Congratulations, you’ve purchased your very own piece of oversized cycling history – Muc-Off’s rule-book-ripping Lightweight Oversized Precision Shifting (L.O.P.S 2.0) system.  


The original L.O.P.S system was developed in conjunction with Team Bahrain-McLaren back in 2019, designed specifically to provide Mikel Landa with a substantial advantage in drivetrain efficiency, at the pivotal stage 20 time-trial at the 2020 Tour de France, a 36.2KM individual time trial from Lura to La Planche Des Belles Filles.


Since the original iteration, we’ve made further refinements, and these have been tested by the World’s best at some of the highest profile races on the planet.


From EF Easypost rider Stefan Bissenger’s win at the time trial at the 2021 Tour de Suisse; to various Gold-medals at the 2020 Tokyo Paralympics; as well as victories with Elite Ironman Triathletes Kat Matthews and Laura Philipp in multiple wins and podiums.


The bearings within L.O.P.S are designed to operate at their optimum performance efficiency when mounted upon your bike, getting you that TT record or previously unbeaten Strava Section you’ve been chasing.  


Unlike other OPSWs, the bearings within the L.O.P.S system do not spin endlessly with a flick of the fingers when off the bike. This is a common ‘test’ done by riders, and there’s a misconception that a freely spinning jockey wheel means an efficient system - Engineering principles tell a different story.  

When a bearing is spun off-bike, it is unloaded. Conversely, when the system is mounted to a bike, the spring tension of your derailer is loaded onto the system; only at that point can the true bearing efficiency be determined.


For validation within our research & development laboratory, we developed and manufactured a specialist custom pulley wheel bearing dynamometer, to accurately replicate the on-bike spring tension load, ensuring our lab data translates to real world usage.


Our bearing dyno measures 20,000 samples per second! A minimum of 6 automated test runs per bearing, which creates 36 million measurements per bearing tested. As part of our continuous R&D programme we have recently tested 36 different types of pulley bearings, even without the repeat tests, that is 1.3 billion measurement points… And that is just one of the data channels! We don’t just analyse bearing torque, but also peak to peak measurements, which are great indications of smoothness and wobble.  


After all this testing, we created our own cutting edge proprietary Muc-Off bearings, a perfectly optimised design for this application, and manufactured in the UK. We don’t create hardware just to look good on Instagram videos, we are focused on race-winning performance, and we operate in cold hard data and facts. The systems are manufactured from the finest materials and rest assured; these are the fastest bearings we’ve ever tested. Period!

Stiffness is critical to efficient shifting, but adding stiffness often means adding weight. L.O.P.S features a ground-breaking light-weight design to minimise this impact, thanks to its construction through additive manufacturing with Ti6Al4V titanium and carbon fibre. The result is a system that maintains precise and optimised shifting performance, each time the system engages or disengages the pulley wheels, less friction is produced – and less friction means more speed.


L.O.P.S has been designed, developed, tested, and manufactured in the UK for Shimano Dura-Ace RD 9100 and Shimano Dura-Ace RD9150 rear derailleurs. You’ll find installation instructions below.  


We recommend that the system be fitted by a qualified and experienced professional bicycle mechanic, so please provide your mechanic with these instructions, prior to installation.  


You are now the proud owner of one of the first L.O.P.S systems ever built, so welcome to a truly unique club.


Now, get out there and chase your time-trial dreams, or destroy that Strava segment. With the world’s most advanced shifting system on your bike, the road is yours!


The Muc-Off product is covered under warranty by Muc-Off to be free of defective parts and materials for a period of 12 months from the date of purchase (or as otherwise stated at point of sale) providing the product is used for normal domestic duties. All warranty periods commence on the date of purchase and are none transferable. This warranty shall not apply to defects caused by misuse, neglect, accident, improper storage, installation or handling, repair, wear & tear or alteration not carried out or authorised by us.

Muc-Off recognises the leading threat to bearing failure is corrosion caused through improper care and maintenance. The warranty does not include bearing corrosion. The guarantee is limited to the provision of a refund within the specified period providing the above conditions are met and the original proof of purchase is provided. This warranty applies to products used for domestic use only and shall not apply to any products used for commercial purposes. Muc-Off shall not be liable in any event at any time for any indirect or consequential loss or damage. The rights and benefits under warranty are additional to your statutory rights which are not affected by this warranty.


We’ve supplied you with Muc-Off mechanics gloves in the box. Please put them on before set-up.



STEP 1. 

Clamp the bicycle securely into a bike stand.


STEP 2. 

Drop the chain onto the smallest cog on the rear cassette.



STEP 3. 

Take the chain off the bike. Using a quality pair of chain link pliers remove the split link from the chain. (If your chain does not have a split link, you’ll need a chain tool.)

STEP 4. 

Remove the rear mech from the bike.




After removing the rear mech from the bike, hold the back half of the mech in one hand with the other holding the pivot point. Push back (pivot point side) snapping the mech open as if it was in first gear. Carefully hold and rotate down the pulley cage.


Then with a plus positive screwdriver remove (by turning anticlockwise) the pulley cage stop screw. While still holding the cage, very carefully allow the pulley cage spring to unwind as it starts to release the spring tension. At the end the derailleur cage will appear to be upside down.


Carefully hold and rotate down the pulley cage. Then with a plus positive screwdriver remove (by turning anticlockwise) the pulley cage stop screw.


While still holding the cage, very carefully allow the pulley cage spring to unwind as it starts to release the spring tension. At the end the derailleur cage will appear to be upside down.




On the bottom rear of the main body of your Shimano derailleur is a black torque mounting bolt.


Using a T10 Torx screwdriver undo the bolt anticlockwise and remove, but be careful not to round it off as this bolt is very shallow.

The trick here is that there’s not much thread on the bolt, so once you can see about 10mm of thread exposed from the body you can pull it straight out the rest of the body by hand. Make sure to put this somewhere safe as you’ll need it later.



STEP 7. 

Then take the grip of the derailleur cage and start to pull the part out of the main body, until it completely slides out with a spring and plastic seal spacer.

STEP 8. 

Once this is all removed from the derailleur body hold it in one hand and carefully remove the plastic seal spacer which will slide off over the spring.




Then you’ll need to remove the spring from its cage. This is hooked into the cage in a small hole, so unhook and remove it.


Both of these parts will be reused when the Muc-Off L.O.P.S 2.0 System is installed so keep them handy for later.





STEP 9. 

Pick up the Muc-Off L.O.P.S 2.0 System and apply some grease on the outside of the mounting post. We recommend you use Muc-Off Bio Grease.


Place the original Shimano tension spring over the mounting post.


Just like on the stock set up the hooked end goes on first and should be placed into the top hole upon the Muc-Off L.O.P.S 2.0 System so it is inserted completely (in the high position).




There are three different spring tension settings on the Muc-Off L.O.P.S 2.0 System. You’ll find the top hole is ‘H’ (high) and ‘L’ (low) is at the bottom.


The differences might seem small, but they do make quite a big difference. We advise you use the ‘H’ tension setting as this creates the most tension to give the most accurate shifting and optimum performance.

STEP 10. 

Then take the plastic washer seal and place it over the spring in the same way that it was removed (top hat up) from the original cage. The flat surface should go on first and the small stepped edge needs to face away from the Muc-Off L.O.P.S 2.0 System body.



STEP 11. 

It’s time to take the Muc-Off L.O.P.S 2.0 System and insert the mounting post (with spring and plastic seal washer on) into the Shimano derailleur body that’s on the bike.

STEP 11A. 

It’s super important to align the 90° end of the spring into the recess on the derailleur body first to ensure it goes together correctly. The plastic spacer will rest freely on the spring until aligned at the back of the derailleur body.



STEP 12. 

Push the Muc-Off L.O.P.S 2.0 System mounting post into the derailleur body and ensure that the cage rotates smoothly and the spring is properly situated, and the plastic seal washer is also located into the recess.

STEP 13. 

Now onto a very important bit.

With one hand holding the Muc-Off L.O.P.S 2.0 System, and one hand supporting the Shimano derailleur body, rotate the Muc-Off L.O.P.S 2.0 System anticlockwise. This is as you are standing to the right of your bike looking at the derailleur.


It will rotate upwards, towards the back of your bike and then downward. Once the Muc-Off L.O.P.S 2.0 System has been rotated one complete turn the stop tower will go past the stop point (you may need to pull the cage out slightly) on the derailleur and you’ll be able to push them both together.



STEP 13A. 

This action adds the spring tension to the derailleur and will allow it to function correctly.

STEP 14. 

It’s now really important to keep one hand holding the Muc-Off L.O.P.S 2.0 System and the derailleur body together so that they don’t separate.



STEP 14A. 

Then take the original black T10 torque screw that was removed earlier and slide it into the mount hole on the underside of the body.

STEP 14B. 

Push this inwards until about 10mm protrudes and with a T10 Torx tighten clockwise to a torque of 1Nm.



STEP 15. 

The Muc-Off L.O.P.S 2.0 System is now ready to be installed back onto the bike. The main bolt that mounts the derailleur onto the bike should be tightened to 8-10Nm.

STEP 16. 

Now would be a great time to stand back and admire its beauty. Maybe take a few photos too.


STEP 17. 

Check the upper and lower stops on the derailleur and adjust the limit screws if needed.


STEP 18. 

Make sure that the spacing between upper pulley and the top of the cassette is 5mm or less. This distance will depend on many factors such as gear ratios, the bike’s frame and set-up. For the best results use a Shimano Ultegra or Dura-Ace cassette (max 32/11T).



STEP 19. 

Get a new chain ready to be installed onto your bike. We
suggest using a Muc-Off Ludicrous ultrasonically optimised chain
for unbeatable performance gains. Go to
to find your closest chain optimisation centre.


53/39 chain rings and 11-(23-32) cassette: 114 links

50/34 chain rings and 11-(23-32) cassette: 112 links

STEP 20. 

Put your chain onto the smallest front chain ring. But if you’re running a x1 set up then keep it as is. To get the correct chain length, pull the chain ends together – like when you need to cut a chain to length. The bottom part of the cage will move downwards and away from your cassette, like the image to your left.



STEP 21. 

When you apply tension to the chain and the Muc-Off L.O.P.S 2.0 System looks to be aligned, the chain needs to be cut and connected by the required number of links in order to achieve enough tension in this gear combination (small chain ring/small cog on the cassette).


It should be one link shorter than Step 20.

STEP 22. 

Now the chain is cut to length, it’s crucial to test the clearance of the Muc-Off L.O.P.S 2.0 System, when the rear derailleur is set in the biggest chain ring and the largest cog on the cassette. Like the arrow shows, the cage should be able to turn anticlockwise.

It’s important that there’s some clearance between the upper pulley wheel and the largest cog on the cassette. If there’s not enough clearance, just adjust the B-tension as needed.



STEP 23. 

Once the chain is installed check the gear change and adjust if necessary. Extra cable tension or Di2 trim adjustments for proper alignment between the cogs and pulley wheels may be required.


STEP 24. 

Now the bike’s ready to rock.