First gear clunk

[Athame57]

Is a noisy first gear engagement the norm on a CB400F or something?  Even after I fitted a 'new' second hand clutch that was way better than the one I was replacing during an extensive rebuild it was soon back to that loud clunk when engaged, sometimes more quietly or louder than other times. could it be just me? Suggestions?

[Bryanj]

I think that is most bikes due to nature of clutch

[Laverdaroo]

If when you roll the bike forward gently whilst popping it into gear does it still do it? If so there’s more adjustment in the clutch.
Also, maybe the chain just needs a  bit of slack taking out of it, that often allows a bit of lash at the gearbox end and a clonk when putting it in first.
One of my VFR’s does it but if you roll it gently, just a couple of inches or as I say just tighten the chain to what it should be it’s absolutely fine and snicks in beautifully.

Have a go at that and report back. First gear clonk is dead common as Bryan mentioned but you can dial a certain amount out with a bit of a methodical fiddle.


Sent from my iPhone using Tapatalk

[Athame57]

Thanks for the answers guys,    a bit of a storm in a tea cup then! 

[Laverdaroo]

Pretty much but you can tell if there’s more adjustment by trying to see which works, dead simple and FREEEEEEE!

Winning


Sent from my iPhone using Tapatalk

[TrickyMicky]

Do you free the clutch off on the first start of the day?    Is your idling speed too high?  If it does it all the time, then yes to making sure the rear chain is not too slack, and also not too much slack in the clutch  cable. (Only adjust this with a cold engine!).  No synchromesh along with a multi-plate clutch means you will never get a completely silent 1st gear engagement.

[Mikep328]

Different oils can produce more/less clunking. I haven't noticed my 400 to clunk any more then many other motorcycles I have owned.  I did have an experience last year where I changed oil and used full synthetic.  It was TERRIBLE for clunking and would seize the clutch if the bike wasn't run for a couple of days.  Put regular oil back in and the clunking was much reduced and the seizing disappeared.

[Athame57]

Different oils can produce more/less clunking. I haven't noticed my 400 to clunk any more then many other motorcycles I have owned.  I did have an experience last year where I changed oil and used full synthetic.  It was TERRIBLE for clunking and would seize the clutch if the bike wasn't run for a couple of days.  Put regular oil back in and the clunking was much reduced and the seizing disappeared.

I use the highly recommended...

[Laverda Dave]

If when you roll the bike forward gently whilst popping it into gear does it still do it? If so there’s more adjustment in the clutch.
Also, maybe the chain just needs a  bit of slack taking out of it, that often allows a bit of lash at the gearbox end and a clonk when putting it in first.
One of my VFR’s does it but if you roll it gently, just a couple of inches or as I say just tighten the chain to what it should be it’s absolutely fine and snicks in beautifully.

Have a go at that and report back. First gear clonk is dead common as Bryan mentioned but you can dial a certain amount out with a bit of a methodical fiddle.


Sent from my iPhone using Tapatalk

My VFR does that same thing Roo and is always a good indication the drive chain needs adjusting. The VFR does seem to be very gentle on drive chains unlike my old 250RSA that appeared to eat a drive chain for lunch!

[Laverda Dave]

Is a noisy first gear engagement the norm on a CB400F or something?  Even after I fitted a 'new' second hand clutch that was way better than the one I was replacing during an extensive rebuild it was soon back to that loud clunk when engaged, sometimes more quietly or louder than other times. could it be just me? Suggestions?

What condition were the cush drive rubbers in George when you replaced the clutch? My 400 would clunk going into first from neutral and would sometimes clunk going into other gears as well. When I rebuilt the Flying Banana (aka Rat Bike) I checked the clutch cush drive on that and it was horrendous the amount of play on the clutch basket. I replaced the rubbers with a set I bought from Max and no clunk since👍

[Athame57]

What condition were the cush drive rubbers in George when you replaced the clutch? My 400 would clunk going into first from neutral and would sometimes clunk going into other gears as well. When I rebuilt the Flying Banana (aka Rat Bike) I checked the clutch cush drive on that and it was horrendous the amount of play on the clutch basket. I replaced the rubbers with a set I bought from Max and no clunk since👍

Hi Dave
During the rebuild the mechanic in charge showed me the amount of play in the clutch unit by causing noise rapidly twisting back and forth it in his hands. I got a new unit from 400Four spares and it did nothing of the sort, only a little bit of noise, so I can only imagine they were ok.

[Oddjob]

There should be no noise, if you can hear any or feel any play in the large gear on the back of the clutch it’s buggered I’m afraid. If you still have the old basket get some new rubbers from Max and do the mod, then swap out with existing clutch.

[Laverdaroo]

If when you roll the bike forward gently whilst popping it into gear does it still do it? If so there’s more adjustment in the clutch.
Also, maybe the chain just needs a  bit of slack taking out of it, that often allows a bit of lash at the gearbox end and a clonk when putting it in first.
One of my VFR’s does it but if you roll it gently, just a couple of inches or as I say just tighten the chain to what it should be it’s absolutely fine and snicks in beautifully.

Have a go at that and report back. First gear clonk is dead common as Bryan mentioned but you can dial a certain amount out with a bit of a methodical fiddle.


Sent from my iPhone using Tapatalk

My VFR does that same thing Roo and is always a good indication the drive chain needs adjusting. The VFR does seem to be very gentle on drive chains unlike my old 250RSA that appeared to eat a drive chain for lunch!

Ehyup Dave, yeah, they’re not bad on chains but that clunk is always a sure fire way to determine that the chain needs a tweak. Two mins on the centre stand for us though. I’ve done 6 CSK’s on the VTEC, in what’s now 187k miles on her. Gotta be good value, it’s not like she’s not being thrashed……..well not all the time!


Sent from my iPhone using Tapatalk

[Oddjob]

We all know that anything over 20 mph and all of Bristol can hear your screaming Roo.

[Laverdaroo]

Morning Fester, screaming with 'glee' that is