The BH Prisma 105 has a compact frame that relies on a generous amount of seatpost to accommodate larger riders (we needed 22cm), which is why it has a 31.8mm aluminium seatpost.
At first glance we thought this might generate some discomfort, but the frame, and to some degree the saddle, do an amazing job of neutralising road buzz and even fairly big hits from heavily rippled roads. It does have a surprising heft for something so small though.
- HIGHS: Responsive and competent compact carbon frame
- LOWS: Comfortable but not especially quick wheels, average brakes
- BUY IF… You want a modern compact frame with Spanish heritage
The medium Prisma accommodated our tester's 178cm frame without testing the seatpost's extension limit, and still had enough handlebar reach without needing a stack of spacers. It's immediately obvious where a compact frame's strengths lie when accelerating, as with such tight triangles and heavily built head tube and BB30 bottom bracket areas, there's no lateral flex.
Stand up on the pedals and the BH responds instantly, zipping up to speed. But although performance felt lively, as the miles wore on we became more certain that the wheels were sapping our efforts and blunting the frame's very good energy transmission.
The 32-spoke Rodi Stylus wheels give a very compliant ride, soaking up uneven surfaces well, but they lack enough go to match the zippy frame. The Michelin Dynamic Sport tyres – an uncommon choice – proved as quick and grippy as any, but were still unable to generate more speed from the wheels.
Climbing out-of-the-saddle had us imagining any number of pocket-size Spanish climbers, as the Prisma danced and skipped its way uphill beneath us, almost as if the carbon fibre was instilled with some sort of Vuelta DNA. It climbs very well, but again, we couldn't help wonder what lighter, swifter wheels would do to the performance.
The fork, with its oversize 1 1/2in steerer, continues the lively and responsive theme, proving reassuring at all speeds, which isn't true of the brakes. The combination of unbranded callipers and the Rodi rims lack bite and power, which could possibly be overcome with a change of pads.
The BH branded aluminium cockpit works in an unfussy manner, though we found the hooks of the drops a little on the short side, and the handlebar bend isn't ideal for large hands.
The Shimano 105 drivetrain and cheaper FSA Omega compact chainset are faultless performers, and although you might need some lower gear ratios if heading for the mountains, the Prisma has the core of a good all-rounder.