[tomf]

I took delivery today of a DID 525 x 106 Links VX Pro-Street Series Xring Sealed Natural Drive Chain for my Triumph TT600. After installation and adjustment I have .75" of play at the tight spot and 1.5" of play at the loosest spot. I've made a complaint to D.I.D. and will post a followup. I'm extremely unhappy right now.

Has anyone else encountered this? i installed the same chain but in 530 on my '03 SV1000S last year. It's been run about 3K miles and has almost uniform free play at any point on the chain.

PS There's about 1 -1.5mm of runout on my rear sprocket. The chain was riveted using the D.I.D. tool and the rivet measures about 5.9mm from side to side which is within spec. No kink in the master link.

 

[schmidt314]

I have seen lots of bikes that have non concentric sprockets front or rear or have been loose and damaged that cause loose and tight spots. Bad wheel bearings can cause issues also.

The VX chains are awesome and I have personally likely installed 75 or more in the past couple of years.

Spin wheel and make careful observation of the frequency of the tight and loose spots. This can quickly tell you if it is sprocket or chain related.

-ms

 

[Missing Link]

Ok.... Did you replace the sprockets at the same time ? If you didn't, dont blame the chain.
You should never put a new chain on old sprockets.

PS There's about 1 -1.5mm of runout on my rear sprocket. The chain was riveted using the D.I.D. tool and the rivet measures about 5.9mm from side to side which is within spec. No kink in the master link.

If you did replace the sprockets, possibly dont blame the chain again, you may have a slightly out of round rear sprocket. And going by the above quote form your post, that may be the case........next, see my next paragraph

OR, the rear sprocket is not centred properly. To see if thats the case, find the tighest spot, and then mark the rear sprocket at the 3 oclock point (so the mark points backward on the bike), loosen the sprocket and see if it can be moved on the hub, towards the front....firm it up again and then spin the wheel..... you will soon know if that has corrected the issue, or at least given you a direction..... Just find the sweet spot and tighten the sprocket up nice and hard....

I have had this issue once or twice in the past, and it was fine once adjusted. I even look at this still now to get the least movement out of the chain, because the more it slaps, the more it wears.....

 

[tomf]

I did a different test where I solidly mounted a point just a millimeter or so inside the chain at the sprocket. Spin the wheel and check to see if the sprocket is round - which it is. There's maybe a millimeter of deviation. Conclusion - it's a poorly manufactured D.I.D. chain.

 

[schmidt314]

I did a different test where I solidly mounted a point just a millimeter or so inside the chain at the sprocket. Spin the wheel and check to see if the sprocket is round - which it is. There's maybe a millimeter of deviation. Conclusion - it's a poorly manufactured D.I.D. chain.

1mm deviation is huge!
-ms

 

[Missing Link]

I did a different test where I solidly mounted a point just a millimeter or so inside the chain at the sprocket. Spin the wheel and check to see if the sprocket is round - which it is. There's maybe a millimeter of deviation. Conclusion - it's a poorly manufactured D.I.D. chain.

If you have even 0.5mm deviation, it is too much, it is NOT the chain that is causing the issue.

I work in the bike industry at a major distriubutor (different brand chain) and i can tell you now, it aint the chain, we have people blaming the chain with the same symptoms and causal effects as yours, and it is an issue with the sprocket. Even though we dont sell DID, i can vouch for them being an excellent chain.

Test this in a different way. Rotate the wheel until the chain is loose, then tighten the chain adjuster by 1mm and see how much the chain lifts.
As i have also said previously, reposition the sprocket, as long as it has some clearance between its centre hole and the hub....

The ONLY thing that MIGHT be wrong with the chain is if the joiner link has been overtightened when installing, test the motion of that joint against the remainder of the chain, that is the only way the chain can cause any issue, as it will not straighten out after it leaves the sprockets, effectively shortening the chain.
IF this is the case, it is not the chains that is at fault, it is the installation, and yes, you can overtighten it if you go just that bit too far.

I also mentioned, have you used new sprockets ?

 

[Junkie]

looking at how geometry works it doesn't surprise me that 1.5mm aka .060 runout on the rear wheel results in a large chain slack change

if distance between where chain contacts front sprocket and rear sprocket is 24" (I think that's in the right ballpark), 3/4" slack (moving up and down 3/8") means the chain length from sprocket to midpoint is 12.0058579. Decreasing distance between contact points by .060 means slack ends up at +/- .76", 1.52" total slack. That's looking at a right triangle with a fixed hypotenuse (12.0058579, determined by initial leg lengths), initial long leg length of 12", initial short leg length of 3/8", final long leg length of 11.97 as we're looking at half the distance and therefore half the change, short leg ends up at .76".

So... the math results in a change in slack of almost exactly what you measure, with a perfect chain.

 

[Missing Link]

Junkie, you spent too much time on this... HA HA

You are dead right though

 

[CAst8ofMind]

looking at how geometry works it doesn't surprise me that 1.5mm aka .060 runout on the rear wheel results in a large chain slack change

if distance between where chain contacts front sprocket and rear sprocket is 24" (I think that's in the right ballpark), 3/4" slack (moving up and down 3/8") means the chain length from sprocket to midpoint is 12.0058579. Decreasing distance between contact points by .060 means slack ends up at +/- .76", 1.52" total slack. That's looking at a right triangle with a fixed hypotenuse (12.0058579, determined by initial leg lengths), initial long leg length of 12", initial short leg length of 3/8", final long leg length of 11.97 as we're looking at half the distance and therefore half the change, short leg ends up at .76".

So... the math results in a change in slack of almost exactly what you measure, with a perfect chain.

#science lol. My brain is definitely not as complex as yours 😂.

 

[Junkie]

I think the math is something you'd have been taught in high school geometry class, if not before (middle school?). right triangles and all... figuring out how to put it to use is a different story.

 

[tomf]

I believe you are right. I will confirm that hopefully after my back feels good enough to install my new sprocket.

PS My "stinks" editorial comment is partially because D.I.D. support is essentially nonexistent. They only refer you to the seller and do not provide any technical information, at least in my case. You'd think this issue would be high on the list after a new install. At least respond with a decent FAQ document.

 

[Missing Link]

The trouble is, you are dealing with people who make something to a spec, they almost never have people working with them that actually use the product, let alone install it......

We, the learned, through hard graft, and loss of hair, have more to offer than the manufacturers in a lot of cases...

Once you have seen the change in your issue, you will know in the future to check for the runout and if you set it up the way described earlier, you will have a wonderfully quiet chain, and extnded chain/sprocket life.....

You mentioned a "new sprocket", i assume the rear ? You ARE changing the front one as well, please tell me you are....
The front hasn't got a big effect on chain tension issues, because of it small diameter, but as far as wear on the chain goes, it would be a shame to see an expensive chain and rear sprocket get chewed earleir than they should.
New all round is far more cost effective than trying to save a buck on one sprocket.....

Hope your back comes good soon mate.....i know what thats like all too well....

 

[tomf]

I bought the bike with almost new chain and sprockets (less than 2K). The previous owner let the chain rust and it never recovered. There was no need to replace the sprockets because the teeth looked essentially brand new.

Update - my new JT Sprockets rear sprocket is rounder than what it replaced and seems to have solved the chain loose spot issue that began this thread.

 

[Missing Link]

That sounds awesome.....
Did you centre the new sprocket by finding any tight spot and then adjusting for it, or did the sprocket fit snug on the carrier ?

 

[tomf]

The hub on that bike (Triumph TT600) has ridges that guide the placement of the sprocket. In other words centering the sprocket is not dependent on the bolts that hold the sprocket in place. I have no way of knowing whether the previous sprocket was poorly machined or maybe got out of round in use. In any case, it's amazing how much smoother the bike is given that the old sprocket was 1 - 1.5mm out of round.

 

[Missing Link]

Glad you are happy (happier) now... it makes riding so much more enjoyable