TESTED: Zelvy I9 Carbon 29 PDL Wheel Set

Words and photos: Chris Herron

In the world of carbon mountain bike wheels, there was a time you used to be able to count the manufacturers on one hand. But in this day and age with carbon being king of materials, I think I’ve lost track of the number of companies making carbon rims and producing carbon wheelsets. With China now producing masses of carbon rims, it’s becoming increasingly harder to find wheels that stand out from the rest. Which is why, when asked to test an Australian-owned and designed carbon wheel set, I jumped at the chance. Enter Zelvy Carbon.

Zelvy Carbon hails from Toowoomba, one of southern Queensland’s inland towns, and one known for some pretty amazing trails and some pretty fast mountain bikers as well. Being 100 percent Australian owned can mean a lot to people looking to support our local industry, especially when they are riders themselves. All the CAD design and 3D printing is done in-house in Toowoomba, and only when they are happy with the product is it ready for production out of Asia. This is pretty standard practice nowadays for most companies.

The wheelset I was sent down to test is one of Zelvy’s latest 29er trail hoops. They are labelled as 29” Industry 9 Wheels 35/30 PRL Boost XD. I wasn’t sure what level of wheels I was receiving, nor the hub/spoke/nipple configuration either. I must say I was pretty stoked to open the box and see some sexy Matte Marble rims laced to Industry 9 Torch Classic hubs. These hubs are up there with the likes of Chris King and DT Swiss.

Zelvy hand build these wheels using Pillar Triple Butted spokes and titanium coated brass nipples in a 32 hole 3 cross configuration, which you know is going to be as strong as they will get. Total wheelset weight is 1787 grams. In comparison, the ENVE M60HV 29 Chris King wheelset is 1764 grams.

A CLOSER LOOK
A quick check over the rim with digital calipers revealed a 29mm internal rim dimension (although widths varied from 28.8mm to 29.2mm) and external dimension of 35mm (with widths varying from 35.1mm to 35.3mm). The average height of the rim is 24.5mm. The website labels these rims as 30 internal / 35 external PDL, but when looking at wheelsets, the rim is labelled as 29×35 PDL. After a bit of searching I found the PDL to stand for “Pretty Darn Light”. These rims come in at 440grams each, which isn’t ultra-light, but you know that the strength to weight ratio is pretty good with carbon so the expectation was they would be super strong.

SETTING UP
The wheels come pre-installed with rim tape and tubeless valves – a nice feature that you don’t get with all carbon wheelsets. Installing the tyres to the rims was relatively pain free, and my brand new Maxxis Ardent 2.4” front and Maxxis Aggressor 2.35” rear rolled on by hand, albeit my veins were popping a bit as they are a nice and tight fit.

Inflating the tyres was super easy with the use of my Bontrager Flash Charger pump. I did give it a try with an electronic pneumatic inflator and that worked a treat as well. Sans Stan’s sealant, they held pressure quite well, but I would never ride without sealant, so deflated the tyres and syringed some sealant through the valves.

Since these wheels were going to be rolling under my personal bike, I switched rotors and cassette and installed the wheels for my first roll out of the garage. One thing to note here is the effect of rim width on tyres. I currently ride with DT Swiss XM401 rims which are a 22.5mm internal rim width, compared to the Zelvy 30/35 with an internal width of 29mm.

After measuring the width of the 2.4” Ardent on my rim and the Ardent 2.4” on the Zelvy rim I was expecting there to be quite a difference in tyre widths. To my surprise, there was only 2mm difference in the outer casing width at the same pressures. I really thought there would have been more of a disparity. That said, the shape of the tyre was a lot flatter on the Zelvy, giving the tyre a larger surface area or contact patch with the ground. This is where a difference should be felt.

Getting the wheels trail ready, I inflated the front to 28psi and the rear to 32psi. Zelvy recommend in their ‘Wheelset Manual and Care Instructions’ to not go below 25psi. I personally never run pressure that low, as with my riding style and weight I find the tyres squirm too much and rim out quite a lot on roots and square edge bumps. Plus, I get the occasional burp from the tyres as well.

LET'S RIDE
The first thing you notice about this wheelset trailside is the noise coming from the rear hub. The 120 points, 3 degrees of engagement coming from the i9 Torch Classic is a sound unlike any other hub. Love it or hate it, one thing is for sure, the engagement is super quick. That being said, I did find that the hub slipped a couple of times under heavy load whilst ratcheting up rock shelving, but this could have been due to new hubs and the grease not being dispersed around the drive shell.

Once I had rolled a few laps of the XC trails to get a feeling for the wheels and to warm up, I started to push harder to see how well they performed when things started getting a little rougher and the wheels were leaving the ground.

One thing that came to mind during the first couple of hours is how lively they felt. It’s hard to describe to someone who hasn’t ridden carbon wheels before, but there is a certain feeling you get with a carbon rim that can’t be felt with its alloy counterpart. The bike seems to just float a little more over the rough stuff and popping off little jumps and out of corners seems effortless and results in a little more acceleration on the trail.

When standing up and stomping on the pedals, the rear wheel had very little lateral flex, and the tyre wouldn’t buzz my seat stays like it sometimes does with my alloy rims.  But cornering is really where carbon wheels shine, and the Zelvy’s really hold their line well in a corner. They are definitely stiff enough to not let the front wheel wander when braking hard and setting up for a corner, and then track their line when the corners are rough.

Hitting some of the larger jumps at my local trails was nothing out of the ordinary, but you get the feeling that when you hit the down ramp the bike just wants to accelerate from pumping the landing. The wheel stiffness was more apparent when jumping and landing into large sections of rock garden, something I wouldn’t normally do on my alloy rims but felt more confident doing on the carbon wheels.

MY THOUGHTS
As an upgrade to stock wheels on a current trail/enduro bike, this wheelset would definitely give your bike something a little extra you may be wanting to get out of it. A good quality, durable and relatively light wheelset would transform a good bike into a great bike – as it’s often said the wheels give you the feeling on the ground. And these Zelvy’s felt great.