SpeedX Leopard Pro

The SpeedX Leopard Pro comes off the back of a very successful Kickstarter campaign, and as a bike it shows some promise, but there are some big teething problems with the current model I've been riding, and I'm not convinced by either the concept or the actualisation of the integrated computer. Overall, it's more miss than hit.

The heart of the bike is the frame, and in this case it's an aero-optimised carbon monocoque made from a mix of high-modulus T1000 and T800 fibres, with the matching fork using the same ingredients. Those are high grades of carbon so you should be able to make a pretty light frame out of them; SpeedX claims a 1.2kg frame weight for the Leopard Pro, which is okay but a fair bit more than many recent aero frames that have been nudging under a kilo. Our test bike came with a raw finish; there's no vanity layer on top and no paint finish. Bikes being shipped in 2017 will have a matt black finish.

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The Leopard Pro is built up with a Shimano Ultegra Di2 groupset and SpeedX's own carbon 50mm section wheelset. The brakes are TRP TTV aero direct-pull brakes, with the rear brake sitting under the bottom bracket and the front at the rear of the fork leg for maximum aerodynamic advantage. The seatpost and handlebar are carbon, and the stem incorporates the SpeedX computer.

You get a Fizik Arione R7 saddle to sit on and flat pedals are included too, although you'll most likely be swapping them out for your choice of clipless ones. Fully built (without pedals), our test bike weighed in at 8.76kg. No two ways about it: that's heavy for a £2,500 aero bike. It's about a kilo over the odds, and even more compared with some, for example the 7.2kg Rose Xeon CW-3100.

Where's the extra weight? Well, some of it is in the frame, but a lot of it is in the computer and its battery. The wheels aren't especially heavy, so the electronics need to be adding around half a kilo in total. Compared with a sub-100g Garmin, that's a lot. Those integrated electronics are one of the major selling points of this bike, so let's explore them in a bit of detail.

Integrated electronics

There's a computer that's part of the stem design, sitting in front of the bar clamp, and it's powered from a battery in the seatpost, which also incorporates an LED rear light that's motion-activated. Cadence and speed sensors are also wired in, as well as Bluetooth and ANT+ connectivity. The integration is pretty neat, and the bike has a big button in place of a stem cap as well as smaller function buttons on the sides. The 320x240 screen is a similar resolution to a Garmin or similar GPS and it's good in sunlight and overcast conditions.

SpeedX claims a battery life of 40 hours: it basically records whenever you're riding the bike, and you can use the big button to switch between displays. The life of the computer is impressive, but it does mean you're lugging a big old battery about; the Di2 in the Leopard Pro runs off its own battery so if your computer dies you'll still have working gears, but it also means you're doubling up on batteries, which adds to the weight.

The cadence magnet is designed to fit in the back of the flat pedals that SpeedX supplies with the bike, in the 6mm hex bolt hole. That means if your pedals use an 8mm hex, as many road pedals do, it won't fit. I Blu-Tacked mine in. It fell out, though. It's somewhere on the Mendips.

The SpeedX integrated computer is designed to sync with a smartphone app to extend the capabilities of the computer. In theory you'll be able to get training plans, turn-by-turn directions, compete against other riders, be part of a global community, all sorts. I say 'in theory' because currently the app is a real weak point of the system. It has a clunky interface and even the most basic functions don't really work. Synchronising data between the bike and the app failed every time, and that means that anything that I've just recorded on the bike is still on it, and not anywhere else. You can also record from the smartphone app, although that sort of defeats the object of having the sensors integrated into the bike.

Updates have improved the app a bit, but it's a long way from being good. You can't even sync to Strava yet, which certainly should have been a must-have on the launch list. That functionality is coming.

Here's where I'm at with the app and the integrated computer: I can't help thinking that it's a solution in search of a problem. You're tying yourself to a specific hardware setup for the life of the bike, when your add-on options are constantly changing. There's nothing that the computer is doing that requires it to be built into the frame. If it were measuring power from strain gauges in the down tube, for example, that might be a reason to build the rest of the electronics in too. But as it stands, the Leopard Pro is only recording the same stuff that you get from non-integrated solutions.

If you're going to use the bike to record all your data, then the SpeedX integrated system does a decent job, assuming at some point the app will work well enough to give you access to it. But the SpeedX computer isn't anywhere near as polished as something like a Garmin 520, and next year there'll probably be a Garmin 530, or 540, or whatever, that'll be even better and you'll have the option to swap. Here you don't.

If you go down the other route and like to use your phone to record and pump that info to a display, then again the landscape is changing and new units like the Wahoo Elemnt are offering more and more functionality.

Then there's the issue of creating another new and proprietary platform. If you want to log all your riding and keep your data in one place then the overwhelming likelihood is that you're already doing that, most likely in Strava or Garmin Connect. If you like to compete against others then you're probably doing that in Strava too, and if you're after a training solution then again there are lots of options, including the highly sophisticated and well-populated Trainerroad and TrainingPeaks.

To be able to offer comparably populated alternatives to all of these on a new, proprietary, platform would require a market share that no major bike manufacturer could realistically achieve, let alone a startup like SpeedX. In the same way that Garmin has tried and mostly failed to get its own segments functionality going when Strava already has a massive following, the SpeedX platform is doomed to remain pretty empty unless it's offering something that's genuinely new, or at least doing the same things much better.

Ride & handling

On to the rest of the bike. How does it actually ride? With a stack height of 564mm and a reach of 408mm, the Leopard Pro is a fairly aggressive machine, and the slightly-sharper-then-usual 74-degree seat tube angle puts you marginally further forward on the bike, which accentuates the nose-down feel a bit. Compared with, say, the Giant Propel Advanced 1 we tested this year, the SpeedX is 17mm longer and 2mm lower at the front, and also 11mm longer in the wheelbase. They're not big differences but they're noticeable.

The Leopard Pro rolls along nicely on the flat, smooth stuff. It's a very stiff unit, and stamping on the pedals results in good straight-line speed when you wind it up. The longish wheelbase translates into a pretty planted ride, and with the low front you're nice and aero in the drops. So long as the surface stays good the Leopard Pro is enjoyable to ride, but it struggles on more degraded tarmac.

Part of the issue is the 23mm tyres; the frame will accommodate 25s and the bike should come with them, because there's not much by way of damping available from the super-stiff frame. Road shock gets quite efficiently transmitted to the handlebar and the saddle. Aero bikes aren't designed to be sofas, but this frame is certainly at the firm end of the spectrum, even for aero. Over rougher roads it's a bit jumpy and that robs you of your form and your power, and consequently your speed.

Climbing is a mixed bag too: if you're powering over a short rise then the stiffness in the frame outweighs the weight of the bike and it's quite a nice bike to punch over a small hill. Standing up isolates you from the road feel too. If it's a longer climb and you're sitting and spinning then you can feel the weight of the bike, and on steeper, rougher bits the Leopard Pro feels a bit skittish and can lack for grip at the rear; Vittoria Rubino Pro tyres aren't the best in that regard and the very stiff frame doesn't help.

Braking

TRP's TTV brake callipers are about as good a set of direct-pull aero brakes as you're going to find, but they're compromised at both ends by the carbon rims and the supplied brake pads, which were grabby and prone to squealing. At the rear the slightly tortuous cable routing to the low-mount brake made the bite feel a bit vague – this isn't a problem limited to the Leopard Pro, by any means – and I had some issues with the brake bite pulsing at one point in the wheel revolution, suggesting that the tolerance on the rim thickness was a little bit out.

In the wet the performance didn't degrade that much, to be fair, but that's from a starting point of being fairly average. It's the sort of brake performance that has you reaching for the drops on technical descents not for aero advantage but because you're not that confident of stopping yourself from the hoods. You'll stop, but you find yourself thinking ahead rather than living in the moment.

The wheels themselves are decent enough 50mm carbon rims on SpeedX-branded hubs. They're not especially heavy at about 1,750g a set, and for a reasonably deep wheelset they're fairly well behaved in the wind, though not as predictable as my current bechmark wheel in that regard, the Swiss Side Hadron 485. The aforementioned issues with brake pulse is an issue, though, and they're a narrow rim design that looks a few years old. Overall I'd prefer for the bike to be offered with a standard wheelset too, so that you can spec your own wheels.

Post truth

The biggest single issue I had with the bike was with the seatpost and the seatpost clamp. I'm a big rider (1.89m, 93kg) and there was no amount of torque I could put into the clamp that would make the seatpost stay put over a long ride. The tolerances between the seatpost and the frame aren't very tight. There are gaps all around, so the seatpost is only in contact with the clamp and the rear face of the seat tube; the contact patches are fairly small. The clamp is a wedge design, which pushes the seatpost against the frame, rather than a pinch clamp that pulls the frame onto the post. That means that you just don't have enough contact between the two parts, even with levels of torque on the single 4mm bolt that I'd never have attempted if it had been my bike, that I'd paid money for. SpeedX supplies grip compound with the bike and I applied plenty, but to no avail – the seatpost kept on slipping. In the course of a three-hour ride I'd have to readjust it about once an hour.

This is a deal-breaker, really, if you're a bigger rider. There's not really anything you can do to remedy the seatpost slippage; it's a design issue and hopefully it'll be addressed in later versions of the bike. If you're a smaller and lighter rider than me (you probably are) then it'll be increasingly less of an issue until it isn't one at all; if you're a 70kg rider I doubt you'd have any problems.

If you're smaller and you set your saddle lower than I do, you may find you have other issues with the charging port for the battery being inside the frame, meaning you'll need to remove the seatpost (or at least hike it up) to charge the computer when it runs down. The port is in a position where a pretty standard bike setup would result in the port being obscured.

This bike is badged up as an XXL, so you might expect it to be 580-590mm long in the top tube, but it's actually only 570mm, and this is the biggest bike that SpeedX has made thus far, although a 590mm size is in the offing. Its frame sizing chart suggests the XXL bike is good for riders with an inseam up to 88cm. If you're any lankier than me, you're going to find the Leopard Pro too small until the 590mm (XXXL, presumably) bike surfaces.

> Read our guide to the fastest aero road bikes

At the moment the SpeedX computer and app aren't as good as the alternatives, and the bike they're physically mated too has plenty of issues of its own. If you want an aero bike and you're serious about your data then for now my suggestion would be to look at a well-reviewed bike and a Garmin computer with a heart rate bundle.

All bikes have their foibles but there's a big list of them – Giant Propel, Canyon Aeroad, Rose Xeon CW, Specialized Venge to name four – that are better than the Leopard Pro. And Garmins have their issues too, but they're still the computer to beat and SpeedX hasn't even got close to beating them on this first incarnation. The Leopard Pro might yet come of age, but for now, look elsewhere.

Right to reply

We made SpeedX aware of some of the issues we had with the bike during testing, and their response is below:

At SpeedX we are constantly reviewing and evaluating our bikes and we have made a number of improvements to the bike to improve performance and deliver the best product possible for the price. There is a lifetime replacement guarantee on SpeedX carbon fibre frames. We also offer a 7-day no-questions-asked return and a 30-day free exchange policy.

Bike weight: We believe we can reduce the weight of the finished bike; more details will be provided in 2017

SpeedForce App: Software updates mean customers will be able to link to third party sites such as Strava from Q1 of 2017

Seatpost: SpeedX will now provide a seal in all Leopard and Leopard Pro packaging for customers to place at the bottom of the seatpost. The bolt for the seatpost clamp has been upgraded which means it is easier to adjust the seatpost. SpeedX will provide extra bolts together with the bikes

Cadence sensor: SpeedX will provide an additional cadence sensor which will be compatible for all pedals.

Tyres: When choosing the bike online there will soon be options to select a wider tyre

Colour Update: All black frames will now be delivered in a solid matte black finish which gives the bike an even sleeker finish.

As this is our first ever product, SpeedX will continue to take feedback on board to develop and improve our product offering, ensuring that customers receive the best possible service.

Verdict

Heavy and stiff aero bike with subpar performance and integrated electronics that feel like a work in progress