Super D

Thank you, okay, one chain is fine.

Btw, I was asking about number of links, not to match my chain to what others have done, but to determine if the chains I bought have enough links to begin with, uncut. I bought 114 link chains.

FBinNY 

114 links is sort of standard pack for chains and is long enough for most road and mtn bikes. You should only need a longer one if using a monster cassette with a largest sprocket of 32 or more teeth combined with a road chainring. I'd expect that no matter how you measure based on your larger cassette, you'll still be cutting off a few links.

Don't over think this. put on the larger cassette, loop the chain around the big/big, and pull it around to where it overlaps. You need 1" (2 links) minimum overlap and can cut off the extra, or leave it on if it's not too long by the small small method. (or anything in between).

Fred Smedley

On my triples Big-big as short as possible seems to give better shifting performance , especially on the small medium chainrings. YMMV.

rydabent

The only way to prevent damage is to set the chain length on the big - big. That way if a rider accidentally happens to cross chain into the big-big nothing will get damaged.

HillRider

+100 The ability to shift into big-big is an absolute necessity for safety reasons. Everyone "knows" you are not supposed to cross chain into that gear but one lapse in concentration can get you there and it MUST work. If small-small also works, that's nice but not a danger if it doesn't.

bradtx

I disagree. I use the small-small method because I swap cassettes around depending on an upcoming ride. I just tested a couple of my bikes and both have enough, actually much more than needed, travel left in the RD's cage to prevent drawing the cage into the spokes.

Brad

HillRider

One more time. This works because you always stay within the wrap capacity of your rear derailleur. Violate that and small-small can lead to a lot of expensive breakage.

IthaDan 

To echo, [most] any situation where you may shift in to small small on a ride, you'd have enough momentum to stop pedaling, shift to the big ring and keep right on riding.

During a panic shift to big big, you don't have that luxury as it's often caused by a hill catching you off guard and nearly only happens when you're already straining to keep moving.

TL;DR: small-small is an upshift, you're accelerating. Big-big is a downshift, you're bailing yourself out of a situation you shouldn't be in.

FBinNY 

If you go back to the beginning of this thread, you'll see that the OP mentioned switching between a larger and smaller cassette. If he follows the big/big approach with his current (smaller) cassette, then switches wheels, he'll be in the same crap hole the big/big method is supposed to avoid.

There's no answer that guarantees no issues. So rather than debate bog/big vs. small/small let's agree that owners need to be aware of chin length and the effects of cassette size changes.

Otherwise, I stand by my opinion (it's an opinion among many) that the safest, most versatile approach to chain length is to use the longest chain your bike can handle that's greater then the minimum big/big +1" length. Longer chains have only a small weight penalty, but offer the benefits of 1-3% longer life, removable spare links if necessary, and more freedom for future cassette changes.

djb

makes me think of hearing the story of when I did some motorcycle racing and being told by experienced guys about some new fellow arriving at a track and asking either something like "what gear can you take turn 4 in" or " where's a good braking point for turn 3" , being told something, going off and flying off the track cuz the answers werent right or right for his bike.

Probably was an old wives tale to get us newcomers to use our own brains, but you get the picture....

HillRider

True, but big-big should mean the biggest large cog you want to use, not the biggest that happens to be on the bike at the moment. I suppose that is just common sense, which, admittedly, isn't as common as it should be.

FBinNY 

In this case, the OP mentioned plans for a larger cassette.

My problem with the big/big method isn't the method, but how it's used. The method determines the minimum length, which is needed info. However, far too many people, including a large percentage of bike shop mechanics consider it the length and cut accordingly. That leaves no option for a larger cassette in the future.

There's no reason to cut to the minimum length, however cutting chains longer than minimum offers various benefits. So unless you're a weight weenie, or have NO plans to change the cassette in the future, you should cut the chain as long as possible as determined by the small/small method, or even longer than that if you're willing to give up granny/small combinations in practice.

Super D

Seems that my best plan is big/big and do it with the larger cassette on the bike. The larger cassette of the two only has 3 extra teeth on the big cog, so I'm thinking it won't be too much extra length. Problem solved?

FBinNY 

larger still top end sprocket. That's what the small/method is about, finding the longest chain your system can handle rather than the shortest.

Super D

Got it, thank you.

vredstein

Just note that the Bicycle Magazine's video has Todd shortening the chain by removing the chain pin from non-drive side to the drive side (pushing it inside to outside). He then connects the chain by inserting the replacement pin from drive side to the non-drive side (outside to inside). This is incorrect. The video from Art's Cyclery shows it done the correct way according to the Shimano Tech Doc-
https://techdocs.shimano.com/media/te...9830688497.pdf
"be sure to insert the reinforced connecting pin from the same side as the chain cutter was inserted (the same direction as when the chain was cut)."

Super D

That is an important detail!

Thanks for pointing it out.

Doesn't it make you just nod your head seeing the Bicycle Magazine video doing it incorrectly? It's silly.

Jed19

I rotate between seven wheelsets with cassettes ranging from (12-25 to 12-28)t, and what I have always done is size my chains big/big with my 12-28s, and no issues whatsoever when I ride with 12-25 cassettes on the same chain.

woodcraft

Longer chain= more chain slap on the chainstay while coasting over bumps.

FBinNY 

Not so. The difference in coasting chain tension barely changes with chain length. That's determined by the RD cage return spring, which generally has quite a few full turns. So a slight change in cage angle, with a longer chain barely makes any difference.

Assuming the spring has 10 turns, each 1/2 turn either way (180° change in cage angle, or roughly the full range of travel) would have a 5% impact on chain tension. Smaller differences would make smaller differences in proportion.

OTOH - cage length does make a difference, because unless the spring is strengthened, the longer arm means that the same spring force produces less force at the lower pulley. Or, in other words, the chain has greater leverage against the spring.

Chain slap is caused by limited height clearance of the chain over the chainstay when using small sprockets (either front or rear, or worst case, both) , and it would take unreasonably high RD spring tension to prevent it. Pedaling over or through bad sections to keep the upper loop tight is the only way to prevent it. Otherwise, use a chainstay protector.

woodcraft

I had compact chainrings installed at the LBS, & they neglected to shorten the chain- it was pretty slappy-

But maybe that was outside of the range we're talking about.

FBinNY 

Or it could have lowered the chain because the rings were smaller.

Super D

You, sir, know a LOT about bike chains!

FBinNY 

Super D.

Is your profile photo fun with photoshop, or real life mixed sport fun?

Super D

It's real, but not of me unfortunately. I like water sports, snorkeling, scuba and free-diving, and of course cycling...and when I saw videos of scuba divers riding bikes underwater, it cracked me up! I adopted one of the photos to hopefully share a chuckle on the board here.