Quick Chain Question

[donkason]

I'm getting a jump on maintenance and I have a chain question.

When I bought my track bike last year, 07 GSX-R 750, the previous owner said he installed a -1+2 setup. The sprockets/chain look to be in good shape, but the adjusters are moved nearly all the way out to get the chain tension within tolerance. I need to snug the chain up again and, to me, it shouldn't be out as far as it is.

1. Is this common with a setup like this?

2. Can I remove a link or two from the chain and get it back in the adjustable range?

I was thinking about replacing the whole setup, but it looks okay and I want to save the $175-$200 for a new setup.

Any guidance would be appreciated.

[TSB67]

Moving the rear wheel forward or back is an often overlooked fine-tuning thing. Yes you can remove links to move it forward, if that is what you prefer. Just make sure you will still have chain slack afterwards - easier to remove links than put them back in.

[donkason]

Thanks for the explanation. I just got my basics dialed in on my suspension and I haven't stepped into the fine tuning yet. I'm a quick "I" at Mid-Ohio so there is a lot of work to do still. I'm sure I'm not fast enough to notice a nuance like that.

[TSB67]

I'm sure I wouldn't notice it either. Just saying someone may have intentionally set it up like that. Adjusters out isn't necessarily bad unless you're running the stock chain and sprockets.

P.S. Or maybe it was just installed by somebody who wanted to err on the side of not removing too many links from their brand new chain.

Edited February 3, 2013 by brn6604

[RHill]

Don't people normally shoot for shorter wheelbase?

[blue03636]

Not necessarily, depends on how the have the suspension set up and it would also make the bike wheelie easier. I would say most shoot for the middle.

[SJC1000rr]

If the chain has stretched so much that it's at it's limit, I would personally err on the side of new replacement. Chains are cheap compared to the damage a broken chain can cause while riding.

[RHill]

Not necessarily, depends on how the have the suspension set up and it would also make the bike wheelie easier. I would say most shoot for the middle.

good point

I think it also messes with antisquat along with swing arm angle and sprocket size.

[Helmutt]

If the chain has stretched so much that it's at it's limit, I would personally err on the side of new replacement. Chains are cheap compared to the damage a broken chain can cause while riding.

This ^^ A new chain and sprockets are far cheaper than repairing possible case damage, not to mention stitches if it happens to chop through boot/leathers. May not hurt to install an aluminum chainguard too if you are still running the plastic stocker.

If it were me, I'd replace it if its stretched to the point of almost the end of adjustment just to be safe

[Tonik]

Are you SURE the chain isn't worn?

[Tonik]

You can check for chain wear with a pair of calipers. When in doubt' date=' swap it out. I've seen a chain let go on a bike before. It's not pretty.[/quote']

This. Unless you know the history for sure the sprockets could look good and the chain could be shot and look perfectly normal.

[donkason]

I was told it was replaced as a set by the previous owner who had 3 track days on it. I have heard the -1+2 conversion moves the wheel farther back causing the adjusters to be near full out. The bike has less than 3800 miles on it and the chain tension was good when I bought it so I don't think he ruined the chain by making it too snug. However, it would be better to not assume such things.

I have a digital caliper. Would I measure it link to link and see where that stands over the OEM length?

Thanks!

You can check for chain wear with a pair of calipers. When in doubt' date=' swap it out. I've seen a chain let go on a bike before. It's not pretty.[/quote']

[SJC1000rr]

If the chain is new/newer then I would definitely adjust it as needed. I ran -1 front constantly on my 600RR, but could run anywhere from 42-45t rears (0 to +3) with the chain ending up the "ok" adjustment area.

As for the -1/+2 thought, that equates to about a +1 in the rear overall which would move the axle adjuster slightly forward, not backwards. Bigger tooth rear sprockets increase's size and brings the rear wheel forwards to the front making a shorter wheelbase. It's a give and take when only using one chain with different sprockets to end up with what you want. (be it accelerations, speed or wheelbase etc)

Edited February 4, 2013 by SJC1000rr

[Tonik]

Sounds like you know the history. I now believe you are fixing something that isn't broke. Fix something else.

[serpentracer]

a good way to tell if a chain is worn is if you can lift it off the sprocket at the back side.

at least that's the way i've seen a honda tech do it on a race bike.

[nk140]

a good way to tell if a chain is worn is if you can lift it off the sprocket at the back side.

+1 on this test. If the chain pulls more than half a sprocket tooth away then the chain needs replaced. I usually replace a chain once a year if it needs it or not.

[gixxie750]

What brand chain? If chain is bad REPLACE!!! If it has aluminum rear sprocket REPLACE! On GSXR its VERY common to run the axle to the back of the swing arm. Also you need to make sure u are at 325-328mm EYE to eye on rear shock and your forks are FLUSH or a little down in the top tree. Moving the rear axle back makes the bike more stable DURING a turn,but harder to to turn in. Myself I am not decided on which way i like.

[RSparky]

Fudged up the quote, on my phone:

"As for the -1/+2 thought, that equates to about a +1 in the rear overall "

I'm no expert racer tech smarty pants, like you, but I'm pretty sure that's more like + 3.5-4 in the rear. Lower in the front gives torque just like higher in the rear.

To op, just find the 10 link length. Most manufacturers have a scale for that. That's how I knew my old chain was shit. you don't need a caliper, just a tape. And google.

[ross]

Fudged up the quote, on my phone:

"As for the -1/+2 thought, that equates to about a +1 in the rear overall "

I'm no expert racer tech smarty pants, like you, but I'm pretty sure that's more like + 3.5-4 in the rear. Lower in the front gives torque just like higher in the rear.

To op, just find the 10 link length. Most manufacturers have a scale for that. That's how I knew my old chain was shit. you don't need a caliper, just a tape. And google.

He was referring to overall chain length and the differnce in sprocket sizes compared to stock dimensions, not what -1,+2 does for torque.

[RSparky]

Duh, gotcha. Carry on.

[donkason]

My chain is an EK520 MKXZ. Per their website pin length is supposed to be 21.50mm. I measures about 10 links on different areas of the chain and had 21.51 to 21.62 on the high side. My caliper wasn't long enough to get a 10 link measurement. Is that enough data to make a determination?

That's the best I could come up with. Also, the chain does not pull off the back of the sprocket. I like to use math and learn something new so I broke out the calipers.

http://www.ekchain.jp/product/street_bikes.html

[donkason]

After some more digging I found the stretch limit of 319.4mm and how to properly measure the 20 pitch length. I'm at 318mm so it's done for. IDK what the previous owner could have done to smoke a chain in such a short time.

Now onto where to buy the kit and brand suggestions. Let me hear then if you have em please! This is my first chain replacement and I plan on sticking with the 520 conversion with -1+2.

Thanks!

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