Best Way To Lower Gear Ratio?
#71
10-05-2008 | 06:17 AM
Tourer
Joined: Mar 2007
Posts: 358
Likes: 0
From: Hammonton, NJ
Just had to add my $.02 worth on something. I've seen sooo many times in this thread people stating that if you lower your final gear ratio (slightly) you will lose fuel mileage. That is not always the case. If you get the engine running say 200 rpms faster but it is in an easier running area of the power band you can actually gain mileage. In other words, the engine may not be lugging as much at say 75mph with the slightly lower gears and therefore may not be working as hard....resulting in better mileage. If higher gearing always made for better mileage they all would be 1:1 and we know that would never work!
Although the statement is often true....it is not necessarily always true. Try the swap and let us know.
Although the statement is often true....it is not necessarily always true. Try the swap and let us know.
#72
10-20-2008 | 01:37 PM
Road Warrior
Joined: Jun 2007
Posts: 1,789
Likes: 4
From: Here
Here's my report on the 49T sprocket change on my '07 RK...
Installed last Wednesday and took off Friday afternoon from Tulsa to northwest Arkansas. From my house to my in-laws is 180 miles. 1/2 is highway (cruise set at 75 mph), the other 1/2 is 2 lane running in 5th at 60-ish. I did this exact same trip in August and got 39 mpg with the highway 2 lane mix (I was almost out of gas when I arrived). This trip I got just under 41mpg which included quite a bit of idle time in Springdale (stupid War Eagle weekend) that I didn't have in August.
Coming back home I stayed off the highways and took 2 lane roads exclusively. I never shifted into 6th and road around 60mph the whole way back. That tank came out to be just over 42 mpg. I never have gotten over 45 mpg with my average being around 40-41.
All that to say... Cruise still works on my '07, no decrease in fuel mileage (possible slight increase when cruising in 6th), and like Tom said, the bike just feels better as the engine doesn't seem to be working as hard.
Installed last Wednesday and took off Friday afternoon from Tulsa to northwest Arkansas. From my house to my in-laws is 180 miles. 1/2 is highway (cruise set at 75 mph), the other 1/2 is 2 lane running in 5th at 60-ish. I did this exact same trip in August and got 39 mpg with the highway 2 lane mix (I was almost out of gas when I arrived). This trip I got just under 41mpg which included quite a bit of idle time in Springdale (stupid War Eagle weekend) that I didn't have in August.
Coming back home I stayed off the highways and took 2 lane roads exclusively. I never shifted into 6th and road around 60mph the whole way back. That tank came out to be just over 42 mpg. I never have gotten over 45 mpg with my average being around 40-41.
All that to say... Cruise still works on my '07, no decrease in fuel mileage (possible slight increase when cruising in 6th), and like Tom said, the bike just feels better as the engine doesn't seem to be working as hard.
#73
10-20-2008 | 05:31 PM
Ultimate HDF Member
Joined: Oct 2006
Posts: 5,977
Likes: 78
From: Nevada
Here's my report on the 49T sprocket change on my '07 RK...
Installed last Wednesday and took off Friday afternoon from Tulsa to northwest Arkansas. From my house to my in-laws is 180 miles. 1/2 is highway (cruise set at 75 mph), the other 1/2 is 2 lane running in 5th at 60-ish. I did this exact same trip in August and got 39 mpg with the highway 2 lane mix (I was almost out of gas when I arrived). This trip I got just under 41mpg which included quite a bit of idle time in Springdale (stupid War Eagle weekend) that I didn't have in August.
Coming back home I stayed off the highways and took 2 lane roads exclusively. I never shifted into 6th and road around 60mph the whole way back. That tank came out to be just over 42 mpg. I never have gotten over 45 mpg with my average being around 40-41.
All that to say... Cruise still works on my '07, no decrease in fuel mileage (possible slight increase when cruising in 6th), and like Tom said, the bike just feels better as the engine doesn't seem to be working as hard.
Installed last Wednesday and took off Friday afternoon from Tulsa to northwest Arkansas. From my house to my in-laws is 180 miles. 1/2 is highway (cruise set at 75 mph), the other 1/2 is 2 lane running in 5th at 60-ish. I did this exact same trip in August and got 39 mpg with the highway 2 lane mix (I was almost out of gas when I arrived). This trip I got just under 41mpg which included quite a bit of idle time in Springdale (stupid War Eagle weekend) that I didn't have in August.
Coming back home I stayed off the highways and took 2 lane roads exclusively. I never shifted into 6th and road around 60mph the whole way back. That tank came out to be just over 42 mpg. I never have gotten over 45 mpg with my average being around 40-41.
All that to say... Cruise still works on my '07, no decrease in fuel mileage (possible slight increase when cruising in 6th), and like Tom said, the bike just feels better as the engine doesn't seem to be working as hard.
#74
10-21-2008 | 03:13 PM
Road Warrior
Joined: Aug 2006
Posts: 1,779
Likes: 70
I brought up this thread in search , my bike is an 07 SG, I did the EVO 30T got rid of compensator sprocket.......
Bottom end is great but I do alot of hwy riding and loss of 6th gear , much more vibration..
sucks. My biggest complaint before I did change was no bottom end , no torque until 3rd gear, so .......
I have 103, with heads, cams etc.......there is no more banging on startup and bike is smoother but the higer rpms and shorter gearing is not for me......
If I had it to do it over, DD6 OR 7 hopefully there will be a better fix down the line....
Bottom end is great but I do alot of hwy riding and loss of 6th gear , much more vibration..
sucks. My biggest complaint before I did change was no bottom end , no torque until 3rd gear, so .......
I have 103, with heads, cams etc.......there is no more banging on startup and bike is smoother but the higer rpms and shorter gearing is not for me......
If I had it to do it over, DD6 OR 7 hopefully there will be a better fix down the line....
#75
10-21-2008 | 03:43 PM
Ultimate HDF Member
Joined: Aug 2007
Posts: 9,486
Likes: 3
From: Hico, TX (once home to Billy the Kid)
I have this one:
Dawgs:
https://www.hdforums.com/m_2806196/tm.htm
Mine:
https://www.hdforums.com/m_3121127/mp...tm.htm#3126300
Dawgs:
https://www.hdforums.com/m_2806196/tm.htm
Mine:
https://www.hdforums.com/m_3121127/mp...tm.htm#3126300
I did NOT loose cruse control.
#76
10-21-2008 | 06:34 PM
Road Warrior
Joined: Aug 2006
Posts: 1,779
Likes: 70
#77
10-22-2008 | 09:34 AM
Elite HDF Member
Joined: Jul 2007
Posts: 4,749
Likes: 15
From: sand mountain Alabama
I wonder if they will work in the '09's? They are fly by wire too...they need to include them in the exclusion statement.
I would like to do something myself but I am going to wait and see if anyone comes out with something else. I like the idea of the 30 tooth engine sprocket and the 49 tooth clutch sprocket but I think it raises the rpms a bit much.
The DD7 may be the answer but as much as I ride I will most likely be trading in another couple of years, I will have around 75,000+- by then. So that would include more loss in $$$
Jim
#78
10-22-2008 | 10:05 AM
Banned
Joined: Jul 2006
Posts: 643
Likes: 0
.
so what is the best way to do the gear change then??....
change the front engine sprocket
(or)
replace the pulley on the rear wheel?...
If the rear wheel route, what is the stock #
of teeth on the rear and do you go up or down
in teeth (and by how many)?
I just want to get into 6th gear sooner...
i know the engine will be turning more
RPM's doing this, I wont be worrying about top end RPM (in 6th)
because I dont plan on flogging her past 90 MPH.
thanks.
.
so what is the best way to do the gear change then??....
change the front engine sprocket
(or)
replace the pulley on the rear wheel?...
If the rear wheel route, what is the stock #
of teeth on the rear and do you go up or down
in teeth (and by how many)?
I just want to get into 6th gear sooner...
i know the engine will be turning more
RPM's doing this, I wont be worrying about top end RPM (in 6th)
because I dont plan on flogging her past 90 MPH.
thanks.
.
#79
10-22-2008 | 10:10 AM
Banned
Joined: Jul 2006
Posts: 643
Likes: 0
The DD7 retails for 2895.00 and yes you will lose the sixth gear light although Baker has worked with Dakota Digital who now has a gear indicator light that works to seventh gear. I understand the cost verses a motor sprocket and a DD7 probably isn't for everyone but the gearing is very nice, its quiet, smooth shifting and really brings the bike to life.
#80
10-22-2008 | 06:42 PM
Road Captain
Joined: Dec 2007
Posts: 501
Likes: 0
From: SW Iowa
Snip:
"For a high tq. big displacement Harley engine? Waste. 6 speeds is honestly too many shift points as well unless the 6th gear is a TRUE OVERDRIVE"
Does not compute! If this were so, these big riggers would only have 4 or 5 speeds rather than 18. After all, those big displacement cummins and cats are 855 cubes and more, and using your logic, they should pull the loads just fine..
Most Ultra guys with a well endowed momma and gear for a day ride probably scale out north of 1200lbs. That little stock 96 cube with a low gear that makes 10 mph at idle just can't easily start out from scratch, especially on a uphill grade, unless you burn the clutch and are very easy with the lever. If it dies in a loaded start-up, it will want to dump both you and passenger on the pavement. I believe a low gear that is a true start-up loaded low gear would be the answer. Once your moving, the rest of the gears are fine, with 6th being a nice relaxing cruise gear, until about 85 mph, when HP power begins to vanish. But who rides 85 mph anyway?
Since no single low gear swaps are out there, and my failed attempt to make the 49t gear conversion work on my bike, the next best thing I found is the stage II kit which is what I got done. I'd say a 30% increase in bottom start-up torque with the SE 255 cams, and a 100 mph top end with fuel economy staying pretty much the same, or a bit better at cruise. I'm not sure about the life span of a 103" vs a stock 96", guess I will find out. The high speed low gear still is not the best, but at least is livable now. The 7 speed trany really appeals to me, especially with the lower low gear, but, the coins to convert are choking me right now. Maybe I will win the lottery?
"For a high tq. big displacement Harley engine? Waste. 6 speeds is honestly too many shift points as well unless the 6th gear is a TRUE OVERDRIVE"
Does not compute! If this were so, these big riggers would only have 4 or 5 speeds rather than 18. After all, those big displacement cummins and cats are 855 cubes and more, and using your logic, they should pull the loads just fine..
Most Ultra guys with a well endowed momma and gear for a day ride probably scale out north of 1200lbs. That little stock 96 cube with a low gear that makes 10 mph at idle just can't easily start out from scratch, especially on a uphill grade, unless you burn the clutch and are very easy with the lever. If it dies in a loaded start-up, it will want to dump both you and passenger on the pavement. I believe a low gear that is a true start-up loaded low gear would be the answer. Once your moving, the rest of the gears are fine, with 6th being a nice relaxing cruise gear, until about 85 mph, when HP power begins to vanish. But who rides 85 mph anyway?
Since no single low gear swaps are out there, and my failed attempt to make the 49t gear conversion work on my bike, the next best thing I found is the stage II kit which is what I got done. I'd say a 30% increase in bottom start-up torque with the SE 255 cams, and a 100 mph top end with fuel economy staying pretty much the same, or a bit better at cruise. I'm not sure about the life span of a 103" vs a stock 96", guess I will find out. The high speed low gear still is not the best, but at least is livable now. The 7 speed trany really appeals to me, especially with the lower low gear, but, the coins to convert are choking me right now. Maybe I will win the lottery?