Does anyone know the exact outer diameter of the 30-tooth end of the Selector Shaft (see pic with red circle below)?

I finally found the perfect 30-tooth offset Shift Arm (pic below) that would give my custom 1985 K100 a straight Shift Linkage Rod (rather than the curved one that broke) from my rearset to the Selector Shaft, but when it arrived the diameter of the offset shift arm was much smaller than the diameter of the Selector Shaft and it doesn't fit.

The purchased Offset Shift Arm has an OD of is 11.35mm
The K100 Selector Shaft OD is UNKNOWN and I'm hoping someone here does know.



I tried to measure it myself with a cheap plastic caliper, but there is no way I'm getting the exact specs on the Selector Shaft.


I figure I'll either find the same type of offset with the correct diameter or try to re-drill the part I have with the correct OD.


If I did want to try and drill the proper OD into the purchased part (pic below);

1. What type of drill bit would I buy?
2. Where could I buy it (I have a drill press)?

Thank you in advance for all the help on this one! I really am hoping to get back to riding before Fall comes - I live in Seattle so the dry days are few and far between.

Thomas


 

G'day tjh1985, According to my verniers, the diameter is 13.75mm . Perhaps somebody can confirm that.

I measure 13.4 with an El cheapo  vernier and sunburnt retinas on an '84 model.

Well, I may not make this discussion any clearer but my 1984-85 gear shifter shaft shows 13.56 - 13.57 OD. Just removed the lever now for the measurement and used a  PA (Princess Auto) Power Fist Chinese product to measure it. I believe the measuring device is reasonably accurate!
Will measure again to ensure my eyes are working properly.
Shep

what is the piece you are wanting to buy for, it looks like Honda to me and if so then it should fit. Many of the Honda splines are the same as the K100.

tjh1985 wrote:The purchased Offset Shift Arm has an OD of is 11.35mm
I figure I'll either find the same type of offset with the correct diameter or try to re-drill the part I have with the correct OD.

The offset shift arm has a hole with a diameter, not an OD. If you expand the diameter of the shift arm hole, you'll remove all its splines. What will keep the shift arm from rotating around the gear selector shaft after you've cut off all the shift arm's splines increasing the hole's diameter? There are tools for the drill press that could expand that hole but I think the project needs more consideration before they are purchased.

Also there's probably two diameters cause of the splines. Maybe removing the bolt helps, or spreading it a bit if it's not too far out.

daveyson wrote:Also there's probably two diameters cause of the splines.

There is the diameter of the hole. The other measurement involves the profile of the spline cut into the hole's perimeter; however, in this case if removing fasteners and spreading stuff is the chosen path, all the ridiculous preoccupation with measurement or fit can be tossed out the window. 

RicK G wrote:what is the piece you are wanting to buy for, it looks like Honda to me and if so then it should fit. Many of the Honda splines are the same as the K100.

@RicKG that is really helpful to know - do you know which Honda models would be the best place to start? The part showing is supposed to be a "universal" size but the part I bought is way too small so I'm guessing it's not for any of the Honda models you are referring to.

Thanks so much for this info

Thomas

Most if not all of the cross frame 4s and twins of the 70s, 80s and 90s used that spline.

Looks like I need to make a custom part and called up a few places in my area (Seattle) to see if they could do it, but haven't found anyone who can make the spline portion.  The best I got was that if I do find someone to drill out a proper fitting spline it will cost me $400-$800 just for that portion. If anyone knows anyone who can machine the spline piece and is willing to pass their contact on to me that would be fantastic. Otherwise I'm back to square one.

I'll close this thread down soon if there is no more activity on it..

Thanks agian,

Thomas

Put the stock lever and footpeg plates back on and see if that works, then you will know if the problem is related to the gearbox or the after market shifter and the same for the clutch cable.

There you go Thomas listen to Rick. Or get a bigger Hammer  Poddy.