As your cycling performance increases, you may find your bike’s stock chainring sizes are no longer optimal for powering up climbs or hitting top speeds on descents. The solution is likely new chainrings, but for many riders, changing them on a Shimano Ultegra drivetrain seems intimidating.
Not to worry – with this detailed tutorial, you’ll learn proper chainring selection, compatibility, removal and installation steps, front shifting optimizations, and everything in between. You’ll gain the knowledge to upgrade your Ultegra bike’s gearing for peak riding efficiency.
Choosing New Ultegra Chainring Sizes
Selecting the right chainring tooth counts is crucial for proper bike gearing. Approach it systematically by considering these key factors:
Assess Your Power Profile
Your sustainable power outputs determine ideal gearing. Higher outputs allow bigger chainrings:
- Beginner cyclists should use smaller rings like 34/50T for easier climbing gears.
- Intermediate riders can run standard 53/39T sizes.
- Strong racers can push taller gearing like 55/42T.
First, objectively assess your fitness. Don’t over- or under-gear the bike.
Calculate Your Preferred Cadence
Identify your most efficient pedaling cadence via a cycling computer. Then select chainring sizes that keep you in this ideal RPM range for flat and hilly terrain. Maintaining cadence optimizes performance.
Analyze Riding Terrain
Where you ride dictates optimal gearing. For example:
- Hilly areas require smaller rings for climbing, e.g. 34/28T.
- Flatlands can use larger rings for high-speed cruising, like 53/42T.
- Cyclocross and gravel benefit from closer ratios, like 46/36T.
Match new gearing to the demands of your local topography.
By methodically considering these factors, you can zero in on the chainring sizes offering the greatest efficiency and performance benefits.
Ultegra Chainring Compatibility
Shimano Ultegra cranksets use proprietary chainring designs, so compatibility is critical for proper shifting and durability. Let’s break it down:
Match Your Crankset Generation
Current Shimano model generations include:
- R8000 11-speed (2016 onward)
- 6800 11-speed (2014-2016)
- 6700 10-speed (2009-2013)
- 6600 10-speed (2006-2008)
Always match new rings to your specific crankset generation for guaranteed compatibility.
Confirm Bolt Circle Diameter (BCD)
Chainring bolts are arranged in a circle of specific diameter, measured in millimeters. Common BCDs:
- 110mm – Standard 53/39T double rings
- 130mm – Compact 52/36T and 50/34T doubles
- 110mm/74mm – Road triple cranksets
Verify the new rings have the proper BCD for your crankset spider.
Choose Your Speeds
Chainrings are optimized for either 10 or 11-speed chains. Select the correct one:
- 10-speed rings for 6600/6700 generation cranks
- 11-speed rings for 6800/R8000 generation cranks
Correct speeds ensure positive shifting engagement.
By diligently matching model generation, BCD, and speeds, you’ll get new Ultegra rings engineered for your specific crankset.
Step-by-Step Ultegra Chainring Installation
With the right components selected, it’s time to tackle the swap. Follow this process closely:
Gather these essential tools:
- Chainring nut wrench – Fits the chainring bolt heads. Usually 8mm or 10mm.
- Torque wrench – Vital for precise fastening to spec. 5-7Nm is common.
- Allen wrenches – For removing crankarms and pedals. Various sizes needed.
- Grease – Prevents corrosion on threads and mounting surfaces.
- Rags – For cleaning drivetrain before installing new rings.
Quality tools prevent slip-ups and damage. Invest in the best you can afford.
Crank Arm and Chain Removal
Gain access to the chainrings:
- Shift chain to smallest front ring and largest rear cog.
- Unbolt crank fixing bolts with Allen wrench. Detach drive-side arm first.
- Remove chain from chainring using a quick link or chain tool.
Tip: Photograph and label parts to ease reassembly. Keep all hardware organized.
Detaching Old Rings
With the cranks off, now work the rings off:
- Loosen all chainring bolts with the appropriate wrench. Remove bolts.
- Carefully wiggle the rings to break them free from the spider. Remove.
- Thoroughly clean the spider mounting surfaces and chainrings.
Inspect spider arms and chainrings for damage like bent teeth or gouges.
Mounting New Rings
Installation is reverse of removal:
- Apply a thin layer of grease to the backside of each new ring and the threaded holes.
- Orient rings with crank logo facing out. Hand thread bolts.
- Progressively tighten bolts in a star pattern to spec torque. Go slowly and recheck.
Uneven tightening can warp rings and degrade shifting.
Reinstalling Crankset and Chain
- Clean and grease crank arm bolt threads. Reattach arms to bottom bracket spindle.
- Loop chain around chainrings and cassette. Insert connecting pin or master link.
- Check derailleur alignment and make any limit screw adjustments needed.
Thoroughly test shifting performance before your first ride on the new rings.
By adhering to this systematic process, you’ll avoid mistakes and enjoy a smooth Ultegra chainring upgrade.
Optimizing Front Shifting After Installation
To realize the full benefits, optimize your front derailleur after fitting new rings:
Set The Limit Screws
Limit screws prevent overshifting and drops:
- Shift to largest chainring. Adjust outer screw so cage aligns without rubbing.
- Shift to smallest ring. Set inner limit screw for clean alignment.
Go slowly and shift back and forth to double check adjustments.
Adjust The Cable Tension
Proper tension enables quick shifts:
- Shift to smallest ring. Unscrew barrel adjuster to increase tension.
- Shift hard to larger rings. If hesitant, back off tension slightly.
- Find the sweet spot between fast shifting and over-shifting.
You may need minor re-adjustments as new rings break in.
Use The Trim Function
Trimming prevents chain rub in crossover gears:
- Shift up cassette in big chainring. At a certain cog, rub will occur.
- Click shifter one click to trim derailleur inboard slightly to stop rub.
- Repeat the process when shifting down cassette in small ring.
Practice trimming for silent, damage-free operation in all gear combinations.
Determining When to Change Ultegra Chainrings
Since chainrings wear slowly over miles, gauging when to change them takes diligence:
Measure Chain Wear
Use a gauge to regularly measure chain elongation. At .5% stretch, both chain and rings are worn out. Replace simultaneously.
A worn chain accelerates ring deterioration. Stay on top of chain wear.
Inspect Tooth Profiles
Look closely for shark fin shapes on the teeth. This indicates advanced wear. Shifting will deteriorate quickly.
Check for Damage
Bent, broken, or cracked teeth radically reduce shifting performance. Replace damaged rings immediately.
Monitor Shifting Quality
Noticeable sluggishness or hesitation when shifting signals worn chainrings. If adjustments can’t restore crisp shifting, new rings are needed.
By frequently checking these indicators, you can change rings at the optimal time to maximize value and drivetrain performance.
Upgrading your Shimano Ultegra bike with new chainrings can provide a real boost in riding efficiency and enjoyment. With this comprehensive guide’s advice on selection, compatibility, installation, adjustment, and wear – you now have the expertise to change Ultegra chainrings quickly and hassle-free.
Apply these insights, choose components strategically, stick to proper procedures, and you’ll be spinning up climbs faster and churning out more watts in no time. Your next chainring swap will be a success. Just remember to put in the leg work to make those new gears pay off!
Mahin Abrar is a passionate writer and outdoor enthusiast. As a regular contributor to Bikepics.net, Mahin shares his knowledge and experiences in the fields of biking, cycling, hiking, and camping. With a deep understanding of these activities and a keen eye for detail, he offers valuable insights and practical advice to help readers get the most out of their adventures. Whether you're a seasoned pro or just starting out, Mahin's writing is sure to inspire you and guide you on your journey.