Chain Length and Strength?

[SquidBonez]

Doing some research for my current build and I have a question. Is a shorter chain weaker? I'm figuring out rear suspension designs and I have an option of either running a swingarm with the engine mounted to it (simple, only needs 1 chain, but not great for jumps) or running a jackshaft so the engine can be mounted to the frame (better, but I would need 2 chains). My concern is that the first chain from the torque converter to the jackshaft would be weak because it would be shorter. Is this true?

 

[ONE-EYE]

Doing some research for my current build and I have a question. Is a shorter chain weaker? I'm figuring out rear suspension designs and I have an option of either running a swingarm with the engine mounted to it (simple, only needs 1 chain, but not great for jumps) or running a jackshaft so the engine can be mounted to the frame (better, but I would need 2 chains). My concern is that the first chain from the torque converter to the jackshaft would be weak because it would be shorter. Is this true?

If you're using a torque converter, you only need one chain (jackshaft to axle sprocket). The belt connects the pullies.

 

[ONE-EYE]

You're probably wondering whether to go with a jackshaft mount that bolts under the motor and behind the motor on the back side or going with a plate that has the mount built into it??? I've heard multiple things either way so I believe it's personal preference. Personally I removed my under the motor jackshaft mount because it was in the way of one of my oil plugs and I was having issues with the bearings so I'm going with one built into the backplate. The mounts that attach to the engine plate I've heard are a bit more stable tho. Dealers choice really.

 

[SquidBonez]

If you're using a torque converter, you only need one chain (jackshaft to axle sprocket). The belt connects the pullies.

Should have clarified - my second idea has the rear swingarm pivoting off of the jackshaft. It doubles as both a jackshaft and a pivot for the rear suspension, meaning chain tension stays consistent throughout its travel.

 

[ONE-EYE]

Should have clarified - my second idea has the rear swingarm pivoting off of the jackshaft. It doubles as both a jackshaft and a pivot for the rear suspension, meaning chain tension stays consistent throughout its travel.

Ahh ok my bad lol for a second there I thought you were trying to run a chain where the belt is supposed to go hahaha

 

[Snaker]

You can get half shafts for your project.
That allows all of the power train being fixed to the frame
Only the rear axles would move with the suspension.

Chain strength: not really a length issue
As strong as the weakest link its said
A short chain can see faster wear cause it goes roundy round more
Theory: more parts = more chances of breaking

 

[Denny]

Because of longer chain slapping around it is under more stress in theory. In my experience I have broke quite a few chains on my dirt bikes, but none on my street bikes.

 

[madprofessor]

Here's pics of the swingarm setup you're talking about, complete with a 30 series TC hanging straight down. The swingarm/jackshaft started out as a single 3/4" x 44" axle, all 8 bearings were installed and bolted down to get the fit right, then the axle was cut into 3 pieces. The sliding motor tensions the primary chain, and the very long (my mistake, could have been a lot shorter) secondary chain is tensioned by an idler sprocket pulling up on the bottom of it...................