WTB KOM Tough TCS 2.0 CVX i25 Rim
KOM Tough is the heavier of WTB's two KOM aluminum layups: the KOM profile family with thicker walls, for riders who have dented lighter rims or ride loaded. At 25mm inside the KOM Tough i25 suits 2.1 to 2.4in cross-country and light trail tires. The rim we build with is WTB's current TCS 2.0 version with CVX (29in W020-0641), the part our distributor stocks. WTB design and make the rim; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer.
We sell it as a finished wheel: choose the hub, spokes and nipples and we lace, tension and true it by hand here.
Design and construction
The KOM Tough i25 is a sleeve-jointed 6069 aluminum rim with WTB's TCS tubeless bead, the Tubeless Compatible System that seats a tire with a floor pump and holds it at low pressure. 4D drilling angles each spoke hole toward the hub flange it serves, so the nipple sits straight and the spoke is not bent where it leaves the rim.
How it rides
At 25mm the i25 is the cross-country end of the KOM Tough range: it keeps a 2.2in tire round enough to roll into a corner progressively, and puts KOM Tough's thicker walls under a tire that would leave a light XC rim exposed on rocky ground.
It suits 2.1 to 2.4in cross-country and light trail tires. In our strength model it scores 4.55 out of 10 — read that against the other rims in the configurator rather than on its own.
TCS 2.0 with CVX
CVX is WTB's patented spoke bed. In WTB's words it strengthens the bed “without increasing weight, by thickening material where it's needed and removing where it's not”, so the material sits around the spoke holes, where an alloy rim cracks. TCS 2.0 adds WTB's Solid Strip under the tubeless tape, which makes a tubeless tire easier to seat and seal.
CVX moved the ERD as well: the CVX KOM Tough i25 measures 603 in 29in, a few millimeters less than the rim it replaced, and those are the figures we cut spokes to.
Specifications
| Wheel size | Inner width | ERD | Weight | Drilling | WTB part |
|---|---|---|---|---|---|
| 29in | 25mm | 603 | 485g | 32 | W020-0641 |
Disc brake only, external nipples, aluminum. WTB publishes a maximum spoke tension of 110–120 kgf for its KOM rims, which is what we build to.
WTB's drawing of the CVX profile gives 30mm outer width and 17.6mm depth.
About this listing
This is the rim on its own, as a component of a hand-built wheel. Pick the diameter and drilling above and we build the wheel around it.
Sizes, fit and compatibility
Listed in 29in, 32 hole, disc brake only, for external nipples. Listed weight is 485g in 29in.
Spoke head is decided by the hub, not the rim: this rim builds equally well with J-bend or straight-pull spokes, and the configurator only offers the spokes that match the hub you pick.
Put it in a custom wheel
The KOM Tough i25 is live in our Custom Wheel Program for gravel and road disc, tandem and e-bike, MTB single-speed and mountain bike builds. Build a custom wheel around the KOM Tough i25 and the configurator opens with this rim pinned at the top of the WTB list, ready for you to choose the hub, drilling, spokes and nipples. It validates every combination as you go, so you cannot assemble a wheel we would not build.
How WTB tests its rims
WTB (Wilderness Trail Bikes, California) builds its rims around the TCS tubeless system. WTB states the Beadlock bead profile is "Designed to ISO/ETRTO standards", that 4D drilling angles each spoke hole toward the hub flange, and that most alloy rims are sleeve-jointed, the rim ends hydraulically pressed over an extruded aluminum insert reinforced with industrial epoxy. KOM and HTZ rims use 6069 aluminum for its "high tensile and fatigue strength"; HTZ e-bike rims add 20% wall thickness over KOM Tough.
Published limits: maximum spoke tension 110-120 kgf on KOM, HTZ and CZR rims; max rider weight 265 lbs for the CZR i23 and 300 lbs for the CZR i30. No per-rim maximum tire pressure is published and no ISO 4210 or UCI certification is claimed.
Testing: WTB states the CZR carbon rims went through hundreds of rims, dozens of layups, three rounds of rider testing and nearly a year on the final design without a broken rim. WTB also states it sent CZR rims to "an unbiased third-party lab" for destructive testing against competitor carbon rims, finding the CZR i23 "38% more impact resistant than their direct competition" and the CZR i30 "10% more impact resistant." The lab is not named.
Warranty: WTB guarantees its products "for at least two years"; Ci24/Ci31 carbon 36 months. CZR carbon rims carry a Limited Lifetime warranty for the original owner plus the Ride With Confidence Guarantee: a CZR broken while riding is replaced free with a free rebuild; one damaged while not riding is replaced at 50% off current MSRP.
WTB's videos
Certifications
- ISO/ETRTO bead design — WTB states its TCS Beadlock profile is "Designed to ISO/ETRTO standards" and CZR TCS 2.0 is ETRTO/ISO compliant (source)
- CVX spoke-bed technology — Stated as patented by WTB (source)
Sources on WTB's site:
- Rim Technology - WTB
- Warranty - WTB
- Ride With Confidence Guarantee - WTB
- CZR i23 Rim - WTB
- CZR i30 Rim - WTB
Everything in this section is published by WTB. ProWheelBuilder is the wheel builder, not the tester, and the rim reaches us as the maker ships it.
Building it at ProWheelBuilder
Spoke length comes from the measured hub and this rim's real ERD — 603 in 29in — rather than a catalog average, so the nipples seat properly instead of running out of thread. Every wheel is laced, tensioned and trued by hand in Georgia, and we check tension around the wheel rather than trusting a single reading.
Labor is included in the wheel price. Tubeless tape and valves are an option at build time.
Warranty
WTB's warranty. WTB's cover depends on the rim: CZR and CGR carbon rims carry a limited lifetime warranty to the original owner, Ci24 and Ci31 carbon rims three years, and every other rim 24 months, all against defects in material and workmanship. A CZR rim broken while riding is replaced free; damage from a non-riding incident is replaced at half the current list price. Claims must be raised within 60 days of finding the defect.
ProWheelBuilder. Any wheel we build on this part carries ProWheelBuilder's one-year warranty in addition to the manufacturer's. Broken spokes are replaced for a year whatever the cause, and all wheel-side labor is included - truing, re-tensioning, rebuilding. Where the maker covers a failed rim or hub we handle that claim for you; where they decline, an eligible replacement comes at 25% off current retail. The customer covers shipping in both directions. Components supplied by the customer are not covered.
Full terms are on our Policies & Warranty page.
KOM Tough i25 questions
Is this the CVX version?
Yes. The KOM Tough i25 we build with is WTB's TCS 2.0 rim with CVX (29in W020-0641).
Why pick the i25 over the i30?
Pick the i25 for 2.1 to 2.4in cross-country and light trail tires. The i30 is the better rim once you run a 2.4in tire or wider.
What tires fit?
2.1 to 2.4in cross-country and light trail tires.
What is the ERD?
603 in 29in. It is the measurement spoke length is calculated from — get it wrong by a couple of millimeters and the spokes either bottom out in the nipple or leave thread showing.
Is it tubeless-ready?
Yes. TCS is WTB's tubeless bead system; we tape the rim and fit a valve when you choose the tubeless option.
Rim brake or disc?
Disc only. There is no machined braking surface on the sidewall.
What drilling is available?
32 hole.
Not sure? Email info@prowheelbuilder.com (fastest) or leave a voicemail on 470-253-0929 — you will be talking to the people who build the wheels.
