Sunrace’s great-looking new NRZ groupset backs up its appearance with a healthy serving of function and durability.
It's pretty exciting to see someone step up and challenge the might of Shimano, Campagnolo and SRAM with a whole new performance-orientated groupset. What’s even better, though, is that this offering from Sunrace is made to some very ﬁne tolerances, using some very ﬁne materials.
The performance turned out to be considerably better than we expected. Our ﬁrst thoughts when we got it all out of the box was that it looked nice, felt nice, but we didn’t expect it to perform as well as gear from more established manufacturers with all their experience behind them.
It’s wonderful to be proven wrong though, with excellent performance from the very ﬁrst ride after a trouble-free and remarkably easy installation and setup.
If you’re looking for something different but you want a system that will still perform as well as the best, this NRZ system from Sunrace is more than worth a casual look.
To give you a better idea of what we really think about it, this groupset is staying on a bike for longterm use – not only because that’s what we always do with new groupsets, but because we’re in no rush to stop using it.
Let’s take a look, then, at the component parts.
STRZ brake/shift levers
If you could put Shimano and Campagnolo hoods into a ‘let’s get jiggy tonight’ machine the resulting baby would grow up to be Sunrace. They are a very pleasing shape, slightly ﬂat on top, and waisted slightly in a new-school Campag kind of way up near the top. They’re a nice place to put your hands for a long time.
The full carbon brake lever has a medium length aluminium alloy lever sitting behind it, and above that a small lever, taking care of braking, shifting up, and shifting down. The shifting mechanism is simple and well made, and the performance was alarmingly good. We weren’t expecting them to be as good as they are.
The force required to shift is between old-school Campag and current Shimano, and yet they give a solid and purposeful clunk every time you shift. They do take a little getting used to though, and at ﬁrst you might be catching the upshift lever when using the downshift lever. Not that this matters, and the downshift lever overrides the upshift one once it’s moving anyway.
You can shift three gears in one sweep on a downshift, and the upshift is a single gear per click only. We’d like to see ﬁner trimming on the front mech shifter though. It wasn’t a problem with the Sunrace front mech and crank/chainring setup, but if used with aftermarket chainrings/cranks that are not correctly installed to the chainline then the lack of ﬁner trimming could become an issue.
All in all though, these are a great set of shifters that function very well and have a wonderfully shaped hood.
Weights: Right shifter 193g, left shifter 192g
A quick deflection test showed these cranks to be only slightly stiffer than SRAM Rival, Truvativ Rouleur and Shimano 105 cranksets. The weight for that level of stiffness is very good though, and the bottom bracket axle is a key factor in that low weight.
It’s a 6Al/4V titanium tubular unit, and from an engineering point of view it’s pretty rare in the road world because the axle’s external diameter is taken down to the root diameter of the internal threads at the non-drive side which accommodates the single crank bolt (the axle is smaller in the middle).
This is how an axle with an internal thread should be made if you’re aiming for a nice long fatigue life – it’s no stronger or weaker, just longer-lasting – so, again, top marks for engineering.
Another great feature is how the cranks are installed. They ﬁt like most other cranks of this style, simply slipping the drive side crank complete with axle through the bottom bracket, but before the non-drive side crank is installed there is a small locking ring that screws onto the axle.
This locking ring allows you to pre-load the ceramic bearings properly using the supplied special tool. The non-drive side crank arm is then ﬁtted, and the inside of the crank arm to axle interface area has a small keyway area which covers and locks in place the locking ring – so ﬁtting and tightening of the non-drive crank arm has no effect upon the bearing pre-load. It’s simple and it works perfectly. The whole assembly is excellent quality, and ﬁtting was a breeze.
The 7075 aluminium alloy chainrings have nice deep teeth and feature a total of six stainless steel shifting pins on the outer ring. These are arranged to shift the chain at the bottom of the power stroke, and in use with the supplied chain they worked in a smooth and efﬁcient manner. We later tried a SRAM PC1090 chain though, and the shifting was outstandingly good.
Carbon composite arms, 6al/4v titanium axle, 7075 aluminium chainrings
With a pin width of 5.9mm, inner and outer side plates with slots in them, and hollow pins, this is one seriously lightweight chain. The shifting performance was quite good, but after trying a SRAM PC1090 on the system we can see there is room for improvement.
If anything is a weak area on this whole new groupset, then it’s the chain. After just 500 miles it had already worn to a length where we’d consider replacing it, and for a titanium nitrided chain we expected better.
Thankfully, though, the whole system worked faultlessly with the excellent SRAM chain ﬁtted, so our advice would be to not bother with this chain at all, and either go for the SRAM PC1090, or the KMC X10SL right away.
Weight: 246g/110 links
BBRZ Bottom Bracket
Just 6g over the claimed weight, this bottom bracket unit was impressive for several reasons. First, the full ceramic ball bearing assemblies were notably smooth with very little seal drag. Secondly, the threads on the bearing cups measured up to a thread gauge perfectly – leading to a snug ﬁt into our Storck test frame when screwing in by hand. Thirdly, there’s just the right amount of thread-locking compound on them.
All in all this is a very high quality bottom bracket unit and the folk at Sunrace have clearly paid attention to all the bits that add up to make a good external bearing design.
Ceramic ball bearings, 7075 aluminium alloy cups, Weight: 95g
CSRZ TAO cassette
If a company wanted to sell itself on the capabilities of its CNC machining work, it could do little better than to use this wonderfully over the top one-piece rear sprocket cluster as an example.
Weighing in at a shade over 100g (but spot-on the claimed weight) for a full 10-speed unit, it is 42g lighter than Campagnolo Super Record, and 50g lighter than SRAM Red. Mind you, being one-piece 7075 aluminium alloy, it should be much lighter. Despite the ceramic coating standing up to all of the abuse that we threw at it, the edges of the teeth are showing wear after a little under 600 miles; that’s not too bad, and to be honest it’s much better than we were expecting.
The shifting performance is excellent, easily as good as Shimano, and yet with the positive, albeit slightly clunky, feel of Campagnolo.
7075 aluminium alloy one-piece, ceramic coated Weight: 105g
FDRZ front mech
This is not just a steel cage front mech with some carbon on the outside for looks; the carbon is laid into a very thin steel plate in order to form a carbon composite reinforced outer mech plate, the steel plates themselves being too ﬂimsy for the job alone.
This makes the outer plate of the cage strong enough, but leaves a wear-resistant steel facing on the inside to push against the chain when you shift. It’s light, durable and incredibly well made, with a tiny amount of play. Shifting, in conjunction with the superb front chainrings, is bang-on. It’s available in bottom pull and braze-on only (you can always buy an aftermarket band mounting, such as the excellent Smolik item).
Outer ring range: 50-56 teeth
Capacity (max difference in number of teeth between two chainrings): 16, Weight: 99g
RDRZ rear mech
Lighter than the claimed weight by 4g the most noticeable aspect about this rear mech was the lack of play. In terms of tolerances then Sunrace is working to a pretty tight set as our test mech, when ﬁtted to the frame, only showed a total of 4mm of sideways movement at the very end of the cage (furthest point from the main mech ﬁtting/pivot bolt).
For a rear mech that’s damn good. The aluminium alloy main pivot bolt is a bonus, as in the event of a crash it is supposed to break, protecting the frame’s rear mech hanger. It’s cheaper to replace a bolt than it is a frame, and in some cases even cheaper and quicker than a replaceable rear mech hanger.
The 11-tooth 7075 jockey pulleys feature ceramic bearings with good quality sealing, and the overall shifting performance is very quick and precise.