No. 6 is a Chinese brand that has gained popularity over the last few years due to its growing reputation for making lightweight carbon wheels that, in independent testing, have been found to be on par with some halo offerings from well-established European and US companies.
Design details
The No. 6 G45R (R for race) is the brand's lightest gravel bike wheelset, part of its ProjectSpeed, which aims to make light, fast-accelerating, responsive wheelsets. Unlike the G45W (W for wide), these feature a narrower rim profile to shave off as much weight as possible.
The rims are hooked, made from Toray T700 and T800 carbon fibre, with a unidirectional glossy finish similar to the Campagnolo C-Lux finish. Both measure 45mm deep, but the front is 34.5mm wide externally and 28mm internally, while the rear is 33mm wide externally and 26mm internally. The claimed weight is 1,195g, and the scales of truth match this closely at 1,198g with rim tape, but no valves or lockrings.
The narrower rim relative to the 'W' offering reduces rotational mass, making the wheels more responsive to acceleration, changes in direction, and braking. This design philosophy continues into the carbon-fibre spokes. The rear spokes are wider at 5mm and are claimed to be more aerodynamic, while the front are still bladed but narrower at 3.8mm. The front uses just 16 spokes in a one-cross 1:1 pattern (eight on either side), while the rear uses 20 spokes in a two-cross 1:1 pattern. Spoke nipples are external for ease of adjustment and made of an aerotitanium alloy.
The hubs are No.6’s own Zero Gravity v.3, featuring a 45-tooth ratchet engagement system, Tripeak ceramic bearings, and compatibility with all Shimano, SRAM, and Campagnolo hub types.
No.6 claims optimal tyre widths of 40-50mm, while the maximum rider weight is 110kg and max. pressure is 110 PSI. Black, white, silver, and holographic decals are available.
Performance
The wheels come with valves, lockrings, and pre-taped rims, and the taping quality is good. I fitted a pair of Pirelli Cinturato Gravel M tyres for testing, in both 50mm and 45mm options. These are tougher tyres to fit, but that is not on the rims. A lever easily slotted the tyres on and the wheels were good to go.
A brief word on rim width, as this is fairly subjective. Both wider and narrower rims have pros and cons. In terms of aero performance with 50mm tyres, the 34.5mm external width is probably narrower than optimal for watt savings. But there are a few potential benefits. Firstly, fitting tyres can be a little easier with a narrow rim, as you have less distance to get the second tyre bead on. Next, at low pressures on wider tyres, if you have wider rims, there is potentially more chance of a rim strike, so reinforcements need to be made. Finally, narrower rims without the required reinforcement are lighter, and on gravel in particular, where speeds are lower and inertial force is harder to overcome, this can be more beneficial when accelerating, especially up climbs.
As I said, this is all very subjective, but I've enjoyed the performance on the No. 6 wheels, even if the aero benefits at the average speed I raced the Gralloch UCI gravel race at are negligible (just over 32km/h).
What I did find is that, for climbing, they are frankly dreamy. From sustained-pace efforts to the starting climb at The Gralloch, they changed speed rapidly, a trait I really like in bunch events like this. The low weight also means more responsive braking and direction changes, which, on technical sections and fast descents into tight corners, proved a brilliant combination. The hub engagement also helps with acceleration, with the 45t ratchet quick to respond and with no give.
I can’t comment on the performance gain of the ceramic bearings or the subjective ‘feel’ of the aero performance, but I can say these wheels are no slouch; tellingly, they roll fast on the road, too. Off-road, tyres make the biggest difference to speed, on tarmac, they play a part but the reduced rolling resistance swings the scales in favour of aero performance and hub rolling. I actually spoke with some of the DAS Hutchinson team and a few of them have used the G45R wheelset as a road race wheel option with wider road tyres. Again, from rim to rim, even at race speeds, the differences are usually a handful of single-digit watts, and they depend on the frame. All I can say is that these wheels ‘feel’ like they perform at a comparable level to other high-end offerings I've ridden, including Scope, Black Inc, Enve and DT Swiss.
I'm far less fond of carbon spokes. I find these somewhat superfluous on road wheels, as they are stiff in some directions but not as strong in others, like torsional forces. On gravel, they just don't make sense, given their lack of resilience against side impacts. On the road, this is rare; on gravel, stones regularly fly up into spokes. I suffered a stone strike at The Gralloch, which caused a splinter to come off one of the spokes. No.6 do supply spare spokes for both front and rear, with no need to remove tyres and rim tape to fit, but, as a rule, carbon spokes for gravel wheels are not something I think is needed. Alloy spokes perform brilliantly and are more durable.
Value
Certainly, $2,199 isn't cheap for a wheelset, and for a Chinese wheelset, it’s significantly higher than it has traditionally been. Those worried about Chinese wheels not being made to the same standard as ‘European and US’ wheelsets need not worry, however, given that the majority of carbon wheels from those brands are made in Asia. The main differences are marketing budget and occasional quality control, but the No.6 wheels run true and have a better finish and roundness than some big-brand wheels I have tested.
However, with the ceramic bearings, 45T engagement, carbon spokes, and a CFD-designed rim that has performed well in independent testing, these wheels are taking on the likes of the Enve G SES 4.5 Pro (£3500 /$3300), Scope Artech 4.G (£3,500 / $4,398), and Roval Terra CLX Aero (£2998 / $3400). Compared with these options, the No.6 wheels offer good value.
Of course, import taxes are an issue, as European dealers are currently limited. However, customer care and service are impressive, with spares easy to purchase and supply. But at this price, the Hunt Limitless 40 UD spoke wheels, which are similarly specified and priced at £2,449, might be a more attractive offer to UK customers at the moment, given Hunt’s proven customer care and service. However, those wheels are shallower and heavier, and are hookless only.
Personally, I have no qualms with purchasing wheels from China. The quality and finish of the No.6 wheels have been superb; the performance matches any top-of-the-range offering, and the customer care has been great. ]
So, are these wheels good value? Yes, compared to the high-end performers they compete against. However, they aren't cheap and still represent a large investment for a set of wheels. You can get similar performance for less.
Tech spec
- Price: £1,699 / $2,199
- Weight: 1,195g
- Hubset: Zero Gravity v.3
- Freehub options: Shimano HG11/12, SRAM XDR, Campagnolo
- Rim depth: 45mm
- Spoke count: 16/20 front/rear
- Rim: Hooked