Shovelhead Transmission Upgrade Options?

[Hdshovelfan]

My bike is a 1980 80ci Shovel and 4 speed, rotary top trans, mounted in a Mid-USA rigid frame. It is kickstart only with points ignition and open BDL primary belt drive.

I need to pull the transmission and at the very least, replace the mainshaft seal. I've not done this before but will get the proper tools and seals and learn how. Other than the leak, the trans works fine.

I do like the current configuration of the bike. But I'd also would like to upgrade to a leak-free, more modern 5 speed set up with a better electric start system in the long term. I believe this frame will accept a softail, 5 speed trans. I know nothing about Softails and have no idea which years are the best options. I also have a Spyke starter and a 'lever solenoid' starter that I ran for a few years before removing the original Shovel electric start system. I don't know if these parts would be compatible with a Softail electric start system.

So to make this upgrade, I would need a 5 speed trans, clutch, electric start components and a new belt drive.

Any suggestions or comments regarding the complexity of this upgrade, or which components would fit and work best would be appreciated. Thx.

[Dragstews]

If you do use the 5-speed Softail trans you can keep the primary drive/clutch you got with changing out the trans mainshaft to a earlier tapper 5-speed shaft ...

[farmall]

I have two Shovels with the All Balls starter motors which are really Denso OSGR motors with a custom end housing (deleting the stock Denso solenoid) like the Spyke parts and the complete Denso OSGR as used on later Softails is vastly better with its coaxial integral solenoid instead of the complex legacy setup in any form.

If you're satisfied with what ya have ya can run a 4-to-5 Speed trans case (S&S and Revtech made them) to just use tapered shaft takeout guts with your existing primary covers, clutch etc. Maybe JB or Dragstews have one laying about. That would use your existing starter, primary parts etc.

https://www.sscycle.com/docs/default-source/instruction-sheets/51-1059_transmission4-5speed_20080204.pdf?sfvrsn=4

I'd just source all the late splined shaft Softail parts (primary and gearbox) and upgrade the lot but your scooter your call.

Since you have a rigid frame no need to notch a Softail case for swingarm clearance. You can see pics of the late starter Drag sold me and the adapter plate in the 92-inch Pan thread for what that looks like. Late transmission cases use the large starter hole shown in that thread.

[JBinNC]

If you do use the 5-speed Softail trans you can keep the primary drive/clutch you got with changing out the trans mainshaft to a earlier tapper 5-speed shaft ...

It would be easier and cheaper to change the clutch hub. More durable too.

Jim

[JBinNC]

OP:

Yes, throw a Softail five speed in it, starter and all. You will need a transmission plate to mate the five speed to your frame. Paughco offers one. As I said above, change the clutch hub for one to fit the splined transmission mainshaft, or change the entire primary drive if necessary. That is FAR better than going backwards to the transmission mainshaft with keyed taper for the clutch hub. You will probably have to change or modify the oil tank to clear the five speed starter, and allow for a large enough battery for the electric starter.

Jim

[Hdshovelfan]

Thanks Guys

In doing this mod, I would plan to change all the components to 'modernize' the whole system. When we built the bike 20 years ago, I worked with a good shop to purchase most of the parts, had them rebuild the engine and trans etc. I would do the same for this upgrade. But I wanted to get some feedback from you guys as to the viability of doing the upgrade. Sounds like it is worth doing.

[Dragstews]

Ya know ... If you had the bucks a Baker 6-speed would be Plug & Play ...

[Sky]

Putting a five speed behind a shovel as well.
Since I have a nice tapered hub clutch setup...
Went to swap in a tapered main shaft, and the tapered shaft was stepped for loose MDG bearings.
The five speed Main Drive Gear bearings were caged.
So, I'm back to finding a splined clutch hub.

Probably could have found a loose bearing MDG to swap in too, but that's a lot of effort for a weaker setup

[JBinNC]

Putting a five speed behind a shovel as well.
Since I have a nice tapered hub clutch setup...
Went to swap in a tapered main shaft, and the tapered shaft was stepped for loose MDG bearings.
The five speed Main Drive Gear bearings were caged.
So, I'm back to finding a splined clutch hub.

Probably could have found a loose bearing MDG to swap in too, but that's a lot of effort for a weaker setup

Yes, the bearings inside the main drive gear are different inside diameters depending on the year model and the style of shaft. So, the shafts are only interchangeable if you also change the main drive gear, and sometimes the c'shaft gear it meshes with. It can become a clusterf. of problems for the novice.

Jim

[Hdshovelfan]

Ya know ... If you had the bucks a Baker 6-speed would be Plug & Play ...

[ATTACH=CONFIG]107428[/ATTACH]

Yeah, I've considered that too and it may be an option. I've had 5 speed bikes and 6 speed bikes. For me, 5 is enough especially with the power of the Shovel. I would like it to work a little less on the highway and drop the vibes down a bit.

The bike is due for a refresh. It runs well and is a hoot to ride. But the trans mainshaft seal leaks like a seive, the brakes need an upgrade, it should probably have a new chain and sprockets and some better switchgear etc.etc. It is a bit ratty. It's not my only bike so I have the luxury of doing it over time.

[farmall]

Remember the top ratio is the same so a five speed is not an overdrive but can work better with tall final drive gearing than the four speed.

You can drop four teeth off the rear without issues.

[rockman96]

Think of a 5 speed, coming from a 4 speed, as being similar to going from a stocker to a small stroker. The 0 to 70 feels peppier with the 5 speed. The mirror(s) however, will still be just as useless at 60+mph without going to an overdrive.

[Sky]

the shafts are only interchangeable if you also change the main drive gear, and sometimes the c'shaft gear it meshes with. It can become a clusterf
Jim

Exactly
And since the trans I'm working with was all Jim's close ratio gears inside, I didn't wanna go searching for a compatible MDG. Bearing and tooth count wise.
Happier keeping the splines anyway. On the Gear AND the shaft.

That's another thing to keep in mind, the MDG splines...
Do you have room for a rear belt or staying chain??
The sprocket/pulley splines have to match the gear.
Think the 1/4" offset belt to chain conversion sprockets line up for most, but you'd better double check your setup.

I'm going with a one inch rear belt. Utilizing a (narrower) evo sportster front pulley and a one inch 60 tooth wheel pulley.
The European belt is like five teeth shorter, should help.

[tomsoftail]

I’m doing the exact same thing. The worst part is the cost. Covid killed swapmeets where a 5 speed softail tranny was $200. I’m sourcing on CL (dwindling returns), chopperswapper and FB marketplace.

I bought the plate from Vulcan here in NH.

[tomsoftail]

Irish Rich has done several of these. He doesn’t like the way I am doing mine, he commented on an IG post. He doesn’t like losing the rear peg factory mounts. I flipped the swingarm mounts. This lowers the bike but I have some V-Rod shocks which are taller in my stash.



I decided to go for it being egged on from Farmall. I’ve read him many, many times explaining the superiority of the 1990s softie setups versus the hitachi crap. He didn’t fail to mention it in this thread.

My bike is a FrankenChop or Bitsa Shovel so no value lost and I got to learn a few things along the way.