1978 r80/7 down shifting issue

Post Reply
Dsmith181
Posts: 5
Joined: Wed Oct 28, 2020 6:07 pm

1978 r80/7 down shifting issue

Post by Dsmith181 »

First of all thanks to everyone for this forum. Been very informative.

I have an issue with my 78 r80/7 where when I try to down shift I can’t engage the shifter I press down and nothing happens.. unless I click up a gear and then go down. Then it engages and I can shift down. The other thing I can do is kind of flutter the shifter if that makes sense. Kind of push it down with the edge of my foot and let it flap up a little. Then I can down shift. Anyone know what I mean?

User avatar
schrader7032
Posts: 7930
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Re: 1978 r80/7 down shifting issue

Post by schrader7032 »

Sounds like your clutch might not be fully disengaging. I'd first consider ensuring that the clutch cable and mechanism is properly adjusted. Tom Cutter has a procedure on his website that works very well:

http://www.rubberchickenracinggarage.co ... stment.pdf

Secondly, it might be time to lubricated the input splines to the transmission. This can sort of be done by sliding the transmission (and everything behind it) backwards about 3/4" and getting a stiff brush down to the splines. Probably best just to pull the transmission and do thorough cleaning.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

User avatar
srankin
Posts: 356
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: 1978 r80/7 down shifting issue

Post by srankin »

A silly thing happened to me. When riding one day, I stood up on my foot pegs and unbeknownst to me, the left one moved down. Down the road when I attempted to down shift, I couldn't get the bike to shift as easily as it should. Getting home, I found the problem, adjusted the foot peg back to it's proper spot and the problem went away.

So, if I am correct, your shifter link has an adjustable rod on it. I would check to see if your foot peg is where you want it and the shift lever is properly adjusted so when you do shift, your foot engages the lever the way it should.

As for the clutch, by all means check and adjust if needed. My 78RS has a grease fitting on the transmission clutch lever, give it a shot of grease. If you haven't greased the transmission input shaft, that is also a good thing to do.

The transmissions on this year bike are pretty robust. unless you have high miles or have been really hard on it, I don't think you should have to open the transmission up. A gear oil change and inspection of the magnetic plug for excessive metal bits may point to an internal problem. Cheers, St.
Owner of a 84, R80RT and 78, R100RS

User avatar
srankin
Posts: 356
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: 1978 r80/7 down shifting issue

Post by srankin »

So, how have you made out?
Owner of a 84, R80RT and 78, R100RS

Dsmith181
Posts: 5
Joined: Wed Oct 28, 2020 6:07 pm

Re: 1978 r80/7 down shifting issue

Post by Dsmith181 »

Hi srankin

I basically just coped with riding the bike this way. I have to shift up before I shift down. It’s a pain but I don’t know what else to do. The peg seems to be at the right height. I’d say the shifting rod (?) is a little wobbly and I thought about trying to tighten the bolt but it’s on the backside and I’ll have to figure out how to get an Allen wrench in there.
Thanks for your help though

User avatar
schrader7032
Posts: 7930
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Re: 1978 r80/7 down shifting issue

Post by schrader7032 »

So, you haven't tried to make any adjustments? What about adjusting the clutch cable and actuation? Is it time to remove the transmission and look at the input splines?

If you feel something is wrong with the foot shifter, you may have to remove the whole setup from the transmission and tighten things up. What part of it is wobbly? Can you take a picture and upload it? The loose allen wrench head that you refer to is tied to part of the driver's footpeg. You would need to loosen the left rear motor mount so that the peg can be removed. But the other parts of the shift mechanism may also need to be removed.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Dsmith181
Posts: 5
Joined: Wed Oct 28, 2020 6:07 pm

Re: 1978 r80/7 down shifting issue

Post by Dsmith181 »

Yes Schroeder, you’re right, I should have just taken my time and gone through the process properly. I replaced the clutch cable and adjusted it exactly according to rubber chicken and now it’s great. I’m impatient and usually conclude the worst case scenario.
Thanks for Setting me and my bike straight!

User avatar
schrader7032
Posts: 7930
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Re: 1978 r80/7 down shifting issue

Post by schrader7032 »

Nice to hear it was an "easy" fix...low hanging fruit as they say! :D
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

User avatar
srankin
Posts: 356
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: 1978 r80/7 down shifting issue

Post by srankin »

Good solution, thanks for letting us know what you found. St.
Owner of a 84, R80RT and 78, R100RS

Post Reply