4. How to Calculate Chain Length

Measure the correct length of a new bike chain.

IMPORTANT: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.
How to Calculate Chain Length
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When you purchase a new chain, it usually comes with extra length so that it is compatible with most drivetrains. How do you know how much length your bike will need? Well, it’s really quite simple…

The first step is to wrap the chain around the largest sprockets on the front and rear, so that the ends meet on the largest front chainring. For this step, it really important to not run the chain through the rear derailleur.

Next, position the chain on the chainring’s teeth at the tightest spot you could connect the chain. Now add one whole inner and outer link, so that you have approximately one extra inch of slack in the chain. That will be the optimal length for most systems.

In future tutorials I plan to discuss the different types of chain connectors and how to use a chain tool to break the chain. The following links provide some more helpful information.


Related Links

Discuss this topic in the Chain Forums

04/17 Cheap, welded chainrings?

Hi. New member.
I working in Cambodia, riding a 2011 Giant Escaper 26" 24SP.
It's not a great bike, but it's what they gave me, and it works OK for what I need.
But now my large chainring is well worn, and has some broken teeth.
Looking to change out the one ring (since the others and sprockets all
look pretty good still), this set looks like nothing I've ever seen before. (Maybe because most bikes I've ridden in the past were of noticeably higher quality.)
There are no bolts/screws holding the rings together! It appears this Shimano set has all t... Read more >>

04/15 6 Speed Cassette Question

Bike is a Fuji Allegro, with a Sun Tour Mighty-6 rear cluster according to the parts listing I found online.

The chain was completely rusted/stuck to the cassette ring it was on, and chains appear to be cheap online, so I'm replacing that.

If I wanted to replace the cassette as well, how can I tell which six speed cassettes would be compatible? Is that even an issue, or are they all basically the same?

I was looking at this one as an example: Read more >>

04/09 Part number for sprocket

does anyone know the part number (or how to find it?) for the 32 tooth sprocket that attaches to the crank? My bike shop guy will take the 38 tooth sprocket (standard factory equipment when you buy the trike new) off, and put the 32 tooth sprocket on for me, but he needs that part number in order to get the 32 tooth sprocket.

The adult trike is a 26 inch, one speed, schwinn meridian.

thanks...

04/06 Annoying Noise


Canvassing opinions on an annoying noise.

The bike is a Ribble R872, high modulus carbon frame, 105 groupo.

I get a rattle/buzz only when in the large chainring and only in the third and fourth largest sprockets. It's high pitched, almost like a vibration. Shift up or down the cassette from these sprockets, no noise. Small chainring, no noise.

I'm pretty capable in terms of set up, I can strip down and rebuild a drivetrain fairly competently so the obvious tweaks in relation to indexing and general set up I don't think are applicabl... Read more >>

04/06 Chainwheel on Schwinn Meridian

I am 85 years old and do not have much strength in my thighs. I just bought a Schwinn Meridian 26 inch trike. Can the sprocket ( I guess it is called a chainwheel nowadays) on the crank be changed to one with a smaller diameter? That way, may be the trike will be easier for me to pedal. Like if it is now a 6 inch sprocket, could I get a 4 inch sprocket put on? Would this be an easy job for a bike mechanic? I suppose the present chain could be used then too if it were shortened?... Read more >>

03/30 Will this chain fit my bike?

Hello I know to some this will be a novice question and you will be disgusted but I don't want to buy the wrong chain. THANKS

Will this chain fit my bike?

[Image: w1temt.jpg]

http://www.ebay.com/itm/110935490423?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT...

03/29 Chains don't move when I pedal forward.

I have a seven speed Raleigh bike. Recently, when cycling the bike stopped moving forward when I pedaled. The gears and tires don't move when I pedal forward but do move when i pedal backwards. Does anyone know how I can fix this?

As someone who is mechanically challenged, I appreciate any assistance. Thank you!... Read more >>

03/25 Bike keeps going into higher gears

I recently put a new chain on my bike. It's a 10 speed. The chain was for a 10 speed. I didn't check the number of links on the old chain. The bike keeps shifting into higher gears and there seems to be tension on the derailleur cable that pulls it into high gears. I've tried adjusting the derailleur but it didn't help. I'm wondering if the chain is too short.

Help appreciated....

02/19 Chain sits on top of chainring when shifting up

Hey guys,

First post here. I've tried searching, but I don't know what you call this.

I have a vintage Schwinn Passage that I picked up a few months ago. At first it worked well, but recently it's been giving me trouble.

When I shift, the chain pops into the higher (larger) gear, but then sits on top of the chain ring. What ends up happening is that the chainring will keep turning, and eventually the chain will pop into place or pop right off.

[Image: 5f9NtSN.jpg]
<...

02/08 Chain question

Over the past few years, I have noticed that basically all the bikes I have owned/sold/ridden have all had chains that do not have a quick release. So, when I need to replace them, I have to get a punch and a hammer to take the chain off. Does anyone know the meaning of this? It has been bugging me for quite some time now because it can take quite a while to punch out one of the pins. Plus, then sometimes the chain is ruined.

-mtnbikr...

01/30 Sears tote cycle

Have an old Sears tote cycle that I'm fixing up. Looks like it was a two or three speed but has no cable or shifter on it. Coaster brake arm has Torpedo Dreigang on it. I'm wanting to get it back to working again.Know nothing about this. I have built motorcycles so I know my way around two wheels. Trying to find out how to hook up a new cable and lever to the rear hub.... Read more >>

01/20 Triple chainset replacement

Hi, new to the forum, need some tech advice:

1) is it normal for the teeth on the same chainring to have different profiles - some are pointed and others shorter and squarer. This is a new Triple LASCO I am looking at in a shop.

2) How do I know if any new chainset I buy, will match my existing spindle? The chainset I have currently fitted is an SR SUNTOUR ZR 120, does that mean the square hole is 12mm?

Many thanks.
Zak...

01/19 Sprocket Does Not Engage

Brand Brand new to the Forum!

I have a Giant Iguana 640 Bike that has been under the house for a couple of years. Used to ride it quite a bit then life kicked in. Just got re-enthused about riding and decided to break out my bike. I cleaned it up and got the cobwebs off.

I am having a problem and have no idea where to start to diagnose it. Everything looks good but if you pedal, the pedals turn but the the rear sprocket does not engage. I can pedal and pedal but I go nowhere. There is no grinding or unusual sounds.

I would appreciate any advise or guidanc...

01/15 7 speed chain

I am currently running a thread on derailleurs regarding 7 speed blocks. However, another bump has appeared in my road - scarcity of 7 speed chains.
I really wanted Schramm, but can't find one, but Competitviecyclist have just told me that the Shimano 9 speed chain is compatible with 7 speed. I am sceptical so I decided to canvas you guys. Can anyone confirm this? Thanks... Read more >>

01/12 Advice needed: Want to upgrade bike to be a better climber

My current set up is a standard 2011 Merida Ride 91:
Speeds 18
Frame Ride Speed-Single
Colour Anthracite(white)
Fork Road CF-S
Front Derailleur Shimano Sora 34.9 Double
Rear Derailleur Shimano Sora SS
Shifters Shimano Sora
Brake Levers attached
Brakes F/R Shimano Sora
Crankset Shimano Sora 50-34
BB Set attached
Chain Shimano CN-HG53
Hubs F/R Shimano 2200
Rims Alex Race24-White-NC
Freewheel Shimano CS-HG50-9 11-25
Spokes Black stainless
Tyres Maxxis Detonator 25 60
H-Bar...

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