Chain Length Question

[dan]

I picked up a 47T steel rear sprocket for my K3 600 the other day. I was led to believe that it would work with the stock chain length but, of course, it doesn't. After a bit more googling it seems as though a 112 link chain should be sweet with it. Does this seem right?

I don't know heaps about this so I'm basically putting it on to see how it feels and I'll make a decision through trial and error. At the moment I'm not seeing much of 6th down the straight at EC (fuck all, actually) so I'm thinking, in theory, it should pull a bit better and leave me in a better rev range going through turn 1 (in theory...) as I'll be shifting down into the power in 5th rather than being stuck in no-mans land.

But hey, then again I might be miles off but I'll guess I'll find out soon enough! Worst case scenario I can always change back if it doesn't work for me.

Anyway, back to main issue right now - 112 chain length sound right?

Thanks!

[Marshy]

Hey Dan, many of us (well, me and other mates of mine, over the years) have made that exact mistake!

What rear sprocket were you starting with? The other thing to consider is the wheelbase change, and the associated changes to the bike's handling, if moving the rear wheel rearwards by a lot. I strongly recommend going 1 tooth smaller on the front, rather than up on the rear. 1 tooth on on the front is roughly equivalent to 3 teeth up on the back, so you get a lot of 'bank for your buck' by changing the front.

There are other advantages too: front sprockets are in the $20 to $40 range, so quite a bit cheaper than rears. They don't significantly change the rear wheel position (only a few mm), so don't throw your handling out. And finally (assuming you have a rattle gun, or the nut isn't welded on due to years of corrosion and gunk), they are quicker to change! No need to remove the rear wheel. Oh, and you don't need to buy a new chain!

[dan]

Interesting point about the front - you might be on to something. I've already bought the 47T but it would probably still be cheaper to change the front and keep the same chain and just hold onto the 47T - I should get away with the same chain, right?

At the moment it is running 45T at the back, 16T on the front with a 110 link chain.

[Marshy]

Yep, it will be cheaper. And if you're looking for a 2 tooth rear adjustment anyway (not fine-tuning with a 1 tooth change), then 1 down on the front will be fine. Almost all racebikes have a 15t front, and many have a 14t. Personally, I'm running a 15t for the Creek, and change to a 14t (same rear) for Wakey/Broadford/Winton.

Also re the chain length, whenever I buy a chain from Motomummy or the like, they always come in the 120 link version, and I don't remove 8 links, so I don't think a 112 will be long enough anyway.

[dan]

Thanks mate, this has been very helpful! Need to get it today - out at CSS tomorrow and want to give it a test run.

[dan]

Bought a 15T front, couldn't get the fucking nut off :(

Is there a trick? Had it in gear, a mate holding hte rear brake on. Could not get it to shift.

In other news when I pulled the sprocket cover not only was I met with all the grease and shit build up you'd expect there was a bolt and washer stuck in that mess. It was away from the sprocket jammed in all the sticky stuff but deadset haha

[chubb]

Yeah its called a power tool.

If you dont have one. Dont put the bike in gear.. puts stress on the box.

Use a piece of wood through the swingarm and wheel. And a big breaker bar.

Is the washer tab flat? The kwaks have a locking washer. Check the gixxer dont have the same thing.

[Marshy]

What Chubb said. If it's been on there a long time (and often even if it hasn't), you WILL need a rattle gun to get it off. Be very very wary of using a massive breaker bar, as it will stress everything - the chain, the gearbox shaft etc. With a rattle gun, even if it's fuck-off tight, you don't even need to hold the back wheel - the rattle doesn't even turn the shaft. It's a totally different approach to using brute leverage, and your bike will thank you for it.

If you have a compressor, air guns are dirt cheap (a mate just got one for this purpose for $30 from Bunnings? Supercheap?). Even a perfectly adequate compressor from the usual suspects is under $100 these days, so if you're gonna change them regularly, just buy the whole lot for a bit over a hungie.

If you don't have either and don't want to buy them, any bike shop, car mechanic, tyre fitter etc etc will have one. Or you can bring the bike over and I'll do it for ya.

I might add that my air gun is totally my favourite tool of all time!! I only use it for front sprocket nuts (and the trailer hitch occasionally), but every time I do use it, I giggle like a schoolgirl!! And a compressor is a tool of 1000 uses, once you have one.

[Marshy]

Oh, and yes, it's amazing what collects unseen behind the sprocket cover!! It should be cleaned every once in a while, just so the chain isn't picking up previously flung-off crap.

[dan]

I hooked up an air-ratchet to my compressor but it didn't have enough grunt to get it off. I had a go with the breaker bar but it didn't feel like I was getting anywhere and I was hesitant to keep going in fear of damaging it.

I'll pick up a proper rattle gun at Bunnings over the weekend and give it another go otherwise I might have to take you up on that offer Marshy - I'll bring some tyres over with me and try kill multiple birds with minimal stones.

Thanks guys!

[Phat3R]

0:39 for lock washer 0:55 for a technique that supposedly works to manually break it.



Beware I am a wrench spastic so above may be of no use at all.

[dan]

Mine actually looks like this and doesnt appear to have the washer lock nut.

Screen Shot 2013-07-04 at 10.01.05 PM.jpg

I'll give it another bash on the weekend and see how I go. Will update!

[BoB]

For those interested in gearing and what happens to your bike when you increase the rear by +2 , change from a 180 to 190 rear or how far the rear wheel moves when you change the sprocket .. even gives you the chain lengths ... type in the details and it gives you plenty of info .

http://gearingcommander.com/

Just select your bike make and model from the drop down menu and edit your current settings and custom settings.. plenty to play with here..

[dan]

Just an update I got the front sprocket on and it was a massive improvement. Really noticed it pull out of corners and was getting up towards the top of 6th down the straight at EC. Thanks for the help!