford Raceway, Victoria

Bridgestone V01 test, Broadford Raceway, Victoria

To order this tire online, go to: http://viets-performance.com

 

December 14th at Broadford Track, Victoria with Champions Ride Days.

 

Ambient 27 – 30C, high humidity with heavy overnight and morning rain.

 

 

Tyres supplied by:

Trackside Tyre Service. (South Australian Distributor for Bridgestone race tyres)

Steve Millar 0419624005,

email steve@tracksidetyreservice.com.au

www.tracksidetyreservice.com.au

Bike:- 2008 R1 supplied by Trevor Green

Forks: Ohlins 25mm inserts, 1.0kg fork springs

–       fork height +3mm

–       preload 8.5 turns in from all the way out

–       rebound at 10 clicks out from max

–       compression at 8 clicks out from max

 

Shock: Ohlins TTX 10.5kg shock spring (+5mm ride height, +2mm shim)

–       preload at 4 turns in from the start of full hydraulic pressure

–       rebound at 12 clicks out

–       compression at 14 clicks out

 

Gearing: 15 x 46, rear axle in the middle of the swing arm slot

 

 

 

Processes:

The above settings were the starting point for the test. Tyres were over inflated and left on the warmers at 85C for 1 hour. Immediately prior to getting on track throughout all sessions, tyre pressures were adjusted as a control for continuity. In session 1 after 3 laps, hot pressure was set and thereafter, all pressure changes followed the above protocol in the pits before getting on track.

 

The track was walked first thing in the morning for some initial visual markers to get bearings for the first session. These would be adapted as pace increased. See the end of the document for those reference points. Broadford is very different with big elevation changes and long braking areas with a great deal of trail braking.

 

Due to insurance restrictions, no cameras were allowed on track so I could not record any footage.

 

 

Session 1: (missed due to wet track and slick tyres policy)

 

 

Session 2 (5 laps)

–       set tyre warmer pressures on the warmers to 30psi front and 28psi rear.

–       learn the track and set an even pace

–       acquire reference points where possible

Feedback

–       not much for reference points other than hard to see low and thin inside curbs of plain concrete (not painted)

–       decent feel on the front tyre under trail braking that diminished by lap 4

–       decreasing feedback from the rear tyre after lap 3

–       both tyres needed more air to regulate carcass temps

Changes

–       front warmer pressure changed to 31.5psi and rear to 31psi of the warmers

–       no suspension changes

 

 

Session 3: (7 laps)

–       better feel for turn in on major corners (T1, crash corner and the final turn

–       oil dry patches and crash marks became useful reference points for each session

–       work on the last 1/3rd of the track for corner entry speed/trail braking

–       use lever pressure during trail braking to flex the front tyre sidewall

Feedback

–       better feel on the edge of the front tyre at all times but a little muted

–       less carcass flex under  g-load and trail braking at apex

–       bike held the line under trail braking

–       great initial edge grip on the front tyre that faded by lap 4

Changes

–       change front warmer pressure to 31psi

 

 

Session 4: (6 laps)

–       assess front tyre edge grip for consistency

–       get into a rhythm early and focus on consistent laps

–       try to improve consistency in the technical section T1 to T3

–       be consistent in overall lap times

Feedback

–       front tyre grip and feedback increased reflecting stable carcass temps

–       just above fork bottoming under sever straight line braking to crash corner T3

–       much improved trail braking confidence

Changes

–       31psi front and 31psi rear off the warmers seemed to be right that day.

 

 

 

Session 5: (6 laps)

–       assess reference and timing for best entry points

–       get into a rhythm early and focus on consistent laps

–       try to improve corner speed and drive T1 to the esses

–       be consistent in overall lap times

Feedback

–       front tyre grip and feedback excellent encouraging faster corner entry

–       just above fork bottoming under sever straight line braking to crash corner T3

–       much improved trail braking confidence

Changes

–       I would have softened the rear shock on preload (removed all) due to the front wheel lofting at 50-65% throttle creating instability on the straight between T2 and T3.

 

 

Summary:

A great ride day with Champions and thanks to Scott and his team for a very positive and enjoyable experience.

 

Managed to get to a consistent pace with 1:06 lap times by session 3 and went appreciably faster in session 4 thanks to a tow from a black TZ250 GP bike.

 

Consistent ambient temperatures allowed us to quickly find an optimal pressure off the warmers that created optimal carcass operating temps indicating that the tyres would stabilize under those conditions and you would not need to constantly chase hot pressures.

 

Steve and I did a rough calculation of the mileage since the V01’s had been put on and we arrived at a number of 500-550km of track riding. The tyres were showing excellent durability with no loss of edge grip after 3 track days and some very hard riding on tracks all of which were run clockwise. There was probably 30-40% left on the right side of both front and rear tyre. Note that while pace was reasonable at all three tracks by the 3rd session, this was not race pace so the above data point would be appropriate for advanced group riders at track days.

 

 

 

 

Hot pressure ranges:

Obviously this will depend on all the normal factors of geometry, weight, chassis, suspension and rider ability with engine power being optimized along with ambient and track temps and make sure to factor in the wind and its cooling or heating effect on the track:

– Front at 30 – 32psi set in the hot pit

– Rear at 30 – 32psi set in the hot pit

 

 

Broadford reference points used (might not be accurate corner numbers – check!)

–       unpainted thin concrete curbs – find them !

–       T1 throttle roll off and straight line braking after track repair section far left into 2nd gear and no trail braking. Pick up the throttle and turn in to a mid corner right hand apex at the curb, then drift to the far left on severe uphill banking (don’t panic – trust where you are and entry speed is critical for correct radius/line)

–       T2 blind entry after the uphill section levels out slightly and mid to late apex against the curb on the right. Roll on throttle as early as possible but beware off camber exit and track dropping away then riding again. High sides here are too common for obvious reasons, so be patient and disciplined through this area!

–       Stay mid track on the seam and then fade slightly left to find the straight line through huge elevation changes on the “straight” to T3 (crash corner). Depending on gearing and engine size, you will power wheelie through this section, so supple suspension is mandatory.

–       T3 is a late entry working slowly back to a mid corner entry for better drive and line/radius to the esses

–       T4/5/6 stay wide on the left for entry to create an optimal radius and  entry line into the esses (easy to create a line of sight to ensure good speed and line into the first 2 esses). Drive into the right ‘S’ curb mid point and immediately flick the bike to the left ‘S’ at mid point on the curbing and then roll off the throttle to weight the front to turn into the last right ‘S’ curb. Apex late for an off camber downhill drive and roll on predictably based on line and camber.

–       T7 requires you to brake early with a severe downhill entry but then rely on excellent trail braking skills going into the apex point. Try to sight the inside curb on the right early and stay 3’ from it initially where the curbing starts but then bring the bike down to the end of the curb to allow for good drive to T8

–       T8 enter with trail braking and mid corner line using the seam in the middle of the track and speed is critical as the track rides up the hill. Just after mid corner you should be at full lean and stay there with gentle throttle roll on for a very late apex against the left curb where the track has been ground down for a very black color as a visual reference. Be patient as you crest and go off camber on to the front straight.

 

By | 2018-01-27T18:46:17+00:00 January 4th, 2018|Categories: Tires|0 Comments

About the Author:

Journalist, published author, 1-1 coach and mentor, video presenter

Leave A Comment