August 5, 2010
We test five inches of trail bike bounce from American company Chumba Racing
Price: £1,599 frame only, including Fox RP23 shock
From: Progressive Bikes
Time Tested: Two months
Chumba is a bike company that has been around a long time on the other side of the Atlantic. Based in California, they’ve been producing a wide range of bikes from hardtails to full on DH race rigs for over 15 years. On this side of the pond they’re relatively new. But that’s set to change, with UK distributor Progressive Bikes bringing in a full range of Chumba bikes. We’ve had the “All Mountain and Trail” orientated VF2 for a couple of months now and we’ve had chance to test it both in the Alps as well as back home on more classically British riding.
The VF2 is aimed as an all-round trail bike. Five inches (127mm) of travel at the rear and the option to run anywhere from five to six inch forks up front. Using a swoopy hydroformed aluminium (aluminum?) front triangle and a carbon fibre rear end. The bike uses a Horst style four bar linkage, the shock being driven by a machined swing link. The bike oozes attention to detail, with the asymmetrical chainstays, full “Enduro” cartridge bearing pivots and anodised bolts throughout. The quality of the construction and paintwork is high, with a number of colours available including anodized finishes. The Chumba logo headbadge is a particularly nice touch. The VF2 uses standard 135mm wide quick release dropouts at the rear. And in a world of oversize headtubes it sticks with a if-it-ain’t-broke-don’t-fix it 1 1/8th headtube and press fit headset.
Progressive Bikes offer the VF2 frame with a Fox RP23 shock as standard for £1,599 or at the moment there’s a rather good value option to upgrade to a Cane Creek Double Barrel coil shock for a mere £150 extra.
The spec of our demo bike was a mix of high end trail riding kit. 140mm travel Fox FIT 32 Vanilla forks with 15QR axle up front. Hope brakes and hubs on Stans rims. Nice and wide Sunline V-One bars. Crank Bros Joplin uppy downy post. Shimano XT drivetrain. Tyres were Maxxis Ardent 2.35″ single ply which were running tubeless with Stan’s sealant.
Of course, as a frame only option the spec of the bike is entirely up to the customer, although rolling chassis options are available with 140mm Float forks, Thomson post and stem, Hope hubs built on rims of your choice and Chumba branded grips and saddle.
Our test frame was billed as a medium and Chumba say this will fit riders from around 5’8 to 6’0. The seattube measured in at 19″ with the toptube being 22 inches top tube centre to centre. Seat tube angle was 73º and the wheelbase was a somewhat short 43″, with BB height at 14″, around a one inch above the axle line. The headangle is on the steeper side for a bike pitched at the rough and tumble side of cross country riding at 68º, but this a trait shared with a lot of the long legged American (and usually California designed) trail bikes, possibly because trails over there tend to be of a fast, sweeping, curvy, brakes-off, not too steep and not too twisty variety.
For the Chumba’s alpine adventure in the bikeparks of Chatel (during the Pass’portes Du Soleil) we had the Cane Creek shock fitted and it’s certainly an impressive bit of kit. This combined with the active rear end meant the VF2 ate up bumps and with plenty of low speed compression added in there wasn’t too much bobbing and bouncing when climbing uphill. The back end never felt too far out of its depth on rough, high speed trails or in the braking bumps. The penalty for this increased performance is in the weight of the shock – comparing the weight of the Double Barrel and an RP23 off the bike is quite a surprise. So once back in the UK we fitted the RP23 to see how the bike performed on the kind of trails most riders would use a 5″ bike for.
On the specific type of fast and sweeping trail it’s designed to work on it makes a lot of sense. The 5 inches of travel will be used due to the speed you’ll hit bumps, landings and corners. It’s certainly not “over-traveled” in that sense. It offers a firm, pingy and “pumpy” handling feel. The rear suspension was excellent; predictable, capable and useable. Not “invisible” and dull, it was just the right side of active and “I’ve bought a suspension bike” fun. There was a bit of lateral twang to be had occasionally but not to a deleterious degree, but that said we’re not sure if most of that wasn’t down to the wheels and/or the thin-walled (inner tube-less) tyres.
However, in the UK we seem to have trails that vary between “straight line sat-down slogs” and “twisty stuff”. At 28.9lbs, the bike in this build isn’t too heavy for XC but the body position doesn’t quite feel right on those sat-down trails, the smaller riders finding the bike was too high and taller riders feeling it was too short, with the oddly slack-feeling-but-not-actually-that-slack seat angle and high front end making it somewhat difficult to keep in a straight line on steep uphills.
On twistier and/or more technical stuff, again it felt a bit too short for the taller riders and too tall for the shorter riders. It was hard to place body weight properly or indeed move around the bike very much. The short wheelbase seemed to work against it and that combined with a high-ish BB and steep-ish head angle led to a riding position that felt more perched on the bike than in it.
This was a bit of a frustrating bike because everything apart from the geometry we actually really liked and enjoyed. The build quality, suspension action and chassis “feel” was first class and if you’re a fan of bikes such as the Yeti 575 and “All Mountain-y” Santa Cruz bikes, then you’ll feel more at home with the geometry and sizing. For the high speed swooping and brakes-off trails the bike was designed for it does excel and it’ll probably suit a lot of people’s predominantly trail centre riding to a T.
For our part, we’d really prefer this bike if the BB was a touch lower and it had a degree or so taken off the head angle and a longer top tube to give a bit more space for the rider to be able to really move around on the bike and exploit that excellent suspension to it’s full potential.
Overall: Great suspension action. Well made. Lovely chassis “feel”. Just doesn’t quite have the geometry to suit our tastes.
UPDATE: Si from Progressive tells us there will soon be a new link from Chumba that will slacken the headangle to 67° and lower the BB slightly…
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