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.

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Discuss this topic in the Chain Forums

11/18 Think I found cause -- Pedal Reverse -- Chain Jumps off

~1970 Gitane Mixte. Prior to rebuild wife could only pedal forwards, as peddling backwards would have chain occasionally jump off.. but only in larger rear gears and larger front sprocket.

To my knowledge, this bike has not been serviced.

I believe I now know why.

If I look from rear of bike forwards with eyes at axle height, I'm seeing the that the chain from what would be the middle of 2 front sprockets, would hit the 4th of 5 gears (next to smallest rear gear)...

Looking at internet posts, this would seem to want to be aimed for the 3... Read more >>

11/17 Changing from 12/25 to 11/28 ?

I currently have Shimano 105 12-25 10S but want to change the rear cogs to 11/28 to make it easier to get up hills, Is it just a matter of switching them over or do i need to do anything with the chain ?... Read more >>

11/11 New chains wearing out quickly?

Hey guys,
I replaced the chain on my wifes road bike about 800 miles ago and I just happened to check it today and it is already at the .75 wear indicator on my chain checker tool. I have kept it lubed(dry formula lube) just about every time we did a century or other ride, but can't figure why they are wearing out so fast. Can't you normally get at least a couple thousand if you maintain them right??
Seems like I read somewhere that if the cassette gears are worn considerably(does not skip a link in any gear) that the chain will wear out quickly. Is this true or am I just crazy? <... Read more >>

10/21 Question about chain length

Hi I have bike called specialized secteur 2013
Did on it 4500 miles and wanted to replace a few parts. Chainring, cassette and chain

I replaced cassette from 12-25 to 11-28, chainring will stay the same I mean 50t. And new chain kmc x9

Can someone please tell me how long chain should be for 11-28 cassette and 50t chainring?

Rear Derralieur is standard sora.


Thanks... Read more >>

10/14 Shimano MF-HG20

Does anyone know how I remove this freewheel?

I can't figure out what park removal tool is required. Is there something more that is necessary?... Read more >>

10/07 Crankset compatibility

Hi, I've currently got a shimano crank-set with shimano 6-speed rear and front derailleur. Is it possible to use a different make if I replace the crank-set, for example if I brought a suntour crank-set? thanks for any advice you can give. Also my current crank-set/drive-train has a wobble in when I rotate the peddles, it's not loose or anything, it just doesn't rotate in a straight line, has a slight wobble to it, is there a way to fix this? thanks.... Read more >>

10/01 Loose chain on high gears

Hi,

I have been doing some work on my bike to get it back in shape. Everything is working perfectly except when im using the high gears the chain become loose.

I also notice that it occurs when im only resting my feets on the pedals. But when I remove my feets from the pedal I notice that the slack from the chain goes away but my pedals are moving forward of it's own. I think that is the problem. Because the whole pedal section should be still and not moving forward of it's own when im in motion.

What could be wrong? The casette? The chain?

... Read more >>

09/30 Bike chain

I am trying to rehab an older model 3 speed sturmey archer bicycle but the chain keeps breaking. Is this a special chain, for example is the linkage metric. Could I go to a local USA bike shop and get a replacement chain? I've tried an Internet search but just keep getting sites for the indicator chain.... Read more >>

09/26 Use Quick Links

There is an alternative to pressing rivets in and out of your chain to install and remove it. It is called a "Quick Link". This can be installed instead of the pin. Remove the opposite pin and install the quick link, as tension is put on the chain the quick link will click into place. The pliers above are the quick link removal pliers. To remove the quick link simply squeeze the pins with the pliers and disassemble the link and remove the chain. The quick link is reusable so you can use it to remove the chain for cleaning also. Take a quick link with you while riding. If your chain breaks, ju... Read more >>

09/24 Triple crankset to Single crankset

I have an old mtb that I would like to change from a 3x8 to 1 1x8. I use the bike as a commuter and have no need for the extra gears. It has a Sakae xr100 crankset wit the gears riveted on. Otherwise I would just remove the inner and outer gears and keep the middle gear scince it is a low enough range for my needs. Can I use a Shimano crankset on this bike? Checking the specs on line says the pedal spindle is square taper and is 124.5 wide. Hope this info helps... Read more >>

09/17 Saving a 1995 Mongoose Alta! - full drivetrain replacement

Hello all,

I have ridden my bike, a 1995 Mongoose Alta, for the past 20 years and replaced just about every component on it except for the frame, FD and front wheel. Gone through 3 RDs, several chains, rear hub, both shifters, etc. I'd estimate it's lasted at least 30k miles. I put road slicks on it and use it as my daily commuter, going 10 miles/day now. Love the bike!

Last week, the chain started skipping when I pedaled har... Read more >>

09/15 Chain slipping on a self-repaired bike

I'm stuck with a problem of chain slipping on my old bike that i wanted to fix myself.

I changed the whole drivetrain and maybe this is as simple as a mismatch since i have about zero experience in bike maintenance, i tought you would know for sure.

Here are the components i chose to put on based on 8 speed compatibility and cheapness:
Front Derailleur: Shimano Acera FD-M360-6
Rear Derailleur: Shimano Acera RD-M360-SGS
Front Chainset: Shimano Acera M361 triple set square taper (42-32-22)
Cassette: Shimano Acera HG41 (11-30)
Chain: Sram 8 ... Read more >>

09/05 Chain slipping when shifting

My old nishiki bike was having some troubles with the chain, when I pedaled hard it would slip and gear shifting was rough so I inspected it and found a seized link and replaced the chain. When shifting (non indexed shifter) sometimes if I'm not being careful the chain will go between 2 gears and spin freely when shifting to a lower gear. My assumption is that my rear freewheel/cassette needs to be replaced, is this the case or is it possible that I did a poor job adjusting the derailleur?... Read more >>

09/02 How To change a Suntour Cassette to a Shimano

Hello All,

I have a 1992 Trek 6000 with the original Suntour AP II 12-30 7 Speed Cassette.

It's now time to upgrade the cassette to something newer. Is it possible to change the hub as well as the cassette with another Manufacturer?... Read more >>

08/31 Help specifying replacement rings set/crankset?

Hi All:
My first post. I have a 2004 Fuji Del Rey Hybrid with stock parts---> http://www.bikepedia.com/quickbike/BikeSpecs.aspx?year=2004&brand=Fuji&model=Del+Rey

I picked up another bike for the puropse of taking this bike off the road for overhaul. It is my utility bike-has a big rack, etc.

I love this bike, it is incredibly comfortable and very upright and safe for city maneuvering and wish to keep it, but... Read more >>

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