5 Speed Gearbox swap for stock 4 spd - 1973 FLH.

[swanboro]

I've owned this pretty much stock bike since new; its got 43K miles, solid lifters, 23T engine sprocket 'cos it hauls a sidecar, low compression kit to accommodate today's low octane, and I'm considering some pre-emptive overhaul in anticipation of riding more this year.
I figured a 5 speed would make highway travel more practical and less strain on the 'old' motor, recognising current highway travel speeds.
Any experience with the gearboxes offered by Baker and Rev-Tech ?
Thanks,
Richard.

[springer-]

I run the Sputhe 5 in a 4 transmission and love it.  Basically the same as the others.  They are not a direct bolt in and will require some custom fiting.  The advantages are closer ratio gears (more of them), less leaks and much smoother shifting.  The final gear ratio for both the stock 4 speed and the 5 speed is still 1:1.  This means it will not change your highway ride at all.  If you run 60mph at 3000 RPM now, you will run 60mph at 3000 RPM with the 5 speed.  I believe Baker offers a 6 in a 4 now as well.

[76shuvlinoff]

  Agree with above, I'm running an RevTech 5/4 in mine since 03. Warning, made in Korea but it has been a fine tranny other than the busted throw out bearing a a couple years ago.
  I don't know about Sputhe and Baker but the RT is approx 1" wider to the right side and on my 76 FLH (big battery) I had to use either a true dual head pipes or the Thunderheader I am running now... and to fit the T-Header I had to space the right floor board out 3/4 inch.  Ripple affect.  Also ,you gotta dink with clutch cable mounting. None of it is a real show stopper, and once it's in the tranny runs fine but be forewarned.
  My sprockets are 24 on the motor 23 on the tranny and 48 at the rear wheel, I'm turning it all with a 93"er, I really like this set-up.

Mark

[ST40]

I was hoping to get a little lower cruising RPM with a 5 speed setup on my FLH, but I see I won't be gaining anything.  So I will have to play with sprocket ratios?  I think I'm running 24 motor, 22 tranny, 48 rear wheel with a 93 incher.      Marty

[76shuvlinoff]

You might be ok with a 25 up front but I hear it gets tight in there.
Some guys run a 24 at the tranny but need to keep a close eye on the chain. I've had mine do some self clearancing with the 23.  I run mine a touch loose with a spring loaded idler under the final chain.

What you get with the 5/4 is betweener gearing for around town and if you run 24/23/48 that extra gear helps on the way up, especially loaded.

I don't have miles of wide open highway around here so it works well for me.

Mark

[randallwhitman]

Money aside, the best of all worlds is a six speed.  Great gearing around town and an overdrive gear for the interstate or lightly traveled country road.  My overall gear ratio (to fifth) is 3.18:1.  In sixth gear, 60 mph=2100 rpm.  The leaders in six speeds are Ultima, Rivera/Primo, Baker, JIMS, and S&S.