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TP 24-May-2005 21:07

Changed the front sprocket
 
Right, I've just been outside and changed the front sprocket on the bike and only managed to strip one thread :(

The stripped thread is the one that holds the sprocket cover in at the top. The bottom one is fine but in my hamfisted gorilla approach I did the top one too tight and it just kind of spins in there now - doh! What can I do to fix this?

Secondly, I've adjusted the chain and done the rear axle nuts up to 33Nm - is this right? I seem to remember hearing 77Nm for somewhere but can't place it.

And thirdly, I know the idea is to line up each adjuster on the back inline with the markings so each side is the same but it doesn't seem right when I do that. It seems like the wheel is out of line and not straight. Trust the markings and get on with it?

tetol 24-May-2005 21:22

the sprocket cover is not a legal requirement tp i would leave it off

Rattler 24-May-2005 21:35

I changed my gearing back to stock for my trip to S/Stone today - but wished I left it as 1 less on the front.

I did manage to pull 110mph down the straight though, but on Andy's 999R I managed 150!!!! No wonder my laptimes were cr4p!!!

I just don't think that a 620 can handle the stock gearing - I am probably better leaving the front stock and going up 1 at the back for the longer circuits I reckon?

Tim

TP 24-May-2005 21:45

Well - it's 77Nm and I'm going to get it as inline with the markers as I can and then adjust to make sure the chain sideplates look straight as the wheel rotates. May have to helicoil my hamfistedness though :( ****!

I agree Tim, the bike struggles to pull 15/46.

I'm going to run 14/46 tomorrow night at Brands (you going to make it?) and see how I get on. I can see me running 14/45 for CC.

I forgot about the clipons mate! Is it too late to pop down and pick them up?

domski 24-May-2005 21:52

Quote:

Originally posted by TP
Right, I've just been outside and changed the front sprocket on the bike and only managed to strip one thread :(

That's what happens to you office boys when you get your fingers dirty :lol:

A bummer though :(

Quote:

The stripped thread is the one that holds the sprocket cover in at the top. The bottom one is fine but in my hamfisted gorilla approach I did the top one too tight and it just kind of spins in there now - doh! What can I do to fix this?

Like Paul says, don't need it for racing, and you'll probably need a heli-coil thingy to repair it. Someone like Skidlids will know what to do.

Quote:

Secondly, I've adjusted the chain and done the rear axle nuts up to 33Nm - is this right? I seem to remember hearing 77Nm for somewhere but can't place it.

Don't do it to 77Nm!!!!!!

I did mine up to 70Nm at Cadwell and Louigi had a hell of a job undoing it coz it span the chain adjuster around and around :(

Just do it up with a spanner, and use the torque in your arm - bare in mind you need to be able to undo it again!!

Quote:

And thirdly, I know the idea is to line up each adjuster on the back inline with the markings so each side is the same but it doesn't seem right when I do that. It seems like the wheel is out of line and not straight. Trust the markings and get on with it?

Don't trust the markings either!!

Louigi told me to use the gap between the back of the adjuster and the hole in the swinging arm (where the spindle slides back and forward). Make the gap equal.

Does that make sense?

domski 24-May-2005 21:53

Quote:

Originally posted by TP
Well - it's 77Nm

Ooops!! :o

[Edited on 24-5-2005 by domskidue]

moto748 24-May-2005 22:12

Ah, back in the days of those old-fashioned double-sided swing-arms... :D

On my old 750SS, I used to measure the distance (clearance) between the "shoulder" of the rear tyre and the swinging-arm, and make sure it was equal on both sides.

Rattler 24-May-2005 23:49

Quote:

Originally posted by TP


I forgot about the clipons mate! Is it too late to pop down and pick them up?

It is now!!!

Tomorrow's OK with me - just don't expect me to be too sociable when the footies on!!!

Tim

TP 24-May-2005 23:52

Quote:

Originally posted by Rattler
Quote:

Originally posted by TP


I forgot about the clipons mate! Is it too late to pop down and pick them up?

It is now!!!

Tomorrow's OK with me - just don't expect me to be too sociable when the footies on!!!

Tim

:lol:

I texted you and rang as well ... nevermind.

Are you working from home tomorrow? Because I'll be heading to Brands early to pick mw up on the way. Briefing is 5:00pm - are you going to book?

the old man 24-May-2005 23:55

Actually the DD regs say that a gearbox sprocket cover is required - though God knows why?!!

77NM/Kg/ft/lbs???? just do it up tight - but not as tight as the top sprocket cover bolt!!!!

Percieved wisdom is that alignment marks are not to be trusted - I have a pair of six foot long straight edges that I clamp either side of the rear wheel; then align the wheel so there is the same gap between the straight edges and either side of the front wheel. If that males sense; assumes the frame is straight as well. BUT I haven't bothered to use it on the 620, just used the alignemnt marks and it all seems OK to me.

ali 25-May-2005 00:09

Several ways of skinning the same cat.... I use a straight edge to the swingarm pivot and score a couple of marks where the centre of the rear wheel spindle is. It's not perfectly accurate, but it's not that important as my frame is bent as a nine-bob note..... :(

Ian's method of using two bloody great straight edges all the way to the front wheel is generally though tof as the best way. I saw one of the BSB teams using this method at Brands on Good Friday so it's probably good enough for DD!

Ali

ps: If you use the torque wrench for when you're bolting into super-soft alloy crankcases, and not when doing up bloody great wheel spindles, you'll probably end up with less stripped threads......

TP 25-May-2005 00:10

Quote:

Originally posted by ali
ps: If you use the torque wrench for when you're bolting into super-soft alloy crankcases, and not when doing up bloody great wheel spindles, you'll probably end up with less stripped threads......

Oh bugger off! Haven't got 100 self tappers to whack in your end can or something?


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