"Clutchless Upshifting?"

[LMT]

I just finished reading an article in Sport Rider magazine. It told all about how to clutchlessly upshift. I do wonder why? I think it's meant for racers mostly, not sure. Isn't it "hard on the transmission?" I know it's a different mechanism but don't the gears clash on a bike like a car? Not sure if I even want to try it. Anybody Kat shift without a clutch?

[BlackburnD]

There have been a few thread on here in the past about, and it seems the general consensus is don't do it unless you really good at it. And never 2-1. Have a look with the search just put clutchless shift in you will get a good bit off info that way.

[Range]

It can't be done on a Katana...the filbert flange will not mesh with the grapple grommet.

You must replace it with a johnson rod

[Range]

[JaxKat]

Oh.

[BLACKDEATH]

35k on my gix. I clutchless upshift all the time.
At the strip and on the street. first -sixth. Never had a problem. Dont know about a kat tho. I only put 11k on it without any problems.

[BLACKDEATH]

35k on my gix. I clutchless upshift all the time.
At the strip and on the street. first -sixth. Never had a problem. Dont know about a kat tho. I only put 11k on it without any problems.

[Built4Speeed]

PostPosted: Tue Feb 27, 2007 12:22 am Post subject:


Range
PostPosted: Tue Feb 27, 2007 12:22 am Post subject:
It can't be done on a Katana...the filbert flange will not mesh with the grapple grommet.

You must replace it with a johnson rod

i love kaleco.

bout time someone put the johnson rod to good use.

[The CyberPoet]

35k on my gix. I clutchless upshift all the time.
At the strip and on the street. first -sixth. Never had a problem. Dont know about a kat tho. I only put 11k on it without any problems.

Most gsxr's will take it... Most kats won't (at least not for an extended time).

See:

http://www.katriders.com/forums/viewtopic.php?t=19424

From: http://www.katriders.com/forums/viewtopic.php?t=19019
Tranny failures (esp 2nd gear failures on the Suzuki's) normally happen as a result of rider abuse (period). Specifically:

(A) Upshifting sans clutch into 2nd without unloading the throttle (can be done, but you need to unload the throttle), esp at high RPM's.

(B) Downshifting sans clutch (no manual-shift bike on the market* is built to do clutchless downshifts -- there simply is no way to raise the RPMs to match the shift and unload the engine/tranny at the same time). Bikes with a slipper clutch remove a lot of the rider risks associated with not matching RPMs during a downshift, but still don't cushion the actual gear-face during the down-shift sans clutch.
* - The new '06 Yamaha FJR has a computer controlled shifting system that takes your foot's input as a signal, using it's own solenoids to shift & handle the clutch -- but it's still not downshifting without any clutch use, just without the need for you to activate the clutch manually.

(C) Incomplete or slow shifts -- shifting on a bike should be a fast, hard snapping action designed to slam home the gear (as verses to a car, where slow shifts are rewarded on those with planetary gears to spin up the gear splines in advance of mating).

This issue has been covered in detail before here:
Clutchless shifting
and there's a good, detailed look at failures here:
NTHSA investigation: Suzuki, sales figures & 2nd gear failure rates for '99 - '01 GSXF & GSXR750's

This little segment specifically from that NHTSA investigation I think bears the most merit to answer your question (Suzuki sez - excerpt):
...motorcycle that has this condition [2nd gear failure] must be subjected to repeated improper and/or abusive shifting (i.e. - incomplete shifting or shifting without using the clutch).

Yes, drag racers and track racers shift sans clutch all the time -- trading the reliability factor for the tenth of a second speed differences. But their vehicles get rebuilt on a regular basis as a result.

Cheers,
=-= The CyberPoet

[katman05]

air shifter

[teddy]

I've done this a few times, but only at low speed just to drop the rpm's a bit. Like doing 35 going from 4th to 5th. I would never do it at 'speed' though, and never ever do it downshifting. I have to find the 'sweet spot' between the engine and tranny rpm's for it to go though, I never force it.

[BLACKDEATH]

(A) Upshifting sans clutch into 2nd without unloading the throttle (can be done, but you need to unload the throttle), esp at high RPM's.


Yes, drag racers and track racers shift sans clutch all the time -- trading the reliability factor for the tenth of a second speed differences. But their vehicles get rebuilt on a regular basis as a result.

Cheers,
=-= The CyberPoet

I unload the throttle electronically with a button. I figure if I can get 3 years and 40+k miles doing this I will rebuild the thing. No biggie. Its a toy.

[Built4Speeed]

friend of mine with a gixxer 1000 does it to shift while doing wheelies.. if you pull in the clutch you'll drop the front, so he just goes right through the gears without any clutch use whatsoever, all throttle control

[The CyberPoet]

I unload the throttle electronically with a button. I figure if I can get 3 years and 40+k miles doing this I will rebuild the thing. No biggie. Its a toy.

As long as you're only doing it on upshifts, and the time-period for the unload is long enough (1/2 second ? ), I wouldn't be very concerned myself.

But whether that tranny will make it to 40k (or won't make it), in large part, depends on the riding habits -- someone who cruises 300 mile trips on the highway or interstate will see 2nd gear only at the start & end of the run, while someone covering just a few miles in the city may see 2nd gear a couple dozen times. The same generally applies to all the mechanical systems on the bike -- people who ride longer distances tend to have fewer hardware failures as a result of their riding habits.

Cheers,
=-= The CyberPoet

[gosman767]

I'm with Cyberpoet, as long as you have some 'mechanical sympathy' then no problem.