MotoGP 2013

**Bender** · 12th July 2013, 08:35

Pedrosa
Marquez
Rossi

**DidJit** · 12th July 2013, 08:53

Paging Dr. Bob... (to translate JB’s hints on the M1 front end tweaks).

**Drew** · 12th July 2013, 09:18

Originally Posted by DidJit

Paging Dr. Bob... (to translate JB’s hints on the M1 front end tweaks).

I can't wrap my tiny brain around it.

That Robert fella is prolly fawning about at Manfield till Saturday night too, so we might not find out any time soon either.

**wharfy** · 12th July 2013, 09:57

Originally Posted by Drew

I cannot help but wonder, what the fuck the Indian fellow who designed and built that was smoking!

Assumed to be Indian, because it's a Royal Enfield according to the tank.

I assumed it was home made from a couple of Royal Enfield 500's bolted together ?

**pritch** · 12th July 2013, 10:13

Pedro - 'cause he won the last three races at the Sachsenring
Rossi - 'cause he won the one before that
Lorenzo - 'cause he'll be there somewhere

In the August issue of BIKE Mat Oxley's article is called "The Ballsiest Corner Of Them All". Turn 11 at the Sachsenring.

"The lap starts slowly with a few slow corners that bring the riders to the top of a hill at Turn Five. From this left hander they plunge downward at ever-increasing speed and always going left. The succession of the six left handers goes like this: 70mph Turn Five, 95mph Turn Seven, 115mph Turn Nine, 120mph Turn Ten. That's thirty seconds cranked hard left, or to look at it another way, thirty seconds with the right side of the tyre hanging in the breeze and cooling down.

The next corner is where the skill and balls really come in to play. Turn Eleven is a real sort-the-men-from-the-boys corner; a 130mph right hander that takes riders over the crest of a hill, from positive camber to negative camber in the blink of an eye. The corner is also completely blind. And riders charge into it - moments after hooking fouth gear with a big handful of throttle - fully aware that the right side of the tyres might not be as hot and sticky as they need to be."

[snip]

"If all this wasn't enough to put the Corkscrew in the shade, Turn Eleven is also a vital corner that can win or lose a race. therefore it absolutely has to be taken at maximum velocity, because a good run through there delivers the extra speed required to lunge at a rival into Turn Twelve, the penultimate corner and the Sachsenring's traditional last-gasp overtaking point. It was here, if you remember, that Casey Stoner crashed out while attacking Dani Pedrosa last year."

All of which makes the riders appear just a little more God like?

**Crasherfromwayback** · 12th July 2013, 10:25

Originally Posted by pritch

[All of which just makes the riders appear a little more God like?

Because I don't believe in God...I'm gonna go with *not well*.

**Mental Trousers** · 12th July 2013, 12:54

Originally Posted by DidJit

Paging Dr. Bob... (to translate JB’s hints on the M1 front end tweaks).

The way I read it is

when he throttles off and starts to apply the brakes the suspension used to be too soft. What that did was transfer too much weight on the front of the bike too early. Doing that made the softer carcass front tyre work too hard. So they've stiffened part of the suspension that is used when throttling off and starting to apply the brakes. That way the weight doesn't transfer forward as quickly and it doesn't make the tyre distort.

It's the opposite of the problems they had with the Ducati, ie not getting enough weight forward early enough.

**Drew** · 12th July 2013, 12:58

Originally Posted by Mental Trousers

The way I read it is

when he throttles off and starts to apply the brakes the suspension used to be too soft. What that did was transfer too much weight on the front of the bike too early. Doing that made the softer carcass front tyre work too hard. So they've stiffened part of the suspension that is used when throttling off and starting to apply the brakes. That way the weight doesn't transfer forward as quickly and it doesn't make the tyre distort.

It's the opposite of the problems they had with the Ducati, ie not getting enough weight forward early enough.

That makes less sense than what Burgess said bro.

Stiffening "part" of the suspension stroke, doesn't seem like an easy feat to me.

I read it to mean that having the whole front end stiffer, was over working the front hoop. But going softer would upset the feel for Rossi...and probably bottom out and start over working the tyre anyway.

I can only assume some kind of two stage valve has been installed, I'm just not sure how it would be actuated. A poppit valve to a softer shim stack would be pointless, so I assume it needs to be mechanical in action.

**Mental Trousers** · 12th July 2013, 13:09

Originally Posted by Drew

That makes less sense than what Burgess said bro.

Stiffening "part" of the suspension stroke, doesn't seem like an easy feat to me.

I read it to mean that having the whole front end stiffer, was over working the front hoop. But going softer would upset the feel for Rossi...and probably bottom out and start over working the tyre anyway.

I can only assume some kind of two stage valve has been installed, I'm just not sure how it would be actuated. A poppit valve to a softer shim stack would be pointless, so I assume it needs to be mechanical in action.

Yes, having the whole front end stiffer was the wrong feel for him. But having the front soft put too much work on the tyre. He needs a combination of both - soft feel but limits how quickly the weight transfers.

The shim stacks are just that, a stack of multiple, flexible washer like shims of different sizes. At different fork speeds different shims affect how much dampening there is. So to change the way the fork acts when you throttle off you change the appropriate shim/s for that fork speed.

Rossi likes a lot of weight on the front end, which means a stiffer tyre is better for him. The current soft tyre isn't working well with that setup so they've had to keep the front end relatively soft while at the same time limiting how quickly weight transfers forward.

**Drew** · 12th July 2013, 13:17

Originally Posted by Mental Trousers

Yes, having the whole front end stiffer was the wrong feel for him. But having the front soft put too much work on the tyre. He needs a combination of both - soft feel but limits how quickly the weight transfers.

The shim stacks are just that, a stack of multiple, flexible washer like shims of different sizes. At different fork speeds different shims affect how much dampening there is. So to change the way the fork acts when you throttle off you change the appropriate shim/s for that fork speed.

Rossi likes a lot of weight on the front end, which means a stiffer tyre is better for him. The current soft tyre isn't working well with that setup so they've had to keep the front end relatively soft while at the same time limiting how quickly weight transfers forward.

I know how a shim stack works.

What I'm saying is, if you stiffen the stack for increased initial damping, you lose complience for the slower fork speed bumps. If you have some nice big soft shims for the slow speed speed stuff, you lose initial resistance because the oil blows through them easily.

**Mental Trousers** · 12th July 2013, 13:34

Originally Posted by Drew

I know how a shim stack works.

Others reading this don't though so sometimes things have to be explained in terms that everyone can understand mate.

Originally Posted by Drew

What I'm saying is, if you stiffen the stack for increased initial damping, you lose complience for the slower fork speed bumps. If you have some nice big soft shims for the slow speed speed stuff, you lose initial resistance because the oil blows through them easily.

If you stiffen the stack overall then yeah. But it sounds like they've only stiffened it in a certain part of the stack while leaving the rest as it was.

**Drew** · 12th July 2013, 14:24

Originally Posted by Mental Trousers

Others reading this don't though so sometimes things have to be explained in terms that everyone can understand mate.

If you stiffen the stack overall then yeah. But it sounds like they've only stiffened it in a certain part of the stack while leaving the rest as it was.

Either I've got how they work wrong, you do, or we're talking about different things.

I think Burgess is saying, that in the first part of the stroke (coming from full extension), the damping is hard. As the forks get lower the damping is reduced.

That can't be emulated with a shim stack alone I don't think. Although, a reduced volume of oil displacement for the lower part of the stroke would do the trick...Hmmm. Really need to talk to that Robert weirdo.