- News
- Reviews
- Bikes
- Accessories
- Accessories - misc
- Computer mounts
- Bags
- Bar ends
- Bike bags & cases
- Bottle cages
- Bottles
- Cameras
- Car racks
- Child seats
- Computers
- Glasses
- GPS units
- Helmets
- Lights - front
- Lights - rear
- Lights - sets
- Locks
- Mirrors
- Mudguards
- Racks
- Pumps & CO2 inflators
- Puncture kits
- Reflectives
- Smart watches
- Stands and racks
- Trailers
- Clothing
- Components
- Bar tape & grips
- Bottom brackets
- Brake & gear cables
- Brake & STI levers
- Brake pads & spares
- Brakes
- Cassettes & freewheels
- Chains
- Chainsets & chainrings
- Derailleurs - front
- Derailleurs - rear
- Forks
- Gear levers & shifters
- Groupsets
- Handlebars & extensions
- Headsets
- Hubs
- Inner tubes
- Pedals
- Quick releases & skewers
- Saddles
- Seatposts
- Stems
- Wheels
- Tyres
- Health, fitness and nutrition
- Tools and workshop
- Miscellaneous
- Tubeless valves
- Buyers Guides
- Features
- Forum
- Recommends
- Podcast
news
chain length calculator.pngChain Length Calculator app now available for Android smartphones
It’s possible to do just about everything from a smartphone these days, and now you can even determine the length chain you need when fitting a new one to your bike using the free Chain Length Calculator.
The app is quite simple, and uses the Park Tool "Rigorous Equation" method to determine the correct length of chain for any given gear combination. The app, currently only available on Android-powered smartphones, requires you to simply input your transmission type (geared or singlespeed), chainstay length and a gear combination. The app then gives you a suggested chain length expressed as a number of links. All you do then is measure out your chain, trim it to length and install it onto your bike.
Riding through the winter places a lot more strain on the drivetrain of a bicycle, especially if you cycle most days and through all weathers. As such, it's prudent to replace a chain before it begins to wear out the cassette and chainring, doing this can save you money in the long run. With this handy app at least you won't have any doubt about how long the new chain needs to be when you fit it.
Of course, you could just measure your new chain alongside your old chain and get the right length. But if you're building up a new bike from scratch and don't have an old chain to measure your new one against, this app would be ideal for getting you the right length for your new build. Plus of course your old chain might not be the optimum length for your drivetrain, if you had to shorten it as an emergency road side fix (or somebody eles did) or whoever fitted it the first time simply got the length slighly wrong.
It’s only available on Android (they’ll release it onto Apple iOS if they get enough interest) and is free to download at https://play.google.com/store/apps/details?id=me.afwd.clc
David worked on the road.cc tech team from 2012-2020. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes.
Latest Comments
- HalfDanHalfBiscuit 2 hours 49 min ago
Per capita thefts isn't all that useful a metric as it doesn't take into account levels of bike ownership. Cambridge is probably the cycling...
- Critman 4 hours 15 min ago
"30mm outer diameter 18mm inner diameter 13.4mm". Good luck finding a skinny tire.
- Destroyer666 5 hours 43 min ago
Ahem, the recommended lockring is just a common through-axle specific lockring, so nothing Miche specific there, and the required tool for it is an...
- Destroyer666 6 hours 38 min ago
Nonono, not those, but those that have constructed Italian cars and motorcycles that have been driven to hundreds of race and championship...
- RoubaixCube 6 hours 47 min ago
This may well be the case although Im unaware of the brands popularity on their home turf. I used to see them being advertised more in the UK...
- qwerty360 7 hours 17 min ago
Arguably sticking it in a bank account is bad....
- Sredlums 8 hours 16 min ago
I'd counter that those brakes were in fact so inadequate that they eventually developed a whole new type of bicycle that was actually suited for it...
- levestane 8 hours 18 min ago
Unfortunately, Africa is heavily exploited both for resource extraction...
- CitizenSmith 8 hours 44 min ago
There seems to be no support for TOO) now - their email and website are defunct. They are inactive on Facebook. Aftter less than a year the rails...
Add new comment
27 comments
I take it all back. I'm sorry. It's brilliant. This app could change the way in which we (humans) look at life. Thanks to your app I have created my own app that works out whether or not I should be angered by fools. Now at the push of a button it tells me to either punch myself in the face or the groin. I have punched myself repeatedly for days now and it's all thanks to you. My hero.
I actually used you app today. It worked, making my life so much easier. It wasn't for my bike I used it, I measured how crap your app is with it and the answer it gave me was 5417. I think it's referring to poo.
Mwahahaha
Si4star or is it si4 chocolate star. I can't sleep thinking how foolish your app is. This kind of idiocy really make me watch to punch myself. You must either be a science geek with little computer skill or a fireman. You won't reply because you know I'm right, you Baffoon.
Si4star. your app is the most stupidest thing in the wide world possibly the universe. You might of made an app that detects dogs poo. Infact that would be better.
All good DavidC, please do rate and review if you use the app.
KiwiMike, you say "erm..." as if I missed something, but you posted that to clear up after missing it out in early descriptions. It wasn't clear in the earlier posts.. stop being awkward.
"Remotely diagnose.. by post.." - stop being a plonker. Grow up.
Just because people do things differently doesn't mean they're wrong. Feedback on the app is great, but you're just being a complete tool.
Go play out on your balance bike. Child.
Dude, I made it *explicitly clear* in both my posts that the time-tested method I described was not including routing via the mech. Anyone can see that. Why you claim it wasn't clear is beyond me, hence my admittedly quasi-sarcastic use of the terms 'erm...'. The suggestion this app is only really of use for a niche case where you were trying to assist someone find the right length without actually being there to wrap a chain around the cogs and overlap it was genuine. I can't see any other use case where this makes life easier or removes the risk of error in measurement or tooth count. Feel free to disabuse us of this notion...
The only tool here is the one you designed, which as I and others have pointed out is a solution to a problem that fundamentally does not appear to exist. You are clearly feeling a bit upset. Sorry for that, but if you put a product up for review you should also be thick-skinned enough to handle discussion around its merits and applicability. No need to get abusive. Chill out. It's a bike.
Fair play for creating an app, but measuring a chain by wrapping around big sprocket and big chainring and pulling tight, then adding 2 or 3 half links (how many is determined by the fact you need to be able to rejoin the two ends) will take no more than about three minutes. Using the app will take much longer, plus doesn't account for full-sus mountain bikes where you often have to add two more half links (4-5 in total) to allow for chain growth when the suspension compresses.
This app surely just does this:
L = 2 (C) + (F/4 + R/4 + 1)
L = Chain length in inches. Round the final result to closest whole inch figure.
C = Chain stay length in inches, measure to closest 1/8”. Use chart below to find decimal measurement.
F= Number of teeth on largest front chainring.
R= Number of teeth on largest rear cog.
Which is fine, and very useful. A standard chain out of the box will not be correct for your bike. Finding the number of teeth on a chainring or cog is usually as simple as reading the number stamped on its side.
This app is far from useless, but not totally necessary either.
The app doesn't use the formula you've stated, it uses the "Rigorous Equation", as stated in the review above.
The rest of your points stand true. All the app does it allow you to use a simple effective formula on the go, and it doesn't take a brain surgeon to read the little number on the chain ring, or read the packaging or the specification of their bike for the cassette size.
It's a formula in your pocket & it saves time. It doesn't profess to do anything else.
- app author
True, I did not read the entire review, instead skimming over it. A skim, and then a second look at the responses left me a bit surprised at the vitriol a simple chain length calculator generated.
It's really no more waste than 99% of apps out there, and I don't install those either. Even if you replace the chains often as a precaution, once you've done it once (and presumably made a note of the chain length), you're good to go thereafter. Simples.
Spoke selector for wheel making could be useful. Yes I know they're online.
I'm currently working on an application to help wheel builders. I'll post here when I get that up for testing if you'd be interested.
- app author
Sigh. So what someone's done is create something where you need to count all the teeth on both cogs, and also know to the mm what your BB-rear axle distance is, AND the app then needs to *correctly* factor in the horizontal difference between your BB's Q-factor and your cogset's inward dimension, which it doesn't ask for, so it must be guessing?
Right. What an utter load of nonsense. W-T-actual in the name of god-F is wrong with going Big-Big (but NOT via the derailleur) and overlapping by a complete link, then breaking the chain there? How hard / idiot-proof is that?
This app is a total and complete waste of oxygen. We have yet to sort out how to stop rain getting inside overshoes, and people waste time on this non-issue.
http://sheldonbrown.com/derailer-adjustment.html#chain
When in doubt, check with Saint Sheldon.
Our Father Who Art in Heaven, Sheldon Be Thy Name
Thy Gears Be Indexed, Thy Chainline Be True
In Fixed, As In Derailleur
Amen.
Or you could just see how many your old one had
I've used the machinehead-software calculator for years. Find it really useful. Recommend it.
Add to the growing list of "Stuff You Didnt Know You Needed Until Someone Invented It"
Admittedly this seems a bit over the top, but the "standard length" isn't necessarily correct for your bike. You may still have to cut it...
^ +1 What he said
Wow, how silly. You still have to fit the chain, which is the standard way of determining proper length. On top of that, unless you're using bulk chain from a spool, you buy the chain in one of a few very standard lengths, so using the app and individually counting out the recommended lengths is a huge waste of time.
The app isn't aimed at pros like yourself. It's for those less confident in sizing the chain themselves. It's giving them the most effective length for the smoothest gear changes and least chain wear.
Obviously with your experience you'd take the "trust my instinct approach", and you've probably fitted a number of chains to the same bike so you know the size.
There is no 'instinct' involved in wrapping the chain around big-big and overlapping by a full link. That's all you need to do. No guesswork, no cleaning the cog to find a tiny number, no to-the-mm measurement between axle and BB centre.
Again, this app is a solution looking for a problem that was solved a long time ago.
When you overlap the chain how much tension do you put on the rear mech springs?
Instinct.
Also, its not a new solution. Its an age old system of measuring. I've simply made it more accessible.
Dude, are you deliberately trying to mislead people or just not bothering to read the comments / links provided and understand the method?
TO BE CLEAR: in this tried-and-tested method, you DO NOT PASS THE CHAIN THROUGH THE MECH.
The overlap of a full link accounts for the required slack that the rear mech needs to let you shift in/out of big-big.
Good on you for creating an app. Super. But it is not needed, introduces the risk of measurement/tooth-counting error and makes the job take longer than it needs to.
I've re-read your posts three times. You make no mention of not passing the chain through the mech.
I'm not a mind reader...
I accept that method is widely used.
erm...
Maybe it's lost in translation.
I accept that if you were remotely diagnosing chain length over the phone or by email or even by post, for someone who knew the tooth count and chainline to the mm but was unable to wrap it around big-big and overlap by a full link, that this app could be useful. Maybe they are standing in a store and have to purchase the exact number of links right then and there, having the bike measurements to hand. That sort of thing.