Going to an online bike store, they offer Road and MTB chains. What is the difference? Is a MTB chain thicker and heavier so if I use it for a road bike will it last longer or are only the side plates thicker and the rollers and pins are the same size so there won't be a longer lasting chain.

The "difference" these days is Marketing, not physical, and you can use them interchangeably as long as they are made for the same number of cogs. A 9-speed road chain and a 9-speed MTB chain are the same except for the labeling.

At one time Shimano made HG and IG 7/8-speed chains that did have slightly different shapes with the HG recommended for road and the IG recommended for MTB use. The overall width and pin lengths were identical and they could be used interchangably with no obvious performance degredation. I used IG90 chains on my road bikes for years and they shifted fine.

Road chain is cleaner

MTB chain may be longer due to longer chainstays, oherwise no differance.

As long it is 3/32" and the correct "speed" then you should be okay. BMX and single speed chains are another story.

The chain doesn't really know or care what kind of bike it's on. As long as sprocket spacing and chain width are properly matched, road, mtn, commuter, etc. it's all the same.

But the is some difference in the amount of strain chains are subjected to in mtn use vs. road use, mainly from hard shifting. So chains that specifically say mtb may be slightly heavier duty than those labeled for road use. Not talking day and night differences, but I wouldn't use the lightest road chains off road.

Road Chain is fussier about things and rants about the Velominati rules all the time. Road Chain snivels, b!tches and whines when it gets grit in its panties. Road Chain shouts at you about going through and off, doing your turn up front and holding your line.

MTB Chain just likes to have fun. It falls off a lot and wears out quicker but gets invited to more parties.

Go to KMC's website and look for yourself. There is no such thing as a "road bike" or "mountain bike" chain, and there is actually very little difference in any bicycle chain except for construction design, and whether they are made of steel or titanium. They are all 1/2"x3/32" or 1/2"x11/128" depending on whether you are looking for a 7/8spd or 9/10/11spd chain (except for the 1/2"x1/8" used for BMX and SS/FGs), and their design differences are based saving weight, adding strength, or marketing.

It you are a clyde, you are using it on a tandem, or if you otherwise need a very strong chain go for one with mushroomed pins, otherwise buy what you can afford. All the rest is BS, but you really need to find another LBS if they sell chains as "road bike" or "mountain bike" chains.....

What is difference between road and MTB chain? <-- NONE

I always just thought one was black, the other was silver. It seems to be that way with stems and stuff.

There is a difference between Shimano 10 speed road and Dyna-sys MTB chains, the road chains like CN-5701 & CN-6701 are directional, for 2x10 setup, where as 3x10 use the older chains like CN-5700 & CN-6700, where as MTB uses the HG-X chain, and the chains like CN-5701 aren't compatible. https://bike.shimano.com/publish/cont...__shimano.html

I have a MTB whose old chain actually broke under stree a couple summers ago while I was showing off in front of my kids. Not a major FAIL but I had to walk it back to motel. It was the end of the ride on the last day of our trip. I tried to whip out my chain tool and do a field repair redeeming myself in my kids eyes, but alas I failed again by not having it with me that day. (naturally, right?)

I have a hybrid with the same # of speeds whose chain I replaced prematurely with new and have been saving the still good old chain. I intend on trying that chain on the MTB and I expect it will work just fine.

I was wondering about that .... could a road chain possibly not be long enough for mtb ?

Generally, Shimano chains come with 116 links, SRAM chains come with 114 links, and KMC come with 112 links, regardless of whether they are 7, 8, 9, or 10 speed, and regardless of whether the are high-end or low-end quality. Very few non-recumbent or Xtracycle bikes require anything longer.

Just today I put a 114 link road chain on the mountain bike I'm building up (8 spd, the road bike is 6 spd). It seems a tad long, but I don't have the front derailleur engaged yet.

From that statement, you obviously need to learn how to size a chain-

I've seen SRAM SL chains, which are marketed for road bike use, fail on the first ride offroad.

Not a riveting failure, the perforated sideplate fratured.

Think about it, an MTB has a 22t front sprocket, and that alone can put 36% higher tension in the chain than with even a 30t road-triple chainring. Ad to that the conditions of nearly stalling on a steep climb off road, and maximum forces at the pedal will be higher as well.

SRAM chains just suck outright! Maybe if all quit using them SRAM will eventually buy KMC and finally have something that I would actually pay good money for.

My old loong chainstay Stumpjumper, I buy chains + a few more links of the same chain.

1/2" by 3/32 wide is 5,6,7,8speed these days , then they get thinner.. but still 1/2"

MTB chains are usually cheaper.....especially in the NOS/C&V market. Otherwise they are usually physically/material-wise identical...except maybe for color or finish. Road riders usually like silver, nickel or gold colored chains more than MTB riders do....

Chombi

shimano 10 road and mtn chains have different shapes and profiles. how much difference it makes i don't know