Head to head
Enve Foundation 45vsZipp 303 Firecrest
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
Enve Foundation 45Zipp 303 Firecrest
- Depth
- 5 mm apart
- 45 vs 40 mm
- External
- 2 mm apart
- 32 vs 30 mm
- Internal
- Identical
- 25 vs 25 mm
- Claimed weight
- 241 g apart
- 1,591 vs 1,350 g
- UK RRP
- £400 apart
- £1,400 vs £1,800
Rim depth
45 mm
40 mm
5 mm apart. Deeper is faster on the flat; shallower is calmer in crosswind and lighter uphill. Neither is simply better.
Internal width
25 mm
25 mm
Identical — both suit the same tyre widths.
External width
32 mm
30 mm
Governs how the rim and tyre meet the air, and frame clearance.
Enve
Foundation 45
RRP £1,400
UCI mass-start road
Eligible — Eligible on the rules we assess
Zipp
303 Firecrest
RRP £1,800
UCI mass-start road
Eligible — Eligible on rim height; tyre choice is restricted