2019 MT-07 Transmission Cut and Shimmed

[hxman]

2019 MT-07 transmission back from R&D freshly cut and shimmed.

 

 

[mossrider]

18 minutes ago, hxman said:

2019 MT-07 transmission back from R&D freshly cut and shimmed.

 

 

Address mixed up? Need mine?

Seriously tho, who did the work?

[1tondriver]

24 minutes ago, hxman said:

2019 MT-07 transmission back from R&D freshly cut and shimmed.

 

 

[hxman]

Services — Performance Motorcycle Transmissions - R&D Motorsports

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They do most of the race bikes.

[Spatt]

Mikes a great guy.  It took us a couple tries to figure it but after I sent him cases we’ve had great luck with them.    He does all the transmissions in our motor builds.  There are other options like some are just shimming and cutting 5th gear but it’s almost the same cost as sending it to R&D and cutting the whole set. 
 

 

[Spatt]

1 hour ago, hxman said:

Services — Performance Motorcycle Transmissions - R&D Motorsports

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They do most of the race bikes.

They mostly big harley stuff.  Super knowledgeable people.  

[sorkyah]

Hmmm

I'm assuming it's not that easy to change the gearing on this?

Wouldn't mind getting rid of first, and changing the ratios of 4/5/6 and adding a touring gear in place of 6th to possibly extend the range of the tiny tank when on trips between states

[Spatt]

3 hours ago, sorkyah said:

Hmmm

I'm assuming it's not that easy to change the gearing on this?

Wouldn't mind getting rid of first, and changing the ratios of 4/5/6 and adding a touring gear in place of 6th to possibly extend the range of the tiny tank when on trips between states

Guess it depends what you mean easy.  It’s just like any other trans. 
 
the goal of this modification is to fix the junk transmission not change ratios. 

[sorkyah]

50 minutes ago, Spatt said:

Guess it depends what you mean easy.  It’s just like any other trans. 
 
the goal of this modification is to fix the junk transmission not change ratios. 

I've never had a motorcycle casing apart

How is the trans junk and what does the modification do to change that?

 

[1tondriver]

33 minutes ago, sorkyah said:

How is the trans junk and what does the modification do to change that?

 

[Spatt]

12 hours ago, 1tondriver said:

For stock power the trans is mostly fine.   But even at the stock power level bobbleheadmoto had issues on their endurance bike at Nelson.   Carl Price ran most of the MA season on a completely stock trans... it’s a bit of luck of tolerance stack up too I can only think.  
 

I personally only had issues at adding power.  The dogs will slip.  The engagement of the dogs in 5th gear is pretty low so that’s where the shimming comes in.  
 

The undercutting allows it to lock up when applying power.  As the trans is driven the dogs pull tighter together due to the angles cut force the gears to want to pull together. The stock gears the dogs are square(ish) and as they wear they radius and slip.
 

When I started working with R&D on the trans I had lost 5th and it would ratchet with anything above 50% throttle.   It took 3 tries to the shimming and angle of the backcut correct.  
 

Edited December 26, 2019 by Spatt

[fzar]

On 12/26/2019 at 7:03 AM, Spatt said:

For stock power the trans is mostly fine.   But even at the stock power level bobbleheadmoto had issues on their endurance bike at Nelson.   Carl Price ran most of the MA season on a completely stock trans... it’s a bit of luck of tolerance stack up too I can only think.  
 

I personally only had issues at adding power.  The dogs will slip.  The engagement of the dogs in 5th gear is pretty low so that’s where the shimming comes in.  
 

The undercutting allows it to lock up when applying power.  As the trans is driven the dogs pull tighter together due to the angles cut force the gears to want to pull together. The stock gears the dogs are square(ish) and as they wear they radius and slip.
 

When I started working with R&D on the trans I had lost 5th and it would ratchet with anything above 50% throttle.   It took 3 tries to the shimming and angle of the backcut correct.  
 

Hmm, interesting. I had no idea what it meant to cut and shim the transmission. I understand what dogs do, (not barking) I'd like to hear more, and how it differs anyway with a slipper clutch? I can't wrap my head around the dogs locked into each other and the slipper backing off the engine breaking!! Sorry, I'm trying my best to keep up.

[Spatt]

10 hours ago, fzar said:

Hmm, interesting. I had no idea what it meant to cut and shim the transmission. I understand what dogs do, (not barking) I'd like to hear more, and how it differs anyway with a slipper clutch? I can't wrap my head around the dogs locked into each other and the slipper backing off the engine breaking!! Sorry, I'm trying my best to keep up.

I guess its kind of related but not at all at the same time.  Your placing complementary angles on the dogs in the transmission that force lock up when driven inside the transmission.  So twist the throttle and the rotational force is trying to drive one angle up the other.  Here is a good example off a Kawasaki forum.

The ramps on the slipper disconnect and freewheel when torque is applied opposite force normal to driving the wheel forward.  The force drives the dogs on the hub apart from the pressure plate rides up a ramp till force is dissipated or throttle is applied again.  Similar to a ratchet but the pressure plate is adjustable in pressure via springs to adjust when the disengagement happens or increase/decrease back torque needed to create the rise up the ramp.

Here is a good illustration from Yamaha