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Question about clutch and hard shifts into and out of 1st gear

mataylor

dipshit
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Bear with me, as I have only been riding for about a year so I dont know all the in's-and-out's of motorcycle engines. That being said, I am mechanically inclined and have rebuilt car engines before so I know the basics.

Anyways, I ride a '77 cb750 supersport and I have a question about the clutch and hard shifts into and out of 1st gear. Basically I have 2 problems/questions:

1. Having only dirt bike clutches as a reference, the friction zone on my clutch seems very short. I have to let out the clutch about 80-90% before the clutch plates start to grab. This leaves about 10% of friction zone 'distance' whereas on a dirt bike a much larger % of the clutch distance is in the friction zone. Are my clutch plates worn/wearing out, or do street motorcycle clutches just have a shorter friction zone than those on dirt bikes?

2. My transmission shifts/clunks hard into--and out of--1st gear about 1/3 of the time. I realize an 37 year old bike isn't going to have a brand new transmission, but is this a common problem? From what I can find it seems that the 2nd-3rd gear transition is usually the one to misbehave.

If I need to replace my clutch plates then maybe i'll take a look at the tranny while Im down there; or maybe ill wait for the winter to tackle the bottom end. Thanks for the help.
 
All My cable operated clutch Honda,s were like that including the 72 I have now, Neutral to first always clunked on Mine also have to search for neutral at times I think it,s just the nature of the beast, My previous hydraulic operated clutch Honda,s were gradual to engage. I would not change out the clutch unless it,s slipping on You. Never had any problems with shifting to second on up.
 
You should start to have clutch engagement about half way. More than likely you are getting some grooves worn in the inner clutch hub not allowing the plates to move as far as they should. This lets the plates drag a bit more then usual causing late engagement and dragging clutch. You will always get clunk going into gear on any wet clutch motorcycle, some are worse than others and oil temp, age and viscosity all contribute to how much drag and how you clutch engages.
 
Thanks so much Digger for ringing in on this one, I have not had a cable operated clutch in decades and I decided to to look at My own, Removed the clutch adjustment cover and found the detent adjuster loose as a goose did all the adjustments per manual and as You said grabs about half way out, Works great! In times I need someone to make something click upstairs:) Thanks again.
 
Thanks a ton to both of you for the advice and piece of mind. dirtdigger, I'm walking out to my garage now to adjust.


much appreciated!
 
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