In geology, the Krumbein scale is used to measure grain size from fine silt to large rocks. The American Classic Krumbein is designed for gravel roads and any singletrack trail that may lie around the corner. Aggressive side lugs provide cornering grip across loose and muddy transitions, while chamfered center tread lugs help to minimize rolling resistance without sacrificing off-road traction. A Tubeless Ready 120 TPI casing with our bead-to-bead Stage 5S flat protection provides a responsive riding tire that can fend off most punctures and tears.
- Fast and efficient tire from loose gravel to single track
- 700x40C, 700x50C, 650Bx47
- Tubeless Ready
- Stage 5S Flat Protection
- Rubberforce G gravel tire compound
- Chamfered center tread minimizes rolling resistance
- Black or tan sidewall
|Protection||Stage 5S Protection|
|Size Options||700x40C (ETRTO 40-622)|
Weight: 585 g
Max Pressure: 55 PSI
700x50C (ETRTO 50-622)
Weight: 735 g
Max Pressure: 50 PSI
650Bx47mm (ETRTO 50-584)
Weight: 700 g
Max Pressure: 50 PSI
Road Hazard Replacement Policy
American Classic stands by our tires, and want to keep our customers rolling. Our Road Hazard Replacement Policy offers our customers the promise that if you puncture or tear an American Classic tire while riding, and it no longer holds air, you can contact us for a claim form for a one-time 50% off the MSRP of the same or comparable product. The replacement program covers American Classic products purchased through authorized dealers, www.amclassic.com, or the American Classic branded Amazon store, and product included as original equipment components of a new bicycle purchase. The Road Hazard Replacement Policy does not include shipping and handling.
American Classic tires have a 2-year warranty against defects in materials and workmanship. Any defective tires will be replaced at no charge. This warranty applies to the original owner with proof of purchase and is non-transferable and non-assignable. The original owner is responsible for all postage costs and transportation risks of the returned product(s). The warranty covers American Classic products purchased through authorized dealers, www.amclassic.com, or the American Classic branded Amazon store, and product included as original equipment components of a new bicycle purchase. The warranty does not cover normal wear and tear, product abuse, commercial usage, shipping damage, improper installation and/or maintenance, negligence, reckless handling, and/or unauthorized modification.
Some American Classic tires are compatible with hookless (Tubeless Straight-Side/TSS) rims that follow current E.T.R.T.O. standards.
- Approved for use: Aggregate, Kimberlite, Krumbein, Udden, Wentworth
- Not approved for use: Lamplighter, Timekeeper, Torchbearer
This list will be updated as we introduce more high performance tire models.
Please contact email@example.com for warranty information and claim forms.