You may not have come across any Slovenian bikes before, but there are a few out there. Probably the best known is Elan, but here we’re looking at an XC race frame from carbon fibre specialists IR Comp. The 3.1 is the middle of a range of three MTB frames. The sub-1kg Race frame has been used to good effect by racers Blaza Klemencic of Slovenia and Austrian National Champion Monica Schachl. Obviously both of those are petite Elite women racers, so the Race may not be of universal appeal – it’s not recommended for riders over 80kg (12.5 stone). Hence the 3.1, which is built to the same design but with more material to come in at 1.3kg and a maximum rider weight of 120kg. Or there’s the Heavy Duty – 1.5kg, max rider weight 150kg. IR Comp also makes road and city bike frames.
Frame
Most mass-market carbon fibre frames are made in one of a fairly small number of factories in far-off exotic locations. IR Comp, though, builds its frames by hand, in house in Slovenia. They’re also full monococques – some carbon frames are made like metal bikes, from a selection of tubes joined together, but IR Comp lays up the whole frame in one piece in a big mould. That means less material (and hence less weight) and fewer potential weak spots. CF is a very flexible material to work with, in the sense that it makes it relatively easy to beef up the parts of a frame that need beefing up and have no more material than strictly necessary in the other areas.
IR Comp appears to have put that ability to good use – the head tube and bottom bracket areas are distinctly chunky. Both have aluminium inserts, while machined aluminium dropouts (with a replaceable hanger) are incorporated at the lay-up stage. The rest of the frame is distinctive in appearance, with a concave-sided rectangular section at the front of the top tube blending in to a large, hollow section at the head tube.
There’s no sleeve at the seat tube – don’t do up the seat collar without a post in there, you might crack it. You get two pairs of bottle bosses inside the main triangle, and all the cable stops and hose guides are bonded and riveted in place. Cable routing is traditional under-the-BB, with a short length of extra housing to route the front mech cable through the chunky BB shell.
The back end is made in a wishbone style, with slightly rectangular stays. Mud room is adequate rather than startling, although you’re unlikely to want to run tyres bigger than 2.0 in a frame like this anyway. The smooth lines don’t offer many places for mud to get lodged, either.
IR Comp has made a couple of changes to the frame since we received this one. The dropouts are now carbon fibre, which we think might be a first for an MTB frame, although we’re not totally convinced that it’s a good idea having seen the effect that a decent QR skewer has on a metal dropout. IR Comp has also abandoned the 34.9mm seatpost dimension and returned to using the more accessible 31.6mm size – we ended up using a 31.6mm seatpost in a 34.9mm shim in the test frame. Only two frame sizes – 16.5 and 18.5 – are available, so if you’re very short or tall you’re out of luck. The 3.1 frame is DIN Plus certified and comes with a five-year warranty.
Components
The 3.1 is available as a frame only, so what you attach to it is up to you. We couldn’t bear to take such a light frame and bolt any more than the barest minimum of parts to it, hence the slightly uncompromising rigid singlespeed configuration you see here. We used a Pace RC31 fork, USE Sumo post, Specialized Avatar saddle, Hope hubs, Mavic 717 Disc rims, Intense 2.0in System tyres, Ritchey bar and stem and finished it off with some Race Face Turbine cranks and a set of old Hope XC4 discs that we had kicking around. They’re not the greatest brakes that the world’s ever seen, but then they don’t have much work to do – the full bike came in at 20lb. To give you an idea of what’s possible, IR Comp has built up one of its Race frames with its own rigid fork and a full complement of gears at under 19lb…
Ride
We’ll admit that we approached the IR Comp with a degree of trepidation. Back in the height of the early 90s lightweight craze we were riding around on sub-23lb bikes and, frankly, scaring ourselves silly as they flexed about, sprang off in unpredictable directions and generally behaved in a distractingly flimsy manner. And then broke.
Then there’s the whole carbon fibre thing. We have little time for those who like to ascribe certain ride characteristics to all bikes made out of a certain material – how a bike rides has more to do with how the material’s been used than what it is – but it’s certainly true that plenty of carbon bikes have exhibited either uncompromising stiffness or a kind of non-springy floppiness that doesn’t really encourage hard efforts.
To say that we were pleasantly surprised would be an understatement, though. The IR Comp is really very, very good. Obviously the fact that it weighs next to nothing helps a lot, but it takes what you put in and does something useful with it – tt feels fast as soon as you start pedalling, and really does make you want to pedal faster. There’s no sensation of deadness or of your efforts somehow vanishing somewhere.
It feels springy, but not flexy, although if you’re a heavy rider you might find it a bit too twangy (although it’s claimed to be strong enough for riders up to 120kg, which is over 18 stone). For an XC race bike it’s remarkably comfortable. I did the first half of a 12 hour race on a bumpy course on it, and only changed bikes because my arms were packing up on account of the rigid fork. There were certainly no problems in the bum department.
It’s also something of a precision implement in the handling department. The angles are listed as 71.5° head and 73.5° seat, which is on the steep side. With the rigid fork, though, both of those got a bit steeper and the 3.1 exhibited some serious agility. It didn’t get too hyperactive, though, although having no suspension helps to stop you getting in too far over your head. All in all, it’s everything that a race bike should be – light, fast and agile.
Positives: Distinctive appearance, fast, very light, lovely springy ride, fast, rarity value, fast, relatively inexpensive, five year guarantee, fast
Negatives: Tricky to get hold of, still quite a lot of money, a bit odd looking
Verdict
Probably the biggest drawback to an IR Comp frame is actually getting hold of one. There’s no UK distributor and frame production tends to be a bit stop/start – at the time of writing IR Comp was concentrating its resources on making wheels for ocean racing yachts. But if you want something lightweight, inspiring to ride and a bit different, it may well be worth persevering. The asking price is quite high for a frame, but compared to high-end carbon frames it’s more than reasonable – considerably cheaper than a Scott Scale, Specialized S-Works Stumpjumper Carbon or Trek 9.9 Elite, although a chunk more than a Giant XtC Composite.
Performance: 5/5
Value: 4/5
Overall: 4/5
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