All gear drives have some noise / whine to them. They have to have some clearance to work. When you roll off the throttle, you change the loading from one face of the gear to the other. Yours has worn some and has additional clearance, hence additional noise. On a rebuild of the rear gear set, that is adjustable. Pulling in the clutch should cause the noise to lessen some as you relieve the gear set of the motor drag. Both of my 700's have a whine in third gear / decelerating. Cause for alarm? Not really. I have used BG extreme pressure concentrate to quiet gear noise with good results. I use it in all my shaft drive bikes.
--- On Wed, 11/12/08, Dennis Hammerl <[EMAIL PROTECTED]> wrote: From: Dennis Hammerl <[EMAIL PROTECTED]> Subject: [Nighthawk Lovers] Re: '84 CB650SC - rear shocks To: [email protected] Date: Wednesday, November 12, 2008, 9:58 PM Can I ask a delicate question ? Are you a large person ? The springs are just relaxing back to the size the shock will let them go to. 30K is not a lot for the bike but Honda rear suspension is not exemplary. I am a rather light person and for the most part my rear suspension is actually a bit hard. As I don't make it work very hard, I expect it will last a long time. Your rear suspension may be sacked as the Brits say. Progressive makes great replacements, but a bit pricey. As long as you aren't causing the rear end to bottom out, I wouldn't replace them. In case you haven't noticed, the forks do the same thing when you get off. Bike suspension has not changed in it's basic concept for many moons. The spring wrapped around the shock absorber is a nice compact unit. ( on a race car they call it a "coil over") The adjuster on the bottom preloads the spring by changing its captive length. The shock controls the spring's action. Most of the shock's control happens to dampen rebound (how the unit returns to normal after being compressed) This is usually expressed as a percentage; 50-50 being the same dampening in either direction, 60-40 would be 40% compression / 60% rebound. ( I had a drag car that used 90-10 front shocks. The front would rise quickly and almost stay there causing weight transfer to the rear.) Your shocks may be bad after 30K and have poor control over the springs, hence the pop-up when you get off the bike. A cool thing to do is to stand next to your bike and grab the handlebars and pull up as hard as you can. Then smear some heavy grease on the exposed fork tubes. Go for a ride. The grease will be wiped off, up to how much of it's travel you used. At rest, the line should be somewhat above the seal that wiped it. If it sets right on it, consider that some work is in order. Sacked springs. --- On Wed, 11/12/08, Gene Henry <[EMAIL PROTECTED]> wrote: From: Gene Henry <[EMAIL PROTECTED]> Subject: [Nighthawk Lovers] '84 CB650SC - rear shocks To: [email protected] Date: Wednesday, November 12, 2008, 2:03 AM My '84 CB650SC with 30K miles, (I got it at 22 K - $650!) and having been laid down perhaps several times by previous owner(s), has the disconcerting habit of "raising up" on the rear shocks as I dismount. That of course causes it to lean more as it raises, and it feels like it will tip over. Of course it won't, really, but it feels strange. I am assuming the rear shock(s) need attention, but because of the coil springs, nothing can be observed. Has anyone else had this problem, and if so, what was the cure? Thoughts, Dennis? anyone? Also, there is a "whine" somewhere - transmission? final drive? - most pronounced when decelerating. Any ideas here? Running Amzoil 90 in final drive, Mobil 1 synthetic in engine. I have done the carbs (plugged low speed fuel passages) new battery, new front tire, front fork leaking on one side (winter repair job). It is a "late in life (I'm 72) addition, and I love to ride it. I am constantly amazed at the good condition of 25 year old parts - especially rubber and plastic - that are still good! Honda, you did one hell of a job in designing and building! It'll outrun a $18,000 Hardly 1200+cc and a BMW ($10,000) 1300+cc. Until I chicken out (make that old injuries triumph over testosterone). Gene --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
