WTB HTZ I 40 Rim
The WTB HTZ i40 is the plus-tire member of WTB's heavy-duty HTZ family: 40mm inside for 2.8 to 3.0in tires, with walls about 20% thicker than the KOM Tough, 6069 alloy, the I-Beam center support, asymmetric spoke drilling and the TCS tubeless bead. It is the rim for plus-tire e-bikes and heavy riders on plus bikes who want a wide alloy rim that will not dent.
This page covers the WTB HTZ I 40 Rim in 27.5in. The HTZ i40 comes from us only as a finished wheel: pick the hub, spokes and nipples, and we lace, tension and true it by hand in Georgia before it ships. Like every HTZ it is 32 hole, disc only and made for 35mm TCS tape, which we fit with a valve.
Design and construction
The HTZ takes the KOM's I-Beam section and adds material everywhere: thicker bead walls to resist dents and pinch flats, a thicker spoke bed for the higher tensions an e-bike wheel wants, and 6069 alloy, which is stronger than the 6061 most rims use. The spoke drilling is asymmetric, offset toward the non-drive side, which brings drive-side and non-drive-side tension close to equal on a Boost rear and makes a stiffer, longer-lived wheel. The TCS bead seats a tubeless tire with a floor pump and needs 35mm TCS tape.
How it rides
An HTZ i40 wheel with a 3.0in tire floats over roots and rocks, grips on loose climbs, and the thick walls and asymmetric rear keep it true under an e-bike's weight and torque. It is a heavy rim, as every 40mm alloy rim is, and on a plus e-bike that is the right trade.
For 2.6in tires the HTZ i35 is lighter; for 2.8 to 3.0in on an e-bike, the HTZ i40 is the WTB rim we recommend.
Specifications
| Wheel size | 27.5in |
|---|---|
| ERD | 569 (27.5in) |
| Inner width | 40 mm |
| Depth | 20.5 mm |
| Drillings | 32h |
| Weight | 718g (650b/27.5in) |
| Material | Aluminum |
| Tire type | clincher tubeless compatible |
| Brake | Disc |
| Spoke bed | Offset 7 mm |
| Nipples | External |
| Finishes | black |
About this listing
Version notes. 27.5in, 32h, about 718g, 40mm inside, 20.5mm deep, disc. The other sizes and brake versions of the HTZ i40 have their own listings; this page is for this one.
This is the disc-brake HTZ i40: plain sidewalls, no brake track to wear, a touch lighter. It fits any disc-brake bike and it is the version most of our customers now build; the rim-brake version is a separate listing.
Sizes, fit and compatibility
The WTB HTZ I 40 Rim comes in 27.5in and 32h drilling. It is a disc-brake rim. We build the HTZ i40 on DT Swiss 350, Industry Nine Hydra 2, Hope Pro 5 and Onyx Classic hubs in Boost spacing, with Sapim Strong, E-Strong or DT Alpine III spokes and brass nipples.
Tire range on the HTZ i40 is 2.8 to 3.0in. Pick e-bike or plus as your bike type in the configurator and it recommends a spoke count and gauge.
Build a wheel around it
Offered for tandem and e-bike, MTB single-speed, mountain bike and fat bike builds in our Custom Wheel Program. Start with the WTB Htz I 40 Rim and the configurator pins it for you, then checks each choice you make against it.
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.
Testing, standards and warranty at WTB
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.
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
WTB makes the HTZ i40; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. We measure the rim before we cut a spoke, bring the wheel up in three or four rounds with a gauge, stress-relieve it between rounds and true it last, then tape it and fit a valve if you want it tubeless.
Only compatible hubs and spokes appear in the configurator, impossible combinations are struck through rather than hidden, and the price is live.
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.
HTZ I 40 Rim questions
What tire width suits this rim?
At 40mm inside this is a plus or fat width, for tires from about 2.6in upward. Running a narrow tire on a rim this wide leaves the casing stretched and vague, so match it to the tire it was designed around.
Which spokes and nipples suit the HTZ i40?
For most riders a double-butted spoke such as Sapim Race or DT Competition with brass nipples; lighter riders can go to Sapim Laser or CX-Ray. The configurator recommends a gauge and count for the HTZ i40 from your bike type and weight.
HTZ or KOM Tough?
HTZ for e-MTBs, downhill, park and riders who dent rims; KOM Tough for trail bikes without a motor, where its lighter walls are plenty.
Which HTZ width should I choose?
i23 and i25 for cross-country e-bikes, i27 and i30 for trail and enduro e-MTBs on 2.4 to 2.6in tires, i35 and i40 for plus tires.
What does asymmetric drilling do?
It moves the spoke holes toward the non-drive side, which evens out spoke tension on a Boost rear wheel so the wheel stays true longer under e-bike torque.
Is the HTZ tubeless?
Yes. It has WTB's TCS bead and needs 35mm TCS tape, which we fit with a valve on request.
Is it tubeless-ready?
Yes. WTB lists the HTZ I 40 Rim as clincher tubeless compatible; we tape and fit a valve when you choose the tubeless option.
Not sure? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build the wheels.
