23. How to Replace Your Chainrings
Basic removal and installation instructions for 5-bolt chainrings on 3-sprocket systems.
This tutorial will demonstrate how to remove and install chainrings. Since there are so many different crank and chainring sizing combinations, I'll stick to the basics and give a general overview of the process based on a 5-bolt, 3-chainring system.
Before removing the largest two chainrings you'll often have to remove the smallest one, which is often threaded directly into your crank arm. Use your allen key to loosen all of the bolts that hold the chainring in place, and then use a marker to make a note of the chainring's position in relation to the crank before removing it completely. Some chainrings have a bump sticking out that should be lined up with your crank arm.
The largest two rings are usually bolted to each other with a nut and bolt. Here you'll need to hold the nut in place with the special chainring wrench while you loosen the bolt with your allen key. Once again it's a good idea to mark the chainring's position in relation to your crank arm. The two largest outer rings often have a few spacers or washers in between, so be sure to note exactly how they came apart so they can be reinstalled correctly.
While it's ok to install a new chainring that has a different number of teeth, you'll want to make sure that your new chainrings have the same side profile as the old ones.
Before you reinstall the bolts, apply a thin layer of grease to the threads to keep out moisture. Now you can reassemble all of your chainrings the same way they came apart.
Make sure all of the bolts are finger tight and then begin tightening them evenly in a star pattern. Start by tightening the first bolt, and then every second bolt until you've gone all the way around. Repeat this process until all of the bolts are tight. Be careful not to over-tighten. Park Tools recommends 44-88 inch pounds of torque for aluminum bolts, and 70-95 inch pounds for steel bolts.
Being new to this hobby I ran across the 12" rule for chain wear. You pull the chain tight, right on the bike, measure 12 links, the distance between 25 pins, and if it measures 12" the chain is like new. If it measures 12 1/8" you throw the chain away and replace it.
Something new to check out now. i imagine a worn chain causes shifting problems as well as drive train inefficiency. Do others here you use this method for determining chain wear??... Read more >>
I am asking this one for my dad (78.5 yrs old). He just got a bike on craigslist (Marin Redwood), comfort style.
He likes it, but wishes that it had lower crank gearing. According to the Marin website, I see that it has a "Crankset: Suntour XCT light 48/38/28".
My dad says that he thinks the chainrings are riveted on, but his eyesight isn't the greatest, and I have not had a chance to go there and look for myself.
Do you guys know whether the chainrings are replaceable on this "XCT light" crankset? I can't find any specific info to ... Read more >>
Have Dahon folding bike with missing chainring guard.
Looking for a source.... Read more >>
First of all I have been trying to research this bike and have come up empty.
What I do know, it has a belt vs chain and it looks a little dry.
I don't even know where to begin to find a replacement for it because I can't find it anywhere on the internet.
... Read more >>
I am buying a new bike, it has a Shimano FC-5703 triple ring crankset, 50X39X30T, bcd 130mm.
I am a casual rider, and really want some type of chainguard on here so that I can ride in jeans without need for a leg wrap to keep my pants leg out of the chainrings.
I do not know what the difference is between a "bash guard" and a "chainring guard / "chain guard".
Regardless, what is the best way to accomplish some type of chainguard on here? What will I need? I can find chain guards sold on ebay made by Driveline, but is that the correct ... Read more >>
I have a 2012 Trek 7.5 Fx Hybrid bike that I need to replace the Freehub body on the rear wheel. There are no identifying marks on this hub anywhere. The cassette that is mounted on the Freehub body is a CS-HG61-9. The gears on the cassette is 11-34 and its a 9 speed. Is there anyway to exactly identify what freebody hub this is so I can get an exact replacement?... Read more >>
Well, hello everyone this is my first post.
I have been trying to renovate an old road bike a British hercules. The thing is that the bike has old components and I have trouble finding other ones. I want to keep the front chainring 48t but remove the internal hub that my gramp was using. Instead i decided to buy a nice wheel with a 9 cassette and the suitable deraileur. Well my main problem is...Will this fit with the 48t chainring? Is the deraileur going to be ok with the claw type hanger (the bike has no built-in hanger)? In copenhagen where I live we have no steep hills, every... Read more >>
I have a two ring Tracer crank on my ross road bike. I am just wondering if it's any good or not.... Read more >>
I got a Bell brand chain from walmart for my other bike and the quick link is so annoying to put back together when I need to take it off for some cleaning. Well, I try and hold the derailleur and put the chain back together but I suffer from panic attacks from time to time and I just get so annoyed with having to hold the derailleur and putting the link back together at the same time. Any tips to help me do it better without getting frustrated or annoyed?... Read more >>
So my bike kind of broke and I adjusted some things to fix it, but then a new problem arose.
The thing that broke and bent badly was the metal that held the two cogs in the back wheel of the bike ( the gear shifting thing) so I bent it back into shape and screwed it back on but whenever I pedal the bike the chains starts going into its cycle but in a few seconds the chain slips off the bottom cog in the gear shift and the chain slowly slips off everything else. Is there anyway I can fix this?[/align]... Read more >>
So I'm new to these forums and also to bicycling, like I just recently learned how to ride a bike and a 2 weeks ago I bought my first bike.
So I have been having troubles with my bike for some days now, It got really bad at one point but I've been able to fix it a bit. With very bad in the form of the chain falling from the front gears.
I have fixed that, however, the chain cannot get to the biggest gear of the front. I'm not really sure why.
Can someone help me?... Read more >>
I'm running a full SRAM X9 / X0 on my hard tail with XT discs. I want to move from 2x10 to 1x10 set up. The biggest cost is the cassette to give me more choice will a Shimano cassette fit onto a SRAM ready hub?... Read more >>
I am/was in the middle of changing a snapped rear axle, and came to the conclusion I needed to remove the cassette to tighten the components of the new axle enough.
Anyhow on removing the cassette/freewheel ball bearings went everywhere and it seemed to be much more complicated than first thought.
Below are a couple of pics of how everything now is.
What do I need to get this thing going again?
Excuse if I have mixed terminology etc, bikes are not my strongpoint although I am curious to learn.... Read more >>
I've been having a problem with a broken new chain. When I removed the broken link, the inside link falls apart. When I remove the inside link, the next inside link falls apart. Is this something wrong with the chain? I haven't had this problem in the past. I noticed that on old chains, the oil and dirt might have been holding the inside link parts together, so I wondered if that's why I didn't notice it before.
Is there a tool to hold the inside links so they don't fall apart? (I guess I could just use a vice grips.)
Thanks.... Read more >>
I'm refurbishing my Dad's old 1998 Trek 820 with the following OEM
specs for the crank and bottom bracket - first bike I've ever done this to but thought it would be an good entry into bike repair (since I just got a bike tool set and XMAS $ to do the project)
Shimano Altus CT92 (24/34/42 Square Taper) 170mm crank length paired with a
BB-CT91E, 68mm / 118mm spindle length bottom bracket
Its easy enough to crossover (and find online) the BB to a UN55 (68mm/118mm/English). The questions revolve around the crank (which seems to be harder to find a repla... Read more >>