*Please Note the Following
- Clutch tension cannot be reset or adjusted on the type 2 systems which were released after this write up. While the outer assembly looks identical, the inner system is not the same and the rear dérailleur clutch will be compromised
Pinkbike and BikeCo.com
are excited to bring back the mechanical “how-to’s” with the new Tech Spotlight articles that you can expect to see on the last Tuesday of every month. Joe Binatena, BikeCo’s owner and world class mechanic, will help walk riders through a variety of tasks, from basic jobs to more advanced work that you'll be able to read about in the future. We aim to provide readers with a gauge on difficulty and risk for these projects, and also encourage you to post any questions in the comment section below when it comes to things that need more explaining.
Identifying and Correcting Rear End Creaks
|Mystery creaks are annoying to you, those you ride with, and pretty much anyone else within earshot, and they're also typically an audible warning that something is prematurely wearing. In this write up we touch on creaks common to the rear derailleur system, including the derailleur linkage, hanger interface, modern dropout, hub axle, thru-axle, and in extreme cases, the SRAM Type 2 clutch system.|
Note on the SRAM Type 2 creak: Here at BikeCo we noted clutch creak on the initial run of Type 2 rear derailleurs. SRAM has revised their assembly procedures since then, however, and the clutch noise has not been a problem for quite some time. If your clutch is creaking we suggest utilizing a professional unless you are extremely confident in your abilities. The Type 2 clutch is not intended to be user serviceable - they’re not going to warranty something that you over-tightened and cracked. Check all of the other suspect creak areas before diving into this job.
Difficulty: medium - special tools and materials required, and a good understanding of the task is required.
Risk: medium - disassembly and reassembly of small parts.
Tools for the Job:
• selection of hex wrenches
• selection of torx wrenches
• torque wrench
• high quality grease
• thread locker (Loctite Blue 242 for metal interfaces, 425 is approved for plastics)
• bearing retainer (liquid and paste types)
• Axles -
This is a very common area for mystery creaks, especially for riders who have to take their wheels off for transport or repairs. Correct axle torque is critical for a bike to work correctly, and you also need to insure that the cam system is lubricated and working properly. A dirty or poorly lubricated cam will feel as though it has tension but it might not be loading the system properly. DT Swiss axles are available as replacements for many systems, and they eliminate the cam design altogether. We've also seen axles tolerances that aren’t perfect for an exact frame system and thus never provide the required torque, although this is quite rare. These situations arise when the threaded portion of the axle bottoms out (runs out of threads
) too early, and it can sometimes lead to premature axle failure. The axle above shows fairly substantial movement on the cam side. In a worst case scenario this can lead to a stress riser on the axle which could cause failure. • Creaks from multi-piece hub axles also are hard to diagnose -
When examining the axle, wear was noted in the area of the hub / axle interface. We expect to see this causing more noise than a one-piece setup, and many hub manufacturers are now utilizing multi-piece inserts to provide maximum compatibility. Removing the insert, we noted wear on the inner and outer shaft that confirmed that it is moving ever so slightly. These particular wheels are often changed from bike to bike, so we flared the insert using a rounded head bolt and vice. The flare provides more “bite” into the hub system while still being relatively easy to remove. Professionally, with a stack of these inserts at our disposal, this isn’t a bad way to go. However, if we were having the same issue on our personal wheels, instead of flaring the inserts we would utilize a retainer paste. Retainer paste (essentially a bearing retainer compound
) designed for aluminum will eliminate the motion and can still be driven out if needed, and is a better solution for the average rider.• Derailleur hanger / dropout / rear triangle interface -
This is an area that often gets overlooked while chasing creaks. This particular assembly consists of three components: the derailleur hanger, the dropout body, and the threaded dropout insert (not shown
). If you suspect movement, or just want to be thorough on your build, you'll want to provide the components with a bit more bite. If there is no substantial wear, blue thread locker provides added traction without becoming too difficult to remove. If you have substantial wear issues there are more aggressive options, however, each more aggressive step will make the eventual removal more difficult. Don’t forget to use thread locker on the hardware before you reinstall. Checking these bolts is important, as they tend to be a bit harder to get to and are therefore often overlooked during bolt checks.• Standard derailleur maintenance should include lubricating the pivot points -
If you don’t have a needle tip for your lube bottle, dabbing lube onto a zip tie is a great way to navigate the lube where you want it without making a mess. Bolt check your derailleur to insure a proper interface - Joe shows how to use a fork axle to gain leverage in a pinch, but be careful not to over-torque. We have noticed that the new eleven speed derailleurs require this service more often than their ten speed speed counterparts - it could be the offset upper pulley adding torque to the system. Taking the time to lube the pivot points will go a long way to your on trail enjoyment. We suggest being aware of what lubes you are using on the pivots as some feature a composite makeup that may not play nice with certain lubes. We recently contacted SRAM to ask if they had a suggested lube for this and at the time they did not. MRP has an interesting page on their website in regards to which lubes
they suggest to be used with their composite parts, and it wouldn't hurt to use that as a rough guide.
The steps shown above should eliminate most of your mystery rear end creaks, although there are some other areas to review: spoke tension, hub bearing condition, cable routing (especially as suspension articulates - typically more of a snap than a creak, though
) and suspension pivots. All of those noises use your rear triangle like a tuning fork, something that can make locating them difficult at times.
Identifying and Correcting Type 2 Derailleur Creaks
If you have watched the video above and confirmed that you do indeed have a Type 2 clutch creak, this is how we would proceed. SRAM does not offer this service as part of its maintenance PDFs, and if you break something you are likely purchasing it. Proceed at your own risk, but we would recommend taking your bike to your local shop if you have any doubts about your abilities in regards to this job. Remember that this service is not to increase or decrease tension, but to eliminate noise.• Step 1 -
Note the position of the clutch pressure assembly as it is originally assembled. In this case we had a scratch we could use as a timing mark - you may want to make a small mark in ink. Also, note the approximate depth from the plastic housing, and feel the amount of tension on the pulley arm for reference. All of these points will help you reassemble the clutch appropriately. Too little tension negates the clutch’s value, but too much tension will prematurely wear the internals and risks cracking the plastic housing. Start by removing the clutch dust cap. Loosen the assembly with a T55 torx - note that there is thread locker on the assembly, and be aware not to over torque and crack the assembly while breaking it free. Once the threads are fully disengaged you can pull the assembly out with pliers. Using a T25 remove the rear derailleur from the hanger. Joe shows you how to do this without removing the derailleur from the bike, but first timers should pull the derailleur off the bike for ease of service.• Step 2 -
Lock the pulley arm in position and remove the stop screw from the pulley arm as shown in the top set of photos. Carefully unwind the pulley arm tension. After releasing the spring tension using two Allen keys, loosen the pulley arm bolt assembly. DO NOT LOOSEN THE ASSEMBLY UNDER TENSION
. If you are particular on torque, you can utilize your wrench to measure ft/lbs. Since this is not a SRAM procedure, we have not found published torque numbers.• Step 3 -
The spring assembly shown in the upper left image is next to come out. Note that first generation springs would come out bone dry, although this spring is well lubricated right from the factory. Tap out the roller clutch assembly, but be careful to not let it go airborne when you do so. It is critical that you understand the orientation of the roller clutch for the system to operate: the clutch catches in one direction, creating tension. In the opposite direction, the shaft will rotate freely in the roller. Use your memory, a video, a photo, sketch, or whatever it takes to remember which way it is oriented.• Step 4 -
Clean the existing grease from the housing, spring, and roller clutch. We like to use Red Devil grease to re-coat the surfaces, and it's key to make sure to avoid getting grease in the threaded internals where you will later be applying thread locker.• Step 5 -
It's time to re-insert the roller clutch assembly. You may need to give it a stiff push it get it back into place, and you will feel a slight click when it sets in. Re-install the spring system. Make sure the spring tail enters the retention slot in the derailleur body (follow the dashed lines in the photo above
). Use blue thread locker on the pulley arm bolt. Insert the opposite spring tail into the pulley arm hole and carefully wind the derailleur. Remember, you wind with the spring, not against it. Begin to tighten the pulley arm bolt into the clutch’s threaded assembly. Do not let go of the assembly, as it's under pressure.• Step 6 -
Carefully engage the pulley arm lock and then torque down the pulley arm bolt. Using blue thread lock, re-install the pulley arm stop bolt into its threaded hold.• Step 7 -
Now it’s time to get down to brass tacks. Using Red Devil grease, we lubricate the center section of the clutch tensioner. Again, be careful to avoid greasing the threads. The method shown above of applying a dollop and spreading with an Allen is very effective for greasing internals. Carefully begin threading the cylinder into the derailleur body. Before completely tightening the assembly, apply a thread locker that is approved for use with plastic - most thread locker will degrade plastic - we use Loctite 425 for plastic assemblies. Carefully re-tension the system. You should return the cylinder to the approximate depth, orientation and torque it started at. Check the tension on the pulley arm, and you ideally you want the pulley arm tension to be how it was from the factory. Something to note: the pulley arm overall tension and the break away tension are different, with the break away tension (amount it takes to begin movement
) is likely to be significantly lower than it was because you have just freshly greased the system. The overall tension to retain the chain as the pulley swings should be similar to stock.We hope that you found tips in this that will help you better maintain your ride. If you made it this far, checking off your good cleaning habits along the way - awesome, you’re doing it like the pros. We will look forward to the next installment here on Pinkbike on the last Tuesday in March. If you have an idea that you would like to see on Tech Spotlight please email Nate@BikeCo.com to let us know what issues you’ve had that can’t seem to be solved and we will put Joe on the task.Do you have a Shimano derailleur the needs its clutch adjusted? www.bikeco.com