“Take the right hand line then let go of the brakes” shouts Chris, the press launch photographer for the new BMC Unrestricted platform.
Chris is perched perilously close to a precipitous 200-metre drop high in the Swiss Jura. The right-hand entry he’s referring to is in fact a 90-degree bend onto a narrow piece of singletrack. It’s littered with sharp rocks and is no more than a metre away from the very same precipitous drop. Sweat drips down my brow as I approach.
BMC Unrestricted: Four bikes, four different types of rider
Despite what the rugged trail in front of me might suggest, I am in fact here for the launch of BMC’s latest Unrestricted gravel range. First launched in 2019, Unrestricted, or URS, was the first gravel bike in BMC’s stable. That number increased to two, when BMC launched its Kaius racing bike.
The Kaius is a useful foil to compare the URS. The former is an aggressive, aero bike, with geometry that mirrors BMC’s pedigree road bikes. In comparison, the new Unrestricted is a brute, featuring across four models with capacious tyre clearances, two types of suspension and mountain bike inspired geometry.
“Having the Kaius in the line up gave us more room to play”, says Stefano Gianaioli, gravel product manager at BMC. “There’s no compromise now for aerodynamics or stiffness. We can focus on capability off-road”.
And with that in mind, each model in the new Unrestricted range represents an increase in off-road capability from the one before. Consider the URS model as the base, from which the next models build.
For example, whereas the BMC URS is a rigid bike, the URS 01 offers BMC’s MTT soft tail suspension and an MTT suspension stem. In comparison, the URS 01 LT offers an MTT suspension fork while the URS AMP LT offers electric motor support in the form of a TQ HPR50 drive unit.
According to BMC, it is now a product range that caters to the broadest possible number of riders.
Frame design and geometry, wide tyre clearances, UDH
The development of the new Unrestricted range is a testament to the rapacious development of gravel over the last five years.
In 2019, gravel bikes were mostly cross bikes, with aggressive geometry to match. In similar fashion, the original Unrestricted range borrowed heavily from the brand’s endurance bike, the BMC Roadmachine. In comparison, the new range has been given specific, and very capable, design changes.
BMC began by creating a new geometry named Gravel Fit, consisting of a longer top tube paired with a shorter stem. It’s a design that has long been employed on mountain bikes to maintain fit while increasing the responsiveness of the bike’s handling. Tweaking the slope of the top tube has also allowed BMC to create more stand over clearance.
The head angle has also been slackened to 69.5 degrees, slowing the bike’s handling on steeper terrain and adding stability on fast-paced descents.
A lower bottom bracket (dropped from 69mm to 76mm) aims to give the feeling of sitting into the bike rather than being perched on top. A steeper seat tube angle also positions the rider over the bottom bracket, improving the bikes’ pedalling on steep climbs.
The frame is now capable of accommodating 47mm tyres, has a host of cargo mounting options on the forks and the main frame as well as options to run full fenders, a rack, and even a dynamo light.
Rugged rubber mounting at the bottom bracket, fork ends and chainstays increases protection from rock strikes. Other modernising details include storage in the down tube and Universal Derailleur Hanger (UDH) dropouts.
Front end suspension and suspension stem
The URS 01 and 01 LT both feature additional suspension dynamics at the front end designed to reduce the sting of the trail, and both bikes use BMC’s MicroTravel Technology seatstays.
Previously used on BMC’s soft tail mountain bikes, these use a damper to provide 10mm of travel. The damper’s firmness is dictated by the size of the bike: extra small, small and medium frames all use a soft density damper, while large and extra large frames use a medium density damper. A third, firm damper is available aftermarket.
On the URS 01, the seatstays are paired with an ICS MTT stem. Licensed from RedShift, it provides 20mm of travel and routes the cables internally. It comes as a medium stiffness as standard.
Stepping up one model, to the URS 01 LT, and BMC uses an MTT Suspension fork, designed with Hi-Ride. This offers 20mm of travel via a coil spring and a hydraulic damper and can be locked out using a dial on the top cap.
Sitting below the head tube, this acts to suspend the wheel over rough terrain versus the ICS MTT Stem, which is flexing at the rider's hands. The latter has a much greater impact on the handling of the bike – something I’ll come to in my riding notes below.
A spring kit featuring three springs of varying firmness and a number of wedges to add progression to the fork is available aftermarket. BMC says the complete suspension fork weighs 1250g.
It’s worth noting that all URS frames are compatible with aftermarket gravel suspension forks, allowing for riders to upgrade should they wish.
Amplified
Adding the final level of functionality to the Unrestricted range is the URS AMP LT. It uses a TQ HPR50 motor and battery system that provides up to 300 watts of peak power.
Prices for the BMC URS start at €4499, the URS 01 at €5999, the URS 01 LT at €6499 and the URS AMP LT at €9999.
First ride impressions
To test the four models of the new Unrestricted range, BMC prepared a two day gravel ride with an overnight stopover high in the Jura mountains.
For the first part of our ride, a gently undulating 30km alongside the river Aare with a sprinkling of singletrack, we were aboard the BMC URS. Ascending 1300m in a gondola we swapped to the URS 01, where we traversed a further 30km along a ridge in the mountains. The following day we swapped to the URS 01 LT to descend the same 1300m on a mixture of cross-country tracks, gravel and road to Neuchåtel.
The geometry changes that BMC has made feel great. The increased standover clearance and steeper seat tube angle create a pedalling feeling closer to a mountain bike than a road bike.
The bike handles wonderfully both on steep climbs and descents, where the longer top tube and shorter stem pairing really help to balance the handling.
On the URS 01 and 01 LT, I also found the MTT seatstays to be a neat way of adding compliance to the frame. The comfort added by these foam inserts is noticeable over the rigid frame, but without any negative or obviously noticeable flex at the rear end.
I couldn’t say the same about the ICS MTT stem on the URS 01 model. Here I found the flex too great, especially when riding on the hoods – the area of greatest leverage over the stem.
It is effective on smoother gravel roads, and improved when in the drops, but on more significant off-road sections I found the flex had the disconcerting effect of pitching me forward. I found the suspension fork on the URS 01 LT improved this, adding comfort without negatively affecting the bike’s handling.
