HarleyTechTalk

Technical Forums => General => Topic started by: rking1550 on June 24, 2022, 06:27:38 AM

Title: Chain conversion and final drive gear ratio
Post by: rking1550 on June 24, 2022, 06:27:38 AM
First a little info on the bike.
01 road king. 120", baker OD6 , 3:37 primary gearing. Stock tranny and rear pulley.

Thinking about going to a chain drive instead of belt. Zippers said 24 tooth front & 50 rear is close to stock.
I've been thinking about going to the 3:15 primary gears as first & second seem to short, those gears go by too quick.
Would doing a 24 tooth front and a 48 tooth rear do about the same thing as changing the primary gearing ?
 Or any othering gearing suggestion are welcome.
Thanks
Title: Re: Chain conversion and final drive gear ratio
Post by: kd on June 24, 2022, 07:03:21 AM
All I can say is 3.15 final gear ratio with my 2011 RGU 120 (GrudgeBox, 660SM, HPI 62/64, Burns) is just about perfect.  I get everything I need street performance wise (including traffic manners) and on the highway.

Last night I had a guy on a black SG (we know black is fast) , pestering me to race.  After passing him drifting sideways on the shifts, belching tire smoke and painting a black road snake through the first 3 gears, when I let off he pulled up behind and behaved himself.  :nix:  Highway travelling at 3,000 rpm has given me improved mileage and roll on power immediately on tap.  Passing a transport I am easily at 100 MPH at the driver's door if I don't baby it. 

I'd say 3.15 final is a good compromise.
Title: Re: Chain conversion and final drive gear ratio
Post by: Hossamania on June 24, 2022, 09:02:35 AM
Sounds like it's working out for you!
Title: Re: Chain conversion and final drive gear ratio
Post by: hrdtail78 on June 24, 2022, 09:06:41 AM
Quote from: rking1550 on June 24, 2022, 06:27:38 AMFirst a little info on the bike.
01 road king. 120", baker OD6 , 3:37 primary gearing. Stock tranny and rear pulley.

Thinking about going to a chain drive instead of belt. Zippers said 24 tooth front & 50 rear is close to stock.
I've been thinking about going to the 3:15 primary gears as first & second seem to short, those gears go by too quick.
Would doing a 24 tooth front and a 48 tooth rear do about the same thing as changing the primary gearing ?
 Or any othering gearing suggestion are welcome.
Thanks

Close ratio 1 and 2 are available for your 5 speed.  Something I always do reworking the older 5 speeds that is getting some power to it.  Stock is 3.24 and 2.94.  Alternative is 2.21 and 2.08.  I mention this because you mentioned 1st and 2nd gear.  Do you have a gearing calc to play with?

Hope this is OK to post.  http://www.bigboyzheadporting.com/Gearratio.htm
Title: Re: Chain conversion and final drive gear ratio
Post by: rking1550 on June 24, 2022, 11:54:18 AM
Quote from: hrdtail78 on June 24, 2022, 09:06:41 AM
Quote from: rking1550 on June 24, 2022, 06:27:38 AMFirst a little info on the bike.
01 road king. 120", baker OD6 , 3:37 primary gearing. Stock tranny and rear pulley.

Thinking about going to a chain drive instead of belt. Zippers said 24 tooth front & 50 rear is close to stock.
I've been thinking about going to the 3:15 primary gears as first & second seem to short, those gears go by too quick.
Would doing a 24 tooth front and a 48 tooth rear do about the same thing as changing the primary gearing ?
 Or any othering gearing suggestion are welcome.
Thanks

Close ratio 1 and 2 are available for your 5 speed.  Something I always do reworking the older 5 speeds that is getting some power to it.  Stock is 3.24 and 2.94.  Alternative is 2.21 and 2.08.  I mention this because you mentioned 1st and 2nd gear.  Do you have a gearing calc to play with?

Hope this is OK to post.  http://www.bigboyzheadporting.com/Gearratio.htm

Thanks for the link, I'll check it out.  No longer stock 5 spd,  Baker OD6 I know baker also offers different 1st gear ratio,  but don't want to go into the transmission.  It's time for a belt and pulleys. It's still got the original 01 parts.  So was thinking chain conversion and playing with the sprockets to make a small adjustment to the gear ratio. Just not sure if that's the best place to do it or how much of a difference it'll make ?? Not looking for a big change.  Don't want to go into the tranny so it'll be the primary gearing or the sprockets. I'd prefer to do it with the sprockets seeing as I have to buy them any way.
Title: Re: Chain conversion and final drive gear ratio
Post by: Ohio HD on June 24, 2022, 12:08:26 PM
If you're an Excel user, you can download this spreadsheet. First tab you setup what you have now, second tab setup what you want to try. The RPM differences are shown for each gear at different speeds.

You can also select different transmissions to see what they change in ratio and RPM.


Gearing and RPM's (https://harleytechtalk.com/htt/index.php/topic,105065.msg1243992.html#msg1243992)
Title: Re: Chain conversion and final drive gear ratio
Post by: hrdtail78 on June 24, 2022, 01:08:27 PM
Quote from: rking1550 on June 24, 2022, 11:54:18 AM
Quote from: hrdtail78 on June 24, 2022, 09:06:41 AM
Quote from: rking1550 on June 24, 2022, 06:27:38 AMFirst a little info on the bike.
01 road king. 120", baker OD6 , 3:37 primary gearing. Stock tranny and rear pulley.

Thinking about going to a chain drive instead of belt. Zippers said 24 tooth front & 50 rear is close to stock.
I've been thinking about going to the 3:15 primary gears as first & second seem to short, those gears go by too quick.
Would doing a 24 tooth front and a 48 tooth rear do about the same thing as changing the primary gearing ?
 Or any othering gearing suggestion are welcome.
Thanks

Close ratio 1 and 2 are available for your 5 speed.  Something I always do reworking the older 5 speeds that is getting some power to it.  Stock is 3.24 and 2.94.  Alternative is 2.21 and 2.08.  I mention this because you mentioned 1st and 2nd gear.  Do you have a gearing calc to play with?

Hope this is OK to post.  http://www.bigboyzheadporting.com/Gearratio.htm

Thanks for the link, I'll check it out.  No longer stock 5 spd,  Baker OD6 I know baker also offers different 1st gear ratio,  but don't want to go into the transmission.  It's time for a belt and pulleys. It's still got the original 01 parts.  So was thinking chain conversion and playing with the sprockets to make a small adjustment to the gear ratio. Just not sure if that's the best place to do it or how much of a difference it'll make ?? Not looking for a big change.  Don't want to go into the tranny so it'll be the primary gearing or the sprockets. I'd prefer to do it with the sprockets seeing as I have to buy them any way.

Got ya.  I am not big on chains for street use.  They have their place and there is no replacement if making gear changes all the time, or having to change wheel base for jumping around classes or different sanctions.  BUT that is me.  With your bolt on rear pulley.  With dyna, softails and international models.  There are plenty of sizes and belt sizes.
Title: Re: Chain conversion and final drive gear ratio
Post by: jmorton10 on June 24, 2022, 01:28:06 PM
Here is an easy gear ratio calculator:

http://www.nightrider.com/biketech/calc_gearratios.htm

~John
Title: Re: Chain conversion and final drive gear ratio
Post by: HighLiner on June 24, 2022, 06:50:27 PM
Quote from: kd on June 24, 2022, 07:03:21 AMAll I can say is 3.15 final gear ratio with my 2011 RGU 120 (GrudgeBox, 660SM, HPI 62/64, Burns) is just about perfect.  I get everything I need street performance wise (including traffic manners) and on the highway.

Last night I had a guy on a black SG (we know black is fast) , pestering me to race.  After passing him drifting sideways on the shifts, belching tire smoke and painting a black road snake through the first 3 gears, when I let off he pulled up behind and behaved himself.  :nix:  Highway travelling at 3,000 rpm has given me improved mileage and roll on power immediately on tap.  Passing a transport I am easily at 100 MPH at the driver's door if I don't baby it. 

I'd say 3.15 final is a good compromise.

Are you using 24 and 55 gears?
Title: Re: Chain conversion and final drive gear ratio
Post by: kd on June 24, 2022, 11:35:22 PM
Quote from: HighLiner on June 24, 2022, 06:50:27 PM
Quote from: kd on June 24, 2022, 07:03:21 AMAll I can say is 3.15 final gear ratio with my 2011 RGU 120 (GrudgeBox, 660SM, HPI 62/64, Burns) is just about perfect.  I get everything I need street performance wise (including traffic manners) and on the highway.

Last night I had a guy on a black SG (we know black is fast) , pestering me to race.  After passing him drifting sideways on the shifts, belching tire smoke and painting a black road snake through the first 3 gears, when I let off he pulled up behind and behaved himself.  :nix:  Highway travelling at 3,000 rpm has given me improved mileage and roll on power immediately on tap.  Passing a transport I am easily at 100 MPH at the driver's door if I don't baby it. 

I'd say 3.15 final is a good compromise.

Are you using 24 and 55 gears?

49 tooth Evo Industries clutch basket with 24 / 57 rear sprockets.