Head to head
Bontrager Aeolus RSL 37vsZipp 303 S
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
Bontrager Aeolus RSL 37Zipp 303 S
- Depth
- 8 mm apart
- 37 vs 45 mm
- External
- 4 mm apart
- 31 vs 27 mm
- Internal
- Identical
- 23 vs 23 mm
- Claimed weight
- 215 g apart
- 1,325 vs 1,540 g
- UK RRP
- £1,100 apart
- £2,100 vs £1,000
Rim depth
37 mm
45 mm
8 mm apart. Deeper is faster on the flat; shallower is calmer in crosswind and lighter uphill. Neither is simply better.
Internal width
23 mm
23 mm
Identical — both suit the same tyre widths.
External width
31 mm
27 mm
Governs how the rim and tyre meet the air, and frame clearance.
Bontrager
Aeolus RSL 37
RRP £2,100
UCI mass-start road
Eligible — Eligible on the rules we assess
Zipp
303 S
RRP £1,000
UCI mass-start road
Eligible — Eligible on rim height; tyre choice is restricted