You can trust Cyclingnews
Our experts spend countless hours testing cycling tech and will always share honest, unbiased advice to help you choose. Find out more about how we test.
Image 1 of 7
Sidi updates its venerable Genius 5.5 with a stiffer and lighter sole.(Image credit: James Huang)
The Carbon Composite sole isn't a true carbon fibre sole but is still very rigid.(Image credit: James Huang)
The new Caliper buckle is easier to adjust on the fly and release than the Ultra SL.(Image credit: James Huang)
The usual padded instep pad offers the same cushiony feel we've become accustomed to.(Image credit: James Huang)
Sidi's High Security Strap inserts carry on for another season and continue to work well(Image credit: James Huang)
The moulded heel cup delivers sufficient heel hold for most users.(Image credit: James Huang)
The Lorica upper is supremely comfortable but could use a bit more mesh for warm conditions.(Image credit: James Huang)
Sidi continues to blend old-world craftsmanship with new-world tech in the latest version of the Genius 5.5 Carbon Composite road shoe.
The Lorica upper's sock-like fit is retained but it's now bonded to a new Carbon Composite one-piece fibre-reinforced sole. According to Sidi, the new plate is 65g lighter than last year's two-piece Hi-Tech Carbon sole while also stiffer through the midsection.
Out on the road, the Sidi Genius 5.5 shines through with a pressure point-free fit that simply disappears on your foot as the hours tick by, although the sparing use of mesh limits the shoe's breathability. The new Caliper buckle sadly loses the old Ultra SL's half-tooth adjustment but is notably easier to loosen while on the bike or release completely at the end of the day. Tightening the buckle up is a bit more difficult, though, as the ratchet lever is rather short and hard to get under with your fingers (especially with full-finger gloves). As always, the Velcro forefoot straps held fast.
It's difficult for us to say whether the new Carbon Composite sole is stiffer than the Hi-Tech sole it replaced but we'll take a weight loss any day, as long as it comes without any other compromises which seems to be the case here. If anything, the one-piece construction should likely hold up better over time than the old Erector bolt-together configuration and the Carbon Composite plate is an enormous improvement over Sidi's nylon Millenium sole.
Either way, the Carbon Composite plate still isn't as rigid as some of the board-stiff true carbon fibre models we've tested before but it's unlikely most riders would notice. This may very well be by intention, as we didn't experience any hot spots underfoot on either long rides or short. Sidi claims that it's possible to have a shoe that is too stiff and it's hard to argue based on our experience here.
On the downside, the Sidi Genius 5.5 Carbon Composite shoe commands the usual Sidi price premium over its competition and they're also slightly heavier to boot: our size 44 Mega test pair weighs 622g with the included insoles. Sure, the standard-width version is about 20g lighter but even so, Specialized's far stiffer S-Works model is 568g per pair in a comparable size while Pearl Izumi's feathery Octane SL blows the scale out of the water at about 460g. Both are slightly less expensive, too, although it's hard to say at this point whether either can match Sidi's renowned long-term durability.
Technical faults aside, the Sidi's compelling argument of perfect fit, unflappable quality, Euro-chic styling and stiff-enough composite sole should more than make its case. They might not be the stiffest, lightest, or cheapest shoes around, but they just feel so good on our feet. For all but the most demanding techno-weenies, that's probably all that matters.
