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Clunky downshift

Posted: Tue Jun 13, 2006 4:47 pm
by jcslocum
All,

Went out for a longish ride, the first this year with the Paso and the downshifts seem very clunky/harsh. Clutch is operating fine with plenty of disengagement. Upshifts are smooth and no false neutrals.

Any ideas besides tearing the clutch pack apart to see if there is a problem in there?

Posted: Tue Jun 13, 2006 7:21 pm
by Finnpaso
I am 90% sure, U have problem inside left engine case: There is onekind "fork", what moves gear drum (with gear lever) inside engine. You can see that fork, when open left side of engine(not so big job: oils away, or turn bike to right side hardly and open left cover). That fork HAVE TO BE in middle position, that gears go esily to down and up !!! You have to measure that fork adjusting to middle! Its very accurate and if fork is not adjusted right, then gear change dont work properly, it depends, what direction it is wrong/up gear problems/down gear problems. This happened to my 907IE one time and i adjusted that fork again and then it started to function very well again... :thumbup: I am quite sure, Your adjustment is wrong now... Not so bad job.. :thumbup: my 750 Paso dont have marked that right middle position, but in my 907 its marked to get right adjustment, so its easier in 907 to adjust it. You can find more details from factory manual.

Posted: Wed Jun 14, 2006 12:34 am
by jcslocum
Antti,

Thanks for the quick reply. I'm not getting bad shifting or false neutrals. These are usually fixed by adjusting the shift fork. The upshifts are fine it's just hard to downshift and it clunks LOUD. I think the clutch isn't fully disengaging. That's my first guess.

Posted: Wed Jun 14, 2006 6:56 pm
by Finnpaso
Measure clutch plates! How many kms You have done with plates? Its quite normal, that after 30 000 - 35 000kms they are out of limits. Surely it depends, what kind of driving... :thumbup: Btw, i didnt get any "bad shifting or false neutrals", when my gear fork was wrongly upset (i dont know, how it had changed to wrong position!!), it only didnt change gear to up, like should! After adjusting it very carefully all started to function very well...

Posted: Wed Jun 14, 2006 7:24 pm
by Skins
:cool:

Are your external linkages from the pedal operating smoothly, Jon?

If not, perhaps the extra force required for the shift is causing the 'clunk'.

Personally, I like to hear a good 'clunk' when I shift, to know she's gone into gear.

By the way, I run a track pattern shift (up for first, and then down) on both my bikes, which I much prefer. I wonder if anyone else does?

Posted: Sat Jun 17, 2006 4:06 am
by delagem
GP Shift, that's the way to go! I tried it one day, just for laughs, and wow, what a difference! It's just so natural to do it that way.

It's almost a requirement if you're cornering hard enough. It can be very hard to get your foot under the pedal when you're accelerating out of a turn while really leaned over.

And then, when you get back on a bike with street pattern, and you come out of a corner in 2nd gear, rap it up to redline, and bang it back into 1st by accident... Now there's some excitement! I sucked the left crankshaft seal right out of my YSR with that mistake one day.

I have converted all my bikes to GP shift except that YSR, and even that can be converted, but it involves splitting the cases and changing the shift drum with one out of an RX50. So I'm waiting until I need to rebuild the motor to do it.

Posted: Mon Jun 19, 2006 3:28 pm
by jcslocum
Skins wrote::cool:

Are your external linkages from the pedal operating smoothly, Jon?

If not, perhaps the extra force required for the shift is causing the 'clunk'.
Yes. I think it's the clutch dragging.

Posted: Thu Jun 22, 2006 5:52 am
by delagem
Your story reminds me of the first Paso I owned, got the damned thing stuck between 3rd and 4th gear on a downshift, on a new bike with less than 3,000 mi on it! And since I was such an excellent mechanic back then, I took a sledge hammer and whacked the gearshift to fix it....

(sorry, most of my stories are of no help)

Well, at least it did free it up!

Let us know what you find out, Jon!

Posted: Tue Jun 27, 2006 8:01 pm
by Skins
:thumbup:


I am very interested to read that I'm not the only one running the track pattern (one up and four down) gear shift on his bikes, Michael. I'm convinced that it's better, and that it's not by chance that it's commonly used in MotoGP. You're to be congratulated, in my opinion, for changing your bikes as a result of experimentation. In my case, I learnt to ride that way, on a Velocette 500.

I wrote an article about reversing the gear shift, and sent it to Mike some time ago, but hasn't appeared yet.

The article (with a photo) describes why I think the track pattern is better, and how I think the manufacturers made a mistake when they standardized the shift the other way. Maybe I'll post the article (if I can still find it on my computer) in this thread.

Does anyone know if the reversed shift pattern is also commonly used on the SBK circuit?

Posted: Tue Jun 27, 2006 8:51 pm
by delagem
Yes, and you have the US DOT to thank for pushing through the standardization, and forcing the rest of the world to bend to it! I forget when, but DOT imposed a standard and wouldn't allow any bikes imported unless they met the standard, early 70's I believe. So everyone switched, as there was no other standard at the time.

I have experimented while in my recliner (where I do my best thinking!) and to me the optimal setup is clutch left, brake right for the hands, brake left gearshift right for the foot controls. Although I've never ridden a bike with this setup...

I'm pretty sure GP shift pattern is almost universally used in SBK and MotoGP; most AMA guys do it too. Although I know a few who refuse to, such as my buddy Doug, an AMA Superbike racer, who runs GMD Computrack Cleveland. He had difficulty dealing with customer bikes that were standard shift, and didn't want to wreck a customer bike that way.

Posted: Wed Jun 28, 2006 9:20 pm
by Fraser
A right foot gear change works very well. My first Ducati a 1975 750 Sport had this arrangement. There is some sort of natural balance involved where your left hand "connects" to your right foot, and viceversa of course. This made gear changing particularly satisfying and you also had better control when braking (right hand/left foot).

If you have every done a layup in basketball you leave the floor with your left foot and control the ball with your right hand. There is some sort of instinctive link here.

I'm sure the DOT standardisation happened in the mid-70s. Have Harley-Davidson always been left foot change? My suspicious mind leads me to wonder if the local industry was after additional protection?

Fraser.

Posted: Thu Jun 29, 2006 2:23 pm
by delagem
You're right to be suspicious of Harley! Starting with their getting the only tire producers in the USA to refuse to sell tires to Indian back in the early 1900's. (If you wanted an Indian, you had to buy your own tires, and supply them to the Indian dealer before you could pick up your bike)

And now the latest deal, with Buell, owned by Harley, where they are the only manufacturer that can run a non streetbike based racer in Formula Extreme in the AMA series. And they still can't even finish a race! Although I must say that the bike does look and sound awesome!

Posted: Thu Jun 29, 2006 3:11 pm
by fasterdammit
To get this thread WAY off topic, I always thought it would be entertaining to see a race bike equipped with a suicide shift ... :toofar: :screwy: :funny:

Posted: Thu Jun 29, 2006 3:57 pm
by delagem
I'm sorry, what WAS the original topic, anyways?

I bet you could find a suicide shift racebike at AHRMA, some of those guys are, well, different. To say the least. Watching the sidecar races is always a good time. Especially when the new "monkey" falls off!

Posted: Thu Jun 29, 2006 4:45 pm
by Skins
:cool:

What's a suicide shift, chaps?

Fraser, there may be something in what you say about left-side vs right-side change, but I don't think it's anywhere near as significant as the shift direction - which must be why the opposite direction is used at the top levels of competition.

I'm so convinced that up for first is better, that when my local dealer first got me to ride a four-valve, I asked them to change the shift direction (it's so easy on a Paso - takes about two minutes) They tried, but it was too difficult, so I rode the bike the way it was. It turned out to have a lovely shift (it was a 916) although like all modern road bikes, it was the wrong way round.