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Chain tension and axle position

Posted: Sun May 11, 2008 4:41 pm
by Gurgus
So, I set my chain slack on my CB450SC tonight and was wondering if anyone had any tips or tricks to setting the rear axle in the proper postion.
I know my chain line is fairly close, just looking for methods to get it dead on. Is a very slightly off chain line a big deal on a motorbike?

Thanks all in advance.

Posted: Mon May 12, 2008 6:04 pm
by redcoat
slightly off can be a big deal if you're running expensive tires and chains. Some off will prematurely wear the tire, chain, sprockets etc. So keep it to a minimum. However, if Honda thought it really important, they would have done something better than those 5 marker lines. Just do your best.

Don't know if it applies to the SC, but the CB- you really should slacken the brake arm, then adjust the chain, then retighten the nut. And, newbie mistake oh those 20 years ago, if you're sitting on the floor behind the bike, leg to either side of the rear wheel, and you're yanking the 22mm wrench TOWARDS you, the axle comes out of adjustment- it drags the axle towards you. Trick is to PUSH the wrench AWAY from you as it goes between 9 and 12 o'clock- that way the axle comes up against the adjusters, and won't come out of the careful position you put it in.

Personally, I have the CB400 (same as yours, not as shiny), and it gets $35 Duro tires, and a EMI or Evi, (something like that) chain for $17, so I don't care. It's all sloppy in a week, but lasts for a year.

Justin

Posted: Mon May 12, 2008 6:57 pm
by Gurgus
Thanks for tips! Im going to give it another go when I get home in the morning from my nightshift. I've done this procedure alot on my bicycles, but this the first time on a M/C. Hoping to get it right and go for a ride.

Posted: Mon May 12, 2008 8:30 pm
by Wrider
My instructor just told us to align it so that the chain doesn't rub on the sprockets.
Set up a drag bike like that one time, the wheel was aligned with the frame and wouldn't go straight, so they aligned the chain with the sprockets and it worked great. After the season they tore the bike down and the frame had a 3/4" jig in it.

So yeah, align it so that the sprockets aren't rubbing on the chain or the tires and you should be fine. Make sure you have proper tension too...
Wrider

Posted: Tue May 13, 2008 4:23 am
by storysunfolding
lol- maybe it's just me but all my swing arms are symmetric I go by eye, adjust with a set of cheap calipers check the distance on each side and once I tighten up and recheck, I use a square to make sure the sprocket is in line with the chain. Takes five minutes once you've done it a few times (track days made it happen faster with my many sets of new tires :laughing: ) and all the stuff you need is less than $10.

Posted: Tue May 13, 2008 5:17 am
by Skier
A trick a long time racer showed me was to roll the rear tire a bit and make sure the chain is centered on the sprocket teeth in the back. A misaligned rear tire will cause the chain to be closer to one side or the other.

Obviously only works if you have a center stand or pit stand, though.