Overdrive 5th gear

Hi Fred,
10, 12 packs. That has to be a record on a bike. The most I carried on my 650 was 2 gallons (US) of beer in my back pack and smuggled it into a "Boston" concert at Giants stadium in New Jersey, back in 1978. I was the star of the show, but you would have been a God.
 
Jefft, Making it taller would have been better, but think about it. This is a constant mesh xmission. The diameter of the gear can't change, but they managed to add another tooth. Wrap your head around that, it's pretty slick.
Again, I went to a 33T rear sprocket and the OD 5th, (it should be called "a slightly higher 5th gear", not an over drive), and I am very happy with it.
 
Marlin72xs said:
Hi Fred,
10, 12 packs. That has to be a record on a bike. The most I carried on my 650 was 2 gallons (US) of beer in my back pack and smuggled it into a "Boston" concert at Giants stadium in New Jersey, back in 1978. I was the star of the show, but you would have been a God.
Click to expand...

Hi Marlin,
while a backpack will go into the stadium with you, the sidecar has to stay in the car park.
This means dealing with the hassle of leaving the show to get the beer.
Or, having each 12-pack preloaded in a backpack so that you and 9 buddies can strap 'em on and take 'em in with you.
It's different at bike rallies where the bike is always with you.
Remove the sidecar's seat & floor rug, dump in 6 bags of party ice atop the beer and your buddies can stop by for a cold one any time.
 
Mr. Spock,
I just typed a novel for you and forum kicked me out. Here is the short version:

The large ID gear @ .984" fits on the .979 shaft.

The smaller ID gear @ .979" fits the .975" shaft

The clearance is .004" to .005" between gear ID and shaft OD.
 
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Spockwerks said:
...Been seeing a lot of talk about micrometers and dial gages but not many numbers. What would help me the most is clearance. Like, the OD of the shaft that goes with the ID of the gear. I suspect there are more combinations than Mike lists. Anyone have a clue on the tolerances of these parts?
Click to expand...

Good question. Haven't seen anything here that goes into that. The MikesXS listing implies running clearances of about 0.004"-0.005" (0.010mm-0.013mm). Being a constant mesh transmission, that 5th gear/wheel simply spins there until engaged, only coupling with the adjacent sliding dog gear. I can visualize it wiggling a little during 5th engagement, a bit more than my liking, but that clearance would make it tolerate cruddy oil. My gut says 0.002" (0.05mm) would be a proper clearance, but the oil better be real clean for that...
 
Well, I opened her up and gave both gears the wiggle test. Place each gear in turn on the dry, clean shaft and see how much you can wiggle it. The more clearance there is the more it should wiggle. If I cannot identify a gear in a blind test by the amount of play in the assembly, then I would have to say that the new gear is within tolerance. BTW the 'old' gear and shaft have about 30K mi on them. They were renewed when I broke a dog off 3rd gear. That was at 35K mi or thereabouts.:bike:
 
Spock, be sure to check the condition of the shifting forks. Twomany mentioned that I may have other issues with the slipping out of 5th occasionally, because I broke my 5th at around 32k.
Sure nuff, the middle fork was actually bent and there were severe scrapes on one side.

When I can figure out how to get Picts on my replies, I will. Until then, I will put a picture of the forks in my album.

Do I know you? I graduated in 69 from paramus HS. Lived ther from 57 thru 74. I married Gay Moulton of the class of 70. Her sister is Suzanne and brother is Pete. I lived on Salem street. I was in a band in HS. I called you Mr. Spock because I'm a Trekkie. Oh, and bought my 72 in 1976. .???
 
Shifting forks look good, straight and featureless. Now I am waiting for camshaft 'O' rings to arrive at my local Yam dealer. I don't buy much from them cause there prices are unreasonable, but an old friend works there and it's always a good policy to be a familiar face around a shop that you know you will probably need some day.
The rest of this post is sorta off topic, sorry lads.
Why Spock, ok Graduated Haddon Twp HS 1969. Had my hair cut like mr. Spock after being suspended for fighting & being a Long hair. The name stuck, and when I started working at Nick's Choppers in Williamstown I needed a biker name. Everybody had names like 'Spider' or 'Skull' or 'Hokker' back then so they named me 'Spock'. At one point more people knew me by that moniker than by my real name.
There was another active painter named 'Spook' who I never met but did get to admire some of his work which was so different from my own in both form and function that I never thought of him as a competitor as much as a compatriot.
Rebels among the rebels.
So if we had met in the 60s or 70s you would know me as 'Spock'. Or the acceptable Trekker variant 'Mr. Spock'.:thumbsup:
 
Marlin72xs said:
Hello Peanut, I can agree with most of what you say, but as for the misnomer of the OD 5th increasing the overall drive gear, I beg to differ. Each gear is independent of each other. When in1st, all other gears are free-wheeling. The trans would bind instantly if they did not. The same goes for all gears. Mikes OD 5th only reduces the 5th gear ratio. All other ratios remain the same.

Hey, no offense, but if I'm missing something or if I read it wrong, please let me know.
Click to expand...

I agree with this. If someone can inform me otherwise, please do.
The reason the 5th gear is useful over a sprocket change is because it wont negatively affect low gear acceleration.
 
I am so glad they came up with that taller 5th gear. I have often found myself wishing for a lower 1st gear because I like that shot in the arm you get torquewise from a smaller drive sprocket or larger back wheel sprocket. But the down side, lower overall gearing really sucks. The Brit bikes used to come with East Coast or West Coast gearing as standard equipment. That meant either one tooth more or less on the final chain drive, my memory fails me as to which sprocket they changed, but East Coast bikes were geared for shorter streets thus more torque = acceleration. While West Coast bikes were geared for longer roads, lower RPM, higher top speed. The off road bikes would come with an assortment of sprockets, standard. Until joining this list I had no idea that Yamaha Had played the sprocket shuffling game except their dividing line was Europe and America. What sprockets did Canadian XS650s come with?:shrug:
 
Hi Spockwerks,
Canadian XS650s were mostly 17/34 like in the USA although my '84 Heritage Special came from the factory with 17/36.
Swapped the 17/36 & stock chain for a 17/33 & o-ring chain after the bike's break in run around Lake Superior.
Swapped the 17 for an 18 then swapped back when I saw what the o-ring chain's heavy duty sideplates were doing to the shifter shaft.
Swapped to 17/38 to pull the sidecar.
The 17/38 gearing lets the rig do ~55mph at the engine's 4,400rpm "sweet spot"
It's so much easier to swap final drive sprocket on Japanese bikes than to swap it on a Britbike where you have to remove the clutch first.
 
Good day, I want to change the transmission of 5th Mike, Mike has 2 versions of the gear, I measured a shaft it's 24,94mm(0.982")
I Have XS650 SJ 1982.
Mike says this year will approach Part #05-0870
Main shaft 0.975 mm ONLY
0.979 inches or 24.82 mm (Hole diameter)
But this is not true, I have larger shaft it"s 24.94mm(0.982") not 0.975 or 0.979 like Mike says.
It turns out, the need for my gear from 73-77 Part #05-0869 ???

If you already have the answer, please answer me.
 
Gefest said:
... I have larger shaft it"s 24.94mm(0.982") not 0.975 or 0.979 like Mike says.

It turns out, the need for my gear from 73-77 Part #05-0869 ???
Click to expand...

Well done, Gefest. You measured the shaft first before ordering.

The large ID gear, Part #05-0869, @ .984" fits on the .979 shaft.

The large ID gear, Part #05-0869, @ .984" should fit on your .982" shaft okay.

In my opinion, that is a better 0.002" clearance fit...
 
Thanks! please tell me, Mike recommends using paired item Part # 05-0857
Why?
it has the same 22 teeth stock ... or there differences?
 

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