Shimano is slowly growing its range of wheels to match its road disc brake offerings. We recently featured a new Polygon road bike in our regular Friday Five-a-side gear feature, which arrived kitted with Shimano’s RX31 wheelset. To our surprise, this incredible value ride was meant to have Shimano’s new carbon-laminate RX830s, so we took notes on both.
Shimano WH-RX830 – £750 / US$1500 / AU$1600
A new release for 2015, the RX830 carbon/alloy wheelset is a non-series model to accompany the likes of Shimano R785 and R685 brake/lever options. Despite their lack of groupset branding, these wheels are closest to Ultegra classification.
The rx830 carbon laminate rims are properly tubeless compatible :
The RX830s are tubeless compatible
The tubeless-compatible rims have a similar carbon laminate construction to XTR, Dura-Ace and RS81 wheels. The disc-only rim has a slight aero profile to it, with a measured depth of 32.5mm. As with Shimano’s XTR wheels, a lack of braking surface enables the carbon laminate to be used to the edge of the tyre bead, allowing for a thinner alloy extrusion to be used.
The rims keep with current trends for wider tyres, featuring an internal width of 17.9mm and an external width at 23mm. Shimano stipulates a 25mm minimum tyre width, and we imagine some will use these hoops with wider cyclocross rubber.
The centerlock hubs are an ultegra-level item with increased sealing for greater protection from grime and muck :
The hubs are equal to Ultegra in quality
The hubs use Shimano’s usual cup-and-cone bearing system, and we’re told they’re similar in weight and quality to Ultegra but with the increased sealing of an XT mountain bike hub. The rear hub is 11-speed compatible and supplied with a spacer for use with 9/10 speed cassettes.
Shimano currently only offers these in a standard 100/135mm quick release configuration. One thing to consider with Shimano hubs is a lack of interchangeable axles, so if your next bike features thru-axles, these wheels won’t be able to follow you.
A Centerlock mount plays host to the brake rotor. Shimano specifies a 140mm rotor, but we’re told by Shimano Australia that the wheel can handle larger without issue.
Both front and rear wheels are laced two-cross with 24 double-butted bladed straight-pull spokes.
Shimano hubs are notoriously heavy and, unsurprisingly, the number of the scales isn’t a strong attribute. Our set weighed 1860g for the pair (840g front, 1020g rear) excluding quick releases. The included long tubeless valves add 18g a pair.
Shimano WH-RX31 – £280 / US$450 / AU$500
Shimano’s rx31 road disc brake wheelset aren’t new, but are gaining in popularity as road discs take off:
First announced in 2013, the RX31s are a more budget conscious option for riders seeking a pre-built road disc brake wheelset. Weight and no tubeless compatibility are the most obvious differences with the far more expensive RX830s. The RX31s are also part of Shimano’s non-series offerings – the quality and features place them somewhere between Tiagra and 105 level.
The disc-only alloy rims are a hair narrower than the RX830s’, with an internal width of 17mm and external at 22.6mm. This means compatibility with rubber anywhere between 25c and 38c.The RX31s are not tubeless compatible.
Just like the RX830s, these wheels are only available with a standard quick release axle on the front, and a 135mm width quick release on the rear. The brake mount is Centerlock and the rear hub is 9, 10 and 11 speed compatible.
Reflecting the price compromise, we weighed our set at 2040g (920 front, 1120g rear) including rim tape, but not quick releases.