I'm new to restoring old Harley's, it took me 61 years to get my 72 FLH.
I went looking for a retro fit 5 speed trans for my bike, and got some good feed-back here on forum.
Then I found that RevTech has a very well priced "5-Speed in a 4-Speed Case with Kicker" when I e-mailed a couple of vendor's to ask what the ratio: of the 5th gear was I was told "

 

Why do you want to to go 5 speed ? The final ratio is the same on both the 4 and the 5 so you don't gain anything but a lot money spent and mod's to a nice bike , you'd have to go a 6 sp to get a real change . Just change up the 1st-2nd ratios a bit higher and that will close the gap on the 2nd to 3rd clunk very nicely for under $300 . Plus a kicker is still a great thing to have on older iron if for nothing else the cool factor in a crowd .

PS stay far away from anything Rev Tech for a shovlehead that stuff is junk .

 

If you are looking for a good tranny other than a stocker, go to Baker.

 

I ran a Sputhe 5 speed for almost 15 years in an old 4 speed wideglide. Totally bullet proof. Never had a problem with it. Fifth gear was 1:1.

 

I'm running a Sputhe 5-speed in my '68 Shovel (88inch, Andrews B, SU Carb), it's a nice upgrade from a 4-speed IMO. My only complaint is no Kicker

 

The old 4 speeds are 1:1 too why I can never see how people think it's an up grade and they have a much lower first gear . Harley went to the 5 to compensate for the lower flywheel weights in the evo's and the lower torque they put out final ratio never changed .

 

To realize the benefits, you need to change the final drive ratio. I ran a chaing so was no big deal swapping sprockets. A lot of the belt guys went to the 61 tooth pulley. On my Sputhe, I ran a much lower final drive ratio which resulted in a significantly less RPM at say 65+ mph then with my 4 speed. I had good bit higher ratio first gear and close ratios up to fifth. I did consider it a big upgrade over my stock 4 speed set up. It gave me considerably better fuel milage as well. The sputhe uses a stock HD gear/shaft set so any kicker that will work on a HD 5 speed will work on a Sputhe 5 speed (provided you have the exhaust clearance).

 

1:1 final being the same on both I'm still not seeing these benefits , doing the sprockect dance for gearing changes is as old bikes them selves .

Back when the 5's first came out in 1980 with the FLT abortions they had it was harley's way to close the front of the gear box with the low end 1st /2nd /3rd issue with the heavier bikes . The old 4's did have a clunky 2nd to 3rd shift and a bit of a gap between that was rough with the added weight on the FLT's and the 5 tighten that up did not change the final at all so NO GAIN .

It's why Andrews put out a close ratio gear set for the 4 speed to close that hole up . To each their own I know I just like people to understand all the real facts behind something before they spend a lotta money . Your going that route get a 6 speed it's the same changes and you get an actual overdrive on that 6th gear it's .86:1 and that will make a difference you will notice for real .

 

Baker makes a six into four with o.d., and a kicker.

Bob
97 Heritage