WTB KOM Light TCS 2.0 CVX i25 Rim
KOM Light is WTB's lighter KOM aluminum layup: the KOM profile family with less material, for riders who want the width without the weight. At 25mm inside the KOM Light 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 W020-0637 / W020-0638), 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 Light 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 KOM Light i25 is the cross-country and fast trail width, light enough for a race bike and wide enough to keep a 2.3in tire stable at the pressures that give it grip.
It suits 2.1 to 2.4in cross-country and light trail tires. In our strength model it scores 4.5 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 Light i25 measures 603 in 29in, a few millimeters less than the rim it replaced, and those are the figures we cut spokes to.
The 27.5in KOM Light i25 is WTB's TCS 2.0 rim without CVX (ERD 566, 430g); it is not currently in stock at our distributor, so it shows as unavailable.
Specifications
| Wheel size | Inner width | ERD | Weight | Drilling | WTB part |
|---|---|---|---|---|---|
| 29in | 25mm | 603 | 453g | 28 and 32 | W020-0637 / W020-0638 |
| 27.5in | 25mm | 566 | 430g | 32 | TCS 2.0, no CVX |
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.
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 and 27.5in, 28 and 32 hole in 29in; 32 hole in 27.5in, disc brake only, for external nipples. Listed weight is 453g in 29in, 430g in 27.5in.
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 Light i25 is live in our Custom Wheel Program for gravel and road disc, MTB single-speed and mountain bike builds. Build a custom wheel around the KOM Light 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.
Testing, standards and warranty at WTB
WTB test the KOM rims to their own impact and fatigue standards and warrant them against defects in materials and workmanship. WTB state the TCS Beadlock bead profile is designed to ISO/ETRTO standards, and that the CVX spoke bed is patented. Their rim technology page covers both, and the 4D drilling that angles each spoke hole toward the flange it serves.
ProWheelBuilder does not test rims. We report what WTB publish and build to it.
Building it at ProWheelBuilder
Spoke length comes from the measured hub and this rim's real ERD — 603 in 29in, 566 in 27.5in — 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. Lace this into a wheel here and the finished wheel gets our own one-year warranty as well as the maker's. For twelve months we replace broken spokes however they broke, and the work on the wheel is on us - truing, re-tensioning, a rebuild where it is needed. If the rim or hub is covered by its manufacturer we put the claim in and chase it; if it is not, we supply an eligible replacement rim or hub at 25% off the current retail price. Carriage both ways is the customer's, and this does not cover wheels built from parts you send in.
Full terms are on our Policies & Warranty page.
KOM Light i25 questions
Is this the CVX version?
Yes. The KOM Light i25 we build with is WTB's TCS 2.0 rim with CVX (29in W020-0637 / W020-0638). The 27.5in size is the earlier TCS 2.0 rim without CVX.
KOM Light or KOM Tough at 25mm?
KOM Light is the lighter layup: less material in the same profile family. Pick KOM Tough if you have dented rims before or ride loaded; pick KOM Light for a race or fast trail build.
What tires fit?
2.1 to 2.4in cross-country and light trail tires.
What is the ERD?
603 in 29in, 566 in 27.5in. 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?
28 and 32 hole in 29in; 32 hole in 27.5in.
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.
