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Discussion Starter · #1 ·
Hi all.

I will soon have my motor split open to replace the damaged bevel gear bearing, so I will take advantage of this work also to replace the parts that appear worn (shift forks, shift rods, gears, etc.) - my '9 is a 2007 with 70000 Km on it.

On the subject there's this excellent write up of 2009 --> http://www.m109riders.com/forums/showthread.php?t=108935&highlight=gears+undercut
It mentioned that Suzuki upgraded the shift forks from 2008, the new forks are less tapered. The shift rods were not upgraded in 2009.

That post dates from 2009.
Does anyone know if also the shift rods have been finally upgraded in the last years? I understand that shift rods are the main problem in the '9 shifting problems (like 2nd gear problem), since they are hollow and they should be solid to prevent their bending.

In that write-up it's explained that the R&D shop that did the gears undercutting provided also solid shift rods, that came from aftermarket rods for the Hayabusa and then cut to length to be compatible with the '9.
If the Suzuki rods are unchanged (still hollow), I might try to ring that R&D shop to see if they could prepare solid rods for me.
 

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Im not 100% sure, but AFAIK, only the forks are upgraded, the rods themselves are the same. When my 2007 2nd gear let go, the repair order had new shift rods on the parts list, but the part number was the exact same as the parts listed in the microfiche online and not an updated part number like the forks were. If that helps
 

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I sent my trans to R&D last winter, they sent me solid rods as well as hardened shift forks. If you're getting rods from them might want to ask about the forks as well. The guy I talked to on the phone was really nice and seemed to love to just talk about bikes. Ended up talking to him for about 45 min about M109's. He was just chatting away so i'm sure he will answer any questions you may have.
 

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Discussion Starter · #4 ·
I sent my trans to R&D last winter
I'd like to send them an email before ringing them, but on their websites I found only a telephone and fax number.
Do you know an email address to contact them?

Thanks
 

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Discussion Starter · #5 ·
Ok, I ringed R&D Motor Sport this week and I ordered their upgraded shift forks, shift rods and 2nd and 3rd gears with undercutting :bigthumbsup:.

I should receive all the stuff in a couple of weeks.
 

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Discussion Starter · #6 ·
I received the ordered parts a couple of days ago and opened the package yesterday to check its content:

Watch Material property Font Jewellery Eyelash

I received the three special-built shift forks (in the brown wrapping), the two solid shift rods and two gears with the racecut modification.
The point is that I ordered the 2nd and 3rd gears with backcutting, yes, but I was expecting a pair of parts for each gear (the driven and the drive) - so why only a part for each gear??
The two gears in the pic are part no. 24321-48G01 (GEAR 2ND DRIVEN) and 24331-48G00

I emailed and ringed Mark of R&D Motor Sport to get an explanation about this point, but he will open again on Monday and so I could not resist my curiosity and decided to post here.

I assume that if you backcut a gear, both the drive or driven parts should be undergo the process, otherwise the ears and dogs would be misligned (as I understand that the stock ears/dogs are at 90 degrees and upon backcutting you modify this angle by approx 7 degrees).
I showed this pic also to my Kawasaki dealer, that is going soon to rebuild my transmission and he had the same doubt.

Any thought on this from the board?
I'm a little mechanical inclined but not enough to understand all this matter and here in Europe the mechanical folks are not used to modified motorcycles transmissions ...

Thanks ^-^
 

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Yes, both those gears sit on the same shaft, next to each other... 2nd and 3rd... and the dogs from 3rd gear slip into the nod gear... they should both be undercut to the same degree...
My only concern here is I don't see a shift drum... believe me you will need to replace this as well !! They are expensive, but it is too big a job not to, and you will find that it will be worn, which creates too much play for the shift fork... the shift fork pin, which sits in the groove of the shift drum, will also be worn, so you really need to replace both...
If you look at the pin on the shift fork, you will see that is has a a rounded shape with a narrowing around the neck... I'm not sure why or what Suzuki were thinking when they designed this fork... the pins should be straight, but the shape they are promotes wear, especially if you go for a long time without an oil change...
I'd like to see pics of the shift forks they supplied you with, special built ??
I'm about to order exactly the same parts that you have here, perhaps, you might be able to help me with contact details for R&D Motor Sport please... thanks :)


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These are photos that I took of the selector fork (pin), and the shift drum (worn groove)...
you can clearly see the wear on the pin and the odd shape...
Generally these pins are straight cut...


This second photo clearly shows the wear inside the shift drum... please don't assemble your motor without replacing it...



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Discussion Starter · #9 ·
I'd like to see pics of the shift forks they supplied you with, special built ??

perhaps, you might be able to help me with contact details for R&D Motor Sport please
Thanks for the explanation.
Please, find the link to R&D --> http://www.r-dmotorsports.com/
I have an email to contact Mark, the guy at R&D - the point is that it's a personal email to reach him at home, so I prefer not to share it here. He told me that he does not use emails for his job.

I've taken some pics of these forks:

Household hardware Metal Bracket Composite material Artifact Wood Tool Metal Bicycle part Fashion accessory Wood Household hardware Metal Auto part Titanium

Also some pics of the solid rods:
 

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Discussion Starter · #10 ·
Another one:

Wood Household hardware Hand tool Finger Wood stain
 

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Discussion Starter · #11 ·
My only concern here is I don't see a shift drum... believe me you will need to replace this as well !! They are expensive, but it is too big a job not to, and you will find that it will be worn, which creates too much play for the shift fork... the shift fork pin, which sits in the groove of the shift drum, will also be worn, so you really need to replace both...
I'm going to change these parts in the pics because I have to replace the drive bevel gear's bearing and to do so I have to open the motor - so I'm going to exploit this to change 2nd, 3rd gears and forks and rods with upgraded new parts.
Nevertheless I never experienced 2nd gear problems and I explained this to Mark - although I asked him whether it was wise to change also the shift drum, he said that he did not think that this is necessary as I never experienced 2nd gear problems.

Should it be worn, I will replace it for sure in any case.
Do you know what the price is for a new one?
 

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I'm going to change these parts in the pics because I have to replace the drive bevel gear's bearing and to do so I have to open the motor - so I'm going to exploit this to change 2nd, 3rd gears and forks and rods with upgraded new parts.
Nevertheless I never experienced 2nd gear problems and I explained this to Mark - although I asked him whether it was wise to change also the shift drum, he said that he did not think that this is necessary as I never experienced 2nd gear problems.

Should it be worn, I will replace it for sure in any case.
Do you know what the price is for a new one?

The pin on the shift fork is ground from one piece. You can see the shape of the pin, it has a slight necking where it joins the body. This I think is the crux of all the issues... generally this pin is straight cut, on every other bike I've seen, always straight...the shape of this pin is significant, as it wears the lower part of the groove, quite deceptive I think... I wonder if there is a machine shop that is able to insert a straight cut pin, in place of the original...

You can see the wear of the groove here, this is the shift fork position when engaged 2nd gear. This is difficult to see with the naked eye, hence the use of a good camera and lens...


It's extremely difficult to measure if a shift fork is bent, but comparing this by eye to the next one, it looks straight, though if it were 2 or 3 degrees out, I don't think my eyes would pick it...
undercutting the dogs to 5 degrees is probably the go... which is what I am doing...

I did price up the shift drum this morning, almost $200AUD, the USA would be cheaper...
For my piece of mind, I would replace it anyway, primarily because it's a mega amount of work to do again...
remember when assembling the gears on the shaft, to use molybdenum disulphide grease, and to put the new circlips the correct way (don't use the old ones)... yes, they can only go one way...!!
One more thing, some of the bushes that go inside the gears, must be lined up with the hole in the shaft, if you don't do this, you're in serious trouble !!

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Ahh, I see the straight cut pins... I have contacted R&D, will order the new forks as well as the solid rods...
Thanks for the link Dommy

I'm not sure why I duplicate the pics above !!
 
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