Too much slack in timing chain?

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Nachoman

Is there too much slack in this timing chain?
And if so, does it need adjustment or replacement?
It's a couple years old and never adjusted, but always well cared for.

http://img234.imageshack.us/img234/1195/img1837vt4.jpg
http://img223.imageshack.us/img223/7618/img1835zj1.jpg

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TandemGeek

It probably just needs to be adjusted via the eccentric. A close up of the timing ring teeth to the right of the crank arm (power stroke) would make it easier to tell just how worn the chain may be.

However, you can check chain wear the same way you would on your drive chain by using a ruler or chain checker. If the pin-to-pin distance over 12 links is more than 1/8" of inch past the 12" mark or beyond 75% worn on the chain checker, the chain should be replaced... unless you've decided to run the chain and chain rings until they're toast (10k or more), and then replace the whole shebang.

Nachoman

It probably just needs to be adjusted via the eccentric. A close up of the timing ring teeth to the right of the crank arm (power stroke) would make it easier to tell just how worn the chain may be.
However, you can check chain wear the same way you would on your drive chain by using a ruler or chain checker. If the pin-to-pin distance over 12 links is more than 1/8" of inch past the 12" mark or beyond 75% worn on the chain checker, the chain should be replaced... unless you've decided to run the chain and chain rings until they're toast (10k or more), and then replace the whole shebang.

My camera is not too good at close up shots.

http://img87.imageshack.us/img87/5337/img1848pa1.jpg

http://img232.imageshack.us/img232/2066/img1847zv1.jpg

TandemGeek

The portions of the timing rings you've photographed don't look bad at all. However, I'd still go ahead and check the sync chain for wear with a ruler or chain checker. While you're at it, and based on what I'm seeing on your chain rings in the background, you might want to check the wear on your drive-side chain too.

Possum Roadkill

I've noticed some of the chain checkers seem to not be so accurate. Usually it's the one's with moving parts. I've seen many that would say a chain was half worn out when it was new. The ones that are just a plate of metal that slide in between the links (one piece) seem to be more accurate to me. I prefer using either one of these or the ruler method.

lopsided

I replaced the timing chain on our tandem recently and found that about half of it had exceeded the wear indicator and the other half hadn't. I determined that it was beneficial to check the chain in numerous points along its' length.

Nachoman

Thanks for the responses.
And I notice that 24 of you think there is too much slack in the timing chain and only ONE of you thinks there is NOT too much slack. Let's here from our loan ranger!

TandemGeek

Let's here from our loan ranger!

One can only hope he or she was being the contrarian or that they are out adjusting their sync chain tension.

Baldy88

One can only hope he or she was being the contrarian or that they are out adjusting their sync chain tension.

I was being a wise guy! I'm glad to see that no one else followed suit on my vote. I ride a single speed MTB and am a frequent chain tension checker.

transam

I would think a timing chain as loose os yours would be in danger of jumping off, especially when riding at a higher cadence or hitting a bump. Has anyone had this happen?

zonatandem

D-r-o-o-p-y chain. Agree on adjusting eccentric a bit.
Looks loose enough to jump off in case of hitting a big bump or loading/unloading inside a vehicle.

stapfam

Once you find out how to adjust the Timing chain- You may find that you have a slack point and a tight spot in the chain. This can be adjusted out by setting the Timing chainrings to take it out- but providing no bent Bottom bracket crank or anything else bent- The easy cure is to change the chainrings to some better quality ones that run true and in a perfect circle. When I got the Tandem- I had the tight/slack in the chain and it took a lot of time to correct. Then on changing the timing chain- I replaced the rings with Middleburn rings and perfect from the time of fitting them. I Cannot visibly see or feel any variation in the chain tautness- even three years after putting the quality chain rings on.

dvs cycles

I replaced the rings with Middleburn rings and perfect from the time of fitting them. I Cannot visibly see or feel any variation in the chain tautness- even three years after putting the quality chain rings on.
Never heard of them. Any links or pictures?

TandemGeek

http://www.middleburn.co.uk/

MTBTandems.com just up the road from us is one of two US distributors. Having fondled the hardware extensively, I can confirm the quality, fit, and finish is top flight. Last time I checked they were still more dialed in to the off-road crowd, more so than the road bike community. Definitely one of better choices for an off-road tandem that needs a cross-over crankset.

dvs cycles

TandemGeek

What specs I COULD find don't show any 130bcd rings.

Send an email to alex@mtbtandems.com

He can give you the latest on what they're offering that might work for road tandems. Again, they're primarily an off-road component supplier.

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