Shimano Pulley Bolt 1.0 g vs Stock 4 g R7170 (3.0 g Saved)

The Shimano derailleur pulley bolts — the two bolts that secure the guide pulley and tension pulley to the derailleur cage — are small parts with a meaningful weight difference across Shimano's Di2 groupsets. TiNE's titanium replacement set weighs 1.0 g for the complete pair, saving up to 3.0 g on the 105 R7170 and Shimano Ultegra R8170, and 1.6 g on the Dura-Ace R9270.

Pulley bolts sit at the lowest point on the derailleur cage — directly above the chain, rotating with every shift. They are small components, but their combined weight across two bolts adds up: 4 g on the R7170 and R8170, 2.6 g on the R9270. TiNE's set at 1.0 g replaces both in one purchase.

3.0 g saved per derailleur on 105 R7170 and Ultegra R8170. The pulley bolts are part of TiNE's three-piece Shimano rear derailleur titanium upgrade: pivot bolt (6.4 g saved on R7170), pulley bolt set (3.0 g saved), and limit/tension bolt set (2.0 g saved on R7170). Together, the three sets remove roughly 11.4 g from the 105 R7170 rear derailleur — a meaningful reduction from one of the lowest components on the bike.

What the TiNE Pulley Bolt Set Includes

The TiNE set includes both pulley bolts — the guide pulley bolt and the tension pulley bolt — in one package. Both bolts are CNC-machined from Grade 5 Ti-6Al-4V with 8 anodized color options.

Guide pulley bolt — secures the upper pulley (the one that guides the chain from cog to cog) to the derailleur cage plate. This bolt rotates with every shift, making smooth thread engagement important for consistent shifting performance.

Tension pulley bolt — secures the lower pulley (the one that maintains chain tension) to the cage plate. Like the guide pulley bolt, it rotates during shifting and needs precise threading for reliable performance.

Weight by Groupset

The 105 R7170 and Ultegra R8170 share the same 4 g stock pulley bolt weight — both save 3.0 g with the TiNE set. Dura-Ace R9270 starts lighter at 2.6 g, so savings are 1.6 g. For R7170 and R8170 riders, the pulley bolt set is the second-largest savings in TiNE's Shimano rear derailleur bolt lineup, after the pivot bolt.

Corrosion Advantage in the Chain Zone

The derailleur pulley area is one of the most corrosive environments on a road bike — directly above the chain, exposed to chain oil, road spray, and brake dust. Stock steel pulley bolts develop surface oxidation over time, especially in wet conditions. Grade 5 Ti-6Al-4V resists corrosion far better than steel, and the CNC-machined threads maintain smooth engagement for reliable pulley rotation over years of use.

For riders who regularly remove pulley bolts for cleaning or pulley swaps, the smooth threading experience of titanium versus corroded steel bolts is a practical daily advantage — no thread binding, no resistance from oxidized surfaces.