Gearshift stuck after stop

[6mmbr]

'06A

I'm cruisin' along backroads at about 45mph in 4th gear.

I come around a curve and Whoa - Stop Sign!

Grab clutch, frt brake, rear brake; bike stays stops great, I get lifted a little off seat from momentum, but OK.

Everything cool, gear indicator says "4th" (holiday mode!)

Go to shift down to 3rd on way to 1st, gear indicator goes blank, and can't get into 3rd.

Upshift gets "4" back on gear indicator; down again goes blank; up again gets "4", can't get to '5'.

Hmmm...

When indicator says '4', I let out clutch a little and yes we move slightly, then am able to go

through gears OK, get to 1st, and move on.

No other problems

comments?

signed,

Curious

 

[fhaze]

Ideally you want to downshift while the bike is moving. If you get in a situation like you did..simply releasing the clutch to the edge of the engagement point should allow you to downshift to first. You might need to repeat the procedure for each gear.

Constant mesh trannys don't like to be shifted without thing moving.

 

[FJR1300]

+1

It's normal...

 

[ionbeam]

Constant mesh trannys don't like to be shifted without thing moving.

Exactly correct. One side of the transmission is spinning while the other side is stopped.
This gear is locked onto the spinning side of the transmission (note the gear teeth in the center):

The shifter forks try to force the three 'dogs' or teeth of the above gear into the holes of this gear (note the lack of gear teeth in the center, this gear gets driven only when the dogs engage it):

When your motorcycle is stopped, you are trying to force the moving dogs into the stopped (non spinning) gear with the holes. Not a preferred situation.

Some racers under cut the dogs a bit to get them to lock into the holes of the mating gear to prevent popping out of gear under heavy transmission loads.

[Gear photos from Jython/Java3D motorcycle transmission article]

 

[Fencer]

It happened to me a few times all under 1000 miles.

 

[jestal]

That happens with every motorcycle transmission around. Always try to shift while still rolling. In a situation like you describe just engage the clutch very lightly to move the gears and the trans will shift. It is just much easier to have the gears moving while rolling along. The problem is more prevalent in higher gears since the slots for the dogs are tighter on the higher gears. Stopping in 4 really makes you susceptable to a blocked shift.

 

[SMC]

:blink: Ionbeam and Jestal, you guys are unbelievable and a wealth of information. Had that happen in the past a couple of times on a couple of other motorcycles and was wondering what I screwed up. Ionbeam...thanks for the photos of the gears to better illustrate you point!

Scott

 

[Toecutter]

:blink: Ionbeam and Jestal, you guys are unbelievable and a wealth of information.

Above and beyong the call, Ionbeam!

 

[nusman68]

Ionbeam-

Hey, great write up, especially with the pics...now will you please put that shit back in my bike?! :dribble: