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Use clutch when shifting?


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After a small break of 20 years I have got back into riding with an 06 YZ 450f . I was primarily a 125 rider and during my last year of racing I raced the 125 (CR125) and open (YZ490) expert classes. When I rode those bikes I never used the clutch for shifting much except for maybe some downshifts/braking. My question is, how necessary is it to use the clutch for shifting on this bike, old habits and riding styles are hard to break, I still have the habit of doing the most of my shifting without the clutch. Is this going to cause me problems or are these transmissions capable of shifting without the clutch also?

thanks for any input...

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It shouldn't need to be clutched at all when shifting. A constant mesh should only engage a gear if the speed of the input shaft and the speed of the gear you are trying to engage are matched, if not it should grind quite a bit.

This should apply for upshifting or down shifting..

I've driven tractor trailers for 15 years, and never clutch except to stop and start.. or if I am in heavy traffic and moving slow with a heavy load. Easier on my spine that way!! I've never had a problem with a transmission.

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It shouldn't need to be clutched at all when shifting. A constant mesh should only engage a gear if the speed of the input shaft and the speed of the gear you are trying to engage are matched, if not it should grind quite a bit.
The attributes you are talking about are those of a synchromesh transmission, not a constant mesh. Both types are constant mesh, but motorcycle transmissions are typically not equipped with synchronizers, simply because their small size makes it unnecessary, in most cases. Making the shift is what matches the speed, and there's nothing particularly graceful about the process.

Some specialized drag racing car transmissions ares are built similar to motorcycle gearboxes (with a technical twist that we won't get into), so that they can be shifted without the clutch. It wouldn't be something you'd want on the street; the noise and shift shock are considerable, to say the least.

Nevertheless, shifting without the clutch by blipping the throttle to relieve the drive load is reasonably harmless. Doing so under a load is not advisable, and will lead to both gears (the one being shifted from, and the one being shifted to) wearing the locking lugs, and eventually failing to hold in gear.

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