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The 2-Stroke Garage => Turning Wrenches => Topic started by: rd400greenhorn on April 11, 2020, 09:59:46 AM

Title: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 11, 2020, 09:59:46 AM
Hi guys

So everything is a first for me on this never ending build

I have decided to tackle the chain, Which i bought over a year ago

Was a regular 530 Kit with sprocket i believe from UK
But looks to My as the chain is to short... And, because I have it raised in the back suspension
Can it be why the chain touches the swingarm?

Or can anyone guide me here 😅🤔

Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: Striker1423 on April 11, 2020, 10:04:05 AM
Your chain should be able to connect one link away with a master. Is the adjuster all the way llose? It doesn't look like it.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: 85RZwade on April 11, 2020, 10:10:50 AM
Your chain looks a bit long in terms of adjustment, NOT saying you need to cut it. Can you pull the axle back any further? Your chain will be tightest when the countershaft, swingarm pivot and rear axle are aligned; that's the position in which you should check tension. Removing the shocks makes it easy to move the swingarm through its travel, and yes, your chain might rest on the front of the swingarm when shocks are fully extended.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 11, 2020, 10:18:31 AM
Ahh.. Might see it clearer now.

Wait, the torque arm. Do I loosene that also? 😂
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: ~JM~ on April 11, 2020, 10:23:49 AM
Check out the swing-arm protection on Dirt Bikes. Usually have a replaceable piece of nylon/rubber/plastic where the chain rubs on the swing-arm pivot.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 11, 2020, 10:41:16 AM
Guide and or advice are truelly appreciated.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 11, 2020, 10:44:19 AM
Here you can see
Chain is not to long as it sits here
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rodneya on April 11, 2020, 10:53:28 AM
That swingarm looks like it should have axle blocks inside the slots at the back instead of the OEM chrome adjusters.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 11, 2020, 11:06:19 AM
Allright
So pushed the wheel All the way forward
That should be My starting point right?

The 95? Link chain i have is a bit to short.

So, get a long chain and cut it to measure?
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: pdxjim on April 11, 2020, 01:49:15 PM
If that swingarm is +1" (or whatever) the stock chain length is gonna be too short.

I always opt for a longer chain than spec and cut it down to length just in case.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: oxford on April 11, 2020, 03:27:26 PM
Quote from: pdxjim on April 11, 2020, 01:49:15 PM

I always opt for a longer chain than spec and cut it down to length just in case.

Same here.  I don't mind spending a few extra bucks and throwing a few links out when I am done.

My starting point is axle all the way forward in the slots.  Then like mentioned pull the shocks and get the counter sprocket, swingarm, and rear axle in a line, use some wire to hold it in that position.  This is the position where you want to set chain tension at since this is where the counter and wheel sprocket are going to be farthest apart.

If you are cutting a chain to length make sure you mark it where it will be a full link.  Before you cut make sure you look at what and where you are cutting and make sure the master link is going to go in.  For someone not familiar you could get it to where you are a half link off and when you cut it it will end up to short.  I will also put a zip tie through the plates I am going to cut off as I will usually pull it back off the bike to cut it.  This way you don't lose track of where you want to cut.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 11, 2020, 03:44:18 PM
Thanks for the advice!!

I got it on,  chain breaked, shortend and assembeled.

Hopefully i did it correct. I certainly did take the chain apart and together by the book.

I pushed the rear wheel forward, measured the chain up in the sprockets, marked, remove and mounted the chain again, and then pushed/ pulled the rear tire back again Till the chain got fighter.
Assume now i tighten up the chain tension and rear axle?
Call it done

Hope so 😅
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 11, 2020, 03:46:46 PM
...

Not tighten anything yey but spins good, dont seem. To tight.

Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: oxford on April 11, 2020, 05:40:09 PM
The chain will get tighter in the picture above as the rear wheel travels upward.  It's hard to tell if you have it to tight or not.  This is where taking the shocks off and moving the swingarm up by hand would come in.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: dgorms on April 11, 2020, 06:04:01 PM
That looks a bit tight, I've always ran my chains on the "loose" side of adjustment, they're happier that way and last longer.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: Striker1423 on April 11, 2020, 07:17:30 PM
You should have about 1 inch of play in the middle of the chain at rest.  Just press up on the bottom of the chain near the middle and measure it. Give yourself 1 1/4" and ride it. The chain should not be a guitar string. It wears everything out fast and in a hurry if you do that.   
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: Dvsrd on April 11, 2020, 07:25:09 PM
If you end up having to buy a new chain, I would recommend going to a #520 with an alloy or Supersprox Stealth rear sprocket, for some weight savings. DIDVX3  X-ring chain is a nice one. With today's chain availability, #530 is total overkill on a 350/400. People use #520 even on 100-150 hp bikes.
Running a too tight chain may end up damaging the countershaft bearing (the bearing just inside the front sprocket), possibly also the rear wheel bearings. I always check chain tension when sitting on the bike, loading the rear suspension.
Title: Re: Chain and trac dynamics swingarm rd400 question
Post by: rd400greenhorn on April 12, 2020, 06:57:02 AM
Yes i found about those 520 to late 😉

Oh well

Measuret in the middle or the chain, from the bottom,
Around 3 cm of travel if pushed up.