Topic: Sloppy shifter

[eigenvector]

Been riding my Nighthawk more and more, slowly I'm getting that thing into reliable running condition.

I have one last item that's dogged me for a long long time - I simply can't figure it out.

The shifter, one of those forward link shifters has far too much slop in it.  I have the shift pedal adjusted as far down as I can - but even with that there's a good 3/4 to an 1" of pedal slop between 1st and 2nd.  This makes shifting into 2nd almost impossible except by having the shifter preloaded right before releasing the clutch and even then it's a gamble.

Question is - where is that slop coming from and how can I reduce it?

[754]

You have to Bush the holes or pivot points. Some by design rattle themselves into wearing things out.
 Are they rod end type or clevises?
 You can see it and we cant, so you will have to examine it to see where the problem is.

[eigenvector]

I always assumed the slop was in the shift mechanism itself between the drum and the contact roller - but I hear you say that it's probably in the actual linkage itself.

It's a ball-socket type linkage.

https://www.ebay.com/i/201545530640?chn=ps

Not mine - just a good image of the mechanism.

Is that basically what you're indicating here?

[eigenvector]

Well, the linkage itself is tight, no slop there - maybe a smidge but not nearly as much as there is internally. 

The shifter moves up, with spring force resisting it about 3/4" when in neutral until it actually contacts the internal drum teeth.  To me that says the shift stopper (#17 in the picture) just isn't big enough.
https://www.powersedge.com/oemparts/a/hon/506c81c0f870023420a3cbbc/gearshift-drum-gearshift-fork

At any rate, I'm going to try swapping out the shift lever with a longer one, see if that provides better foot position.  Need to get a longer bolt first.

[754]

Longer one, even more slop..

[eigenvector]

Yeah I know, but if I can get a better grip on it with my boot it might help.

Guess I can see about finding a shorter shift lever, but that would just make shifting even more uncomfortable.

It's just a bad shift mechanism all around.  Overly complicated, jammed in there between the muffler, kickstand, and oil fill spout.

[scottly]

Please post a pic of your shifter from the side.

[eigenvector]

Done

[scottly]

Your angles are all wrong. If you draw imaginary lines through the pivot points, they should make close to 90 degree angles. Is that a punch mark just to the left of 12:00 on the shifter shaft?

[eigenvector]

That is a punch mark.

I welcome any back of the head smacks indicating my stupidity.  I put this bike together from basically scratch when I got it - so I had little to go by and the shop manual is terrible.

[scottly]

Pull the lever of the shaft (you will have to completely remove the pinch bolt first) and rotate the lever clock-wise until the punch mark aligns with the slit. Was your bike shifting "backwards"? Down to upshift and up to downshift?

[eigenvector]

If nothing else I noticed the punch marks - there's a punch mark on the shifter arm as well I didn't see.  Line them all up and indeed the whole mechanism forms a relatively square shape.

Not that it helps the issue - there's still about 3/4" travel in the shifter from neutral until it hits the shift drum.

But hey - I'm starting on solid ground now - no guesswork about how it's supposed to be oriented.

[TwoTired]

I have a CB700SC Nighthawk Shop manual.

It shows the shifter arrangement as depicted.

[eigenvector]

Yeah that's about right.  I think that pic is from the 750 because the shifter is different, larger drop, but generally that's consistent with what it looks like now.

Still has too large of a throw.

There's an upgrade kit that at least used to be available for this bike (and all Honda bikes that share this transmission - quite a few actually) that replaces the shift stopper with a larger contact wheel and I think a stiffer return spring

Just for reference, here is a before and after.
Before - neutral
After - contacting shift drum

[scottly]

The angle between the arm and the rod still looks wrong to me. Try rotating it one or two splines clockwise.

[eigenvector]

I haven't really thought about it that much, maybe hashing it out tonight with you guys has made me stop and think.

I STILL think it has too large a throw, but squaring up the angles serves a very useful purpose that I haven't considered until you pointed it out.  All the motion is now tangent to the shift shaft which rotates it the furthest.

Maybe it's the beer.

[Terry in Australia]

Have you got the correct shift lever on your bike Rob? I just googled your Nighthawk (we didn't get them out here, thank God) and every pic I saw had a much shorter shift lever than the one in your pic?

[eigenvector]

Wouldn't surprise me if it wasn't, everything else about this bike is wrong.

I'll keep looking around for another shifter.

Edit:  Naw, it appears to be the stock shift lever.

[eigenvector]

So what are my options here?

The shift mechanism is (now) arranged correctly.
The throw is just too long between 1st and 2nd.

What would be a good solution if I wanted to make shifting this beast easier?

[Gene]

I AM NOT AN EXPERT but had a decent Nighthawk until I wrecked it recently - we put a longer shifter mechanism on it for precisely the reasons you described earlier - but - no way around that jump from 1st to 2nd. I apologize for not having an answer to your question, just saying that apparently it's common - that leap. All the other gears seem(ed) right. P.S. - I really did enjoy the "overdrive" gear

[eigenvector]

I appreciate you chiming in.  Yeah, that gap is just huge.

I have a new shift lever on hand, now I need to get an insert that fits it - stock insert is a little too long for this one.

By the way, did your leak oil like a sieve too?

[eigenvector]

Well I've done my best on the outside.

Replaced the shift lever with a shorter one - definitely helps with the shift, but it still a huge gamble whether it will decide to shift or not.

At this point I think all the work has to be in the inside.  I can chalk this one up as my extended project.

[Gene]

I appreciate you chiming in.  Yeah, that gap is just huge.

I have a new shift lever on hand, now I need to get an insert that fits it - stock insert is a little too long for this one.

By the way, did your leak oil like a sieve too?

It has/had zero leaks. Even after the wreck. go fig.

[eigenvector]

Something that always troubled me about the shifter itself is that the cover had a screw going through the cover but all it seemed to do was plug a hole in the cover itself.

On the opposite side of the cover is a hole in the shifter itself, plus there's another hole in the shift selector.

I'm thinking,
1)  Just a coincidence and don't do what you're thinking of doing...
2)  That screw broke off and it's supposed to go through all 3 items - and that's why your bike isn't shifting so well.

I can't seem to dig anything up on it and that screw IS supposed to be there per the diagram of the shift cover.

Thing is - if I stuck that screw in there - how's the shifter supposed to move?  Isn't it pivoting about the center axis?

[jgger]

Maybe it's there to check the alignment/timing of the shifter, you know like stuff a rod in there to see if everything lines up? IDK.

I had a Montesa dirt bike that checked the timing in a similar way. Rotate the flywheel and install a pin in a hole that should have lined up with the pick up coil at a specific measurement BTDC. Just a guess.