Overdrive 5th gear

XS John runs 18/29 sprocket's, along with a lowered compression ratio. His runs excellent, and his doesn't ratchet on the city street's. He also weighs like 150#, so. I run a 17/31 combo on mine, & freeway travel is not so bad. I think at 65/70 mph, I am running about 4500 rpm. Not real sure, but it's allot less than it was with the stock 34 tooth sprocket. My fuel mileage is around 50 mpg. I weigh in at 200#, and city driving is good. I think that a 30 rear would be better. Also, if I get into a jam on the freeway, drop down 2 gear's & let 'er fly, gets me out of trouble. Also gets me ticket's. Awe shit.
With the gearing I got, it still pulls really good. If you go with the 18 tooth front, you gotta remove the shift shaft guard.And my bike is stock with the exception of pod's & Mike's 2-1 pipe.:shrug: I am pretty happy with the setup I have. If I was gonna do a major run, to like Chicago or something, I would put a 30 on the rear.:bike:
I plan on trying a 18 X 30-32. I have the stock setup now. It sucks on the highway. Everywhere else is fine. Over 60 is starts to vibrate bad.
Whats on stock 76? Im out of town (as always) but I have to order some parts from mikes, it would be nice to order the sprocket combo too.

Ive always run 18: 30*( or 29), still pulls like a train & you get near-on 90mph at 5,000 rpm
I'm currently running a 17 front and 30 rear on my 1975 with the 18" rear rim.(the wheel size makes a big difference!) It's excellent on the freeway but starting in 1st is tricky. I only weigh 150lbs and the bike is a bit anemic in 1st gear. The 30 tooth rear sprocket would probably be good for a 16" rear rim. I was able to use the original chain with the 30 tooth sprocket, but just barely and I had very little adjustment room.

I've got my cases split now to install the 5th overdrive and am planning to run a 18 34 sprocket combo. With any luck I'll still be able to do freeway speeds but not lose the low end grunt that I bought the bike for in the first place. Will let you know how it turns out.
I dont understand that, mine have 18" rear rims and with an 18 front 30 rear i can pull away easily in second gear ..If first gear disintigrated I wouldnt miss it too much !
Timing set too advanced will make the lower revs weak will taller gears.....try setting the timing an 1/8" or so retard from the F mark at 1200.........xsxjohn
By raising the swingarm pivot (what I'm trying to do), relative to a line between the center of the countershaft sprocket and the center of the rear sprocket(rear axle), it plants the tire under acceleration.

So to answer your question, I'm trying to achieve improved handling and traction.

You're talking "anti-squat" - the same effect as raising the front of a four link in a car.
If you go with the 18 tooth front, you gotta remove the shift shaft guard.:

I left my guard in place when i did the 18t front sprocket. Just trim the guard mounting bracket (the "leg"that goes to the bolt) shorter and it moves enough to clear the sprocket and still keep the chain off of the shift shaft. sorry i didnt take any pics but if you have been inside one you know what im talking about.
Yes I know that mate, Im saying Ive used 18 tooth sprockets on all my XS's for the last 30 years and never needed to remove or trim the shift guard .. What I meant was that some 'heavy-duty' chains are 'deeper'
I just took that nasty guard off and removed about a 1/3 of the shift shaft under the chain........xsjohn
TC........Had some pics but can't find them .....just mark under the chain on the shift shaft and remove the front sprocket and grind the top of the shaft where the chain would touch ....the shaft is plenty tough to loose a 1/3 or so for sure....did mine on the bike with a dremmel and grindstone........

Hey all, read on here the other day that the Mikes 5th gear O/D will fit a slightly worn (used) pre 78 gearsets & the original post stated that it has done with no issue, does anyone know who posted this & is this true
I don't know about that, may be true. My engine is a '78. Been running mike's 5th gear for a year now, and it's popping out of gear in 5th if I give it too much throttle. All other gears are fine. Haven't had the chance to tear it down and sort it out yet.