Sloppy as hell downshifts

is it just me, or are these bikes hard as hell to downshift while matching rpm's accurately?

I don't know if my technique is right, but it's what I've always done and it worked with the Nortons and the Guzzi. I have my first two fingers on the brake which I squeeze just before coming into a corner. At the same time I shift down and blip the throttle to match rpms in the lower gear.

When I do this with the VFR700, I either get no blip (because there is too much slop in the throttle) or overdo the blip so I get too many rpms. About the only way I can have any luck matching rpms is to ignore the front brake entirely and take the slop out of the throttle before blipping it. Needless to say, this makes for very non-aggressive driving...

Either I am way out of practice, or the throttle situation is just not good. The throttle in both my previous bikes only controlled 2 carbs (Norton) or 1 throttle body (Guzzi Quota), and I think neither had a "return" cable, depending on springs for return. You could dial all the slop out of the cable. I recall turning the handlebar on the Norton and having the idle go up a bit. It was worth it to have no slop there.

Has anyone eliminated the return cable, or put a return spring in and left the return cable sloppy? Of course with 4 carbs, it's already hard to twist the damn thing. Just reinforces my old prejudice that more than two cylinders on a motorcycle is masturbation. :smile:

 

1.) Adjust your cables; or
2.) Get new cables. They're stretched.

I have no problem rev-matching.

 

I have adjusted them. They have the minimum specified takeup in them (but not zero, which is only possible with a spring return).

New cables is probably a good idea though. This bike has 48k miles.

Your bike is not gen 2, which may be worse in this respect.

 

Left shiftfork split. End of the shift drum blown out. Mainshaft 28mm lockwasher split in two. locking snaprin missing . Thats the cause of this trans problems. I know Im rebuilding mine.Parts are next to imposible to find now. does your shift loose any gears when shifting ? I hope not ,if so you'lle have to crack the case. sorry...Mike R..

 

Practice makes perfect......its not the bike, and I due not care for the bad attitude towards my second hobby.:biggrin:

 

i.don't.believe.that.cables.stretch.and.can.be.re-adjusted.if.they.do

keep.practicing

 

Mine's so smooth the clutch isn't even necessary (but I use it).

 

If you can't get the cables to adjust, it's because there is somethig wrong (worn out or linkage bent, etc...) NOT because of having a return cable. When you open the throttle, you should still be able to let go and the throttle return closed, just as if it had no return cable.

It sounds like your technique may need a little work, or some practice. I usually downshift right before hitting the brakes, letting the engine braking slow me, along with the brakes, and getting in the right gear to pull out of the corner.

 

You can adjust the cables at both ends. Cables don't stretch that much. Could they be adjusted the wrong way?

"Of course with 4 carbs, it's already hard to twist the damn thing. "

Aaahhh the old Norton limp wrist syndrome. Speaking of masturbation, that just may fix your wrist:thumbsup:.

 

Touchy

If you have issues with a carb bike .....try gen 6 fuel injection......Very touchy.Not bad mouthing gen 6.....fuel injected bikes are all very finicky with throttle.Tough to ride wheelies on fuel injected bikes period.

 

Never heard of such a thing....clean from 1400 to 12.5K.....can tell it is a little rich and there is probably another 4-5 hp hidden in there. I have had zero issues with PGM-FI.

 

Ah, no, nothing wrong at the gearbox end.

Only when the thing you are practicing on works properly. Otherwise it's like trying to dance in barn boots. I've been riding since 1969, so I think I can figure out when something is not right by now.

No, I don't either. Still, they are old cables, might be part of the problem but probably not all of it.

Don't quite understand this comment. I can adjust the cables. I just don't like that a return cable design does not allow you to adjust every last bit of slop out like a spring return can be done. You can adjust a spring return so the throttle at idle is not even sitting on the idle stop screw, but hanging on the cable instead. Not possible with this design. It means when you open a throttle adjusted that way on a spring design, the revs climb immediately, rather than having to turn the throttle for a bit before things start climbing. Not a huge factor, but just one more thing adding to the problem.

I've been downshifting and braking simultaneously for a long time, don't see why I should have to stop. But you are right, doing it in two separate actions does get around this issue, at the expense of being smooth and fast...

I have discovered one other thing. I wonder if my twist grip is too "fast"? I marked it with masking tape, and found that from idle stop to wide open, I have to turn the grip not even 1/4 turn. This seems faster than my other bikes. Combine that with the initial cable slop required by the return cable design, and some general sloppiness from wear at the grip itself, and maybe just old cables, and it may all add up to the cause of this problem. Does anyone know if grips are available that require more of a turn to get to full throttle? With this fast grip, it is like it's either all on or all off. I even have trouble just starting the bike from a dead stop; either too much throttle or too little.

It's either the hookup point of the cable at the grip, is too large a diameter, or the hookup point on the "drum" (or whatever you call it) at the carb end is too small a diameter. Too much throttle movement for a given grip movement.

 

I fiddled with it some more. When I took it apart I found one cable had way more friction than the other, even with lube, so it sounds like new cables are in order. Not supposed to last forever I guess.

I also found gunk between the twist grip (nylon sleeve) and the handlebar, which I cleaned out. Looked like old handlebar paint.

And I found when I pushed the grip toward the center, it was very hard to twist. I think these are aftermarket grips (they say "ProGrip", not "Honda") made of very sticky rubber, which sticks to the grip housing or the bar ends. I put a spacer under the bar end to give it more room, but may just get some different grips that won't stick like that. Or something... Funny how I want to take all this friction out, while people are adding it with their cruise controls.

I still want a grip that is "slower" than the one on there.

I wonder if it would work without a return cable? There is a return spring... Of course a return cable is a safety feature. I had one of the carb slides stick wide open once on my first Norton, that was interesting...

 

Even with a return cable you can adjust all slack out of the throttle. Part of it is setup when you adjust the pull cable at the carb. That should be close to taunt. Then you can fine adjust it at the bar for zero slop.

 

Well, you can, but if you think about it, it puts a strain on things to have no slack there. It's like adjusting desmodromic valves to zero clearance. Turn the handlebars and that zero slack might turn into negative slack, and bend something.

 

Question: have you checked to see if this has the stock needles? The dynojet needles cause this exact thing. When I first broke open my carbs Toe noticed it right away. I replaced the needles and boots I got some from another member and now the throttle is smooth and gradual.

 

Thanks for the tip. I will look for that when I get into the bike more. As it is now, I'd rather not tear it apart with some summer still left.

 

Yes your quite right. If you run the cables wrong, around steering head/elec wiring and the choke cable is part of this. Then you may get that effect. If the cables remain free, not taunt, then no negative slack will be encountered. If you do have to raise your needles, a .020" washer is basically the same height as the groove spacing in other Honda needles. Also specified in some jet/needle kits. Not to say a .010"-.015" wouldn't work either for fine tuning.

 

I ride a gen 2... I have no problem matching RPM's, and I ride twisties pretty regularly... could be your return cable, Mine's given me problems in the past...

Or, maybe you just need to practice and queetcherbeechin... :thumbsup: