Head to head
Fulcrum Speed 42vsShimano Ultegra WH-R8170 C36
Both sections drawn to one scale, from each maker's published geometry. The differences you can see in the drawing are the differences that exist.
vs
Fig. — rim sections, one scale
Fulcrum Speed 42Shimano Ultegra WH-R8170 C36
- Depth
- 6 mm apart
- 42 vs 36 mm
- External
- 1.5 mm apart
- 26.5 vs 28 mm
- Internal
- 2 mm apart
- 19 vs 21 mm
- Claimed weight
- 103 g apart
- 1,385 vs 1,488 g
- UK RRP
- £400 apart
- £1,800 vs £1,400
Rim depth
42 mm
36 mm
6 mm apart. Deeper is faster on the flat; shallower is calmer in crosswind and lighter uphill. Neither is simply better.
Internal width
19 mm
21 mm
The wider rim is built around a wider tyre. Match this to the tyre you actually run, not to the bigger number.
External width
26.5 mm
28 mm
Governs how the rim and tyre meet the air, and frame clearance.
Fulcrum
Speed 42
RRP £1,800
UCI mass-start road
Eligible — Eligible on the rules we assess
Shimano
Ultegra WH-R8170 C36
RRP £1,400
UCI mass-start road
Eligible — Eligible on the rules we assess