Getting a 120R installed this week and looking for some feedback on whether or not to change the sprocket to a 30 or keep it stock with the 32. It's an 08 Streetglide. Any suggestions please let me know, theres no labor cost because the bike will already be apart. Thank you.

 

Hell yeah, its not like the 30 is gonna make it rev too high, it just gets it back to around 3 from that ridiculous 2.79. I'd do it in a heartbeat if it's apart.

 

i put a 31 in with my 120r it seems to be perfect for launching. the 30 will be too much gear. i am going back to the 32 because I broke a 139 tooth gates belt yesterday.
The 120 has plenty of torque to pull the 32 stock gear and will get better fuel milage for long trips. If you want to gear it go with the 31.

 

If you are referring to a EVO Industries 30T comp sprocket,I would HIGHLY recommend not to do it.Because you will snap the output shaft off the flywheel.Trust me I know this from experience, a very expensive experience.Alot of guys are switching the rear pulley to a 68T sporty sprocket.Try to utilize your comp. sprockets they're there for a reason.Especially when you get into the big horsepower bikes.I know DragosBikeWorks has a kit to convert your belt drive to a chain drive that still utilizes your rear comp for I think around $600.It's heavy duty stuff.

 

A change of just one tooth on any of the drive components is hardly enough to notice! Changing from a 32T to 31T is just 3%, or 1mph per 1,000rpm. To get any benefit from such a change a 30T would be more worthwhile.

I assume you are talking of changing the trans pulley and currently have a 66T rear pulley? Stock gearing is 2.79:1. Changing to a 30T will give 2.98:1. Some HDF members have changed the rear pulley to a 68T as well, which gives an even better overall ratio of 3.07:1, or a total of 10% more torque at the rear wheel. Every little helps!

 

That is correct, talking about the trans pulley. A bunch of my friends are going down one tooth but from what I've read on here I'm still not sure it's worth it. Half the people say do it and half the people give me other things to try. The only reason I had considered this was because the bike is already apart.

 

I don't have the braggin' rights of a 120R, but am running my S&S107 with a top (fifth) gear of 3.37:1. To put that into context if you on your bike and I on mine were alongside each other in top gear, your gearing means you only have similar torque at the rear wheel to me! If I catch you right/wrong I may even steal a roll-on against you!

You really should give some thought to improving your gearing! A 30T will give you the edge over my bike.....

 

I installed the EVO 30 tooth sprocket.

By the way, the generator doesnt have to come off to remove or install the inner primary.

Pretty cool job to do. I liked it.


Higher RPMabout 3000 RPM at 75MPH.
Did this about three years ago, have not had a problem with it.

There is a 49T ring gear conversion also from EVO Industries. I hear you will loose cruise control by doing the swap.
May have to have the SERT upgraded to the TTS Mastertune so you can get the cruise control back by changing the primary ratio.

Oh - you loose your 6th gear light with the 30 tooth set up, dont know why.

 

I have an SE 120R in my 2006 Street Bob. This bike is very high geared but the 120R has more than enough torque to pull it.

 

His FLHX is higher geared(the worst geared hd ever, I have one) and weighs more, different situation, unless you have geared yours for even less revs.