Stronger Chain Help

Afternoon/Morning/Evening All,

I have recently built up a Tangent Drive 3220 motor and as expected I keep snapping chains

I am having issues with finding info about stronger chains but seem to keep coming up with the differing widths (1/8 3/32 etc) of chain and some say they are no stronger, just that they have wider pins but not thicker side plates.

Now I am happy to reduce the number of gears I have on the cassette to run bigger spacers between sprockets if that allows me to run a thicker and stronger chain but I am a little lost on where to find any info on suitable conversions and chains...hell I am happy to go for a internally geared hub with a single rear sprocket if a thicker chain can be run.

The riding is great fun whilst the bike (2006 Specialized Stumpjumper FSR Expert) is rolling along but I just snapped two chains 5 times out on the trail today and that is taking up precious riding time!

side note....Race Face Narrow wide 38t chainring still drops chains....3 times last ride. My 32t hope one did not...but then it hadnt had such a beating to be fair.

Ebike specific chains:
http://www.kmcchain.com/en/search.php (pick "e-bike" on the list on that page),
or
http://www.connexchain.com/en/e-bike-chains.html

Cheers buddy I'll check them out asap...it must be a chain alignment issue as the output chain is handling double the torque just fine!

I've seen whipperman chains mentioned several times now. ..probably be my next chain

There could be other factors also. Don't make the chain too tight. Alignment as others mention. Make sure no kinks in chain (most likely not the case if brand new). Are u launching really hard in a tall gear. John bozi tried a few chains in his thread also. Hope that helps.

Bike chains are made to withstand a constant 100W load, with occasional 200W-400W peaks. As much as the sellers want to claim that theirs is "stronger" than the competitions...the difference between brands is likely to be very marginal at best. It is not only the thickness of the side-plates that is at issue, it the quality and strength of the steel used...which is hard to measure for the average consumer.

Lately there have been several brands who have advertised that they have "ebike mid drive" chain. Only time will tell who has the good stuff, and I suspect that this thread will draw links to info that may prove useful on this subject...

Space permitting, if you use larger sprockets but maintain the same reduction ratio, it will reduce the force on the chain while retaining the same gearing. The only trade-offs are a bit of extra weight and sprocket cost along with a faster moving chain

Not only is alignment critical, but so it rigidity of the structure, because perfect alignment can change greatly with flex in the structure. Even a great builder like Recumpence had that issue when he initially started to really up the torque.

Great replies, thank you.

I have had a play about with the alignment and re-tightened the front freewheel/spider bolts and removed and replaced the crank arm on the drive side...one half power test run and all is ok so far but the weekend will tell the whole story with another off road jaunt.

Prop shaft seems appealing to me right now!

I replaced my new and snapped Shimano chain with a simple new SRam 951 cheap chain and also a new cheap shimano 9 speed rear cassette and had a blast today with no chain or gear issues...aside from the dropping of the chain off the Race Face narrow wide 38t chainring but thats another problem for another day!

1/8" chain doesn't work on derailleur bikes, generally. It's for single speeds. It comes in heavy duty versions, too.

3/32" chain is for derailleur bikes. The higher the number of speeds it's designed for, the thinner the side plates are. But accordingly, the narrower the chain, the stronger the material it's likely to be made from, and the more aggressive the riveting of the pins.

If I were having problems snapping chains, these are the things I'd do, in order:

1) Make sure the chainline is good. The middle of the chainrings should lie in the same plane as the middle of the rear sprockets.

2) if you're pinning the chain back together with a tool, don't. Use a quick link. You damage the side plate of the chain when you push a pin out and back in. Get rid of it and replace with a quick link.

3) Stop shifting under power. Just don't do it; it's stupid.

4) If I had more than 7 speeds in back, I'd switch to 7. That means a 7 speed shifter too. The derailleur will probably work if it's for 8 or 9. Use a 7 speed chain. I like the KMC Z51, because it comes with a quick link.

5) If I still had problems after that, and if they were related to breakage of the chain sideplates or pulling out the rivets, I'd try an old style flat sideplate chain like the KMC Z33. A chain like that has the thickest sideplates of any 3/32" chain, plus rivets that stick out beyond the sideplates. It's cheap, too. It won't do anything good for the quality of your shifting, though.

6) Still busting chains? Try a single speed bike. Or a scooter.

All good info although from what I have read the difference between 8 9 and 10 speed chains isn't plate thickness but rather pin width, however, I could be wrong!

spinningmagnets said:

Bike chains are made to withstand a constant 100W load, with occasional 200W-400W peaks. As much as the sellers want to claim that theirs is "stronger" than the competitions...the difference between brands is likely to be very marginal at best. It is not only the thickness of the side-plates that is at issue, it the quality and strength of the steel used...which is hard to measure for the average consumer.

Click to expand...

Power causes wear, torque is what snaps the chain. A good bike chain should withstand a ~250 lbs rider STANDING on one pedal with their weight, I'm not sure how much torque that is, but it's a lot. Shifting under load will brake chains though, due to the combination of torque and side-loading.

Chalo said:

5) If I still had problems after that, and if they were related to breakage of the chain sideplates or pulling out the rivets, I'd try an old style flat sideplate chain like the KMC Z33. A chain like that has the thickest sideplates of any 3/32" chain, plus rivets that stick out beyond the sideplates. It's cheap, too. It won't do anything good for the quality of your shifting, though.

Click to expand...

I am in the market for a new chain, so I go searching for what you use Chalo.
Z33 is indeed dirt cheap, ~$5 and your X8.93 in your other thread compared to the Z51 --LINK--

I normally always go KMC anyways. But I will go for the Z33 because I need two for the long chain of Townie 21D.

I also need to buy freewheel, abviously Shimano is the way to go judging by your posts so 14-34 seems average, but how much of a difference would a 13 or 11 make in the grand scheme of things, better to have those gears then a higher tooth count gear.

Z33 is not intended to work with indexed shifting. Z50 is, but it's like '80s index chain. Both of them require you to pin them back together, which always leaves a weak spot, no matter how careful you are.

Z51 is the minimum I'd choose to use for an index shifting bike. And I have used it, often.

Z72 is the default 6/7/8 speed chain at my shop now. $12 full retail over the counter.

gsa103 said:

Power causes wear, torque is what snaps the chain.

Click to expand...

In my observation: grime, corrosion, lack of lubrication, poor chainline, and poor choice of sprocket sizes cause wear. Riveting the chain back together instead of using a snap link, or shifting under full power, are what will break it.

Clean, well lubricated chains with good chainline and high tooth count sprockets can last almost indefinitely. Machinery's Handbook has some good guidelines in this regard.