[ukzx10r]

Ive always wondered how to get the perfect chain tension?
Manual says a distance of play is to be set at the tightest point of the chain but it doesnt state if that is with bike weight only or with rider on.
Reason i asked is because i jacked my rear end up a few mm and the chain looks slack when on the stand but tighter when i sit on it.
I know the swing arm angle changes the chain tension alot at the beginning of the stroke but its even more so now i raised the rear.
Would it be best to sit on the bike and make sure the chain still has specified slack measurement at that point?

 

[SkyDork]

The chain is at the tightest point when the swingarm is inline with the front sportier and basically parallel with the ground. The slack in the chain is adjusted to account for the movement of the swingarm up and down. And the slack is usually set with it in unloaded position. Of course, the slack will change if the swingarm is moved. The point being that the slack is just there to prevent it from being too tight and pulling the transmission when the swingarm is at the tightest location.

 

[thundercoupe9]

Like skydork said, the distance from front sprocket to rear sprocket increases until there is a straight line between center of front sproket/swing arm pivot point/center of rear sprocket. Chain slack all depends on motorcycle's mass, riders mass, rear spring rate and the type of riding that you do. You don't want to have the chain too tight because it will limit your rear suspension travel and will put more wear on the transmission bearing.

 

[scout]

When on rear stand chain needs about one inch slack. Chain tightens when off the stand...not sitting on it, if I recall; I never micro manage the super street chain but the EZ chain 525 whatever had to watch as it stretched each ride with the met rr rear tire.

 

[LDH]

Don't forget that if you have raised the rear ride height of the bike as many have that you also have to increase the amount of slack in your chain to compensate for that.

 

[renais]

I was advised to have 12-15mm slack when sat on the bike. I believe most racers like to run the chain slightly on the slack side.

 

[ukzx10r]

I have roughly 25mm of slack when on paddock stand. When i sit on it its probably about 10mm but i dont think it can get any tighter than when everything is all in line.
Its slightly slacker when the rear end is off the ground ie: very hard breaking.
But i hope this will not cause any issues

 

[scout]

I have roughly 25mm of slack when on paddock stand. When i sit on it its probably about 10mm but i dont think it can get any tighter than when everything is all in line.
Its slightly slacker when the rear end is off the ground ie: very hard breaking.
But i hope this will not cause any issues

Just use steel sprockets and work on riding techniques. If chain is too tight the bike will tell you. I think when approaching a stop it makes me aware of chain too tight but can't report exactly what the bike does as can't remember. But it does. Too tight is rare. Too loose is disaster.

 

[LDH]

Just use steel sprockets and work on riding techniques. If chain is too tight the bike will tell you. I think when approaching a stop it makes me aware of chain too tight but can't report exactly what the bike does as can't remember. But it does. Too tight is rare. Too loose is disaster.

Scout, everything I read from you is either incoherent drivel or just incorrect spew and I can never tell if you are trolling the forum for a reaction or just did way too many drugs when you were learning to ride. Either way is fine with me, but in the interest of being helpful to others you are anything but...

Too tight happens all the time and is way more catastrophic than being too loose. I turn away half a dozen riders at every event I work Tech at because their chains are out of spec and more often than not they are too tight rather than loose.

If a chain is too tight it not only hinders the full movement of the suspension, but also excessively wears on the sprockets and pulls on the countershaft to the point it can damage the bearings and seals resulting in big repair expenses along with dangerous handling conditions.

If a chain is too loose it causes accelerated wear on the sprockets and issues from slop in the drivetrain all the way to slipping off the teeth.

The issue is that it is way easier to unwittingly get the chain too tight and cause damage where as too loose is much more perceivable and thus correctable before serious damage occurs even by novice riders.

 

[scout]

Scout, everything I read from you is either incoherent drivel or just incorrect spew and I can never tell if you are trolling the forum for a reaction or just did way too many drugs when you were learning to ride. Either way is fine with me, but in the interest of being helpful to others you are anything but...

Too tight happens all the time and is way more catastrophic than being too loose. I turn away half a dozen riders at every event I work Tech at because their chains are out of spec and more often than not they are too tight rather than loose.

If a chain is too tight it not only hinders the full movement of the suspension, but also excessively wears on the sprockets and pulls on the countershaft to the point it can damage the bearings and seals resulting in big repair expenses along with dangerous handling conditions.

If a chain is too loose it causes accelerated wear on the sprockets and issues from slop in the drivetrain all the way to slipping off the teeth.

The issue is that it is way easier to unwittingly get the chain too tight and cause damage where as too loose is much more perceivable and thus correctable before serious damage occurs even by novice riders.

I report my experience only. I enjoy scanning your opinions.

 

[Ramirez]

Anybody had any problems about the chain hitting the low underbrace of an chromoly swingarm? I 've tried adjusting to less than 1/2 inch and still hits

 

[AFM54]

Bike on the rear stand (or kickstand) without the rider, find the rough middle of the chain between the two sprockets. Give yourself two to three fingers stacked distance from the top of the swing arm to the bottom of the chain. Seems to work on every bike I’ve raced. And as mentioned before, a chain too tight is worse than a chain too loose, and a change in geometry affects chain tension.

 

[badexample]

Anybody on here tried this??

or

 

[C3L1CA]

Anybody had any problems about the chain hitting the low underbrace of an chromoly swingarm? I 've tried adjusting to less than 1/2 inch and still hits

I don't have an underbrace but my chain will sometimes slap down on the top of the swing arm if I don't stay on top of the tension and I get too much slack.

https://dmeracing.com/product/chain-roller/

You could try a chain roller or something along those lines for the under brace. I know DME makes one and I'm sure other places do too.

 

[Sneekey10R]

Anybody on here tried this??


Tru-Tension Chain Monkey - Motorcycle Tutorial - How to adjust a motorcycle chain - YouTube

or


Motion Pro Slacksetter Chain Adjuster Tool Review from Sportbiketrackgear.com - YouTube

I use the motion pro slacksetter and it works pretty good. I always go back and double check it with a tape measure and seems spot on.

 

[ddipaola]

If your chain is too loose you're going to unseat the teeth and rollers upon decel. Chains on decel they tend to lift up off the teeth. When you see sprockets that look like 39 point stars and lose all their pitch that's a clear sign the rider didn't give 2-shits about chain tension. Dude's probably rocking 3"+ of slack. On the other hand if your chain is too taught you will not be able to articulate the swingarm. As the swingarm lifts, or as your shock compresses, the distance between the rear axle and the front sprocket increases, so I'd say that, combined with swingarm flex and clearances is where the OEMs get their ideal slack #. In other words... just go by the book on this one.

 

[Cable]

Not really an answer to the OP's question, but FWIW, whenever I adjust the rear axle for chain or sprocket changes, I also measure the distance between the center of the axle and the center of the swingarm pivot on both sides. This helps to ensure that the wheel isn't crabbing.