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Reserve 30 I9 Hydra wheelset review

Santa Cruz’s carbon wheel brand’s wide enduro wheelset

Our rating 
4.0 out of 5 star rating 4.0
GBP £1,899.00 RRP | USD $1,899.00
Reserve 30 I9 Hydra mountain bike wheelset

Our review

A well-built pair of wheels that are competitive on weight and packed with features
Pros: Classic carbon ride feel; accurate and direct; top-quality build and finish; impressive rear hub
Cons: Firm feel might not be for everyone
Skip to view product specifications

Reserve’s wheel line-up is constantly growing and, save for the 31|DH wheelset, this Reserve 30 is its hardest-hitting pair of hoops, designed to withstand the rigours of the Enduro World Series courses.


The price is high, but for that, you get carbon rims, top-spec spokes, Industry 9 hubs and a lifetime warranty on the rims (original owner only).

You can choose DT350 or Chris King hubs if you prefer, for less or more money respectively.

Reserve 30 I9 Hydra specifications and details

The 30mm internal-width carbon rims contribute to a very competitive 1,890g weight for the pair.

The rims have a reasonably deep build, with some additional reinforcement around the spoke nipple holes.

Thanks to their inwardly curved shape, I didn’t have issues getting tyre levers hooked over the rim wall, and due to an average outside diameter and reasonably generous central well depth, getting tyres on and off posed no problems.

The central well is nice and wide, so there’s plenty of space for a tyre’s bead. Furthermore, I found the Reserves easy to inflate, and tyres popped into the bead at very achievable pressures.

The rims come pre-taped, which I approve of, and the included valves posed no issues with clogging or restricting airflow.

Reserve 30 I9 Hydra mountain bike wheelset
As small a detail as it is, I really like the highlighting of the valve’s location.
Russell Burton / Immediate Media

The red decal might only be a small design touch, but it makes locating the valve so much easier.

Each wheel uses 28 spokes, butted to save weight and offset by 4mm to the disc side to aid spoke triangulation.

Industry 9’s Hydra hubs have a frankly ridiculous 0.52-degree freehub engagement angle, which means they have the quickest pickup of any of the wheels I had on test, as well as the most high-pitched buzz as you freewheel.

Hub options include XD or Micro Spline freehubs and six-bolt or Center Lock rotor mountings. The front hub caps pull off nicely, revealing the hub’s well-greased cartridge bearings.

Reserve 30 I9 Hydra mountain bike wheelset
Super-quick pickup from the Industry 9 hub.
Russell Burton / Immediate Media

Removing the rear hub’s end caps is a touch tougher, but only because there’s more resistance.

Keeping the cassette connected to the freehub makes pulling it off a touch easier, in my experience.

If it matters to you, the packaging in which the wheels arrive is great – a well-packed box that includes a pair of cloth wheel bags.

Reserve 30 I9 Hydra performance

The weight of these wheels is on a par with the other carbon hoops on test, though they’re a touch lighter than the Zipp 3MOTOs. Much like the Enve and Syncros wheels, the Reserve 30s have a firm but not harsh feel on the trail.

There’s less deflection than many of the alloy wheels I tested and less than the Zipps too. They have a very direct, accurate feel through turns, with no lag when you hoick the bar from side to side.

I’d say they’re a tad less comfortable than the Zipps, and many of the alloy wheels, but that’s not to say they’re uncomfortable to ride on the bulk of trails. Long gone, it seems, are the days of super-harsh carbon hoops.

Reserve 30 I9 Hydra mountain bike wheelset
The front hub rolls smooth.
Russell Burton / Immediate Media

The freehub is incredible. On my test hardtail, the instant reaction to pedal inputs makes the Reserves some of the snappiest feeling wheels I’ve ever ridden out of the corners, with basically no lag between pedal input and acceleration.

As detailed in my other wheel reviews, links below, if you have a bike with lots of pedal kickback, this may be exacerbated with the Reserves.

I can’t finish this review without mentioning that I did blow through the rear rim while ragging one of my test bikes down a particularly rocky track.

Sadly, this did write off the rim. It was not the only wheel to suffer damage during testing, though it’s worth noting that, as with any carbon rim, damage tends to be terminal.

However, as detailed on Reserve’s website, its support is: “Lifetime. Not limited. If you do actually manage to break our rim while out riding, we’ll replace it for free.”

Reserve 30 I9 Hydra mountain bike wheelset
Firm, but not harsh, the Reserve rims feel good.
Immediate Media

It is also fair to note that, outside of this test, I have written off carbon wheels from a number of other manufacturers on these test tracks – it is a risk when riding any wheel hard on rocky terrain.

As such, it feels unfair to criticise Reserve for this damage – at the same time, it would be remiss of me to not mention it.

For added context, it is the only Reserve wheel I have ever written off since they started appearing on test bikes a few years ago, so I do not feel there is a particular reliability issue with Reserve’s wheels.

Reserve 30 I9 Hydra bottom line

Reserve’s 30 wheels have that distinctive carbon feel – stiff and accurate, but not as harsh or as uncomfortable as carbon wheels used to be.


Their weight is competitive, build quality excellent and the I9 hubs are a total revelation. They don’t pip Zipp in the performance stakes, but they’re a lovely pair of wheels.

How we tested

Wheels are a pretty pricey upgrade, so we put 12 trail/enduro sets to the test to find out if there’s an inherent benefit to pricey carbon fibre hoops or is alloy better for hard-hitting rims?

The wheelsets were taken on back-to-back runs down selected tracks in the Welsh woods and at BikePark Wales. They were pummelled over and into rocks and drops, turns and berms, and off-camber roots.

To keep things fair, all our testing was done on the same bikes, both hardtail and full-sus, with the same tyres (thanks Specialized!) at the same pressures.

We tested 29in wheels, but most are offered in 650b versions too. While we predominantly ran 2.6in rubber, we also slung some 2.3in tyres on, and we varied the pressures between test sessions to see what difference we could feel.

Bikes shouldn’t be a pain to live with, so we took into account the ease with which tyres could be fitted and inflated. Likewise, we considered how easy it was to access bearings and swap freehubs, too.

Also on test

Product Specifications


Price GBP £1899.00USD $1899.00
Weight 1,890g (29in) – as tested per set
Brand Reserve


Features Weight (f): 894g
Weight (r): 996g
Engagement angle: 0.52 degrees
Brake type Disc
Rim internal width 29.5mm
Rim material Carbon
Spoke count 28 front, 28 rear
Wheel size 29in/700c