We review the Planet X Stealth Pro SRAM Force Ironman triathlon bike

Planet X Stealth Pro Sram Force

Direct-sell specialist Planet X has been selling its Stealth Pro time trial/triathlon frame for years. Up-to-date speccing and an unbelievable wheelset for the price still make this lively lightweight the go-to affordable aerobike in 2012.

Planet X’s evergreen Stealth still offers astonishing value and velocity on a proven lightweight platform

It might not be new, but the fundamental fuselage details haven’t dated either. The profiled head tube smooths out the minimal frontal section while blended main tube, seat tube and rear stay junctions, plus a full width bulged bottom bracket means it’s still as wind slippery as most frames. The horizontal dropouts with wheel adjuster screws mean you can tuck the wheel right into the wheelhugger cut-out. There’s plenty of internal space which means you don’t have to cut the seatpost if you’ve got short legs. Only external rather than internal cable routing is an obvious budget feature compared to newer/more expensive frames. Frame and, particularly, fork are competitively light weight for any aero bike, let alone a frame which sells for £499 on its own.

This pricing is possible because Planet X direct sell from their warehouse. While this model is billed as the SRAM Force version, it’s actually a Force/FSA and SRAM Apex kit mix. The Planet X semi-carbon cockpit is no lighter than an alloy equivalent and the base bar grip shape and sharp elbow pad edges caused several problems for our testers. The direct sell situation means you can effectively custom spec your bike from an extensive range of alternatives though. Even better, the bike builders at Planet X are nearly all massively experienced riders – including several legendary Yorkshire time trial and road race champions – who are happy to pass on their in-depth experience if you ring up after some advice.

Any quibbling about groupset family feuds and bar grumbles also pale into insignificance when you see what wheels this spec option is rolling on. The carbon fibre 82mm front, 101mm rear tubular specific Planet X wheels are impressive though. The tyres glued onto them are top quality handmade tubs that normally cost £50 each and the difference they make puts the PX into a totally different class to the other bikes here.

We’ve been test riding the Stealth for years, so there was little to surprise us. Despite it’s relatively light weight, it’s no noodle when it comes to putting the power down. That means a lively and responsive ride on rolling hilly roads or any course with a lot of pace change, adding versatility to the obvious value appeal of the Stealth. Steering is quick and responsive too, which is great for short-course races, if occasionally unsettling at speed with the deep wheels.

Minor gripes aside, the overall ride of the Stealth is smooth enough to spend 112 miles on without dreading a marathon after. You still need to avoid big potholes and maybe lift off the saddle slightly on rough sections, and we didn’t like the shape of the base-bar grips. You’ll rarely be rattled out of your rhythm when you’re tucked and pedaling hard, though, which is the crucial thing for maximum aero efficiency. Pushing the saddle right forward is enough to increase the middling seat angle if you’re a forward position fan.

It’s the wheels that really lift the Stealth head and shoulders above the opposition here though. To be honest we’re not normally fans of deep-section wheels – particularly on bikes for beginners – and there were definitely some nervous, gusty moments from the simple slab-sided rims in windy or traffic-heavy situations. They’re not the stiffest tracking wheels either, which combined with the fast handling to create some anxious moments when cornering hard. In terms of straight-line speed though, the advantage the wheel and tyre combo provide is just astonishing. We swapped them round all the bikes just to check it was the wheels that created the performance chasm between the Stealth and the others. Riding two up, whichever bike was rolling on the PX wheels and Crono tubs would be cruising comfortably while the other rider had real difficulty trying to keep up. Lightest weight on test meant the advantage ran all the way from mock T1 exit sprints up to extended head-down threshold surfing with a blurred big-ring gear. The Planet X wasn’t the fastest or most confident bike tested here. The wheels are a moot point too, as while the £599 standalone price of the wheels and tyres is a bargain, adding it to the cost of anything but the Mossa would price them out of the test.

+ Light weight, reasonably smooth and responsive aero frameset
+ Great value complete bike kit with quality tubs on aero wheels

– Flexy, gust-prone wheels can be unnerving for novices in bad weather
– Several testers didn’t like the shape and feel of the carbon cockpit