Ibis Blackbird Send 1 Rim
The Ibis Blackbird Send is the alloy rim designed for the maker's own wheels and sells bare for builders, and it does one clever thing: the bead walls are hollow box sections rather than solid, which gives the tire a broad, edge-free contact patch that resists pinch flats and sidewall cuts without adding weight. It is 35mm wide inside, 17mm deep, 32 hole, in 27.5in and 29in, with Stan's Bead Socket Technology for tubeless. The Send 1 is the front-specific rim at about 565 grams in 29in; the Send 2 is reinforced under the bead for rear use.
This page covers the Ibis Blackbird Send 1 Rim in 29in, 27.5in. The Blackbird Send 1 is not sold bare. You choose the hub and the rest of the build in the configurator, and it ships from our shop in Georgia laced, tensioned and trued by hand.
Design and construction
Most alloy rims have a solid bead wall with a sharp inner edge, which is what cuts a tire on a rock strike. The Blackbird Send's bead walls are hollow boxes, wide and rounded on top, so a hard hit squeezes the tire against a broad surface instead of a blade; the idea was borrowed from the maker's carbon rims and it works just as well in 6061 aluminum. The BST bead, licensed from Stan's, seats a tubeless tire with a floor pump and holds it at low pressure. The 35mm width suits 2.4 to 2.6in tires.
The Send 1 is the lighter front layup; the Send 2 adds material under the bead for the loads a rear wheel sees. Standard nipples, J-bend spokes, 32 hole, disc only.
How it rides
A Blackbird Send wheel is wide and forgiving. The 35mm bed gives a 2.5in tire a square, supportive shape at low pressure, the hollow bead walls take rock strikes without cutting the tire or denting badly, and the BST bead keeps the tire seated. It is a sensible weight for its width and it rides like a much more expensive rim.
For a matched pair we build a Send 1 front and a Send 2 rear, which is how the factory builds them.
Specifications
| Wheel size | 29in, 27.5in |
|---|---|
| ERD | 604 (29in), 566 (27.5in) |
| Inner width | 35 mm |
| Depth | 17 mm |
| Drillings | 32h |
| Weight | 565g (700c/29in), 543g (650b/27.5in) |
| Material | Aluminum |
| Tire type | clincher tubeless compatible |
| Brake | Disc |
| Nipples | External |
| Finishes | black |
This listing
This is the 29in, 27.5in listing of the Blackbird Send, 32h, about 565g, 35mm inside, 17mm deep, disc. Pick the size that matches your frame; the profile and construction are the same across the range.
The disc version of the Blackbird Send has no brake track, so the sidewall is a plain extrusion that saves a little weight and never wears; it is the one to choose for any disc-brake frame. The rim-brake version, listed separately, has a machined sidewall.
Sizes, fit and compatibility
The Ibis Blackbird Send 1 Rim comes in 29in, 27.5in and 32h drilling. It is a disc-brake rim. We build the Blackbird Send on Industry Nine Hydra 2 and 1/1, DT Swiss 350 and 240, Hope Pro 5, Onyx Vesper and Bitex BX 211 hubs in Boost spacing, usually with Sapim Race, D-Light or DT Competition spokes and brass nipples.
Tire range on the Blackbird Send is 2.4 to 2.6in with tubeless-ready tires on the BST bead. Give the configurator your bike type and weight; it picks a sensible spoke count and lacing pattern, which you can override.
Build it with us
We build this rim to order. Open the Custom Wheel Program with the Ibis Blackbird Send 1 Rim already selected and pick the parts around it; it is offered for tandem and e-bike, mountain bike, MTB single-speed and fat bike builds, and the configurator will not let you assemble a combination we would not build.
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.
What Ibis says about testing
Ibis Cycles' S-series carbon rims (S35 and S28) were developed with Stan's NoTubes; Ibis states it licenses Stan's patented Bead Socket Technology (BST), which lets it reduce rim cross-section height so the rims are more compliant vertically. Ibis states the rims use Toughened Hybrid Carbon, a proprietary toughened resin in the beadwall that lets the wall flex and shrug off impacts, and at the 2019 launch Bikepacking.com reported Ibis' claim that the new rims were 9% better at resisting impacts than the previous Ibis wheels. Ibis publishes no impact-energy, fatigue-cycle or ISO/EN test figures.
The S35 29 in rim is 41 mm outer and 35 mm inner width, 18.3 mm section height, 604 mm ERD, 445 g, drilled 32h with a 5 mm spoke offset, the same rim front or rear, for 2.35 in to 2.8 in tires. Ibis lists wheel build location as USA for the S35 and S28 carbon wheelsets and Taiwan for its aluminum wheels. No rider weight limit or maximum tire pressure is published on the rim pages.
Certifications
- Warranty — Lifetime warranty against defects in materials and workmanship for the original owner; impact damage case by case or via no-fault replacement at a minimum charge; rims bought before January 1st 2023 covered 7 years against impact and defects (source)
Sources on Ibis's site:
- Ibis Warranty Policy
- S35 Carbon 29" Rim - Ibis Cycles store
- Ibis Wheels
- Ibis wheelset details (S35/27.5 Carbon i9)
- Bikepacking.com: Ibis Cycles and Stan's launch new S-Wheels and rims (2019)
Ibis publishes those results; ProWheelBuilder builds the rim into a wheel and does not test it in a lab.
Building it at ProWheelBuilder
The Blackbird Send is made for Ibis; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. Every Blackbird Send wheel we build gets spokes cut from the rim's measured ERD, is tensioned in stages with a gauge, stress-relieved and trued before it ships. Tubeless tape and a valve are fitted on request.
In the configurator you will only see parts that fit this drilling; combinations that are not made are struck through, and the price updates as you pick.
Warranty
Manufacturer's warranty. Ibis warrants this product against defects in materials and workmanship. The duration, conditions and claim process are set by Ibis and can change without notice, so ask us and we will confirm the current terms before you buy.
ProWheelBuilder. If we lace this into a wheel for you, that wheel also carries ProWheelBuilder's own one-year warranty, which covers broken spokes regardless of cause and all wheel-related labor, including truing and rebuilding, for a year from purchase. Where a rim or hub is covered by its maker, we make the manufacturer's claim for you and coordinate it; where it is not, we offer an eligible replacement rim or hub at 25% off current retail. Shipping to and from us is the customer's. This cover does not extend to wheels built from components you supply yourself.
Full terms are on our Policies & Warranty page.
Blackbird Send 1 Rim questions
What tire width suits this rim?
35mm inside is an enduro width, meant for 2.3 to 2.6in tires. It gives a big casing a square, supported profile so you can drop pressure for grip without the tire folding, which is the whole point of a rim this wide.
Send 1 or Send 2?
Send 1 is the lighter front-specific rim; Send 2 is reinforced under the bead for the rear. We build them as a pair.
What do the hollow bead walls do?
They give the tire a broad, rounded surface to hit on a rock strike instead of a sharp edge, which resists pinch flats and sidewall cuts without adding weight.
Is the Blackbird Send tubeless?
Yes. It uses Stan's BST bead; we tape and fit a valve on request.
What tires fit the Blackbird Send?
2.4 to 2.6in. A 2.5in trail tire is the pairing most of our customers run.
Is it tubeless-ready?
Yes. Ibis lists the Blackbird Send 1 Rim as clincher tubeless compatible; we tape and fit a valve when you choose the tubeless option.
Which spoke count should I choose?
It depends on your weight, terrain and the hub, not the rim alone. The configurator recommends a count from your bike type and rider weight, within the drillings this rim is made in.
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.
