Roczen - Factory Transmission

Listened to the review pod with Matthes. He said Kenny has been racing this whole time on a stock transmission. If so, that’s impressive. Kenny has been up there with the boys most weekends.
 

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motomike137
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1/13/2025 10:43am

Wonder if he is only running a 3 or 4 speed?

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1911
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1/13/2025 10:45am
Listened to the review pod with Matthes. He said Kenny has been racing this whole time on a stock transmission. If so, that’s impressive. Kenny has...

Listened to the review pod with Matthes. He said Kenny has been racing this whole time on a stock transmission. If so, that’s impressive. Kenny has been up there with the boys most weekends.
 

I thought I heard someone say Kenny has not had a factor transmission since 2016? Honda did not have factor a transmission ?

JazzyJJ
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1/13/2025 10:46am

They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage should be huge. Why would you not ride a works transmission if you had them available?

soggy
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1/13/2025 10:46am

Wonder if he is only running a 3 or 4 speed?

Taller first and second gear for sure.

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GrapeApe
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1/13/2025 10:51am Edited Date/Time 1/13/2025 10:51am
JazzyJJ wrote:
They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage...

They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage should be huge. Why would you not ride a works transmission if you had them available?

I'm not sure they have a works transmission available. There's no one in Japan building anything and the JGR and Yosh hand me downs have to be expired by now.

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1/13/2025 10:56am

‘Factory’ transmission. 

Doesn’t mean he hasn’t been using a ‘modified’ transmission this whole time. 

On a big old 450 on a SX track, does anyone know how many gears they would use? 

2nd to start?

3rd most of the track and 4th for the whoops? 

That’ll leave 1st & 5th redundant. They likely weld up the selector drum grooves so 1st & 5th cannot be selected. Then remove those gears from the cases completely. At one time to fit the rules the gearboxes had to contain the same number of gears as the stock bike, so they’d make those redundant gears out of nylon and fit them, so they were in there to fit the rules, but wouldn’t (couldn’t) be used. 

I’d imagine a ‘factory’ transmission is made of higher quality materials and therefore can be milled out to be lighter. 

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twotwosix
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1/13/2025 10:56am

There was a time when many of the factory teams would run a 3 or 4 speed trans for SX. I think it was most prevalent when the two stroke to four stroke transition was happening if I remember correctly. 

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soggy
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1/13/2025 10:56am
JazzyJJ wrote:
They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage...

They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage should be huge. Why would you not ride a works transmission if you had them available?

GrapeApe wrote:
I'm not sure they have a works transmission available. There's no one in Japan building anything and the JGR and Yosh hand me downs have to...

I'm not sure they have a works transmission available. There's no one in Japan building anything and the JGR and Yosh hand me downs have to be expired by now.

Kenny confirmed it himself soo….

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1
1/13/2025 10:59am
Listened to the review pod with Matthes. He said Kenny has been racing this whole time on a stock transmission. If so, that’s impressive. Kenny has...

Listened to the review pod with Matthes. He said Kenny has been racing this whole time on a stock transmission. If so, that’s impressive. Kenny has been up there with the boys most weekends.
 

1911 wrote:

I thought I heard someone say Kenny has not had a factor transmission since 2016? Honda did not have factor a transmission ?

Kenny himself said that he had not run a factory transmission since 2016. 

You however raise a good point. Surely Honda has factory transmissions, so I guess either Kenny never liked it or he has made a mistake by saying 2016 was the last time he ran one.

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GrapeApe
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1/13/2025 11:02am
JazzyJJ wrote:
They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage...

They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage should be huge. Why would you not ride a works transmission if you had them available?

GrapeApe wrote:
I'm not sure they have a works transmission available. There's no one in Japan building anything and the JGR and Yosh hand me downs have to...

I'm not sure they have a works transmission available. There's no one in Japan building anything and the JGR and Yosh hand me downs have to be expired by now.

soggy wrote:

Kenny confirmed it himself soo….

Confirmed that he has one available or that he does not have one available? 

1/13/2025 11:04am

From.what I understand is that he has one now. Lord alone knows where it came from.

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1/13/2025 11:09am
JazzyJJ wrote:
They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage...

They brought it up during the broadcast as well. Ricky tried to explain it but outside of the better finishes and tighter tolerances, the gearing advantage should be huge. Why would you not ride a works transmission if you had them available?

I love me some James Stewart in the booth, but his attempted explanation of a factory transmission did not land lol. "It's like putting a manual transmission in your car"....

If I was one of the "growing the sport" demographic I'd maybe be thinking oh crap the rest of these privateers have automatics?

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Nairb#70
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1/13/2025 11:21am

When Doug Henry won Las Vegas SX in 1997, the first win for four strokes in SX, his bike had a 2 speed transmission.

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soggy
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1/13/2025 11:22am
GrapeApe wrote:
I'm not sure they have a works transmission available. There's no one in Japan building anything and the JGR and Yosh hand me downs have to...

I'm not sure they have a works transmission available. There's no one in Japan building anything and the JGR and Yosh hand me downs have to be expired by now.

soggy wrote:

Kenny confirmed it himself soo….

GrapeApe wrote:

Confirmed that he has one available or that he does not have one available? 

that he's using one.

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GrapeApe
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1/13/2025 11:29am
soggy wrote:

Kenny confirmed it himself soo….

GrapeApe wrote:

Confirmed that he has one available or that he does not have one available? 

soggy wrote:

that he's using one.

Then I'm confused about the point of this thread lol. Obviously there's some context out there I have missed. Moving on . . .

soggy
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1/13/2025 11:31am
GrapeApe wrote:

Confirmed that he has one available or that he does not have one available? 

soggy wrote:

that he's using one.

GrapeApe wrote:

Then I'm confused about the point of this thread lol. Obviously there's some context out there I have missed. Moving on . . .

he hasn't had one available in the RMZ until this season apparently is the scuttle.

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seth505
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1/13/2025 11:35am

He hasn't had a factory trans on a Suzuki since being on an H&H Suzuki.   Still funny how the 'shittiest' bike off the show room floor is the one that is closest to stock out of all the top racers racing SX.

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brocster
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1/13/2025 11:46am
seth505 wrote:
He hasn't had a factory trans on a Suzuki since being on an H&H Suzuki.   Still funny how the 'shittiest' bike off the show room...

He hasn't had a factory trans on a Suzuki since being on an H&H Suzuki.   Still funny how the 'shittiest' bike off the show room floor is the one that is closest to stock out of all the top racers racing SX.

But so many in here say its an “outdated Tank”,  maybe there is some confusion with the man in the mirror…

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501Ross
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1/13/2025 12:08pm
seth505 wrote:
He hasn't had a factory trans on a Suzuki since being on an H&H Suzuki.   Still funny how the 'shittiest' bike off the show room...

He hasn't had a factory trans on a Suzuki since being on an H&H Suzuki.   Still funny how the 'shittiest' bike off the show room floor is the one that is closest to stock out of all the top racers racing SX.

brocster wrote:

But so many in here say its an “outdated Tank”,  maybe there is some confusion with the man in the mirror…

Still the best looking one though 🤘

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lumpy790
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1/13/2025 12:10pm

I suspect the "stock" transmission is not "stock" but has been through the whole transmission rebuild and polish process that every team and most privateers do.

 

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bigk218
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1/13/2025 12:16pm

Factory transmissions


Yet we need the homologation rule to level the playing field for privateers. 

What a joke this sport is. 

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cwtoyota
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1/13/2025 12:43pm

The term "factory transmission" from the rider's perspective could mean something from a 3rd party supplier too.

There have been weaknesses in the production transmissions in some models over the years.   Those may not be weakness in terms of durability or torque holding capacity, but also in terms of shift quality.  They will use a different shift detent cam or a modified production cam to reduce the chance of the bike going into neutral on a light shift by the rider or a bump to the shift lever.  They can also increase the tension of the shift detent spring to more tightly hold the bike in each gear position.   Anyone with some basic technical understanding and fabricating skill can do those mods to a bike, especially the experienced guys on support / satellite teams.

I have not ridden any RMZ model in years, so I don't really know if they shift poorly or have durability issues.

There were some KX250F models in the past with a false neutral between 2nd & 3rd gear for example.  An upgrade shift cam and detent cam would likely make those bikes 100% reliable.

The YZ250 two strokes that a lot of us ride have a transmission made of glass.  Gears are weak, shift forks are a bad design, etc.  I do a host of mods to them and replace nearly everything inside to make them safe.

It is my understanding that (at least in the past) they could not reduce the number of gears in the transmission per AMA rules.  They just put a plastic gear in there to take up that space while also reducing weight.   Obviously the plastic gear would be wiped out if the rider engaged it, so those transmissions have a different shift cam that eliminates the corresponding shift position, turning them into a four speed.

It is also my understanding that some teams have different primary gears available to them.  The primary drive gear is on the end of the crankshaft and the primary driven gear is the huge gear on the back of the clutch basket.  Swapping these gears around changes the ratio of all four or five gears in the transmission, it is equivalent to changing the sprockets without the effects on chassis dynamics due to chain torque.

When you hear a factory rider say they're "clearing the triple in 1st gear", they likely have something similar to our 2nd gear due to the changes inside the gearbox and primary drive ratio changes.   Also the change in ratio between each gear may be different.

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Nairb#70
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1/13/2025 12:50pm

I think its all just part of an inside joke.

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MxAddic
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1/13/2025 1:11pm

It's only one race but...

Its Working GIFs | Tenor

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UGOTBIT
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1/13/2025 1:15pm

I’ve heard Mitch gets “factory” trans parts from a company based out of UK? Wonder if they are using a 3rd party vendor like mentioned above to get some custom ratios for Ken?

Has there been any durability issues with the RMZ trans?

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philG
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1/13/2025 1:29pm
UGOTBIT wrote:
I’ve heard Mitch gets “factory” trans parts from a company based out of UK? Wonder if they are using a 3rd party vendor like mentioned above...

I’ve heard Mitch gets “factory” trans parts from a company based out of UK? Wonder if they are using a 3rd party vendor like mentioned above to get some custom ratios for Ken?

Has there been any durability issues with the RMZ trans?

Pro Circuit used X-Trac transmissions, they may well still do so, they had them on display at the Autosport UK show at the NEC last year, they are one of the providers of gears for F1 and other high end motorsports.  

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1/13/2025 2:22pm
Listened to the review pod with Matthes. He said Kenny has been racing this whole time on a stock transmission. If so, that’s impressive. Kenny has...

Listened to the review pod with Matthes. He said Kenny has been racing this whole time on a stock transmission. If so, that’s impressive. Kenny has been up there with the boys most weekends.
 

Nothing ordinary, some top guys opt for the stock ratio, i depends on what they like.   

Some major teams from the decade of Reed , Stew, RC era that used stock on occasions, even if they had access to HRC, KHI, etc.   

 

ML512
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1/13/2025 3:15pm
UGOTBIT wrote:
I’ve heard Mitch gets “factory” trans parts from a company based out of UK? Wonder if they are using a 3rd party vendor like mentioned above...

I’ve heard Mitch gets “factory” trans parts from a company based out of UK? Wonder if they are using a 3rd party vendor like mentioned above to get some custom ratios for Ken?

Has there been any durability issues with the RMZ trans?

philG wrote:
Pro Circuit used X-Trac transmissions, they may well still do so, they had them on display at the Autosport UK show at the NEC last year...

Pro Circuit used X-Trac transmissions, they may well still do so, they had them on display at the Autosport UK show at the NEC last year, they are one of the providers of gears for F1 and other high end motorsports.  

Yup, they still do as far as I'm aware.

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mxav8r
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1/13/2025 5:04pm

Factory transmission and shift drum from another brand and a couple generations old.

IMG 2660 5IMG 2653 3
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