left- or right-hand thread?

I'm trying to remove the front sprocket from a CBR600, but don't know
which way it is threaded and the manual doesn't give any indications.
I'd rather not **** it up by trying to undo it in the wrong direction,
so if anyone could please enlighten me that would be much appreciated!



Damien
GPX250 -> CBR600 -> Shadow?

 

think about it...which way does the sprocket turn to make the big wheel go
round forward?

so sprocket turns anticlockwise..

now which way to ensure the nut doesnt come undone?

have fun! a dirty job

 

so to loosen the locknut...turn it anticlockwise...standard thread ....lefty
loosey rightey tightey.

design principal?

ie. assuming the locknut is held still , the operational action of the
sprocket rotation (anticlockwise) should tend to ensure the nut remains
tightened rather than loosening.

 

well yes, that is the logical way to do it...but I'd rather ask a
silly question and get it right than make an assumption and break
something because I got it wrong!

So that would be left-hand thread then?



Damien
GPX250 -> CBR600 -> Shadow?

 

*looks innocent*

who me?



Damien
GPX250 -> CBR600 -> Shadow?

 

You may be surprised if you automatically think it is a LHT.
Does the nut have any "valleys" cut into the points of the hexagon to
indicate it may be a LHT?
If rotation direction was the only criterion of LHT v RHT then all motor
cars would have LHT/RHT on the front wheel axles - doesn't happen.
Cheers,

 

Nope, nothing special about it. I figured it was RHT to start with,
but it was on so goddam tight and when I mentioned it to a friend they
asked if maybe it was LHT instead - and I didn't know. So I thought
rather than maybe end up stuffing something up, it would be prudent to
make sure before proceding any further. It's not something I've ever
really had to worry about before, hence the uncertainty. But alx's
post was very helpful

So my next question is: how the hell do you undo something that just
does NOT want to come loose?


Damien
GPX250 -> CBR600 -> Shadow?

 

You put the socket onto an Impact wrench, lock the back wheel (friend on
brake will do it) and smack the wrench with a club hammer.
Well, that's the way we did it when I was a mechanic....
But now they have air driven stuff....
RexT
R80 (dirty white...)

 

Without LHT indicators on the nut, I would just bend the lock washer out
of the way and use a rattle gun and assume a RHT. If this doesn't work,
reverse the rattle gun. You could always check the service manual, or
see if any CBR600 internet sites have a tech section.
Cheers,

 

I've tried belting the damn thing into next week (with brake engaged)
and it just wont budge. $60 for a rattle gun is sounding better by the
moment...


Damien
GPX250 -> CBR600 -> Shadow?

 

I tried a cheap rattle gun and couldn't shift the last one I did... I
had to go to work and use the 3/4 drive compact one... some of them are
bloody tight!


G-S

 

head to the local mechanic and get them to undo it then do it back up again
and head home and attack it again

prob wont charge you if they are a nice bloke

 

See my thread up above about engines blowing up...

Went and bought a rattle gun, and solved that problem very
easily...now I just need to work out where the **** I'm going to find
a 12mm hex key to undo the one remaining bolt that's holding the
engine in...stupid fucking engineers always have to make it bloody
difficult, don't they? No one sells bloody 12mm bloody hex keys, only
bloody 10mm bloody effin bloody hex keys...


Damien
GPX250 -> CBR600 -> Shadow?

 

Hex? You've been jinxed.

---
Cheers

PeterC [aka MildThing]
'81 Suzuki GS450-s (gone on to better and brighter things - I hope)
'87 BMW K100RT (write-off)
'81 Yamaha Virago (XV) 750H (work in progress)
'01 Yamaha FJR1300

www.dmcsc.org.au
http://eladesom.com.au/ulysses/
# 37181

 

well there is another option

get a bolt with a 12 mm head and 2 x nuts

put the nuts on the bolt and tighten the nuts together

insert the bolt head and remove allen bolt

cheaper than hex key

 

Thanks, but I've already tried that and it didn't work. The engine
bolt is so goddam tight that no matter how tight I did the nuts,
*they* were what turned, not the engine bolt - in fact, the "hex key
bolt" ended up shearing between the nuts. This one is going to need
the real deal, I'm afraid, even if that is the more expensive option.

The other part that's shitting me at the moment is that the front
sprocket is on so tight also that even the rattle gun can't even budge
it even a tiny bit.

This is definitely not my week at all.



Damien
GPX250 -> CBR600 -> Shadow?

 

ok try a tool place , there is a few online

you can buy one or you can buy a set

12 mm is out there

 

There is a 12mm hex key in the set at work... but that's a _big_ set and
it cost a pretty packet. Maybe if all else fails you could get a single
12mm hex key (I know they sell replacement ones).


G-S

 

As I said in other posts... you _can_ get the 12mm by itself, and for
the sprocket use a good 3/4 drive rattle gun (with a reducer if needed)
and run it off a good compressor... it'll shift. If that don't work
then I can loan you a 1" drive rattle gun that'll shift rusted on truck
wheel nuts....


G-S

 

I'm not going to worry too much about the sprocket for now. I was
going to be replacing the chain this week anyway, so I just broke the
clip and pulled it off that way. Not too keen on clip links anyway, so
good riddance to it! Important thing is I can now at least get the
engine out (well, once I've got that bloody 12mm hex key at least!)
and find out the extent of the damage and work out what needs doing to
fix it. If I still have no luck with the sprocket, then when it's all
back together again I'll just trailer it around to the bike shop for
them to fit the chain instead and they can worry about how to get the
sprocket off instead of me!

For now, it's time to service the carbies and generally give the rest
of the bike a good going over...figured it's a good time to do it,
since it's all in pieces now anyway!


Damien
GPX250 -> CBR600 -> Shadow?