3.37 gearing

[jazzman713]

i have a 06 road king 88" getting ready to put in the cam conversion kit with andrews 21n cams i would like to know if it would be worth the 400 to do this or not this is a bike i only take on trips 100 miles or more at a time solo rider zippers air set up and duals thanks

[HotRock]

It depends on you and your riding preferences.   If you like snappy performance, pass-a-truck quick, great pulling up a mountain, and don't mind a few more revs in all the gears, then by all means go for it.   However if you are a lazy slow goer and don't ever get in any hurry, like the lower engine rpm then stay with the stock gears.   I ride with three old guys that don't give a sh## about performance and never turn over 4000 rpm without shifting to the next gear and love bragging about fuel mileage.

[Sonny S.]

All very good advise   

I removed the 3:37 from my 01 Ultra. I on the other hand tour a lot and often do 800-1100 miles in a day.
My future plans are to put the 3:37 back and install a 6spd. Santa forgot the 6spd so it'll have to wait a while   

[jazzman713]

what is it that you like about it i have never changed any gearing before. i to like to take trips and just want the bike to get when i need it to i dont have alot of money so im looking for whats the best bang for the buck.im thinking im going to stay with an 88 for some time

[Sonny S.]

3:37 really brings the bike to life...QUICK !
Down side is it makes ya feel like you need another gear at 80 mph because the rpm's are higher.

As suggested, do the cams and then decide.....you just might be surprized   

[Sonny S.]

lol... yeah this is my second with 3.37 also. First was a 2000 FLHTCUI. I put 32K miles on it the first year I had it and got very tired of the high rpm's on the highway   

[jazzman713]

how long should it take to put these gears on a bike.im hoping to be in the shop 1 time
-cams
-race tuner
-good tune
-thats why i have been asking.

[RK101]

Jazzman I think 05FLHTC in post #2 gave you some real good advice.
Sonny also gave you some great input  I put 32K miles on it the first year I had it and got very tired of the high rpm's on the highway   

   

[jazzman713]

thank you all i will stick with the cams. there is just so much on this board that my head just spins at times

[truck]

thank you all i will stick with the cams. there is just so much on this board that my head just spins at times

                                                                                     

[jazzman713]

is there a gearing like this for a 1200 sportster

[Rusty Steel]

With a chain drive I can pick and choose my final ratio…

[ClassicRider2002]

-

"......i have a 06 road king 88" getting ready to put in the cam conversion kit with andrews 21n cams i would like to know if it would be worth the 400 to do this or not this is a bike i only take on trips 100 miles or more at a time solo rider zippers air set up and duals thanks......"


Jazzman713~~

At the end of the day of course it becomes your personal decision....and depending on how mechanically inclined you are and what your finances allow for.....you could indeed make the modification from 3.15 gearing to the 3.37 gearing and if you didn't like it go back to the 3.15 gearing and be out probably $100.00 inclusive of everything....as you could always resell the parts you acquired for the modification, you might be out depending upon mechanical skills 10 hours.....to put in and then if you decide to pull out.....

If the pie is 100% I would say that 80% love the modification to 3.37 gearing with the 20% that don't having approximately 15% of those coming from the softail frames and the 5% coming from the touring framed bikes......which means statistically speaking that an overwhelming majority that take the time to make the modifcation to their RK's is over 95%.

I for one believe that it's the best bang for the buck.....in terms of modifcations......but I would have this to add.....you should do this modification either before  or after your cam modification.....don't do the two together.....if you try to do them as a combo modification you really will have no idea what promoted your positive or negative response should there be a negative response....did you notice I merely said "negative" response....because there will probably be a strong positive response....and I am referring to the seat of the pants experience....

I have provided a LINK to an INDEX of THREADS which discuss this very topic.....I am sure you will find additional answers to all of your questions which will bring in many other opinions that may lead you to a quality decision.....

SIMPLY, CLICK, VIEW, & READ:

INDEX OF 3.37 FINAL GEARING DISCUSSIONS

Hopefully you will find all of the information helpful......

WOW Jazman....your allowing someone's "audible" tone to effect your decision process......lol now this is a new one....I wonder what all those bikes from 1999 - 2001 with MM EFI that came with 3.37 gearing have allowed the Owners to feel.....ahhhhhh their probably deaf and have no idea what's going on.....but I assure you it's not from the 150 rpms that are higher....[look at chart below] it's called wind damage on an open ear going down the open road slappin against those ear drums....   You just took what someone above has said for "audible" tones without even questioning what exhaust they are running......

Ok I run a 2002 RKC with a SuperTrapp 2-1 15 discs closed end cap....and wear a full face helmet and get reversion sounds of course because of the harmonics created with the "plastic" helmet.....so I wear ear plugs.....lol do you know guys that you can loose your hearing without a helmet quite easily just do to wind noise.....but we don't want to take this "THREAD" off track.....but please.....

Here are the gear ratios for 3.15 gearing vs 3.37 gearing:

4th Gear  3.15    3.37

50 mph    2550   2700
55 mph    2800   3000
60 mph    3050   3250
65 mph    3300   3500
70 mph    3550   3800
75 mph    3800   4100


5th gear  3.15    3.37

55 mph    2300   2450
60 mph    2500   2650
65 mph    2700   2900
70 mph    2900   3100
75 mph    3100   3300
80 mph    3300   3550
85 mph    3500   3750
90 mph    3700   4000
95 mph    3900   4200
100 mph  4100   4400
105 mph  4300   4650
110 mph  4550   4850
115 mph  4750   5100
120 mph  4950   5300

A couple of quotes that helped me decide where I wanted my TQ the strongest. Too many people quote max numbers, but what they don't tell you is what their TQ/HP curves actually look like getting them to their max numbers.
From July 2003 Hot Bikes: “Wayne “Speed” Hanson” Dyno Tuner w/over 35 years of tuning and racing experience. Since Harleys are big bikes, it’s far more important to tune them for maximum acceleration than it is for top-end power. A bike should accelerate as fast as it can from 2500-4500 rpms, with the best all around performance. With a heavy bike like a Harley, you really want to concentrate more on bottom-and mid range performance, since those are the areas of the power band that are the most important. Faster acceleration and a smoother power curve is always better than chasing a few extra ponies at the top.

Nigel Patrick (Patrick Racing) in American V-Twin Engine Hop-Up and Repair book ”says he tries to build engines that have really good response between 1500 and 3500 rpm because that's where most of us ride most of the time."

A good low-end torque motor always has the advantage from stoplight to stoplight.

A more conservative engine port design is likely to give better street performance. This type of port design will not give the big CFM numbers published by most companies that sell aftermarket heads like Branch, Mackie, Edelbrock, etc. The average person buying a set of heads or porting job makes the assumption that bigger is better.  If you ride a heavy bike like a Road King or always ride two up, IMHO more emphasis should be placed on having the engine produce good low end torque.  The majority of virtually any Harley motor's life is spent in the mid-portion of its rpm limits, between 2000 and 4000 rpm. At open-road cruising speeds, that range is more like 2500 to 3500 rpm. With current Big Twin gearing, in 5th gear at 60 mph the RPMS @ 3.15  will be 2500 while the 3.37 gearing at 60 mph will be 2650.  Moving up to 85 mph in 5th gear will present 3500 RPMS with 3.15 gearing while 3.37 gearing will in turn bump that up to 3750.  Even when accelerating to cruising speed, few of us use more than 4000 - 4500 rpm as a shift point. Very seldom, in day-to-day use, do our engines get near 5000 rpm, let alone 6000.

So.....for one I do not see the need for running a 6th gear either....but once again that is a entirely different discussion.....and also perhaps beyond the scope of this "THREAD"......


Regards,

"Classic"