RE: Shifting without the clutch

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RE: Shifting without the clutch

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RE: Shifting without the clutch - 7/25/2005 9:47:57 PM

Twowheeljunkie

Posts: 19
Joined: 3/16/2005
Status: offline

I read a Klik & Klak article a couple years ago about speed shifting a car. They said it's like crossing the street blindfolded, most of the time your going to make it; but if you don't, its going to be ugly. Basically, if you dont time it just right you risk crunching the gearbox... bent shift forks, broken teeth and general ugliness something like bolts in a blender.

Totally guessing, but is this the risk when you downshift w/o the clutch??

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Post #: 16

RE: Shifting without the clutch - 7/25/2005 10:48:56 PM

chainstretcher

Posts: 4158
Joined: 11/5/2004
Status: online

Car tranny is completely different scene than a bike tranny -- modern bike gearboxes are synched up to allow upshifts without the clutch. Down shifting is right out because you'd have to match engine speed to the lower gear. Too high and you'll hear gear teeth being ground down -- too low and you could slide the rear. I've only ever missed an upshift when USING the clutch. It's always a more positive shift when I don't use the clutch.

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Post #: 17

RE: Shifting without the clutch - 7/26/2005 1:30:37 PM

Litre1

Posts: 44
Joined: 7/18/2005
Status: offline

There was a one page article in one of the major magazines recently (Cycle World I think) about clutchless upshifts. The writer was at a trackday and couldn't believe how many people were wasting so much time and energy using their clutches. The article went on to tell why clutchless upshifts cause no harm to a modern sportbike. I'm thinking it was early this year, maybe.

(in reply to chainstretcher)

Post #: 18

RE: Shifting without the clutch - 7/26/2005 2:04:39 PM

chainstretcher

Posts: 4158
Joined: 11/5/2004
Status: online

I read the same thing in Motorcyclist about a year ago. But don't try it on your car's 5 speed tranny

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Post #: 19

RE: Shifting without the clutch - 7/26/2005 4:06:34 PM

Firefox11

Posts: 110
Joined: 4/14/2005
Status: offline

I have been placed in the situation with a broken clutch cable that forced me to ride my old bike (katana 600) without a clutch at all. I can tell u from personal experience, it most definately can be done with upshifts as well as downshifts. The trick is to make sure you time the shifts in between the acceleration and deceleration points. If you find that right rpm, the shifter will "slip" right where it needs to go with ease. I was doing downshifts as easily as upshifts, and doing that with no clutch can be tricky! The fun part was getting it rolling while popping it into first without killing the engine!!! I had to ride 20 miles back home, and I made it without too much headache. (I had to stop on downward slopes everywhere.. Try rolling a bike uphill to slip it into first gear!!)

Honestly, I don't see why I would use this on the street.. My personal thought on the issue, its MUUUUUUUCH cheaper to replace clutches, then to replace shift forks, shift drums and gears.. And in learning this procedure you can increase wear on your transmission for no real benefit on the highway. Seconds count on the racetrack, but in the streets whats the rush? Of course if you do it "Right" it doesn't hurt the transmission etc etc, but my personal opinion, why risk it? If it works for a year, great.. But if all throughout that year you have been shifting wrong and it damages your shift forks, u will be removing the motor for a overhaul that wasn't necessary! Use wise judgement in your decisions on how to ride your ride. If I'm not on the racetrack, I'm using my clutch.

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Post #: 20

RE: Shifting without the clutch - 7/31/2005 4:51:18 PM

InTheMaking

Posts: 33
Joined: 7/31/2005
Status: offline

Hi all, I'm new to this whole forum thing, I do know my way a little around a bike tranny, first of all they do not even have syncromesh like a car the reason they are always in sink is because bikes have what they call a CV (Constant Velocity) transmission.

This means all the gears are always turing at the same time and are always engaged on the face. since bike gears are always engaged u cannot really grind the teeth of one with the teeth of another, The tranny changes its ratio by locking different gears to the primary and secondary shafts.

I have a 87cbr600 that I have been drag racing for about three years now and the tranny is still good.

(in reply to Firefox11)

Post #: 21

RE: Shifting without the clutch - 7/31/2005 9:38:52 PM

superflyRR