Editor’s Note: What you will read is the truth about the writer’s knowledge of big twin H-D transmissions. So this tech is a work in progress. As we glean more notes and information we’ll add it. If you have a question don’t hesitate. We’ll find the info and install it into this tech until this puppy tells us everything we need about tranny fitment.–Bandit
A week before Daytona Bike Week, I received the following e-mail from Bandit:
“Hey, I need an article. It’ll be easy, give me a call.”
Of course, I called him immediately anticipating the need for a fictional story entailing girls and bikes and booze. I love writing within the biker genre because anything goes, and there are no rules to break. That’s the beauty of Bikernet, you can write anything, as long as it’s entertaining. So I call the big guy, and he tells me he wants an article about transmission selection for custom bikes. You know; what fits what, and how to decide among the thousands of combinations which transmission works best for each style of riding, frame, tranny plate and wide tire application. I assured him I thought it would be a very informative article. I also agreed it would be fairly easy. Once I hung up the phone, the walls of reality came crashing down on me.
I did what any red-blooded American would do in this situation. I said fuck it all and rode to Daytona for bike week.
After a week of drinking beer, watching half-naked women, and generally acting like a fool, I was ready to tackle article. Looking back, I was around all the most influential bike builders nationwide, for a whole week, and didn’t get shit. If I was more than half retarded, I would have gleaned as much information from them as humanly possible. I had access to the newest of the new and the best of the best. While I did ask lots of questions, for the life of me, I cannot remember what anyone said. I returned home empty handed and more than half-baked. Knowing I was up shit’s creek without a paddle, I decided to see the only man who could help in a situation of such dire magnitude.
Kent Weeks, a.k.a. The Lucky Devil, has a fabrication shop in Houston, Texas. The Devil builds some of the sickest and cleanest bikes to ever grace the pages of biker rags such as, BIKER, STREET CHOPPER, and HOT BIKE. I figured he would be able to give me some answers. I made the trip to his shop aboard my Springer Classic; one saddlebag stuffed with notepad, camera, and pens, the other stuffed with pictures of my family to use as sympathy in case he was in a bad mood. You have to be prepared when visiting the Devil himself.
Lucky Devil Metal Works is stuffed into a half industrial-half residential area of North Houston. Just bordering Tomball, Cypress, and Houston, this shop is tucked away inside the epicenter of an evil triumvirate of money, power, and greed. The Devil sits right at home.
As I pulled into the parking lot, Rigid Frame Richard was escorting a lovely model back to her car. He had just finished a photo shoot for the Girls of Bikernet and was tiredly trying to talk the lady into a more despicable encounter. The model was smoking hot, and looked relieved to escape the terrors hidden within the Devil’s doldrums. Hell, Richard looked like a gnome servant ready to slice your throat at the slightest hint, so she probably was twice as scared with the Devil’s evil grin sneering behind Richard’s lens every minute.
Let’s not forget the evil temptress, Holly. She was pacing back and forth on seven inch stilettos cracking her whip every few minutes. Hank, the pit bull from Hell, was attached to Holly by some type of invisible force causing him to never be more than two feet away from her. Any sudden movement and he would transform into a deranged beast clawing and snarling uncontrollably, only to be subdued by a single look from Holly.
The model pulled away so fast that her tires broke free causing the familiar sound of rubber melting against the hot asphalt. I didn’t expect to see her back again. I also noticed the temperature seemed to be getting hotter the closer I got to the devil’s office. Richard snarled some insults at me as he left and Kent invited me in with a sneer. Holly smiled as usual, but I could only guess the evil plots running through her mind. I probably resemble a fresh sacrifice ready for the altar of Hell. The Devil only knows what evil thoughts she contemplated with her evil grin.
I asked the Devil about the transmission query as quickly as I could, hoping he would give me a quick lesson in the art of transmission selection, and I could split. Instead, I got choked by Holly’s whip while the devil stood inches from my face seething chants of madness and witchcraft.
In a moment of sheer panic, I pulled Holly’s whip with my left arm and spun her towards the Devil, causing her to land squarely on his lap while setting his ass on the desk. It was a picture perfect move executed Chuck Norris-style. Too bad there were no movie cameras around to capture it. I knew they would probably end my life with some form of satanic torture, but I wasn’t going down without a fight! Both smiling as if everything had happened according to plan, Holly lit a cigarette and slithered into the next room while Devil perched his evil hooves on the desk and started to ramble about the art of bike-building, Devil-style.
“I don’t worry about whether they are made to fit or not, I just make it all work. Any builder worth a damn does the same thing. If you are building bikes for a living, that’s how you do it. You just make it work. If something doesn’t fit, you cut and weld until it does. That’s all there is too it. Now get your ass out of here before I send Hank out for his afternoon snack!”
I backed out the front door, never taking my eyes off the Evil One. As I rounded the corner and began to turn around. walking toward the bike, Kent met me face to face. His nose was touching my nose and I could see the demons within his soul behind the most evil yellow, piss-colored eyes any man has laid eyes upon.
“Tell Bandit we will meet again soon,” he snarled. “He may have won the last time, but his payment is almost due. I will be watching.” With that he disappeared like dust as I stood wondering if I needed repent for my sins before the demons dragged me to hell’s kitchen. My mouth was dry, my throat hurt, and my vision was crossed. I am not sure what happened after that, but the next recollection I have is riding down the solid white stripe on Sam Houston Toll Way so I wouldn’t have to pay a toll.
It was an overall odd day. Once I pulled into the garage at home, I went to bed a shivering mess. Flu-like symptoms had engulfed my body, and I just wanted to escape to my bed and forget the horrors I had just witnessed. I was tormented all night with nightmares about Devil, Bandit, and the evil Holly torturing my body while driving me insane with incessant hissing and squealing. I awoke just wanting to be done with this devil article and get the demons out of my mind. As I researched the net and compiled all the information I could find, I was tormented with the same evil nightmares every night. I was being haunted by the Devil and his merry little crew of minions until I finished this my evil task. We better get to it quick.
The number of ground-up bikes in the marketplace today makes the idea of building a custom from the ground up much more appealing. We’re going to try to take some of the confusion out of the transmission selection for your build, or even for replacement or upgrade.
Today you have quality transmission manufacturer’s producing kick ass parts ready to rock….with the proper application. You see, when Harley introduced the Softail in the mid ‘80’s, it also created the need for a different tranny case than was necessary for the FXR and later DYNA line. As the ‘90s came to a close, 200 rear tires were more and more popular, causing the need for custom frames, swingarms, or serious modification to both. Today we have monster 300 tires, Right Side Drive Drop Starter style transmissions, Left Side drive with offset, and so on and so forth. Truthfully, it’s enough nonsense to drive a man to jerking off and ripping the hair from his head. Let’s see if we can simplify things a bit and also describe several manufacturers we work with.
Seriously, the single most important step is planning and education. You have to research the shit out of these products before you bolt something to your bike, right? My bike is my only transportation right now, so I need her to run ALL THE TIME! I can’t tear her down over a weekend and find out halfway into the process that I don’t have a tranny that fits my motor, or vice versa. So here’s my best shot.
The first thing I noticed is many of the manufacturer’s offer tranny styles for four or five speed frames. Even West Coast Choppers CFL frame is designed with a standard 5-speed tranny plate. 5&6 speeds use the same case and same mounting as stock Harley’s. Four-speed mountings and stud placement is different, thereby necessitating the need for a special mounting plate. Basically, you have to know what the fuck you want before you order the parts.
As I researched the web for transmission applications, I noticed that everyone offers Softail style tranny’s for “up to ‘99”. I wasn’t sure why this was, so I made a call to my man Jaz at Roadmax (R-Max). I figured he would be able to explain the concept behind it for me.
I would later find out that Harley held a design patent that restricted people from manufacturing transmissions that would bolt directly to their Twin Cam motor. Instead, you would just order the 6-speed conversion and slip it right into the stock case. This all sounded simple enough, but what about the guy building a ground up custom using a 110 in Revtech motor?
Hey, like my Pop always told me,” Keep it simple stupid ass.” Well, he said something close to that. Check below for the chart listing what each manufacturer offers and what you can mate it with. I will do my best to give you a better understanding of what is available now, but I can’t promise miracles. Get a drink, sit back, and try to dig your way through another one of my “Terrible Texas Techs”.
There are several manufacturers of replacement transmissions that are worth a damn. You can choose from Baker Drivetrain, Roadmax, Rev Tech, and JIMS. While there are others out there, we will concentrate on these four for this article. Here’s what we have to work with.
Road Max-
Here’s an excerpt I stole from their website:
Roadmax transmissions are engineered and tested for maximum performance. Prepare to shift effortlessly, with precision-ground close-ratio gears and our proprietary shifter drum design. Roadmax performance transmissions are built in our modern DAEPOONG factory under the strictest controls in clean assembly rooms. With a focus and commitment to quality and value in the motorcycle market since 1998, Roadmax continues to introduce new products for the American v-twin motorcycle. Many American builders recognize Roadmax as the best performance value in the market today. Not all transmissions are created equal; insist on Roadmax.
Sounds pretty good to me, maybe their writer should’ve been commissioned for this article. R-Max offers all the tranny combinations for whatever builds you are deciding to try. There are some uncommon combinations they cannot do, like an FLT touring model with the oil bag under. Jaz explained that the volume of requests for this combination just doesn’t exist, making it very costly to the manufacturer with little reward. Basically, they would never sell enough of them to pay for the tooling. Who’s building that kind of crazy shit, anyways?
R-Max has several different combinations and setups which they sell with a four speed or five speed plates. You, the builder, just have to tell them what you want when you order your parts. Say you don’t know what kind of frame you have, maybe from a swap meet or a buried barn treasure?
R-MAX USA OEM style Left Side Drive Transmissions feature a stock style case for original replacement or custom applications. The cases are cast and machined with access for electronic speedometer sending units. Internals consist of, SAE8620H precision cut full-width gears that are back cut and diamond media blasted for a very smooth and quiet operation. Shift forks are made from ALBC3 alloy because of its tolerance of heat treatments, and this gives R-max shift forks superior strength, when used with their proprietary shift drum will give you smooth positive shifting and longer reliability.
Our OEM style 5 speed transmissions utilize a stock gear ratio
6 speed transmissions utilize a 2.94:1 2nd gear, 1.60:1 3rd gear, 1.23:1 4th gear, 1.00:1 5th gear, and .86:1 overdrive gear ratio for 6th gear.
Available in Natural, Black, and Polished finishes
All models come standard with chrome plated top covers, side covers, shift lever and hardware.
R-MAX USA transmissions are backed by a full 3-year unlimited mileage limited warranty.
1987 – 1999 Softail Models
1990 – 1998 Dyna Models
1991 and up FXR Models
R-MAX USA Right Side Drive Transmissions were developed to accommodate wide tires on custom motorcycle applications. Right side drive transmissions reduce the need for offsetting the transmission when installing a 230 series plus tire, therefore greatly improving balance characteristics and handling of the motorcycle. The cases are cast and machined with access for electronic speedometer sending units. Internals consist of SAE8620H precision cut full width gears with increased dog area, are back cut and diamond media blasted for a very smooth and quiet operation. R-Max shift forks are made from ALBC3 alloy because of its tolerance of heat treatments, and this gives their shift forks superior strength, when used with their proprietary shift drum will give you smooth positive shifting and longer reliability. Each unit is fully assembled to stringent specifications complete with pushrod installed and a 32-tooth phosphate coated (for corrosion resistance) pulley. Right Side Drive Transmissions are available in mechanical or hydraulic. The Hydraulic cover uses a 10mm banjo, and 11/16 bore slave cylinder.
* Roadmax recommends a maximum tire size of 250mm *(Right side drive tranny photo)Bullet information around the pictures:•
Available in mechanical or hydraulic OEM style 5 speed transmissions utilize a stock gear ratio•
6 speed transmissions utilize a 2.94:1 2nd gear, 1.60:1 3rd gear, 1.23:1 4th gear, 1.00:1 5th gear, and .86:1 overdrive gear ratio for 6th gear.•
Available in Natural, Black, and Polished finishes•
All models come standard with chrome plated top covers, side covers, shift lever and hardware. •
R-MAX USA transmissions are backed by a full 3-year unlimited mileage limited warranty.•
1987 – 1999 Softail Style Mounting•
1990 – 1998 Dyna Style Mounting
2000 Up Twin Cam 6-Speed Conversion Kit
The R-MAX USA 6 speed twin cam conversion kits are an economical way to get that 6 speed transmission you want for your ride and keep that stock look. Designed to fit in stock twin cam cases with no modification, this kit features a 2.94:1 1st gear ratio and a .86:1 ratio over-drive 6th gear, the same as in their complete transmission assemblies. Their kit comes complete with silicone bronze shift forks and proprietary shift drum for smooth and positive shifts every time. This complete kit is the ideal upgrade for big bore motors and long distance riders alike.
032-0016 Speed Conversion Kit for Softails
032-0026 Speed Conversion Kit for Touring
You see, they offer several combinations depending upon which build you plan to embark on. When looking at their Softail and Dyna line-up, you will notice they list the years up to 1999. That’s because of the Twin Cam motor available after 2000. For these applications, R-Max offers a 6-speed conversion kit which will fit directly into the stock 5 speed cases with no modification to the cases or frame.
Just a note from all of these manufacturer’s, if you go larger than a 230, you would be better off using a Right Side Drive (RSD) transmission. Some say up to a 250 is ok, but I say horseshit! The handling is greatly compromised once the rear tire size increases due to engine offset. Because these bikes were designed to have the Drivetrain line up in a straight line with the engine, once you begin using an offset, the bike will handle like a bear. How many bikes have you seen at the rallies with a wear pattern on only the side 1/3 of the tire? That is because of the horrible lean you have to employ to keep the bike straight.
For the record, I think a 200 would be the largest tire to use with a stock formatted left side drivetrain. Overall, R-max offers every combination you could look for in a custom build. The main thing is to research what you are building and if you have questions, give Jaz a call at 1-866-R-MAXUSA. He will be glad to hear from you and let him know you heard about him on Bikernet. You can also hear Jaz talk about the innovations R-Max has in store for the future on Bikernet Radio here on the website.
JIMS USA has a very, very large selection of transmission parts for every application imaginable. Like BAKER, these guys have been at this for a very long time and have products built for very early Harley’s all the way up to 2006 models. You want a 6-speed in a 4-speed frame? No problem? You want a 5- speed converted to a 6-speed? Just give them a call. Do you want to build a Shovelhead style motor with a 5-speed kicker? JIMS can help you out. They offer one of the largest ranges of applications on the entire web. Go to www.JIMSUSA.com! They have lots of new products to help top builders such as Russell Mitchell, to the little guy building a bike in his garage for fun. Like R-Max, they have products built especially for certain builds. I think the most impressive area of the JIMS line has to be their conversion kits for the big inch motors so popular today. Here’s a few of their products:
You want strong? JIMS has strong! JIMS new Fat 5 Overdrive is simply the strongest, toughest gearbox made…Period. JIMS took advantage of its new, more compact shifter technology to increase the width and strength of every gear. The width increase varies from 18% to 53%, depending on the loads each gear set must carry. Big power is more popular than ever. Large engines like the JIMS 120 deliver double the stock power and torque. When such power is linked to the ground through high torque clutches and big sticky tires, the peak loads on transmission gears rise far above what stock transmission gears were designed to endure.
Available as a complete transmission or as a superkit, isn't it time you check one out?
They also offer such products as RSD transmissions. As a matter of fact, here’s what they say about it:
“Right Hand Drive done the right way! JIMS Right Side Drive 6-speed transmission has the most innovative design, strength, quality and durability in the industry. It looks as good as it works too! A drop in for most major manufacturers’ frames, the JIMS Right Side Drive is sure to improve your bikes performance as well as its looks.”
Well, it certainly sounds like they know what they’re talking about. Just listing these two separate manufacturer’s products opens the doors for a ton of options available to builders everywhere. Shit, it seems possible to make any combination necessary for any type bike you want if you do the research. We ain’t done yet! Hang on.
JIMS has all the transmission parts you need but be advised. When shopping for one of their transmissions, they recommend installation by a qualified mechanic only. Although they offer drop in transmissions for 2000 and later Big Twin’s to include the Softail line, their 5 & 6-speed Overdrive transmissions for a 4- speed frame are for custom applications that will require machine work. Check their catalog and order ALL the parts necessary for your particular build.
RevTech from Custom Chrome Inc. offers a wide range of parts for your build needs. Here is a description of their 5- speed transmissions.
RevTech Transmissions Feature:
Standard 2.94:1 close-ratio first gears
3.24:1 stock-ratio first gears available in transmissions for Softail 1991 thru 1998 Dyna Glide and 1993 thru 1998 FLT, FLHT, FLHS and Road King models
Assemblies and components are interchangeable with OEM transmission
Cases with black-wrinkle, powder coated gloss black or polished finishes
Forged Aluminum trapdoors for increased strength and durability
Extra material in high-stress areas of the cases
Access hole for electronic speedometer sensor (except on the 5-speed in a 4-apeed case transmission)
Back-cut gear dogs for smoother shifting and accurate engagement
8620H chrome moly steel used for all gears
Gear faces honed and ground and computer-fitted for minimum vibration
Hard-chromed main and countershafts
32-tooth front pulley included (23-tooth chain sprocket on the 5-speed in a 4-speed case transmission)
Lower case studs already installed
Includes a quart of RevTech transmission lube
They also offer 6-speed transmissions with a 5-year 50,000 mile Limited Warranty. Take note of the “Limited” and read everything when the package arrives. That’s not all- here’s some more neat stuff-
RevTech® 4-Speed Transmissions for Tin Primary Models
Got a '36 Knuckle? Maybe a '48 Pan? Here's the answer. RevTech® complete transmissions for 1936 thru 1964 Big Twins have all the great features of our 4-speed transmissions above. The biggest difference is that they altered the casting molds to remove the primary mounting ears used with aluminum primaries. The result is a transmission that bolts into virtually any kickstart frame – rigid or swingarm. And it's perfect for building a 'retro' custom bike that uses tin primary, chain final drive and kick starter. All Rev-Tech Transmissions come with Rev-Tech's five year or 50,000 mile limited warranty.
Installation Notes:
Transmissions should not be used with final belt drives.Kicker arm may interfere with some exhausts. Late-style 'swing-out' kick arm provides sufficient clearance.
RevTech® Complete Close-Ratio 4-Speed Transmissions
Complete 4-speed transmissions are designed around RevTech® cases and highly-regarded RevTech® close-ratio gear sets. Bolt it in and just add oil (and even that's included) the 2.44:1 close-ratio first gear model has a 1.35:1 close-ratio third gear and is ideal for FX models. With 2.60:1 close-ratio first gear and 1.35:1 close-ratio third gear it is perfect for FL models. Both sets provide a more usable first gear and eliminate second gear 'clunk' with better pull in third gear. RevTech® gear faces are honed and finish ground for maximum strength and precise engagement. Shifter clutches and shifter dog faces are widened .020″ for better durability. RevTech® 4-speed cases are machined from '356' aluminum alloy castings and heat-treated to 'T6'. They are finished with a chrome heavy-duty kicker kit and chrome ratchet top. Included is a set of 1:1 ratio speedometer drive gears, a chrome clutch release lever with chrome cover and a 23-tooth transmission sprocket. Transmissions are shimmed and tested and include studs for installation on the mounting plate and the inner primary. They fit most stock and custom 4-speed Big Twin frames using running gear from 1970 thru early-1984 (see notes), and may use either early (1936-64) or late (1965-84) transmission mounting plates. Natural Aluminum Case. All Rev-Tech Transmissions come with Rev-Tech's five year or 50,000 mile limited warranty.
Installation Notes:
These transmissions should not be used in models with final belt drives.Recessed screws on kicker require shimming the stock battery box mounts with the included spacer kit. Mid-shift FX models use included shims for mounting the brake pedal backing plate.Shift pattern is reversed when installed in mid-shift models.Kicker arm may interfere with some OEM exhausts.
Five-Speed in a Four Speed Case with Kicker
The ultimate transmission for the retro look. Get the classic look of a four speed kicker and the performance benefit of a smooth shifting 5-speed. This transmission is a bolt-in proposition for virtually any electric-start, four-speed Big Twin. It combines a heavy duty kicker assembly with the early five-speed end cover and clutch actuation lever with five-speed shifting mechanism, gears and top cover in a four-speed-sized case. What could be better than a classic Shovelhead that shifts better than the newest showroom models? All Rev-Tech Transmissions come with Rev-Tech's five year or 50,000 mile limited warranty.
Notes: Does not fit Softaill frames. Comes with 23-tooth chain sprocket and is designed for chain final drive only. No provision is made for electronic speedometer sensor.
Five-Speed in a Four-Speed Case
Here's a transmission that's a bolt-in proposition for virtually any electric-start, four speed Big Twin. It combines the early five speed end cover and clutch actuation lever with five speed shifting mechanism, gears and top cover in a four speed sized case. What could be better than a classic Shovelhead that shifts better than the newest showroom models? All Rev-Tech Transmissions come with Rev-Tech's five year or 50,000 mile limited warranty.
Notes: Does not fit Softail* frames. Comes with 23-tooth chain sprocket and is designed for chain final drive only. No provision is made for kickstart mechanism or electronic speedometer sensor.
Transmissions for FXR
Like our other 5-speed versions, these assemblies are perfect replacements for a custom-built or stock FXR in need of a new transmission. The cases are extra-beefy to correct weaknesses in the factory design, and the gears and shafts are stronger and shift better. You simply can't find a better transmission. For all FXR models from 1990 thru 1994.
Transmissions for Dyna Glide® Models
Like our other 5-speed versions, these assemblies are perfect replacements for a custom or stock Dyna Glide® in need of a new transmission. The cases are extra-beefy to correct weaknesses in the factory design, and the gears and shafts are stronger and shift better. For all Dyna Glide® models from 1991 to 1998. Available in stock and close ratio 2.94 first gear models with black or polished cases. All Rev-Tech Transmissions come with Rev-Tech's five year or 50,000 mile limited warranty.
Transmissions for Dresser Models
Now the legendary high quality RevTech® 5-speed transmissions are available for dressers. Engineered and manufactured at a state-of-the-art facility to rigid standards and perfectly suited for use as replacements for Original Equipment units or for special construction projects. For all Road King®, FLT, FLHT and FLHS models 1993 to 1998.
Transmissions for Softail® Models
Now you can solve the most difficult part of building a custom-framed scooter with a brand new RevTech® 5-speed transmission. Engineered and manufactured at a state-of- the-art facility to rigid standards and perfectly suited for use as replacements for Original Equipment units or for special construction projects. For all Softail models from 1990 to 1999.
Stock or Close-Ratio 5-Speed Transmissions
When it's time to put a bulletproof 5-speed transmission in a Big Twin, there's nothing available that can touch a RevTech® transmission. Gear sets are precision-engineered to provide the strength to handle anything you can throw at them, and are available with stock 3.24:1 or close-ratio 2.94:1 first gears; the stock-ratio provides smoother, easier starts on heavy bikes or gives maximum initial acceleration on performance bikes. On lighter Big Twins, the close-ratio sets provide more first gear speed and fewer gaps between first and second.
BAKER DRIVE TRAINS
Okay, Okay….I’m starting to get a little bit confused and overwhelmed by all this. Let’s look at Baker Drivetrain. I’ll post a few words about their trannies and maybe I can tie all this together with a helpful table that might tie it all up into one “cheat sheet” type of page. If I do a decent enough job, let Bandit know so I can kick this moniker of being a bad tech writer.
Baker Drivetrain…who doesn’t know who they are? These guys are the innovator of all the aftermarket transmission specialists available today. Several American manufacturers use their transmissions exclusively, such as Big Dog and builders such as Rick Fairless. Baker has the best advertising scheme of all the manufacturers and seems to stay one step ahead of the trends at all times. Who can say 6-speed without thinking of the inventor himself, Bert Baker! The man is a genius and his company is producing the very best available today. All you have to do is log on to his website, www.bakerdrivetrain.com, and you will get a step by step instruction on what to do and what product to order.
Baker was the first to create and market a new set of gears for your OE transmission to convert it from a 5 speed to a six speed.
XL fans will love the 6-speed kit that installs directly into the stock Sportster up to 2003.
Baker’s specialty flowed from just 6-speed kits to overall kick ass 6 speed transmissions for all the different Harley models, except for the V-Rod. Harley guys are extremely faithful to Harley products and their motors are usually rebuilt over and over again. With the installation of a Baker transmission, you can add many more years to the life of your bike.
Look, I can go on and on talking about what fits what, but you are the one who has to do all the research and decide what tranny will fit your needs. There isn’t an exact science to the whole thing; you just have to plan before you start buying parts assuming they will fit. An experienced bike builder makes it work, but for the average Joe, proper planning will go far towards having a safer and easier build. Check out the following tables and see which application fits your needs better. Keep it together, and take care!
