Why does by gearbox seam so loud? [Archive] - Yamaha R1 Forum: YZF-R1 Forums

: Why does by gearbox seam so loud?


greatheathen
01-14-2007, 09:27 AM
I have recently become very aware of the clunking sound when i shift.
I have had the bike for a very good while now know every single little sound it makes. It just seems to me that every gear i shift is just very loud now no matter what method i use to shift.
#1 what causes the sound in all motorcycles when you shift? and #2 why would mine suddenly seem louder than usuall in all gears. I changed the oil yesterday seeing that it is a wet clutch but alas, it made no difference.
There is a small chance that it is my imagination but i seriously doubt it.
When i shift into first most of the time now it has a small jump or maybe jerk you could call it at times. The clutch is adjusted properly and seems to disingage fine but i just don't know.
Any thoughts would be much appreciated, thanks. I have 10,000 miles on it Btw.

1longR1
01-15-2007, 10:41 AM
you have 6 gears on 2 shafts. when you shift gears, you are moving a gear into another guy on one shaft, and then that gear will spin gear via teeth on other shaft. when you shift 1 time you have 2 gears on one shaft meeting together that are not spinning at exact same speed, and same thing is happening on other shaft at same time. so you have 3-4 gears moving and meshing together at very high speeds, plus shift drum rotating and moving 3 shift forks. its a well orchestrated dance in gearbox. doesnt take much to disrupt them. slightly bent shaft, rounded dog, rounded gear, worn shift fork... lotsa things can make different noises. Your best bet is to take it to a good mechanic... talk to local guys..ask who best sportbike mechanic is in your area.. call him up and tell him whats going on.. just dont take bike to dealer.. make arrangements with guy to ride it outside of dealership.. or make sure he is one to look at your bike...request him!! maybe just your imigination..but if it feels like its not right..have it checked.