CeramicSpeed OSPW RS 5-Spoke Shimano 105 7150

$629⁰⁰

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The CeramicSpeed OSPW RS 5-Spoke Shimano 105 7150 typically ships in 5-8 business days

CeramicSpeed | SKU: 113492 | Option: Black

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CeramicSpeed OSPW RS 5-Spoke Shimano 105 7150 Info

The CeramicSpeed OSPW RS 5-Spoke Shimano 105 7150 is CeramicSpeed's oversized pulley wheel system built for Shimano's 105 Di2 electronic groupset, using the brand's classic open 5-spoke pulley wheels rather than the solid Alpha Disc design found on higher-tier OSPW RS versions. It replaces the stock rear derailleur cage and pulleys with a larger-diameter system designed to reduce chain articulation and friction through the drivetrain, while giving the rear derailleur a more contemporary, angular look that matches current bike and groupset design trends.

The 5-spoke pulleys run on CeramicSpeed's standard handbuilt bearings rather than the ADR-protected bearings used in the Alpha Disc version, which keeps the price down while sticking with the same hand-assembly process CeramicSpeed uses across its pulley lineup. The open spoke design is lighter and simpler than a solid disc, though it doesn't offer the same sealed-off protection against mud, dust, and debris working into the bearings — a real consideration if you regularly ride wet or gritty roads.

Where this version matches its more expensive Alpha sibling is the cage itself: CeramicSpeed reinforced the OSPW RS cage for added strength and durability over earlier pulley systems, and it includes the same customizable spring tension, so you can fine-tune cage preload and shifting feel to your specific 105 Di2 setup rather than running one fixed setting.

The premise behind any OSPW system is that larger pulley wheels reduce how sharply the chain has to bend as it wraps around them, which lowers friction through the drivetrain. CeramicSpeed doesn't publish a specific wattage figure for this model, so the honest way to frame it is a friction-reduction upgrade rather than a guaranteed number of watts saved.

At $629.00, this is the more accessible way into an OSPW RS system for 105 Di2 — you get the reinforced cage, adjustable spring tension, and CeramicSpeed's hand-built bearings without paying for the Alpha Disc's debris protection. It's a fit for riders who want the look and friction-reduction premise of an OSPW system but ride mostly in clean, dry conditions where the extra sealing of the Alpha Disc matters less.

The RA Perspective

We like that this version gives you the core OSPW RS upgrade — the reinforced cage, adjustable spring tension, and CeramicSpeed's hand-built bearings — for $70 less than the Alpha Disc version. If you're not riding in mud or grit regularly, that's money saved without giving up much.

The tradeoff is the open 5-spoke design. It's lighter and it's been CeramicSpeed's standard pulley shape for years, but it doesn't seal the bearings off from road spray, dust, or debris the way the solid Alpha Disc does. On a dry crit bike or a fair-weather Sunday bike, that's a non-issue. On a bike that sees wet commutes or gravel sectors, we'd point riders toward the Alpha version instead.

As with any OSPW system, we won't tell you a specific wattage number — CeramicSpeed doesn't publish one for this model, and the honest pitch is reduced chain friction, not a guaranteed speed gain.

We'd recommend this to 105 Di2 riders who want the OSPW look and friction-reduction premise without paying extra for weather sealing they won't use.