Tire and brake upgrades: what the stock specs tell you

Before you spend money, read what is already on the bike. Spec facts below come from maker pages; recommendations are editorial and marked as such.

What stock bikes ship with

Specialized Turbo Levo 4 Comp: SRAM Maven Bronze 4-piston brakes with 220 mm front / 200 mm rear rotors and Butcher GRID GRAVITY tires. Trek Rail+ 8 Gen 5: Shimano MT620 4-piston brakes. Giant Trance X E+ 3: Shimano BR-M420 4-piston brakes with 203 mm rotors and 29x2.6 in. Maxxis Assegai / Dissector tires. These are the bikes' own specs, so you may not need an upgrade at all.

Editorial: tubeless and sealant for desert thorns

Our editorial view: desert goathead thorns make tubeless setups with sealant a common choice. We are not citing a source for this; ask your local shop (Hurricane and St. George shops can tell you what they see).

Editorial: brake pads

E-bikes are heavier than analog bikes (compare the weights in our database: 43.98 lb Heckler SL 70 vs 34.06 lb Hightower 90). More mass means more heat on long descents; ask your shop about e-bike-rated pads for your brake.

Sources for factual claims are listed below; paragraphs marked "editorial" are our opinion.

Sources

  1. official · Specialized: Turbo Levo 4 Comp · checked Oct 31, 2026
  2. official · Trek: Rail+ (Gen 5) product page · checked Oct 31, 2026
  3. official · Giant: Trance X E+ 3 spec sheet (Giant US showcase) · checked Oct 31, 2026
  4. official · Santa Cruz: Heckler SL 70 (2026) · checked Oct 31, 2026
  5. official · Santa Cruz: Hightower 90 (2026) · checked Oct 31, 2026