Halo White Line Disc 700C Dyno front wheel

Halo's White Line Disc 700c Dyno Wheel is a solid and reliable option that's well built and suitable for all sorts of year-round riding. It's good enough to earn a place even on the best audax bikes out there.

The White Line series is Halo's entry level road range, and the White Line rim is a 25mm deep single chamber alloy one that has an internal width of 19mm. That makes it good for a range of tyres from road into gravel sizing, with Halo suggesting that widths of between 25mm and 38mm would be suitable.

The ETRTO chart has 28mm as the minimum width, with tyres up to 62mm supported. Realistically you're likely to be fitting a tyre between 28mm and 45mm on this wheel, depending on whether you're on a road or gravel bike, and you'll be fine.

The rim is tubeless compatible, and supplied pre-taped and tubeless ready. I fitted a 28mm Giant road tyre and a 40mm CST gravel tyre, both tubeless, and found both easy to fit. They also went up fine. The rim has a decent well in the centre to give you a bit of wriggle room in getting tight beads over the lip.

In the centre of the wheel sits an SP dynamo hub, and exactly which one depends on which build you're buying. Our 12mm thru-axle version has a PD-7 hub, while quick release (PD-8) and 15mm (PD-8X) wheels are available too. Prices and weights vary a bit too – plus the two thru-axle builds have 28 spokes to the QR wheel's 24, as you're more likely to point them at rougher terrain.

All the wheels use plain gauge black spokes and black brass nipples. My review wheel arrived true and has stayed nice and tight throughout testing.

It's not the most exotic build, and that's reflected both in the price, which is very competitive for a dynamo wheel, and the weight.

Ours weighed in at 1,090g including rim tape; not featherlight for a dyno wheel, but certainly not bad, and probably weight isn't going to be your main concern with a wheel like this anyway. You'll need to add a disc rotor too, which is a six-bolt fixing.

The PD-7 dynamo, at 419g, claims to be the lightest 12mm through-axle dynamo hub on the market right now, although it's not really a component you'll be looking for huge weight savings on. What you want it to do is to supply power reliably, and it certainly does do that. Like many dynamo hubs it's rated at 6V and 3W, which is plenty of power for a front and rear light, or for a converter to charge USB devices such as an Igaro D1.

Connecting your lights or devices is simple enough, with a pair of open connectors covered by a simple plug that you can just poke the wires through. If you're connecting more than one thing at the same time, it's worth soldering the wires together to make sure you get a good connection.

According to SP's own graphs you'll be getting that 6V/3W from around 15km/h, so any time you're cruising on the flat you'll easily be able to see your way or charge your phone. Below about 10km/h the voltage and power start to drop quite quickly, and on really steep climbs you'll get a flickering beam as the power resolves into individual spikes as the magnets move past the stator (the coil of wire that generates the power).

Your power that's being turned into electricity consequently isn't being translated into forward motion, and a dynamo isn't 100% efficient at its job – this means you'll lose a bit of that power entirely. This deep dive into a number of dynamo hubs found that the SP PD-8 (a similar design to the PD-7) was only around 34% efficient, so when generating 3W of power you'd be losing about 8.5W to the dynamo overall.

If you're the type who might find yourself at the pointy end of an ultradistance race, then the drag might be something to consider, but for your standard winter rider or audaxer it's not going to be an issue. Coming straight from a more expensive SON Delux dynamo on a pair of Hunt Superdura Dynamo wheels I didn't notice any extra drag from the cheaper SP unit, and in fact I'd say that at higher speeds the SP dynamo was a bit better in terms of output; it offered a slightly brighter beam from my lights.

When not connected to a power drain the resistance is pretty minimal, and if you spin the wheel with the bike in the stand and nothing connected, it'll keep going for a good while.

A dynamo wheel is something you'll be using through the year, in less than ideal conditions, so you want it to last. I've had no issues with my test wheel, and the SP range of dynamos has proved to be pretty reliable. Liam put 10,000km into his SP PL-8 dynohub during testing, which included half of the Transcontinental race, with no issues. If you do need to replace the bearings or any of the internals, it's not really a user-serviceable unit, so it'll have to go back to base.

Value

At around half the price of an equivalent SON dynamo hub at rrp, the SP dynohubs are good value, and if you're not into building your own wheels then this is a reasonably inexpensive option that performs really well.

It's possible to get an SP Dynamo wheel from a number of other sellers, including Spa Cycles and St John St Cycles, both of whom cater very much for the touring and audax crowd; prices are pretty comparable, although the specs are all slightly different. This Halo wheel is solidly built, tubeless compatible and not overly heavy, and it's worked flawlessly in testing, staying true even on rough gravel excursions and kicking out plenty of power for lights after dark. It's a very good choice.

Verdict

Very good dynamo wheel for commuting, audaxing or touring