Spain’s BH have been making bikes since 1909, won the first Tour of Spain and were the first company to build a monocoque carbon frame under 800g. So the Prisma has some history to live up to.
Highs: The Prisma offers a lively but predictable ride from an advanced lightweight frame
Lows: Some vibration through the bar and stem; ‘washing line’ cable below the top tube
Buy if: You prefer a performance edge to outright comfort
With lengthened chainstays, a taller head tube and increased fork offset, the Prisma has a longer wheelbase and more stable handling than its top G5 race machine sibling, and is intended to be a pro-level ‘performance endurance’ bike.
Early signs are promising. The sub-1kg compact frame’s large down tube swells at each end to meet the head tube, and envelops the chunky press-fit BB30 bottom bracket. Deep boxy chainstays lead to carbon dropouts borrowed from the G5, and adjoin triangular seatstays in a subtle hourglass shape which flow into a short wishbone top section, keeping the back end as tight as possible.
The top tube curves towards the stout head tube, leaving the rear brake cable suspended like a clothesline beneath it. The straight fork, with its tapered alloy steerer, gives great front-end solidity with sharp handling. While the bonded and riveted front mech hanger works well, the riveted down tube cable stops are quite close to the front tyre, making us nervous when trying to adjust them on the move.
Shimano Ultegra shifts and stops you well, and the rock solid bottom bracket helps the BH climb and accelerate tidily. The Prisma is a lively ride, the compact frame stiff and responsive but still comfortable over rougher stuff.
Keeping things taut are the Shimano RS10 wheels, which perform better than their mass would tend to suggest. With 16 straight-pull aero spokes up front and 20 rear, they spin up well and are fairly efficient. The Rubena Racing Pro Syrinx tyres grip and roll well too, their 127tpi casing and medium silica compound giving very predictable cornering.
Despite a lengthy 34.9mm diameter alloy seatpost, very little road vibration reaches the comfortable San Marco Spid saddle, although the same can’t be said of the bar and stem, which can get tiring after hours in the saddle. In all though, a strong contender from the Spanish contingent.