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.
My new 10 speed Shimano 105 block came with a skinny aluminum spacer, which was intended to fit behind the block. Does this always need to be fitted or is it for special circumstances? I also have new 10 speed specific wheels and the chain does clear the spokes without the spacer. The new chain is not smooth under pressure, could taking out the spacer be a solution? Thanks.... Read more >>
Dear friends, I wanna buy a bike that will provide me both road and trail usage. and it should be also economical. There are lots of level of quality between shimano accessories such as Tiagra, Xtr.. and also same thing for Sram. Could you advice me the correct hierarchy between models acc to price. And advice a bike for both road and trail usage.Thanks in advance.. http://bikebest.net/versus/... Read more >>
The metal cap at the end of my derailleur cable somehow came loose so now the cable end has unravelled into multiple strands. They are a cut hazard and look ugly. Appreciate any suggestions on how to fix.... Read more >>
It's presently 0 Degrees F, with a -16 wind chill in Chicagoland...
It's been ~3 months since the overhaul of the 2 bikes, and I've been alternating them from the repair stand (Bunji Straps hanging from ceiling joist in basement)..
When I started I figured a squirt of oil was all that was needed. I had no idea what nice bikes I had!
I learned about strange part sizes from Here & Internet.
I learned about parts & "Alternate Parts" procurement from LBS, Here, & Internet.
I learned about loose bearings from the first dis-assembly.. and found b... Read more >>
I have two Deore LX derailleurs... one is a RD550 and the other is a RD565.
Which one is a better derailleur or is there a better one?? Any differences between the two other than the model number?? Both have the SGS long cage.
Trying to figure out the Shimano numbers and quality grades.
Thanks... Read more >>
I have a Boarman Hybrid Pro (2010 Model - White http://road.cc/content/review/4160-boardman-urban-pro-ltd) and the I have had a lot of repairs on it recently.
After the latest repair I noticed the chain was wobbling from left to right more than what I expected. I bought it back to the bike shop but they gave me lip service on the cause and the repair for the problem.
With further inspecition I noticed that that both rear derailleur pulleys are wobbling and are l... Read more >>
Hi, I need to replace and old broken RD-TZ30 drlr 7 speed.
Does anyone know if the Shimano Acera M360 7-8 Speed would be an ok replacement?
It is for an old (but much loved) Schwinn Jaguar beach cruiser.
Thanks!... Read more >>
I took off my rear derailleur to clean my bike and i need help putting it back on. Its a shimano derailleur with the hook. And i have a diamondback mountian bike. If anyone can help it would be appreciated!! I dont remember exactly how it was attached to the frame
Jay... Read more >>
I have an early 90's Merlin MTB frame with 90's era Shimano xt and xtr on it. I now use the bike primarily as a pavement hill climber (I live in a hilly residential area) with maybe 20% off road. Recently, the front derailleur stopped returning when released by the shifter. The derailleur shifts to a larger chain ring perfectly. When shifting to a smaller chain ring, the shifter appears to release the cable correctly, but the derailleur is not returning, despite obvious slack in the cable. I have to kick it over with my heel. Lubricating the various pivot points did nothing. I assume the... Read more >>
I purchased a 18 speed bicycle with shimano gears having revo shifters yesterday.
Today I noticed that while shifting from 2nd gear to the third gear it skips the third cog at the back and jumps to the fourth. There is no issue with other gears.
I would like to know why has this happened and at the same time what can be done inorder to fix this problem.. Kindly reply.. ... Read more >>
I've got an old high end Giant mountain bike I'm wanting to convert to a gravel bike, mainly changing the MTB bars to CX/road bars with integrated brake levers/shifters. Any recommendations for some road shifters/levers that would work with the Deore XT 7 speed / triple front derailleurs and cantilever brakes? Don't want to spend a lot, so replacing lots of other components isn't an option.
Thanks for any help you have.... Read more >>
I don't exactly know how it happened. I've been trying to fix it for days but nothing works.
So let's say you had a 1-9spd derailleur:
If we would want to shift to the biggest cog we would go to the 1st gear, and if we would want to shift to the smallest cog we would go the the 9th gear. BUT that's not the case in my rear derailleur. I could only go to the 2nd smallest cog, and if I would want to shift to the biggest could I would only have to shift 8 times, this means that I would have 1 more shif... Read more >>
i dont know whats really going on but when i was riding my $300 swiss mountain bike i took a brake then got on and tried to peddle. it spawn around w/o catching the back tire. i checked to see if the chain was on, it was. i was having very slow reaction with the front gears with alot of noise before this. i have not used this bike no more then 4-6 times.
if anyone can help thanks. if i can repair it my self i would rather do that since i dont have cash for a repair person..
(but i did notice it started to catch when i go down the drive way (going somewhat speed... Read more >>
I'm a real novice at this so please make allowances! I was having trouble (front derailleur) shifting up from first to second. When I flicked the shift lever into 2nd, the cage would move across seemingly correctly, but the chain would struggle, make a lot of noise and refuse to shift up. If I pushed the shift lever over a little more - towards 3rd - and held it for a couple of seconds, the chain would move up on to 2nd position and stay there OK. I tried to correct this by increasing the tension a little on the shift wire. The result of that was that it shifts up to 2nd correctly, but wo... Read more >>
I'm re-bearing, lubing, and overhauling my wife's 1969-70 Gitane Grand Sport Mixte, and I'm showing here the 'status' of the re-build... Expenses so far: ! $40.00 if I split the cost of tools in half!
Overall she's happy with the improvements in bearings and lube, and she's 'buying' the improvements in the braking system that hasn't arrived yet... but..
As only a wife can do... She says: "You know, I like the location: (Stem Shifters) of what you have on 'YOUR BIKE', and wish I had the same on: "My Bike"...... I have to reach too far to change gears..... Read more >>