njkayaker

Regarding cross chaining, how much is too much?

Clearly, the advice says not to use the big/big or small/small sprocket/chainring.

But is the next biggest sprocket or next smallest sprocket OK to use?

If you have a triple, are all of the rear sprockets fair game [for the middle chain ring]?

I looked on Sheldon Brown and did some searching here but I did not find any specific answers.

(Bonus points for backing up your opinions with a reference!)

LeeG

I would think length of chainstays would also have some influence. Using the middle ring on a triple with a long chainstay touring bike would allow a full swing across the cassette whereas a short chainstayed road bike with a double might eliminate the outer two cogs.

Panthers007

Those are the extreme examples of cross-chaining. But any time the chain is deflected off in an angle it will contribute to the necessity of replacing your chain. It's a good idea to try to find alternative gears using a larger rear and larger front chainring that doesn't deflect the chain as much. But it really doesn't matter - your chain will wear to the point of replacing regardless of what you do.

DMF 

A lot of it is relative. Cross-chaining increases chain wear, for instance. How fast wearing is too fast? Does FD rub drive you crazy? Then it's a problem.

With compacts for instance, you just about don't have a choice but to use the whole cassette in each ring. Triples, OTOH, there's no need to cross-chain. In granny, the overlap from the middle ring starts about 3-4 cogs in so why even bother with the other 5-6? In the middle ring the whole cassette is available, though I try to stay off the littlest. In big ring I'll go all the way up to the biggest and its neighbor. FD rub reminds me to shift.

P.S. I am my own reference.

njkayaker

Keep in mind that cross chaining causes extra wear on other parts too (ie, sprockets and chainrings).

Oddly, there isn't much overlap (ie, same gearing) between my lowest and middle chain ring. There is overlap in the range but the actual gears are in between.

DMF 

Fwiw, I occasionally use most of the cassette in granny, but that is on extended climbs where the grade varies and a shift to the middle ring wouldn't last long. When the terrain is rolling, I shift back up as soon as possible. Same rule applies to granny as to big ring. Just avoid the little cog and its buddy, and if you do occasionally go up there, don't worry too much about it.

njkayaker

I see that "occasionally" is OK. The problem is what is the rule to follow so you know what to do only "occasionally"!

DMF 

Why do I feel like we're not connecting?

dbc

Don't over-think it too much. The world is not going to end even if you use the extreme cross-chain gears.

But if you are really concerned, you may want to pick another gear if it sounds "noisy".

merckx_rider

I use all the cogs in any chain ring, always have. At a stop, i've gone into first gear with the big ring and on short downhills I've gone into the small cog/small ring.
I don't ride for all day in those combinations but I've never had any problems either, road or mtb.

Hydrated

The lawsuits that companies are subject to in today's litigious business environment have forced bicycle manufacturers to build idiot-proof bikes. They must build bikes with gear combinations that are unlikely (or impossible) to drop a chain or pop a link due to gear choice or cross chaining. You can just see some dude who rides in silly gear choices and falls off of the bike suing the manufacturer out of existence.

So if your bike still has the factory setup, chances are that you couldn't cross chain enough to cause real problems if you tried.

When you get out on the fringes is where you run into problems that force you to use your head. Like my everyday bike... it has a triple with a 26 tooth granny and an 11-34 cassette on the back. I can carry a load and climb walls with that setup, but I realize that some gear combos simply aren't that smart to ride on.

jccaclimber

If I can feel it or hear it, it's a problem. If not I let it go.

njkayaker

I did get that your rule is not to cross the two end sprockets (not unreasonable).

I'm looking for the general rules (ideally, with some support) that people advise. "Occasionally" indicates an exception to the general rule. It seems obvious that occasionally cross chaining isn't likely to cause the world to end.

This isn't going in a useful direction. It's seems more reasonable that problematic setups are avoided by manufactures because it's easier and more reliable for people rather than "litigation" issues. I'd say it's more reasonable to let experts to choose problematic setups rather than foist them on everybody.

Anyway, cross chaining that doesn't work isn't relevant since you can't use it. It's the advice about cross chaining that does "work" that is relevant. The general reason to avoid cross chaining that "works" is to reduce wear on components (not that it doesn't "work").

Hydrated

Well... it certainly looks as if you know exactly what the deal is... no matter what input you get from others. Why did you even bother asking for advice?

njkayaker

It would seem that the reason not to cross-chain is pretty well-known (the "why"). Mentioning Sheldon Brown points to whatever reason he might have said.

I'm certainly not asking for irrelevant advice (a weird conspiracy theory about "litigation" doesn't seem to be relevant let alone correct).

Does cross chaining concern just the end cogs or should the advice not to cross chain include more cogs than that?

It's not the "why". It's the "what". (Though, people might say the "why" isn't an issue, which would mean all of the cogs are fair game).

operator

Rofl. Wow. This post is just so full of incorrect I just facepalmed lawl.

Hydrated

You can laugh if you want, but I can tell you how I know that the legal aspect is the driving force behind many of the design decisions made by bicycle manufacturers:

When I was a starving college student (in 1982) I made extra money turning wrenches for Dixon's Bicycles in Macon, Georgia. We were a Trek dealer back when Trek was a much smaller company... and we sold quite a few of them. Upon purchasing a bike, many customers would immediately ask for freewheel and/or chain wheel swaps in order to get the appropriate ratios for what they wanted to do with their bike.

In response to a request from a customer, we called Trek to ask for a super wide range freewheel for a Trek touring bike setup. The answer that we got from the guys at Trek surprised us... they told us that they weren't ALLOWED to gear new bikes that way from the factory. As a dealer, we could swap the gearing however we wanted... but Trek wouldn't do it as a factory modification at any price.

According to our contact in Waterloo, the company would only go so far with gear setups because of the potential for lawsuits. For example, experienced riders know that riding a small cog with the small chain wheel may induce an excessive amount of slack in the chain... leading to chain suck or a dropped chain. The Trek boys were very conscious of the possibility that someone who got hurt using a Trek bike this way could potentially make a case that Trek manufactured an "unsafe product". So they admitted that this prevented them from equipping their touring bikes with anything with a low low gear and a fairly high gear in a single package. So they sold the bikes with gearing that was often less than ideal.

So... tell me where I was incorrect, my facepalming friend.

nitropowered

I go big-big all the time. You just don't care when you are racing. Shifting down to the small ring and then shifting back up to the big ring could cost you, especially if the chain doesn't shift back up to the big ring smoothly. However, in small-small, the chain tries to shift up to the big ring so its pretty unusable.

But if I'm just riding around/training and go up to big-big, I'll shift down a few cogs and drop to the small ring

joejack951

A wide range freewheel, chain slack, and cross-chaining are all independent issues. You can cross-chain a bike regardless of what gearing it has and with or without chain slack. You can get excessive chain slack on a bike regardless of gearing with or without cross-chaining. You use a wide range freewheel and not have issues with chain slack nor be forced to cross-chain.

With the correct rear derailler, it's difficult to put together a gearing set up that will still shift properly between chainrings and yet result in excessive chain slack. You'd need to swap chainrings and use the widest MTB cassette currently available. There are no off-the-shelf crankset/cassette combinations that would put you excessively outside of Shimano's conservative specs for their SGS rear deraillers. 53/39/30 with an 11/34 cassette is only 3 teeth beyond the 43 teeth for which they are spec'd.

Hydrated

You're totally missing the point that I was trying to make...

My point was not whether the gear combos WOULD work... my point was that manufacturers normally build bikes with gearing choices configured smack dab in the middle of the usable range. What I call "generic gearing". They won't build bikes with gearing out on the fringes of what's possible... mainly for two reasons. Because most new riders want "generic gearing" where every gear combination is ridable and because they have to build bikes that are idiot proof (hence making them basically lawsuit proof too).

To relate this to the OP... I was trying to say that if his bike was still in the stock configuration as it came from the factory, then chances are that the conservative setup of the factory gearing would make it unlikely that any of the gearing choices would cause much damage due to cross chaining.

FBinNY 

There is no absolute answer to how much cross-chaining is OK, or not.

Any properly set up bike with enough RD take up capacity will allow any combination of cross chaining with no immediate damage. On some bikes crossed combinations will ghost shift when backpedalling, but that's no crisis.

Other than that, understand that as the chain angle increases so does chain and chainring wear. So it isn't a question of how much is too much, but that some is undesirable, and more is worse.

You're also more limited if you have an index front derailleur that doesn't have adjustable trim. Without trim adjustment, excess crossing will cause the chain to rub and slowly saw through the FD cage. And with some cranks or chainrings, the small small combinations cause the chain to rub the inner face of the adjacent larger chainring.

With that in mind, I suggest that you avoid cross chaining in the name of efficiency, but not be anal about it.

joejack951

What are you basing the above on? It doesn't agree with reality. For example, an Ultegra GS rear derailler is rated at 37 teeth capacity. I can show you plenty of stock bikes configured with a 52/39/30 triple and a 12/27 cassette which pushes that derailler to it's max capacity (22+15=37).

It is true that a manufacturer wouldn't make a bike without enough links to use the big/big and/or with too many links to use the small/small. But that doesn't seem to be what you are saying.

Panthers007

I simply rebuilt my entire drive-train when I bought a Trek 7.5 FX. Trek didn't even offer, on their top-grade hybrids, what I had in mind. Now it has Ultegra Hollowtech II triple 52-39-30 cranks, Shimano XTR FD, SRAM PC-991 chain, Ultegra 6500 RD, SRAM PG-970 9spd 12 - 26 cassette. I wonder how far off the medium that would be?

It would run tight circles around the original.

johnknappcc

You *could* crosschain, but why *would* you.

Extra wear, extra friction.

Look down at your chainline while riding and see just what those gear combos look like. If the bike is making noises, it's telling you it isn't the best way to go.

Its similar to a manual transmission in a car, have you heard what taking off in 3 gear sounds like? Its the way your car says "don't do that".

njkayaker

No, there isn't an absolute answer.

In a technical sense, some degree of cross chaining is the norm.

At most, depending on the number of chainrings, only 2 or 3 gears could possibly have zero cross chaining! It's even possible to have no gears that have zero cross chaining.

If you are avoiding something, it's implicit that the thing you are avoiding is "too much".

The problem is that this is advice is too vague. The "standard" advice to avoid using the biggest or smallest gears isn't vague but I'm wondering if it is complete enough.

Excessive noise is useful information. Given how many people seem to be OK with noisy shifts, it would seem that many riders are hard of hearing!

======================

Wading through all of the waffling here ("chances", "unlikely", "much"), I suppose I'd conclude you are saying not to worry about cross chaining at all. Are you normally so afraid of making a commitment?

======================

Yes, they are independant issues. Also, most bicycles are set up to minimize the other problems.