• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Sprocket and chain to lower RPM's at 70 on a 550l

  • Thread starter Thread starter Black 550 L
  • Start date Start date
B

Black 550 L

Guest
I would like to lower the rpms on a 1980 gs 550 L from 5900 at 70 to about 5000. What chain and sprockets would you recommend to do this or is this something I should even consider doing.
 
GS550E runs lower rpm at freeway speeds than the L model because the rear wheel is larger, so it should be fine for you to do it through sprocket gearing. Dropping 900 rpm at 70 mph is not very realistic though. Simple thing to do is go up one tooth on your front sprocket - this will drop the rpm by about 300 rpm or something near. You can also drop the rear sprocket size by a couple of teeth if you want more of an overdrive. Pretty easy change.
 
Try calling Z1 enterprises. I spoke to a guy on the phone just yesterday to order a new chain and sprockets. I ended up doing a 630 to 530 chain conversion, and we (he) calculated out some drive ratios on the phone to get me a slightly lower rpm on the freeway. Great experience.
 
It's pretty easy calculating rpm reductions when changing sprockets.

Stock gearing for a 1980 GS550L: 15T front and 51T rear.

Stock bike runs 5900 rpm at 70 mph (as stated)

If you changed up to a 16 T front the new speed would be 5900 x 15/16 = 5531 rpm

Now if you went to a 49 rear it would be 5531 x 49/51 = 5214 rpm

Understand that when the gearing is changed like this the bike will require more clutch slipping to get off the line and the top gear acceleration will be less.

Good luck.
 
JC I'm right behind you

JC I'm right behind you

I guess I need to go count the links on my existing chain. I got the wrong valve cover gasket from APE, so I will order gaskets and conversion from Z1.

Who did you speak to? Did you get an O-ring chain? Which one?

Posplayr
 
I spoke to Jeff @ z1. I think I got the RK X ring chain (x is better than o from the marketing material I've read :D )
 
You must log in or register to reply here.
Back
Top