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ALUGEAR AERO Shimano 12s chainring kit with bolts – 48/34 to 56/40
Reduced price:
€169.90
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ALUGEAR AERO Shimano 2x12-speed chainring kit without cover: aero outer ring, matching inner ring and 4 bolt/nut pairs. Fits Shimano 105 R7100, Ultegra R8100 and Dura-Ace R9200, including R8100-P/R9200-P. Lower-cost alternative to the aero-cover kit, with less dependence on hard-to-source covers. Choose 48/34, 50/34, 52/36, 54/40 or 56/40. Visible bolts, straightforward installation.
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ALUGEAR AERO · 2x12-SPEED KIT · NO COVER
ALUGEAR aero chainrings, without the extra cost or wait for a cover
Keep your Shimano 105 R7100, Ultegra R8100 or Dura-Ace R9200 crankset and install a matched pair of black ALUGEAR AERO chainrings with mounting bolts. Enjoy lightweight CNC-machined chainrings designed for Shimano 12-speed double drivetrains, without the model-specific decorative aero cover.
Complete kit: 2 chainrings + 4 bolt/nut pairs
Shimano: R7100 / R8100 / R9200
5 ratios: 48/34 to 56/40
Why choose the no-cover kit?
The ALUGEAR cover gives the crank-to-chainring junction a smooth finished appearance, but adds cost and comes in crank-specific versions that have been difficult to source in 2026. This kit focuses on what matters most: two matching AERO chainrings and the correct mounting hardware.
- A more accessible price than the equivalent kit with aero cover.
- Less dependence on cover stock — no need to wait for a crank-specific R7100, R8100 or R9200 cover.
- Straightforward installation using the four supplied ALUGEAR bolts and nuts.
- The aero outer chainring remains — only the crank/chainring junction has an exposed finish.
Our view: the bolts are visible, and we think that is a fair trade-off. This kit offers a simple, quick way to fit lightweight aero chainrings to Shimano 105 R7100, Ultegra R8100 and Dura-Ace R9200 cranksets. For many riders, it is the sweet spot between price, availability and practical performance.
Choose the right chainring combination
| Combination | Best suited to | Main benefit |
|---|---|---|
| 48/34 | Climbing / endurance | Accessible outer ring and a 34T inner ring |
| 50/34 | All-round road | Classic compact gearing with an aero outer ring |
| 52/36 | Sportive road riding | Balanced speed and versatility |
| 54/40 | Racing / fast roads | Performance-oriented gearing |
| 56/40 | TT / triathlon | A large gear for sustained speed |
Use ALUGEAR's matched combinations for the best front-shifting performance. With a 56T outer ring, check the front derailleur's adjustment range; an adapter may be needed depending on the bike.
Prefer a fully integrated finish?
The ALUGEAR kit with aero cover uses the same chainring family but adds a crank-specific cover to conceal the mounting area. Choose it for its seamless appearance, or select this no-cover kit to save money and avoid cover-related delays.
Explore the ALUGEAR kit with aero cover →Shimano compatibility and what's included
Compatible cranksets: Shimano 105 FC-R7100, Ultegra FC-R8100, Dura-Ace FC-R9200, plus FC-R8100-P and FC-R9200-P with Shimano's original integrated power meter.
Standard: Shimano asymmetric 110 mm BCD, 4-arm interface, road 2x12-speed transmission, Shimano HG+ 12-speed chain.
In the box:
- 1 black ALUGEAR AERO outer chainring, selected tooth count
- 1 matching black ALUGEAR inner chainring
- 4 ALUGEAR chainring bolts and 4 nuts
Not included: Shimano crank arms/crankset, aero cover, chain or tools. While this type of bolt kit may also suit certain Shimano 11-speed assemblies, the chainrings in this product are specifically 2x12-speed; choose dedicated chainrings for an 11-speed drivetrain.
Materials, weights and installation tips
Construction: round, CNC-machined 7075-T6 aluminium chainrings with black anodised finish, made in Poland. Tooth profiles, ramps and shifting aids designed to work as a matched ALUGEAR pair.
Manufacturer-stated chainring weights: 50T 112 g; 52T 127 g; 54T 143 g; 56T 171 g; inner 34T 26 g, 36T 29 g, 40T 40 g. The 48T figure is not published. Weights exclude mounting hardware.
- Remove the original chainrings and position the matching ALUGEAR outer and inner rings.
- Attach them using the supplied ALUGEAR hardware (6.5 mm bolts with 7 mm nuts). Do not substitute aero-cover bolts.
- Follow ALUGEAR instructions: 5 mm hex drive and maximum tightening torque 10 Nm.
- Check front derailleur height and limit settings, chain length and condition, plus frame clearance if fitting a larger outer ring.
Also consult ALUGEAR's installation guide and your crankset manufacturer's instructions before fitting.
Frequently asked questions
Are the four bolts visible?
Yes. This is the visual difference from the cover kit. The aero outer chainring itself remains unchanged.
Does it fit Shimano R8100-P and R9200-P power meters?
Yes. ALUGEAR lists compatibility with these original Shimano integrated power-meter cranksets.
Can I use an ALUGEAR outer ring with my original Shimano inner ring?
We do not recommend it. ALUGEAR designed its 2x shifting system around the matching outer and inner chainrings.
Why might the no-cover version be easier to find?
It does not depend on separate crank-specific aero cover stock, which has been inconsistent in 2026. Availability of chainrings and bolts still needs to be checked when ordering.
ALUGEAR is an independent brand. Shimano, 105, Ultegra and Dura-Ace are Shimano trademarks or product names. Any Shimano crankset shown in an installed-product photograph is for illustration only and is not included.
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