700c/29" CX 25i & Sol Rider (29" SR 25i)
XC layup. 24H, 28H, 32H,  or SR 24H, 28H, 32H

- ideal for 1.8 to 2.3 XC tires under 700g
Weight +/-10: 450g
Outer width: 29mm, Inner width: 23mm, Depth: 32.5mm
ERD: 578mm

29" x 30i & Sol Rider (29" SR 30i)
TRail 28H, 32H, Enduro/DH 32H, or SR 28H, 32H layup options
- ideal for 2.0 to 2.3, & up to 2.6 tires
Weight +/-10: 495g [TRail & SR] or 590g [Enduro/DH] 
Outer width: 36mm, Inner width: 29.5mm, Depth: 31mm
ERD: 584mm (DH add 1mm)

29" x 35i & Sol Rider (29" SR 35i)
TRail 28H, 32H, Enduro/DH 32H, or SR 28H, 32H layup options
- ideal for 2.3 to 2.6, & up to 2.8 tires
Weight +/-10: 515g [TRail & SR] or 630g [Enduro/DH] 
Outer width: 40mm, Inner width: 34.5mm, Depth: 31mm
ERD: 584mm (DH add 1mm)

29" x 40i - for 29-Plus tires and frames
TRail 32H, Enduro/DH 32H layup options
- ideal for 2.6 to 3.0 & up to 3.5 tires
Weight +/-10: 530g [TRail], 595 [Enduro]
Outer width: 45mm, Inner width: 39.5mm, Depth: 31mm
ERD: 584mm

Since 2012 ... The Highest Performance & Most Durable Carbon Fiber Rims for MountainRoad, Gravel, Adventure & E-Assist Bikes


AM/Trail (the "new XC") Derby rims are for technical-trail riding, no large drops

Enduro racers and any high speed trail riders, should use a Derby DH rear rim

​​650b/27.5" BX 25i

XC layup 28H, 32H
- ideal for 1.8 to 2.3 XC tires under 650g
Weight +/-10: 415g 
Outer width: 31mm, Inner width: 25mm, Depth: 32.5mm
ERD: 540mm

27.5" x 35i & Sol Rider (27.5 SR 35i)
​TRail 28H, 32H, Enduro/DH 32H, or SR 28H, 32H layup options
- ideal for 2.3 to 2.6, & up to 2.8 tires
Weight +/-10: 490g [TRail & SR] or 580g [Enduro/DH] 
Outer width: 40mm, Inner width: 34.5mm, Depth: 31mm
ERD: 542mm (DH add 1mm) 

27.5" x 40i - for 27-Plus tires and frames
TRail 28H, 32H, Enduro/DH 32H layup options 
- ideal for 2.6 to 3.0 & down to 2.4 tires
Weight +/-10: 540g [TRail] or 580 [Enduro]
Outer width: 45mm, Inner width: 39.5mm, Depth: 34mm
ERD: 540mm

27.5" x 45i - for 27-Plus tires and frames
AM/TR 32H, Enduro/DH 32H layup options 
- ideal for 2.8 to 3.0 & up to 3.8 tires
Weight +/-10: 530g [AM/TR], 560 [Enduro]
Outer width: 50mm, Inner width: 44.5mm, Depth: 34mm
ERD: 538mm, Note: Spoke off-set from rim center: 5mm​

XC, TR, or DH - Which type?

The 30i TRail Derby Rims are about the same weight as 22mm inside wide major brand's "light weight" XC aluminum rims.

The external design and all dimensions of the rims are the same for either XC layup, TRail layup, or DH layup, for each wheel size. Additional carbon-fiber layering inside the hollow "double-wall" rims is thicker and stronger than XC in the TRail and further reinforced DH options. The DH ilayup s about 35 to 50 grams heavier in carbon-fiber than the AM layup.

CX, BX (Cross-Country) layup Derby rims are for small light weight tires under 600 grams and 2.3 maximum tire size, with short knobs or semi slicks for mainly smooth hard pack and gravely conditions, and where wheel rolling climbing weight and acceleration is more important than descending control. Although DH bike riders call their 6-inch travel Enduro-DH bikes their "XC bikes", use of aggressive tires more than 2.3 and 600 grams is not "XC".

TRail layup Derby rims are for technical trail medium size knob tires under 800 grams, except if plus size for technically difficult trails and where climbing wheel weight and rear tire rolling ease is as important as descending control, through rocks or roots with rare in-trail small drops less than 2 foot vertical. Free-ride larger drops and stunts and Enduro-DH high speeds are not TRail layup technical trail conditions, for such extreme riding DH (Enduro/DH and Downhill) layup rims are required for shuttle and DH park and for the rear wheel for Enduro-DH racing and similar descending high speeds.​

DH (Downhill, Enduro/DH) layup Derby rims are for maximum durability under the hardest riding conditions for any weight rider of extremely rocky trails and large drops and jumps. "DH" Derby rims are required for DH bikes, and required for at least the rear wheel of Enduro bikes for Enduro/DH racing and similar high speed descending uses. Also DH layup Derby rims are required for tandem mountain bikes, and mountain E-bikes, and riders over about 250 lbs.

Rider weight is almost not a major factor for durability. Sharp rock hits and suspension bottoming loads focus more than 1000 lbs of acute input causing flex to a rim. Aluminum rims could bend or dent from sharp or heavy hits, but carbon-fiber will flex. And excessive flex and repeated excessive flex damage carbon rims. Usually excessive flex causes internal damage at first, called "micro-fracture", where the actual carbon fibers split microscopically. Additional excessive and normally intended flex will open the internal fracture further, until the internal layers separate enough to become unable to support intended loads, and many months later after the initial excessive hit flex the rim wall collapses showing as a surface crack.

Derby Rims are not for weight weenies. These very wide trail rims are for high performance bike handling, improving the performance of nearly any trail tire. The TRail rims are about 0.75 lb, about 300 grams lighter per set than an equivalent width aluminum rim. This is a huge weight improvement in rolling weight. With wide Derby Rims there are additional effective ways to reduce weight. Some examples: Wide rims with smaller tires have more traction and cornering grip than a high volume tire with bigger knobs on narrow 25 mm internal width rims. And Sapim CX-Ray spokes drop about 100 grams compared to common double-butted spokes.

26" x 35i
TRail 28H, 32H, Enduro/DH 32H layup options
- ideal rim width for 2.3 to 2.8, & up to 3.0 tires
Weight +/-10: 470g [TRail] or 510g [Enduro/DH]
Outer width: 40mm, Inner width: 34.5mm, Depth: 31mm
ERD: 518mm (DH add 1mm)Type your paragraph here.

All Rims

  • Material: UD carbon-fiber
  • Spoke holes - Mountain: 32, 28.
  • Spoke hole size: 4.5mm (for external nipples)
  • Spoke hole alignment, for all rims: Centered aligned, All rims have spoke holes angled towards hub flanges. Key/First spoke: Stand up the rim vertical as if ready to roll forward, with valve hole at the ground. Looking down at the valve hole, the 1st spoke hole forward of the valve hole angles to the right-side hub flange, next spoke hole forward angles to the left side hub flange, etc.

  • ​​
  • Presta valve hole, required length: 44mm minimum
  • Recommended max spoke tension: 125KgF
  • Recommended rider weight limit: 175 lbs / 90kg  for XC (CX & BX) rims, 225 lbs 100Kg  for TRail, 300 lbs 135Kg for Enduro/DH rims
  • Max tire pressure (mountain): 32 psi (for road use of mountain rims), 22 psi for 2.6 and larger tires. Max for Enduro/DH race/park/shuttle: 30 psi
  • Tire pressure to seat beads of most new tires, with soapy water or bead seating lubricant: 35 to 40 psi for mountain rims
  • Tubeless rim tape maximum recommended width: 14mm for 25i, and 30i rims; 20mm for 35i; 20-30mm for 40i and 45i rims; Only tape within the center channel, do not taping over the bead seats for best results.​.