Great info on carcass temps and how it all works to give you more tyre life and grip.

[SuperSonic]

Thank you Mental Trousers

[Robert Taylor]

I think Dave has probably worked out that Kiwis are quite an inquisitive bunch of people!

[Robert Taylor]

Just to follow through on this Dave is of course 100% correct. Using a laser gun to measure tyre temperature is largely of course a nonsense, core temperature is EVERYTHING.

We ( KSS ) have been measuring tyre core temperatures now for about 3 years and have stored some quite useful knowledge in our heads.

Dave may care to elaborate but it seems that if you get a significant drop in track temperature the corresponding drop in tyre temperature can be at least semi exponential.

During winter road racing we are doing everything possible to get heat into the tyres with such tricks as lower tyre pressures and firmer ( yes firmer ! ) suspension settings to make the tyres move more and generate heat. In summer road racing we are often trying to remove some tyre temperarture. By continuously measuring tyre core temperatures we get a pretty good indication of where we need to head with suspension settings, both external and internal.

For those considering buying a tyre temperature probe you have to be VERY careful about what you purchase, cheap is not best. Impeccable accuracy is vital as is fast response time. Figure on spending about $300 for a good one.

Same with tyre pressure gauges, we have found so many that are inaccurate and all manner of other things are often blamed.

[SuperSonic]

Trail braking from Dave Moss Facebook page.

Based on tire tech week and your increased understanding of carcass flex, you can understand now why trail braking is an art using decreasing brake pressure to manage carcass flex to allow braking and steering simultaneously (let's exclude tire/tyre pressure for now).

Obviously when you brake there is weight transfer occurring based on brake pressure and brakes used (front only, front and rear combined). Apply, squeeze and modulate is the accepted mantra when straight up and down and this will flex the carcass accordingly. At this point as the bike is leaned in, more load is placed on the tire so brake pressure needs to diminish ensuring the tire is not overloaded and therefore collapses/fails to result in a low side. Therefore we constantly manipulate brake pressure under trail braking conditions to ensure grip levels are high, weight transfer is stable (apply, let off, apply, let off - nooooo!!!!) and the bike continues to steer.

http://feelthetrack.com/testing-prog...ster-cylinder/

Obviously the goal is to spike brake pressure quickly to set the chassis and weight transfer, and then taper that pressure off in a measured way depending on the corner, speed and g-load. The resulting visual curve should be smooth, not jagged. Does that make sense?

http://feelthetrack.com/testing-prog...-profile-test/

Now, think how you brake, what kind of carcass you have and how all of this relates as a whole. If you can see that pictures in a series of dots, it won't take long to connect them and the visual picture become clear especially with the video links I posted (videos are at the bottom of each page)

[SuperSonic]

2: Trail braking Part 2

Weight transfer moves backward away from the forks as trail braking pressure is released, the forks extent to ensure that happens. The finesse you use to bleed off/reduce brake pressure is absolutely critical. Again, we need changes in the chassis to evolve not suddenly occur. In this moment, a lot of riders "drop' the brake lever at the completion of trail braking - that means the forks extend suddenly so what happens to the front tire contact patch in that moment? Light bulb going off? Yes it should - here's the second type of low side crash that happens.

If rebound damping is incorrectly set and there's no enough damping - what happens to the fork? It rises for sure, then it goes back into a second stroke suddenly reloading the tire. Want to guess what happens next?

The smooth transition from trail braking gives us a flat or neutral chassis immediately prior to getting on the throttle to continue the rearward weight transfer. What you want to try to develop is the removal of brake pressure coordinated with a slow roll on of throttle simultaneously.

We can all blip and pull the front brake - so the skills partly there already. You just need to shift you focus and develop the finesse needed to be smooth = practice!!!

Now watch the Accossato video again, but from this perspective of brake/throttle coordination as trail braking ends.

http://feelthetrack.com/testing-prog...ster-cylinder/

[SuperSonic]

I have an early start tomorrow and will be gone most of the morning so I will do the Thursday post now. Keep sharing!

Transitioning from brakes to throttle.

Yesterday we talked about learning to remove brake pressure while simultaneously rolling the throttle on. The Accossato video really shows that skill set nicely, but what about weight transfer to the back of the bike?

Maintenance throttle keeps the chain tight loading the rear shock but doing so with an even force to create chassis stability. We all have long corners both on the street and track where this skill is critical as you wait for the corner exit to come into clear view. You have to factor in speed and therefore lean angle to = radius line. Take out some throttle the radius decreases, add some and it will increase. Most importantly, speed and lean are critically balanced together, otherwise the bike wobbles meaning cornering speed is too slow (not debating body position here).

Accurate speed, lean and radius manage the even load on the tire sidewall unless you have traction control (but generally that is only effective on acceleration and that can have a sudden and dramatic effect on the sidewall of the front AND rear tire).

I know - you just started visualizing that so go ahead and run the scenario through your head frame by frame for both soft and hard carcass tires......... keep going!

As we accelerate, the load to the rear tire needs to get there smoothly. Does it?

Read this first:
http://www.feelthetrack.com/testing-...hock-on-track/

Then watch the video:
http://youtu.be/V7tN8VxVIFo

What do you now understand after the text, video and reflective thought or discussion about weight transfer and carcass flex?

[codgyoleracer]

Dave has some bloody good stuff tucked away on that web site of his. Well worth a sift through and it applies to many differnet levels of rider it seems.

Good on ya Dave for sharing the knowledge, and taking the time debunk some gnarly topics that sometimes get a little over-analysed.

[roogazza]

Dave has some bloody good stuff tucked away on that web site of his. Well worth a sift through and it applies to many differnet levels of rider it seems.

Good on ya Dave for sharing the knowledge, and taking the time debunk some gnarly topics that sometimes get a little over-analysed.

Admittedly I haven't read everything on his site as yet but looking at the last couple of posts on Trailbraking it made me think that I don't recall any mention of rear Trailbraking ?
Is this something that is not used as much on more modern machinery ?
Must admit it is something I still do all the time, it seems it is instilled in there from long ago from the days of riding monsters in the handling dept.
Yes G good stuff , must read some more on his site.