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Taller 5th with stock parts??

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I'm looking for a Higher 5th gear. Baja Designs doesn't make thier kit anymore, nor does IMS.

From what I can tell. It looks like a second set of stock 3rd gears could replace 5th and yeild a .809 ratio (stock .909) roughly like dopping 5 teeth on the rear spocket when shifted into 5th :applause:

For this to work the spline count and diameter on both the main and countershaft must be the same:confused: Could someone confirm this for me??

Then the 22t 5th gear-non-splined on the mainshaft would get replaced with a new 21t gear(stock 3rd on the countershaft-non-splined)

finally the 20t 5th gear on the countershaft-splined would get replaced with a new 17t gear (stock 3rd on the mainshaft-splined)

Both 3rd gears new from service honda are less than $100

Someone please tell me why this won't work.

Thanks

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Yes, These same two gears are already being used for 3rd, but on the opposite shafts. The MS CS are parallel, so gear mesh would be perfect.

The I.D. on both non-splined gears are the same.

The things I'm not 100% on:

1.are the gear widths identical (they look like it)?

2.Will the 4 dog clutch teeth on the side of the gears mesh properly(they look like they will)?

I'm just trying to find these things out without having to tear down my trans to see if it will work.

Any one in the Tahoe/Carson city area have a trans apart I could look at??

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Maybe PM or call up a engine builder? Like RHC? try and get a hold of him on the 250 forum..maybe?

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why dont you just put a 450X transmission in there, or if you could find one for a good price, buy a 450X bottom end and install it and then sell your R bottom end to pay for the 450X one. just an idea

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I have a 4th gen frame a 450x motor won't "bolt in" and the X gears are thicker than the R gears so they won't swap. Plus I like the R close ratio 1-4 and just want a higher 5th.

Idealy a BD 5th would be perfect .75, but I'd settle for my .809 plan. FYI a 450x=.826 and 450r=.909

ndekens, thanks I'll look for RHC

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why dont you just put a 450X transmission in there, or if you could find one for a good price, buy a 450X bottom end and install it and then sell your R bottom end to pay for the 450X one. just an idea

Out !!! go on git !!

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Voo Doo, I installed a BD WR gear set last year so I have the stock 3rd, 4th & 5th gears that were replaced with the BD gears. I can post photos and/or measurements. Let me know what you want to see and I'll post it for you.

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kjlectric, Thanks. That's just what i was looking for.

The 20t splined 5th gear should be almost identical to the 17t splined 3rd gear, other than obviously the tooth count and O.D.

And the non-splined 22t 5th gear should be, also in the same way, similar to the non-splined 21t 3rd gear.

Let me know if you see any differences, especially I.D. spline count.

If I'm not mistaken, the BD kit Replaces both 5th, 4th, but only one 3rd gear, so you may only be able to compare on set of the gears Im' interested in. But I could be wrong.

Thanks

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Here's the info I can provide. It's not a final answer, but is better than nothing.

The spline count and diameter of the 3rd and 5th gears appears to be the same.

The gear labeled 9 on the fiche, which is the splined 3rd gear on the mainshaft (M3 in the service manual), has circlip 29 and splined washer 26 on both sides.

The gear labeled 15, the splined 5th gear on the countershaft (C5), also has circlip 29 and splined washer 26 on the shift fork side. They're not on the other side like the 3rd gear since the 1st gear sits on a smaller diameter section of the shaft. It has washer 28 instead. The spline count and diameter should be consistent through the whole gear, but this may mean that other features on this side of the gear are not interchangable.

According to the service manual, their non-splined mating gears, M5 (14 on fiche) and C3 (10 on fiche) have the same ID. Not sure about their width.

As for or the rest, only someone with the gears in hand could tell us if the other features are interchangable. The shift fork groove width, diameter, and location, and the dog dimensions need to be the same on M3 and C5. The overall width and any dog features need to be the same on M5 and C3.

There's no spec in the manual for the shift fork claw ID or the gear groove OD. I know that in some transmissions, the shift fork grooves have different diameters, but since C5 is a 20t and M3 is a 17t, I wouldn't be surprised if they were the same.

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Thanks amcgraw,

The splines on M3 and C5 looked the same to me also, but I wasn't sure.

I'm still curious about the other features also. I need to see the gears in hand.

I'd love to have that taller fifth, especially for only the cost of the two gears

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Voo Doo, I finally took some quick shots of the gears that I have. Not the best photos. Your right, the CS 3rd gear was not replaced so I only have the MS 3rd and both MS & CS 5th. The dogs are slightly wider on the CS 5th gear than the MS 3rd gear.

P1010009.jpg

P1010005.jpg

P1010004.jpg

P1010003.jpg

P1010002.jpg

P1010001.jpg

Hope the photos help. let me know if you need anything else. Good luck!

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This has peaked my interest. I've also spend some time researching how to change the gearing on my 04. Not too much out there but this would be pretty cool if it worked.

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I really think that someone needs to try this, unless it is really not feasible.

I love this website......

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Wow, kjlectric! That's exactly what I was looking for.

The dogs on 3M are just slightly smaller than 5C, so they should fit into the C1 and C3 gears the need to mesh with.

Most everything else in within a half a mm.

I'm 95% sure this could work with very minor shimming at most.

But, do I have the balls to tear into a perfectly working bike to find out for sure ???

Hmmmm??

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Nice reply kjlectric. If I had done it, it would have just been numbers!

I don't mean to be a pest, but did you get to measure the shift fork groove diameter?

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