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.
For this job, you’ll typically need a 5mm allen key, a chainring nut wrench, and some waterproof grease. On some bikes, you may find it easier to remove the right crank arm before you begin.
Chainring Removal
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.
Chainring Installation
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.
Related Links
Related Tools
- Shimano TL-FC20 Dustcap Pin Tool
- Park Tool HXS-1.2 Hex Wrench Set
- Shimano TL-FC10 Crank Extractor
- Park Tool PAW-12 Adjustable Wrench
- Park Tool SK-3 Starter Mechanic Tool Kit
- Park Tool PK-3 Professional Tool Kit
Categories
Discuss this topic in the Drivetrain Forums
Replace 14-28T Sprocket With a 13-28T Sprocket?
Lastest post 8 months agoWould there be any issues with one less tooth on the high gear as regards shifting or otherwise?...
Read moreChains
Lastest post 1 year agoJust bought a new bike. It has a KMC H700 8speed chain and I am would like to know if, when the time comes and the chain must be replaced, I could replace it with a Sram PC 850 8 speed chain that I have on hand....
Read moreMatching New Chainring to Freewheel
Lastest post 2 years agoThe chain is slipping on my MTB when I'm on the middle chainring and smallest sprocket on the back, but only when I put a lot of force on the pedals. I replaced the chain last year along with the 7 speed freewheel and the middle 32T chainring. I've probably cycled only 1000 to 1500 miles since and tried to only oil the chain when it was clean, so I'm not sure whether it is excessively worn (have...
Read more26" Mongoose Excursion
Lastest post 2 years agoHi, All! I recently got a broken bike from one of my friends, and want to fix it as a fun project. Seemingly its chain is off from the rail and completely distorted like a helix, so it needs to be replaced. Also, rear derailleur is shattered into two parts, each has a gear, not sure if it can be repaired as I'm a total newbie, so I decided to buy a new part for it as well. However, I don't know ...
Read moreChain getting sucked in by fat tire
Lastest post 2 years agoHi, my chain on a 2016 Specialized fatboy keeps getting sucked into the tire and comes off when I am in the top gear coasting. I have had multiple bike shops look at it and they say that those bike are not made to be in the top gear which sound ridiculous to me. It also been suggested that I change the front sprocket from a 28 to a 32. Also the chain measured fine. Any suggestions?...
Read moreTrek 820 (1998) Crank and Deraileur Replacements
Lastest post 2 years agoI'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...
Read more42 chainring
Lastest post 2 years agoI fitted a black 105 5800 compact chainring set (50/33) when I built my new bike. I prefer the 50 chainring cos, on our flat terrain, I can push it, but I can't push a 52 0r 53. However, I would like to change the 33 inner ring for a 42. I have found some rings with the same PCD, but they all seem to have some qualifications which I don't entirely follow. Is there a straight forward way to ...
Read moreChain issue
Lastest post 2 years agoHi, I have the following issue on my bike (see video): https://youtu.be/XtuR7BI_7SU When stopped at traffic lights I need various attempts at putting the pedal at the correct hight to set off. Is this to do with play in bottom bracket or another issue? I have this play in bottom bracket: https://youtu.be/ikX9hNyDs6g It's an old bike so do not want to spend much money on it. I can live with th...
Read moreChainring guard or bash guard installation
Lastest post 2 years agoHi, 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 w...
Read moreChain dropping?
Lastest post 2 years agoI'm having an issue on my CX bike. Which is shimano with 38/48. On the last 2 rides when I'm in the lowest gear on the cassette my chain drops off the small chain ring. It doesn't happen on the 2nd from lowest gear on the cassette. I decided that maybe my rear mech was limited enough so perhaps was pulling the chain off at an angle. Therefore I played with the Lo limiter screw and indexing ...
Read moreChain wear indicators
Lastest post 3 years agoI recently picked up a Park CC-3.2 to put in my portable bike tool-bag (12 inch ruler won't fit). With it one of my chains that measures fine with the ruler, fails, even at the .75 side. Reading on the subject states that the CC-3.2 doesn't take into account roller wear, which the Shimano TL-CN41 does. So, I took a popsicle stick (perfect thickness) and shaped it to press the roller nearest th...
Read moreStay spacing for 6-speed freewheel
Lastest post 3 years agoI have an older frame with an ultra-6 freewheel. When the rear wheel is removed the stays measure 122.78 (hub is a 120 for the ultra-6). I can cold bend it out to 126, I'm sure, but do I need to if I just put a regular 6-speed freewheel on? I'm not sure how tight that would be as far as the chain scraping the frame. has anybody tried it? Has anybody bent a 120 out to 126 or 130 without p...
Read moreChanging cassette fail
Lastest post 3 years agoHi all. 1st time post. I am unablr to remove the cassette from my rear tyre. I followed the easy tutorial on bikeradar but havent managed to get any success. See link to pics of my cassette and the lockring i bought. http://s1067.photobucket.com/user/Nexus62/library/Mobile%20Uploads I think i know where i went wrong. The lockring i purchased didnt fit properly, so i just used a spanner to remove...
Read moreChain slipping off gear shifter(?)
Lastest post 3 years agoi've recently started riding my bike for exercise. was going well for a couple weeks, but a few days ago the chain on my bike has been slipping off of what i think is the gear shifter. it is very annoying and i haven't been able to ride my bike because of it. Edit More info: i have a Schwinn Ranger 10 speed. the gear only slips like that in high gear. it does not slip while in low gear. i have...
Read moreChain ring compatibity
Lastest post 3 years agoI have an older(vintage) bicycle, it,s a 7 speed using suntour radius parts. I want to change out my chain ring. Some say compatible with 9 or 10 speed, does it really matter? If I buy the same rings as 52/42 with the right BCD....
Read more
