42. How to Check For Chain Wear
Demonstrates how to measure a worn out chain using Sheldon Brown’s ruler technique.
One of the most common problems I hear about is chain skip, which is when your pedal slips forward while pedaling under pressure. This is usually either caused by a stiff chain link, worn freehub body, or by a worn chain and freewheel. In this tutorial, we’ll learn how to diagnose a worn drivetrain.
Watch the stiff link tutorial first to make sure that isn’t your problem. Once you’ve ruled out a stiff link it’s time to check if your chain is actually worn. Chains will ‘stretch’ over time, because the pins and bushings start to wear, which causes them to start skipping. There are many tools available that measure chain wear (listed to the right of the video), but the easiest and most accurate way to check is by simply using a ruler.
With your chain still on the bike, place the ruler’s ’0′ inch mark directly above the center of one of your chain pins. Now count 12 complete links. A complete link equals 1 inner and 1 outer. A rivet on a new chain should line up exactly with the 12 inch mark using this method.
According to Sheldon Brown, if the rivet is less than 1/16″ past the mark, your chain is ok. If it’s between 1/16″ and 1/8″ past the mark you’ll likely need a new chain, but your sprockets should be ok. If it’s more than 1/8″ past the mark, you’ll have to replace both the chain and rear sprockets.
The reason you’d have to replace the rear sprockets is because they generally wear with the chain. While the chain is ‘stretching’, the gap between the teeth on your sprockets also gets wider and wider. This causes the chain to ride up over the teeth and slip while pedaling under pressure. If you install a new chain on an old sprocket, you’ll probably be able to see gaps of light through the teeth as shown. Here’s how to replace a cassette or a freewheel.
Your front chainrings generally won’t need replacing. Because of the larger diameter, the front chainrings usually take twice as long to wear. If worn they are very easy to spot, as they’ll start looking like shark teeth. Here’s how to replace your chainrings.
I just got my new Saracen Urban ESC. It has 3 gears in front and 7 at the back.
Couple of issues I have noticed when changing gears. The front derailleurs works fine when changing in to a lower ring. But when i try to shift it up I have to press the shifter twice. First time does not change the gears and make a horrible metallic sound, feels as if the bike is gonna crash.
How can I fix it?... Read more >>
I just bought a Mountain Bike that I suppose you would classify as a beginner one (Giant Revel 2) and it has been a great experience getting back into riding. Not too long ago I sort of crashed, what I mean by that is I hit the side of an object and ever since that point my front shifting is seeming to suffer. First problem was that shifting from 1st gear to 2nd gear would not always work, it just wouldn't catch and would make a clicking noise as expected. Also shifting into third would do the same. I tried adjusting the shifting knob (the one by the actual gear change on the handlebar) and no... Read more >>
Thanks for taking the time to read my problem. I have recently bought a new bike. It is around 3 weeks old and done 112 miles on it. Recently it has started taking ages to shift up a gear on the rear cassette and occasionally it feels like it is trying to change gear on its own. The shift down is fine at the moment. In another 3 weeks the bike will have a 6 week free service. Is it worth waiting till then to let the professionals look at it or is it a quick fix I can do myself? I want to keep it in tip top condition so dont want it getting any worse or even damage it by putting mo... Read more >>
I'm trying to do some basic bike repairs, but I've stumbled upon a problem I cannot solve.
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I've watched hours of tutoring videos all over the internet in search for an answer. This forum is probably my last shot at it. The gears on the left (for the front derailleur) don't change the gears on my bike, because the shifter cable is out. I've been trying to reinsert my shifter cable for my FD, but only gear one and two work, and it's too stiff for the third gear. Ahhhh! Please help!!... Read more >>
Rear Derailleur shifter: Falcon Index System thumb shifter.
The high and low limits are set correctly because I can shift through all the gear with no problem. I just have to hold the shifter in place. If I let go, it will move all the way to high gear (small cog). It won't stay in anything but the highest gear by itself.... Read more >>
I recently purchased a Genesis Roadtech bike from Wal-Mart. It's a road bike but I have no idea how to use the shifters on this bike. The image is where the shifters are located.
I'm just getting into cycling so some of this stuff is still very new to me.
Thank you in advance for help advice.... Read more >>
I currently ride a Giant Revolt 2, 2014 model Cyclocross bike.
Last week during my commute to work I lost a spacer from my rear cassette so had it repaired by a local guy who is a friend of mine.
He managed to get every gear sweet bar the highest (small cog) on the rear cassette, it shifts nicely from the second smallest cog down to the smallest cog but it won't go back up - only on that one lowest gear.
He took it to his workshop over night and fit a new cassette and removed a link from the chain as the chain was still slack but that... Read more >>
I have a Sturmey Archer gears on my bike with a following shifter:[attachment=5222]
However I would like to change this shifter for modern one -the one I currently have is a bit rusty and its though to change gears sometimes.I have found this model:
3 SPEED NIMBUS SHIFTER
FITS 22.2MM BARS.
Will this shifter be suitable to replace the old one?
Thanks... Read more >>
I have a second hand, 18-speed, index shifting bike that I use for getting back and forth to school and running some errands. I've been having trouble shifting gears on it. The right gear shifter works fine, but the left one is struggling. When I twist the shifter into a new gear, the actual gear doesn't change. It will however randomly clunk into a new gear when I'm riding and haven't recently changed gears.
I've attached a photo showing the back gears. Let me know if something different would be more helpful!
I really now nothing about bik... Read more >>
Sorry if this has already been covered, I'm new to all this
I have recently had my cogs and chain replaced on my mountain bike due to wearing which caused my chain to slip in a number of gears, have spent a few days adjusting the derailleur thanks to online videos, and seem to have everything working perfectly with the exception on one gear,
when the chain is on the largest chainring and the largest on the back the chain seems to jump and make a loud noise, I have noticed the lower jockey wheel may be the cause of this, as this is where the chain seems to be jumping ... Read more >>
Hi, I'm new to the forum and this is my first post. I don't quite know how to explain it but will try to do the best I can.
I have a Mongoose mountain bike which I picked up for nothing. It had 2 broken spokes which I fixed quite easily. Bike works really well apart from the gears for the back sproket. It will change from 4 to 7 and back from 7 to 4 but then doesn't go any further. I have uploaded a Youtube video
I don't know what the parts are but there is a little cog that works like a ratchet. Once this gets to 4 it reaches the max for the lever. i.e.... Read more >>
Okay, so about a month ago I bought this used bike to have a cheap way into the sport. It's been working great for the past few weeks, but then I started to notice my rear shifter getting tight. I have twist grip shifters. It's gotten to the point where it won't down shift at all. I'm certain it's the shifter though and not the derailleur as I can I push the derailleur into gear and it allows me to downshift if I'm holding it in. It seems like the cable is too tight or something. I'm not sure how to go about fixing this issue.... Read more >>
I have trek bike and use it occasionally. My rear derailleur is broken and part of it hanging. I tried it put it in but it doesn't hold on anymore.
Please suggest if it can be easily fixed or need to take to a bike repair shop. Added some pictures... Read more >>
Where can I find clamp on 12 speed downtube indexed shifters?
Right now I have friction shifters mounted on the stemof my 86 Fuji Allegra and I'm looking to upgrade to indexed shifters.
Thanks!... Read more >>