I may be getting in over my head but if I can get a few more thousand miles out of this thing, I think I'll wait until the snow flies and try to tackle this myself...at least the disassembly/reassembly...and hopefully learn something in the process.

I think I will change out either the motor sprocket or the transmission sprocket at the same time. 1997Bagger...what are the advantages or disadvantages of changing the transmission sprocket over the motor sprocket (if there are any at all???)? Thanks!

 

No difference whether you change the motor sprocket or the trans sprocket. Each tooth you drop will give you 3% more torque but will also add 3% more rpm's. Just so you know HDforum members get a 10% discount from us.

 

6 speeds work great in an evo if you have the right overall gear ratio. Look at it this way the bigger Twinkies went to 6 speeds but they also changed overall gear ratio to a 3.15:1 I wouldn't even consider a 6 speed in an evo until I had a 3.31:1 ratio, great giddy up and go and good cruising. However I do have a built motor well..

 

What he said, trans sprocket will change your speedometer inaccuracy some, primary will affect load put on the starter during cranking, neither a big issue.

 

That's good to know! I appreciate the info on the % for torque and rpms. That is very helpful. If I end up going back with a 6 speed, it will be a Baker...no question about it. That being said, I wouldn't know which one to choose. In it's current configuration, my bike is only putting out 80 ft lbs of torque although I hope to improve that in time. I don't think I want to drop back down to a 5 speed when it comes time to do my rebuild b/c I spend a LOT of time riding over 80 mph. I ride the bike about as hard as you can push her. That being said, it would be nice to get a little more (as in more torque) out of 2nd-4th than she has now...but that might end up being something that can be corrected with a little more HP. I wish there was a way to get 1st a little lower but with more top end. If I went back with the same Ultima tranny, I'd definitely be changing my motor sprocket (although I don't know how much that would affect 1st, which is my only real concern with that). Do you have any recommendations??? DD6 or the OD6.?.? ...or do you offer a different set up that will give me more torque in the mid-gears???

Thanks again. One thing I have to keep in mind is the fact that when it comes time to do an engine rebuild, I'm going to be stepping way up in HP...I kind of need a tranny that will work now but will also be suitable for a bigger motor. Thanks again!

 

Both transmissions will accomplish the same thing, but the DD6 will be smoother, quieter and more efficient. With the DD6 we don't overdrive the transmission we overdrive the primary. We give you a 28 tooth compensating sprocket and longer chain. So at 70mph in 6th gear you will drop about 500 rpm's but the transmission is only spinning the 1:1 6th gear pair. The only drag on the system when in 6th is the bearing itself so when in 6th it is 99% efficient.

All that being said the DD6 does have is limitations. The dog tooth undercut is only 1 degree where with the OD6 has 4 degree undercut. This means a torque limit. I don't know how big you plan on going with your motor build but here is a general rule of thumb to follow. Below 130 foot pounds of torque DD6 above OD6.

If you want a little more pull on the highway do this:

OD6 use with a 31 tooth transmission pulley
DD6 use with a 27 tooth comp sprocket

Hope it's clear as mud now.

 

Sure is! I appreciate the feedback...and will probably go with the DD6 when the time comes. Thanks again!

 

Thanks for the info Mark. A Baker is in my near future for my '92 FXR. Still figuring out the OD vs DD set. My shift pawl spring broke and when I saw what I had to do to replace it, I though I might as well pull the trigger on the 6 speed I was planning on doing someday...

Feeling like my bike must have a non-stock sprocket or pulley as I'm around 3900rpm at 80mph....seems high from what I'm seeing others posting. I have a stage 1 and mild cam in an otherwise stock (far as I know) configuration. Am I down a tooth or two? I'd count, but I've never opened up a bike before like that before. Does that make the OD6 a viable candidate or am I still in DD6 land? Not looking to hot rod...need more 80+ cruise in 6th without sacrificing 1 - 5 ratios.