Tech Tuesday - Chain Length Basics

May 1, 2012 at 0:05
May 1, 2012
by Mike Levy  
 
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Length Does Matter: Chain length is one of those important setup points that often gets overlooked both when building up a bike from scratch, or when replacing a worn chain. In fact, it is so common that there is a good chance that many of the bikes on your local shop's showroom floor are sporting too long of a chain, an oversight from the factory that can often lead to dropped chains or inconsistent shifting. While an over-length chain can cause some annoying issues, one that is too short can be downright catastrophic. The best case scenario is that your bike will refuse to shift to the larger sized cogs or chain rings due to too much chain tension. Worst case: you could not only rip off your bike's derailleur hanger or destroy the chain and derailleur itself, but even bend over the chain ring due to the massive forces involved. It's fair to say that a bit of carelessness when it comes to chain length can quickly make for an expensive repair bill.

Derailleur Cage Counts: Your bike's rear derailleur also plays an important role in managing chain length. Its hanging cage and pulley wheels take up the chain's extra slack when in small cog and chain ring gearing combos, but the spring loaded cage can also rotate forward to compensate for added chain tension when you are in a larger sized cog or chain ring. Derailleurs are available with short, medium, and long cage lengths depending on what your bike requires. The general rule of thumb is that the larger the gearing range, the longer the derailleur cage needs to be. This is because of the massive difference in chain slack when in certain gearing combos on bikes with three rings and wide range cassettes, while bikes with only a single chain ring can often get away with a short cage derailleur. Using a short cage derailleur on a bike with a very wide gearing range (a triple crankset, for example) will require a chain that is overly long to compensate for the lack of capacity in the derailleur's short cage, while the opposite is true of a long cage derailleur on a bike that doesn't necessitate it - there will be no happy medium setup. In short, the wrong length derailleur cage will make determining proper chain length nearly impossible.

Tech Tuesday
Too much chain length and you'll have shifting issues and suffer from dropped chains, but too little could rip your bike's derailleur right off. Have we scared you into checking the chain length on your bike?


Some helpful pointers

• The term 'chain growth' refers to the distance between the bottom bracket and rear axle lengthening as the bike goes through its travel. It is important to determine chain length on a full suspension bike when it is in its fully compressed position, and with the chain in the largest cog and chain ring. This will tell you the maximum chain length required.
• While today's 10 speed, dual chainring setups can often be ridden in the big ring and big cog combo (otherwise known as being 'cross geared'), it isn't recommended for bikes with triple ring cranksets. Even so, it is best to set chain length when in the big and big combo simply because it isn't uncommon to accidentally shift into such a gear by accident when out on the trail. Better to be safe than sorry!
• Advanced riders on bikes with double or triple ring setups will sometimes purposely run the chain too short for the bike to fully bottom when in the big cog and big chain ring combo. This setup puts the onus on the rider to not shift into such a gear in order to prevent damage, but is done to add chain tension when in more common gearing combos to limit noise and the chance of losing a chain. No, we don't recommend it.
• New bikes will often ship from the factory with a stock chain length that is far too long. Just because your bike is brand new from the shop doesn't mean that its chain length is correct. It's always best to double check.
• Derailleur cage length varies between Shimano and SRAM, and there can even be differences between different model years of the same derailleur. This means that a new derailleur necessitates checking chain length.


The Full Suspension Factor: Setting up your bike with the proper chain length isn't a difficult task, but the job does become more complicated if you ride a full suspension bike. How so? Many designs use a layout that, whether employed intentionally to increase pedalling performance or not, moves the bike's axle further away from the bottom bracket as the bike goes through its travel (this is known as 'chain growth'). This rearward axle path may be present throughout the entirety of the travel, or only during part of it, but it does mean that a full suspension bike will nearly always require more chain length to compensate.

Tech Tuesday
Bottom the suspension - Full suspension bikes will often have the most chain growth when at full travel, so this is where you'll have to size the chain. If your bike uses an air shock, simply let all of the air out by depressing the shock's schrader valve as you compress the suspension (be sure to write down your air pressure before doing so), or remove the valve core to allow all of the air to escape. Bikes with a coil shock will require the shock to be removed, the coil taken off, and the shock to be reinstalled.

Place the bike in a repair stand and shift to the largest chain ring and cog combination before lifting up on the rear wheel in order to fully bottom the suspension. Either have a friend hold the bike in this position, or place it on the ground.
Tech Tuesday
Chain too short - Your bike's rear derailleur will tell you the entire story. The photo above, taken when the the bike is fully bottomed out, shows the derailleur cage pulled fully forward and nearly parallel with the bike's chainstay, and the upper pulley wheel is also making contact with the largest cog. This setup would equal disaster if the rider was to bottom the suspension while in this gearing combo, likely resulting in damage to both the derailleur hanger and the derailleur itself. Links must be added to the chain.
Tech Tuesday
Chain just right - Note the angle of the derailleur cage compared to its postion in the second step. Adding just two links to the chain allowed the derailleur cage to relax, leaving enough slack to prevent any damage from occurring.
Tech Tuesday
Just loose enough - Shift the bike to the smallest chain ring and smallest cog - the combination that will result in the most chain slack. The photo on the left is close to the ideal setup, with the chain still having enough tension from the derailleur cage to keep it from hanging loosely. Conversely, the photo on the right shows the derailleur's cage in its fully relaxed position, letting the chain hang too freely with not enough tension. This setup could result in sloppy shifting or dropped chains over rough terrain.




Past Tech Tuesdays:
TT #1 - How to change a tube.
TT #2 - How to set up your SRAM rear derailleur
TT #3 - How to remove and install pedals
T #4 - How To Bleed Your Avid Elixir Brakes
TT #5 - How To Check And Adjust Your Headset
TT #6 - How To Fix A Broken Chain
TT #7 - Tubeless Conversion
TT #8 - Chain Wear
TT #9 - SRAM Shift Cable Replacement
TT #10 - Removing And Installing a Headset
TT #11 - Chain Lube Explained
TT #12 - RockShox Totem and Lyric Mission Control Damper Mod
TT #13 - Shimano XT Crank and Bottom Bracket Installation
TT #14 - Straightening Your Derailleur Hanger
TT #15 - Setting Up Your Front Derailleur
TT #16 - Setting Up Your Cockpit
TT #17 - Suspension Basics
TT #18 - Adjusting The Fox DHX 5.0
TT #19 - Adjusting The RockShox BoXXer World Cup
TT #20 - Servicing Your Fox Float Shock
TT #21 - Wheel Truing Basics
TT #22 - Shimano Brake Pad Replacement
TT #23 - Shimano brake bleed
TT #24 - Fox Lower Leg Removal And Service
TT #25 - RockShox Motion Control Service
TT #26 - Avid BB7 Cable Disk Brake Setup
TT #27 - Manitou Dorado Fork Rebuild
TT #28 - Manitou Circus Fork Rebuild
TT #29 - MRP G2 SL Chain Guide Install
TT #30 - Cane Creek Angleset Installation
TT #31 - RockShox Maxle Lite DH
TT #32 - Find Your Tire Pressure Sweet Spot
TT #33 - Three Minute Bike Preflight Check
TT #34 - MRP XCG Install
TT #35 - Stem Choice and Cockpit Setup
TT #36 - Handlebars - How Wide Affects Your Ride
TT #37 - Repairing A Torn Tire
TT #38 - Coil spring swap
TT #39 - Trailside help: Broken Shift Cable
TT #40 - Installing a Fox Float Air-Volume Spacer
TT #41 - Replace the Seals on Your 2011 RockShox Boxxer World Cup Fork
TT #42 - Clean and Lubricate Your Fox F32 Dust Wiper Seals
TT #43 - Thread Locker Basics
TT #44 - Install a SRAM X.0 Two-By-Ten Crankset
TT #45 - VPP Suspension Bearing Service
TT #46 - Rotor Straightening
TeT #47 - Finding and fixing that creak
TT #48 - Bleed and Service Magura Marta Disc Brakes
TT #49 - Cup and Cone Hub Basics
TT #50 - Install and Adjust Pedal Cleats
TT #51 - Cup and Cone Hub Rebuild
TT #52 - Converting Mavic Crossmax SX Axles
TT #53 - Cassette Removal and Installation
TT #54 - Cane Creek AngleSet Installation
TT #55 - American Classic Tubeless Conversion
TT #56 - Wider Rims Are Better and Why Tubeless Tires Burp Air
TT #57 - Pedal Pin Retrofit
TT #58 - Bleed RockShox Reverb Remote Lines
TT #59 - Cutting Carbon
TT #60 - Silence That Squeaky Disc Brake
TT #61 - Five Minute Wheel True
TT #62 - Removing Bike Rack Rattle
TT #63 - Inside Shimano's Shadow Plus Mech and How To Adjust It
TT #64 - Steerer tube length
TT #65 - Marzocchi 44 Rebuild
TT #66 - RockShox BoXXer TLC
TT #67 - Ghetto Tubeless Tire Inflator
TT # 68 - RockShox BoXXer Seal Replacement
TT #69 - Ghetto Dropper Post
TT #70 - FSA Orbit Option Install
TT #71 - How to Bleed Formula Disc Brakes
TT #72 - Crankbrothers Kronolog Cable Replacement
TT #73 - Three Ways to Save A Leaky Tubeless Tire

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104 Comments

  • + 62
 Like boobs too big and they flop about like spaniels ears and ruin your day.
  • + 10
 They're never to big.
  • + 33
 Nah just your hands are too small Razz
  • + 0
 ....what?...too big?...wtf!?
[Reply]
  • + 5
 Maybe its just my smartphone (aka dumbphone), but I agree with TomC that the chain is in fact tighter in the lefthand photo, according to the angle of the lower cage.

Seems like a fairly comprehensive write-up but one thing it might fail to mention, depending upon your perspective, is that having a little longer chain is a bit of a fail-safe for long distance trail riders. If you permanently damage a link you can remove it and still have the proper chain length, assuming you have everything to adequately repair the chain.

But my favorite, or at least most memorable trail repair is turning a geared hardtail into a singlespeed because of a destroyed chain /and or derailleur. You can usually find a somewhat tight gear.
  • + 6
 But also, if you are going to be carrying a chain tool or other tools, and are on long rides you probably have a backpack. In which case its just as easy to take a few spare links with you, and just replace the damaged link there on the trail.
  • + 1
 How do you add more links? Do you need two master links?
  • - 2
 I tried using a chain tool on my KMC hollow pin chain (shit chain) in the woods and the pin's end got slightly mushroomed and would not go back into the holes. I have never had a problem rejoining a solid pin Sram or Shimano chain. Live and learn, But after having snapped rejoined chains on long rides far from my vehicle I've stopped trusting rejoined broken chains. I would use master links. I have 2 on mine now and always carry a spare.
  • + 2
 I've never had a single issue since I started using the rule my boss taught me.......
shift to Biggest ring up front + smallest cog in back, then install the chain at a length that allows the der. to be perpendicular to the chainstay.
-this is only for hardtails, rear suspension usually necessitates at least 2 extra links
  • + 1
 i just broke my brand new 9spd chain yesterday. since id never had a 9spd before, i didnt know that you join the ends with a master link, instead of pushing the pin out, like normal chains. live and learn.
  • + 0
 I don't set up bikes with extra length but I have had it requested. Probably wasn't worth mentioning since having it the ideal length for shifting performance is more important. I agree that KMC is inferior chain. Also don't always assume you need a longer chain because of rear suspension, with some designs you don't so there is no need to take the air out of the shock to check.
  • + 0
 Use KMC chains - strong great shifting ultra reliable. HOWEVER you can't have everything these chains are SO strong they can ONLY be joined with KMC quick links. Good article.....
[Reply]
  • + 8
 Is it just me, or does pinkbike not know its left from right on the bottom 2 pictures...
  • - 20
 no, it's just you ;-) Chain in the picture on the left is sagging, pic on right the chain is tensioned
  • - 6
 True...although...more info would have been nice. I get away with a 1x10 drivetrain 11-36 cassette on a short cage XO and I run it fairly short with no issues at all shifting.
  • + 7
 It's not just you
  • + 2
 the angle of the dangle would indicate they mixed up their left and right.
  • + 6
 @thatgeeza ...Really? Do you even ride a bike?
  • - 5
 No it's not just you, you're right the photos are the wrong way round.
  • + 28
 Gentlemen, if you believe that the photo on the right shows a chain under greater tension than the one on the left (thus the "wrong way round"), please go ahead and continue to enjoy the constant delight of dropped chains.

It doesn't matter what it "looks like", your eyes can deceive you. If the derailleur has reached its maximum extension, as PB has suggested, it will be under less tension than that on the left; therefore more likely to drop, and that is the point PB want you to understand. So no, the photos therefore are not the wrong way round.

This MTBR thread post about rear cage length is a good place to start to understand if your cage length is correct, and from there there is an alternative method of getting chain length right without using the rear derailleur. It is one I have used for years on both single and twin ring setups and works.

forums.mtbr.com/2019042-post2.html
  • + 20
 @thatgeeza -you are absolutely correct as is Pink bike. - Others - the pic on the right has the derailleur all the way back - too much chain = no tension in the derailleur. The correct one is on the left - can you not see it has tension in it?

Read again and look at the pics.
  • + 8
 unless they've changed it, the caption is correct.. i.e. the chain on the right is too long/slack as evidenced by the the der cage being all the way back.
  • + 9
 The pic and description are correct. the pic on the right has the cage too far back which will cause it to 'bounce' when you hit a bump, causing a dropped chain.
  • + 1
 Sorry, I meant to say to thatgeezer (BTW you agreed with Tom) - Sorry, but pinkbike has it correct.
  • + 4
 Pinkbike is correct - the chain is tighter in the picture on the left, which is as it should be.
  • + 2
 They have since corrected the story. Originally it said left was loose right was tight.
  • + 1
 @ orientdave, in that mtbr link you posted theres a section on measuring out the correct length by wrapping the around the big cogs but bypassing the derailleur, and then adding two links to compensate for adding the derailleur (I assume). Will this work for all cage lengths?
  • + 1
 Oh wait I see now, so you use the formula with the values assigned for certain derailleurs along with your cog sizes to get your chain length by links?
  • + 1
 What did I say wrong to get neg propped again?
  • + 1
 The pic Left is tensioned, the pic Right is sagging. PB is correct. It's Not clear who you agreed with originally, Ratts. but all the sarcasm is starting to steer this thread in circles and I think you're catching some flak. Don't sweat it, bro. You know how this shit goes.
  • + 1
 @smells
It's not chain length by links.

Bypassing the derailleur and adding two links works for all cage lengths in my experience IF you have checked that your cage length can handle your ratio of biggest to smallest cogs/rings (and that is where you use the formula).

If you don't check whether your cage length can handle the ratios you have on the drivetrain there is an increased possibility that something might go wrong.
  • + 1
 Thanks Orientdave I'm going to try that method out.
  • + 1
 @neimbc "@thatgeeza -you are absolutely correct as is Pink bike."

They have since edited the article, (correcting it to left = tensioned correctly).
Also thatgeeza is still incorrect, he thinks the pic on the right is tensioned correctly.

How is thatgeeza absolutely correct?
  • + 1
 husabergforce - like you said it's been corrected, so that was written or noticed before the fact - it's getting all confusing now! Lets go ride.
  • + 1
 It's been changed but since they don't say so we get neg propped. I stand by my original statement above.
[Reply]
  • + 3
 I also think that between the last two pictures, the one on the left is the more "ideal" cage position in the small/small combo. The one on the right looks completely relaxed offering no tension at all.
[Reply]
  • + 2
 Unless I am mistaken, the chain should never be crossed, even on the bike stand, since it will cause the derailleur to be pulled on an angle and may cause the derailleur hanger to slightly bend. Checking for the right length should be done like in this tech tuesday but with the chain not going through the derailleur. This way nothing can be damaged, as long as there is not a lot of torque on the chain.
[Reply]
  • + 1
 I've had a few problems with chain drop and I have a fairly new chain. I also started using a dry Teflon based lube, could it be that my chain has stretched or that I am using too much lube? Any responses would be greatly appreciated!
  • + 2
 It might be that your chain is new but the rest of your drivetrain is old. Check the teeth for wear. Do as the article says and get the chain length right. Check the chain line and derailler adjustment too. No such thing as too much lube Wink
  • + 1
 Thanks man, but I basically got a drive train overhaul last year, new rings, the works... however... the derailleur is old.... that may be my problem... And don't even get me started on burs or teeth,last year I spent quite a few hours trying to file down each tooth before I realised I needed a new drivetrain. Razz
[Reply]
  • + 1
 I can't seem to get my chainline right.
I have a SRAM x.0 short cage mech, but a 11-36t casette (10 spd). I was told this should work just fine, but the jockey wheel feels constantly like it's skipping, and I can;t get into 1st gear.

Is my chain too short, or will that set up never quite work well?
  • + 1
 I've read about a bunch of difficulties keeping the 1x10 set ups dialed in. Esp the Sram. Very fussy, the slightest bent hanger will disrupt the delicate precision. The cogs and chain are also thinner and weaker leaving even more chance for slight twists and bends. There is not much wiggle room for mal-alignments. I don't have 1st hand experience about 1x10 but one common note was that the Sram 10x cog's quality seems to be severly lacking vs the 9x cogs. The 1x10 X9 and X7 derlrs quality appears to be lacking also. After I snapped my (1x9) X9 and X0 in 6 mos I changed back to Shimano. Just my experience. You might start with looking at your hanger , though.
  • + 1
 Go to a shop that has a tool to gauge if the hanger is straight and, if not, bend it back. 75% of the bikes I see come in to the shop have a bent hanger that you can't see with the naked eye. Next, make sure that your limit screws will allow your derailer to go in to the gears properly. Pedal the bike while it's in a stand while moving the derailer by hand into all gears. If it doesn't go into all gears properly with the hand test, the limit screws need adjusted to allow the derailer to shift into all of the gears. Make small adjustments so you don't end up with the derailer in the spokes. Lastly, the barrel adjuster will allow you to fine tune, which 10 speed needs a lot more of with cable stretching and gears being so close to one another. Hope that this helps!
  • + 1
 dualsuspensiondave and bryanbanter both - thanks very much, I will try your suggestions over the weekend
[Reply]
  • + 1
 This link is worth reposting: forums.mtbr.com/2019042-post2.html
The guidance on chain length provided in the MTBR link is the same guidance that is provided by both SRAM and Shimano.

Bottom line: Unlike what this article is saying, chain length is independent of derailleur choice.
[Reply]
  • + 1
 Mike Levy, could we please have some clarification here? You said that, "The general rule of thumb is that the larger the gearing range, the longer the derailleur cage needs to be". This rings true with size of the front rings, however the range of gearing in the rear is not dependent on the derailleur cage length. This is a myth that confuses many people that run 1 x 9 or 1 x 10 setups. Each derailleur will be different on the max rear cog that it can handle. Thanks Mike, keep up the good work!
  • + 1
 Yes, each derailleur will have a maximum size for the rear cog but this is a separate issue. The article is correct if the gear range on the rear cassette changed from 11-25 to 11-34 for example you would need more links in the chain and possibly a longer cage on the rear derailleur.
[Reply]
  • + 1
 and if i run single speed like 1x1 and no travel on the rear how do i know that my chain is too short or too long? well the wheel axle must be the closest to the front for better trick or more back if you want more stability on landing the tricks... true story Wink
[Reply]
  • + 1
 My tip: My perfect chain length is 'normal perfect chain length' PLUS one set of links. That why if I break a chain I can remove the twisted/busted links out on the trail and then be good to go for the rest of the life of that chain (four months or so, depending on the weather).
[Reply]
  • + 1
 the way i learned at a mechanic school i went to is that in the small small combo, you should pull the chain so the der is just barely extended. this is because you will never go in the small small combo unless you are a terrible rider. and it makes the chain the perfect length. for a dh/fr bike though, for me, i have a 1x9 set up with a short cage for that, i just put it in the small cog and pull the der so it is pulled a little more extended than in the left pic of the last 2 photos, then i just dont use my biggest cog cause it is pointless on a dh/fr bike. thats how i do it and it works perfectly for me.
  • + 2
 I learned it that way as well, at UBI. I have been doing it that way for years, on my own bike and on customers'.
  • + 1
 Setting it up that way makes no sense at all and reaffirms all my doubts about UBI mechanics. You aren't even taking into consideration what the big ring is so you are essentially saying you would put the same length chain on a bike with 48 tooth big gear as one which had a 32 big ring, assuming they both have the same small-small combo. That's just retarded, one bikes chain would have much more unnecessary slack than the other. Same with the biggest gear on the cassette, needs to be taken into consideration when sizing a chain. This bad UBI technique may work ok some of the time, and if you like to do things the lazy, short-cut way then I'm sure it's fine for you, but it is clearly not the ideal way to size a chain. Sometimes I check the small small to check how slack it is there when deciding where to cut it, but I would never only rely on that, I always check the big-big also to see the whole picture.
  • + 0
 Well I'm sorry you feel that way, but I've been a professional mechanic for over 10 years and I have always sized chains this way. I have never had a problem with this method. I think perhaps you are unclear on what the UBI method actually is. It's not like we just put it in the small/small combo and then cut the chain. Pulling the chain to tension the derailleur just enough that the chain is not doubling back and hitting the pulleys achieves the perfect small/small chain tension. From there it's cake. I have never had the chain too short to get into the big/big combo with that method. I think you need to simmer down a little. Worry about your own shit.
  • + 1
 The mechanical techniques I use are not shit, but if that's how you refer to your own work so be it. Secondly, I'm not worried about your technique, I'm just being critical of it. You offered no technical rebuttal to my criticism, you just got defensive. It's an incomplete method which can lead to problems on some bikes, which is why I would imagine neither Shimano nor SRAM recommend the lazy UBI method. Both of you UBI mechanics also failed to mention the necessity of adding extra links for some full suspension bikes, and yet the lazy UBI method has the most potential to have problems because of this. Not saying you guys aren't aware of it, but you both failed to mention it. 10 years mean nothing if you are mis-trained, close-minded, and take short-cuts. And don't necessarily connsider UBI a Badge of Honor. I knew one boss who wouldn't hire UBI grads without significant experience, he would rather train a newer mechanic himself.
  • + 4
 That's so nice for you. Thank you for being overly critical of other people. Talk about being closed-minded...

Why can't you accept that the UBI method works fine? Were you molested by UBI? Where did they touch you? Show me on the doll.
  • + 2
 Because it doesn't always work fine, I already explained why, and you countered my criticism first with defensiveness, and now by implying that someone at UBI molested me, and you want details? So that's why you went there. Nice distraction technique but you are now only
making yourself look like the tools you apparently don't know how to use.

It's a poor method which can lead to either having too long or too short of a chain than what is ideal. If it was the best way to size a chain the chain manufacturers would recommend it, because it is easier. But they don't, only shitty UBI does. Why do you think that is?
  • - 1
 If you seriously believe that manufacturers always know the best way to install their products then you are the biggest tool ever. The one major thing I have learned in my time as a mechanic is that manufacturers will always err on the side of safety and convenience when recommending installation of their products. They are trying to cover their collective asses. They are not God. They are no infallible. There are other methods besides theirs that work fine for installation of their products.

And since I see you have no sense of humor, I must assume that you were indeed molested by someone at some time. Maybe by a mechanic? Show me on the doll where he touched you.
  • + 2
 I never said manufacturers "always" know the best way to install their products, I was just pointing out that none of them use the less than ideal UBI method. In this case I don't think the manufacturers are as concerned about safety , it's shifting performance they have in mind.

The UBI method is especially bad considering the wide range of todays cassette's. According to the UBI method, you would put the exact same length chain on a bike that has 48-36-24 gearing in front and an 11-36 in the rear as a bike that has 32-24 gearing up front and an 11-28 in the back, assuming they both had a long cage derailleur. The second bike would have an unnecessary slack chain, it would be more likely to fall off and get chain sucked and damage the frame, more likely to rattle around on rough downhills
(more frame damage), and more
likely to have sloppy shifting. But all that would be "just fine" with you and your amateur UBI method.

If I have no sense of humor then why are you lamely attempting to
copy my jokes? Pull something more creative out of your toolbox. But I don't want to see your doll, I think we've all heard enough about your obsession with that. Must suck to not get the real thing, but hey, your obviously the kinky type.
  • + 2
 I base that last comment on the last paragraph of your two most recent posts. Go back and read that stupid shit you wrote, you don't handle criticism very well do you?
  • + 0
 Go back to school and learn proper grammar before you come at me with your bullshit mechanic methods.

And you honestly think that I would just leave a chain too long on a customer's bike? If it's too long after I install it, I take out a few links. It's really easy. You make it sound like cosmetic surgery.
  • + 2
 But on the second bike, the chain would be too long because you used the UBI technique, which you previously said always works fine. If the UBI method works fine, why would you ever have to take any links out? Because it obviously doesn't always work fine. Which was my whole point in responding to your first post. Do you not realize
you just flushed your whole argument down the toilet?

Not only do I honestly think you would leave a chain too long, I'm sure you have left customers chains too long more than a few times since you've been using this crap method for 10 years.

Funny that you say I'm coming at you with "bullshit mechanical
methods" when I have never explained on this thread exactly what my method is.
  • - 1
 Oh my god dude, get a life!
  • + 3
 Man, you guys.... Back in the day, I did the small/small setup. However that was 44/32/22 and 11/28 or 30. That worked fine. Even magazines recommended that setup. Then came the 32/34 rear cogs and that changed it a bit. The last long cage I bought was setup big/big because of the 34. I run a hardtail and when I went to a 34 setup, the chain would have fits on the downhills or any bumps for that matter. And dropped chains, middle to granny. So I changed to an XT mid cage and the noise is pretty much gone, no dropped chains. Yes I run a triple. And yes it will go big/big (setup big/big) and there is too much slack for small/small, probably a link. I set it up this way to maybe avoid a big/big mis-shift. I doubt there will be any mis-shifts, I know where it's at, even without indicators. I set it up like that incase my daughter's ride my bike. In my case, I believe a small/small would be a better initial setup, because I'd never go big/big. I've been a mechanic for over 20 years and I do believe the safer setup, for non-mechanics, is the big/big. Sorry.
  • + 2
 Thanks oldschool43. Your comment was needed. I was worried that seraph and Protour's little spat would detract from what I see in my experience is a real issue.

With everything in life"rules of thumb" rely on the person applying the rule to appreciate and understand the principles behind why the rule will generally work and equally importantly why, where, when and how that application may not be appropriate.

I see Protour has a very valid point. I run a 1x9 Sram drivetrain on three bikes. These have anywhere from a 32 to a 38 front ring and an 11-28 through to 11-34 cassette. I also used to run the same two cassettes on a 2x9 where both grannies were 22, giving me 38-22 and 32-22.

Using the small-small method would give me the same chain length on both the twin front ring bikes yet different lengths on the single ring bikes. Using the big-big method would give me different chain lengths on all.
At first sight then surely the small small method is a short cut...many may think.

An amateur with no or little mechanical experience or who does not bother to do the necessary research to inform themselves is left with no option other than to plump for one and hope for the best - not a good option Instead, as you have said, use your own expereince.... listen to your drive train people... pay attention to how it behaves in the more extreme ratios out on the trial.... get to know your ride for pete's sake....

None of the optinos are the only way, TRY THEM YOURSELF people and get a sense of achievement from feeling more connected to the bike bneath you and how it reacts to how you set it up. Try small-small and take your bike out and see how it works. Try big-big and do the same, get a few cheap mechs of different cage lengths and try, try, try.

Cinfidence on the trails that your drivetrain is not going to be the reason you walk home makes for a better ride.
  • - 2
 I find that my modified small/small method works perfectly for every bike out there. I have never mis-sized a chain using this method. That's all I have to say.
  • + 1
 Yes you have. Your a short-cut taking mechanic and you suck at debating things. A thorough mechanic checks big-big and small small, and takes everything into account.
  • + 0
 Oh so you've met me in real life? Seen the bikes I work on? Buddy I'm the service manager at a locally-owned shop with over 10 years of experience, I do not cut corners like people who work at chain stores (no pun intended). My chain-shortening methods have never failed me and I have installed thousands of chains over the years.

You need to stop trolling my posts and get a life. Worry about your own shit.
  • - 1
 I'd say that Protour is right in this. Seraph, no need to bring you doll fetish into Pinkbike. It's kind of creepy.
  • - 1
 Kid, you're 14. You don't get to talk here. The adults are speaking. Go back to bed, you're having a nightmare.
  • + 2
 What makes you think that just because I am 14 that I cant voice my opinion. If you can explain that to me in a way that makes sense, I will be quiet. Also, what makes you bring all this dumb shit like your doll fetishes and kids dreams into biking conversations? I am starting to worry.
  • + 0
 Because you can't possibly have enough experience in the bike industry to comment on what we're discussing. Your personal feelings towards me are moot.
  • + 1
 I have worked as an intern in a shop for a year, but whatever. But in the future, It would be best to leave personal fetishes out of biking conversations
  • - 1
 Oh my a year! I have been working in a shop for almost as long as you have been alive. And I have no idea what you're talking about with the doll thing.
  • + 0
 Seraph admits he takes short-cuts.....them denies it. Not only a slacker, but a delusional one who with a thick skull and reading difficulties. I clearly described why his technique is inferior, sic ripper essentially also described why it sucks, yet here he is continuing to defend himself putting the exact same length chain on a bike with a double 32-48 and another with 1 gear up fron-a 32. And if the 1x9 bikes had an 11-22 and the bike with the double had an 11-36 they get the same length chain. You ARE a slacker mechanic and more especially a completely incapable thinker if you don't get this by now.
  • + 1
 Dude, you need to give it a rest. Nothing you say will change the way I size chains, and nothing you say will make the way I size chains not work. Move on with your life.
[Reply]
  • + 3
 Literally wish this was posted about a week ago when I got my new bike and absolutely destroyed the derailleur and the hanger along with two spokes.
  • + 1
 That is an issue with your limit screws set wrong. The screw with the "H" by it needs to be adjusted to limit the derailleur from going up into the spokes.
  • + 1
 You mean the screw marked L for the spoke side
  • + 1
 Yes, my mistake. I was very tired. "L" for low gears.
[Reply]
  • + 1
 I didn't totally understand the derailleur cage phrasing, but I do know what happens if you spec a SRAM medium cage derailleur with a 2x10 setup. With a chain that had its length adjusted with the big x big + 2 link method, the SRAM med cage RD doen't provide enough tension when in the small chainring up front and the smallest 4-5 cogs, and you end up with all shorts of shifting problems if you somehow end up in that gearing.

When in doubt, go long cage. It's what a vast majority of complete bikes ship with. I think SRAM med cage was designed for 1x10 or maybe micro geared double+bash (ex. 24/32/bash + 11-32).

I learned my lesson the hard way. I heard/read people mentioning that med cage provides better tension, with chain drops being one thing that was noticeable reduced, which I really wanted to address, and wrongly assumed that it'd work with my 11-36 and 28/42 setup on my FS trail bike.
  • + 0
 My SRAM medium cage derailleur works great with my 2x setup. My guess is that you're doing something wrong, or your chainstay is a very strange length.
  • + 0
 You should never be in the big x big gears together at all. Those ratios are meant to be had in the smaller front ring and about midway though the cassette.
  • + 1
 Also I don't think that any medium cage could accommodate a double with a 42-tooth front ring. My double is 11-36 in the back with a 22x36 ratio up front and it is flawless.
  • + 0
 I have a 24-36 up front with an 11-34 9spd medium cage X9 and it is crap anywhere beyond about the 4 biggest cogs when I'm on the 24 up front. Even with a chain tensioner on the front to try and pick up the slack the chain gets a ridiculous amount of droop. If i shift into the 24 - 11 combo without the chain tensioner fitted the chain almost touches the ground.

I used the big to big, shock fully compressed + 2 links method which is what is detailed in the instructions that came with my SRAM chain. Shifting is fine generally but the chain slack on the small chainring is ridiculous.
  • + 0
 I have run countless 22/36x11-34 9-speed setups in the past without a problem.
  • + 0
 Except that the chain was probably too long on some of them since you use the lazy UBI method.
  • + 1
 No, never too long on any of them. I think maybe you're unclear on what the UBI method actually entails.
  • + 0
 Derailleur cage sizing is based on chain wrap capacity. It is the difference between big/big and small/small. Each derailleur is designed to accept up to a maximum chain wrap capacity. Chainstay length is not a factor, nor is the amount of chainrings you have. For example, the chainwrap capacity of a SRAM X.O 9spd. rear derailleur is 45-long, 37-medium, and 30-short cage. This is the correct method in determining derailleur cage length.
  • + 1
 Partially right. But if your theory is correct then road bikes with triples could be running short cage derailleurs. The number of chain rings up front has a direct effect on how long your derailleur cage needs to be. Three chain rings will require a long cage derailleur (medium for road) because of the difference in chain ring sizes. The longer cage takes up the slack in the chain that is created when the ratio in the front is increased or decreased. A short cage would not be able to handle three chain rings; either there would be far too much chain slack in the small ring, or the derailleur would explode trying to make it into the big ring up front.
[Reply]
  • + 1
 please please do a tech tuesday on how to service the fox 40 dampener cartridge. It was mentioned in "fox lower leg removal" that there would be another one soon to show how to service the cartridge but nothing yet....
  • + 1
 There are comprehensive videos on youtube that walk you through it.
[Reply]
  • + 1
 So what does that dropout adjustment screw do?

I currently use a long cage derailleur to minimize chain damage on the bottom of my chainstay.
Thinking about going with a short cage and a Bionicon C-Guide.
  • + 1
 That allows you to adjust how far the derailleur pulley is away from the cassette. In the biggest ring on the cassette, the jockey wheel should have one full link between the cassette and derailleur.
[Reply]
  • + 2
 thank you PB!!! shifting to 2x10 in a couple of weeks with an entirely new drivetrain and this information is priceless for hamfisted newbie mechanics like myself
  • + 1
 hamfisted? haha...what is that anyway
[Reply]
  • + 0
 there's 2 ways to get a proper chain lenght or tension...#1 wrap the chain around the smaller cog in the back and smaller chainring, when the derailleur becomes perpendicular to the ground when you join the 2 ends of the chain, that's where you need to cut. #2 (better for freeride/Dh bikes) wrap chain on middle chainring and on smaller cog on cassette then pull on both ends until you create a 1''-1.5'' tension between the chain and the 2nd derailleur pulley (upper). and you are set
[Reply]
  • + 1
 Yep. I ripped up a hanger, x.9 derailleur and screwed up some spokes by having a short chain. This is an easy, useful tech tip.
[Reply]
  • + 1
 OMG! we're suppose to read ALL THAT?!?! wheres the video damnit!
so TLDR...
[Reply]
  • + 1
 is there anything you need to do differently when you add the bionicon c-guide v.02?
[Reply]
  • + 1
 Stupid question: In the "Just loose enough" section (two last pictures), is the suspension still in a bottom out position?
  • + 2
 No, you would want the distance to be as short as possible. The derailleur will compensate for chain growth.
[Reply]
  • + 1
 photos are ok!
[Reply]

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