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6 Speed Transmission revisited

46K views 153 replies 61 participants last post by  streetrodracer 
#1 ·
Ok, I know there are alot of posts on 6 speed transmissions for the Vrod, but I have a question for you more knowledgeable types. I did a google on 6 speed transmission for vrod and it took me to jpcycles.com to a generic right side 6 speed transmission. Just wondering if this would work on a 2011 Nightrod Special? Would be nice to know before I spend close to $1k.
 
#2 ·
Nope. HD Aircooled types have a separate housing for the tranny and it can be changed out to whatever you want/afford.

Vrod tranny is integrated into the engine case, so you're stuck with 5.
 
#6 ·
Yes they did, but this gear is designed to facilitate racing, the stock 2nd gear has more narrow teeth in a helical cut which have been known to break under racing conditions.

VH, makes two versions of 2nd gear one which complies the Destroyer setup and is an acceptable substitute to remain in SPEC compliance with VRD class racing rules. The gear on the far right is the new VH 2nd gear.



The other, also a straight cut gear is designed for street bikes that might be under greater stress due to BiG bore, Nitrous or Turbo applications that are being raced.

The ratio changes on these gears are negligible.

I'm with the other guys who suggest changing your final drive ratio to get the high gear engine RPM's down, but don't compare the RPMs to an EVO or TC, the Revolution engine is much happier at a higher number, get acclimated to it.
 
#7 ·
I'm still waiting to acquire pieces/parts so I can get with a gear vendor to investigate different gearing. I'm not really willing to pull the working engine out to do this....

Changing either pulley only changes final drive, I want my cake and eat it too.... lower 1st gear like running a 26t pulley, and then 5th to be like when running a 30t. :D
 
#10 ·
Thats the answer I've been looking for for a good while! I asked this very same question about a year or so ago--and asked if there were any physical limitations inside the tranny case to prevent a taller 5th from being installed.... money considerations for the gear itself aside... nobody ever gave me a straight answer. What part causes the interference? Is it just a very tight tolerance to the case?
 
#9 ·
Make a case with room? Would a higher ratio 5th gear seriously just not fit? Sorry, I haven't been in a tranny yet myself.


Sent from my iPhone using MO Free
 
#12 ·
The 6th gear is as easy to build than a 3rd cylinder.:D
 
#13 ·
Check out the photo above. I circled the edge of fifth in the attachment. This the gear that needs to grow and its opposing gear to shrink. If I am not mistaken, 5th is part of the shaft meaning you would need to manufacture the whole output shaft...I could be wrong.

Anyway, in my attachment I circled where the gear would hit the case. Looks as if there is room. but you can't see down around the bottom. It's very close.
 

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#15 ·
I think our bikes with 5 gears is perfect. I used to wish for a 6th gear out on the highway, but what would it really do for us? Maybe drop the revs by 300-400 rpms & 75mph? It's not worth it. In 5th gear @ 50 mph I'm @ 3000 rpm. (In these bikes thats on the verge of lugging the motor (bad) If you had a 6th gear & shifted into it you'd be lugging the motor @ say 2500-2600rpm. That would do damage to the motor over time. I hope HD never adds a 6th gear.
 
#16 ·
As many times as this has been discussed I am sure if it could be done it would have been done. Major bucks to be made but who is going to spend all the R& D $ to build something like this? Very few people with little return on investment. Just mt 2 cents FWIW


Sent from my Motorcycle iPhone app
 
#20 ·
Remember the documentary concerning the creation of the VROD, a lot of time was invested in aesthetics & engineering, trying to get 4.99 lbs in a 5.00 lb sack.

I do not think they were as concerned with us desiring to retrofit & modify the core components like the tranny and other items :angeldev:
 
#23 ·
The current 5th gear ratio is 25 teeth on the input gear and 26 teeth on the output gear which is a 1:1.04 gear ratio. If you switch those gears around and put a 26 tooth input gear and a 25 tooth output gear the ratio goes to 1:.96 which is a change of 7.7% and where you were normally running at 5000 rpm it would reduce the rpms to 4615 a drop of 385 rpm. There is most definately room in there to add one tooth to the input gear. Cost is a whole other story on this one though.

Mike
 
#25 ·
Don't know. The output 5th gear is machined with the shift fork boss as part of the gear while the input side is machined with the holes for the shift dogs to engage it and the shafts look to be different sizes but hard to tell with all the gears on there. One thing for sure, it would not be a direct swap and would require some machining and at least one completely new gear. I have a complete transmission gear set that I have kept for a spare sitting on the shelf.

Mike
 
#26 ·
I have a gear vendor already on board..... i just need parts to start the work
 
#30 ·
Keep in mind that you'll need to think about what that change will do to the 4th-5th gear transition. It'll make that a taller change and might make it less drivable at lower speeds.
 
#32 ·
4th to 5th is only 10% now, so any additional spread would be nice.

I'm waiting to hear back how long they'll need a case and gears...
 
#35 ·
I looked at it about a year ago. Only thing I could come up with what to create a two speed planetary in the rear hub. Never could find the metalurgy to deal with the power and torque.

If you find a solution I would be in pending pricing. I am not looking for cheap, just not looking for real expensive so a new bike is cheaper.

I will say this may create a problem with long cruising, as this engine is really designed to start breathng correctly at about 4300 RPM. At this RPM is is as close to zero dead volume on the exchange as it will ever get. It stays that way clear to 9600 RPM, but about 4300 is the first time you see the engine exhaust its lungs completely and pull in all the new fresh O2 to mix with the fuel.

Prolong operation at RPMs less than the Zero Dead Volume Exhange range may start to create valve seat burn and piston problems.
 
#51 ·
How do you know that this engine is not breathing before 4300 and that this may create valve seat problems. What are you basing this on. Can you point me to something about this. Is it your opinion or fact. Not trying to start anything, just want to know.
 
#36 ·
Have discussed a 6 Speed with someone who could build it, but hasn't. Because you have to tear down the motor to get to the trans, they don't think the market is big enough to justify the R&D money. If enough of you seem willing to buy one, I might be able to put things together to make it happen. Tried to tell them that V-Rod owners are crazy, and a lot of us tear the motors down anyway, for other reasons, like it's not fast enough already, lol. I don't really even care about making money off it, although it would be nice. I just want a 6 or 7 speed trans that bad. I have over 60,000 miles on my B, and I love it. It would be great to not turn 4000-5000 rpm on the freeway though. Most of the folks I have talked to would buy one. I need enough pos feedback to convince an investor, or group of them, that these will sell. If I can do that, then we can pony up the R&D money, and get the trans people to build them. They told me it can be done, they just didn't think they could justify it financially. Talk to me, folks... Would you buy one, if it was available?
 
#42 ·
For me its to have the best of both worlds, low first gear, and a higher top end gear. A 10% split from 4th to 5th on these bikes is stupid IMHO.
 
#43 ·
I would be interested if narrowed gears will be enough strong and the price <$2k.
 
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