This one dropped in on us unexpected last week – a first ride on the new Bos air shock. What a treat!

Having spent some time on the brilliantly controlled, super sensitive Stoy shock and Idylle fork the opportunity to try out the new Bos air offering was an opportunity not to be missed for many reasons. One is that UK Bos importer Roger Estrada had one bolted to his Lapierre Zesty – a bike that’s on the top of my trail bike benchmarks right now.

Cosmetically the new shock comes beautifully packaged. A Gucci box and some subtle sticker work – all well and good. The key technical features of the VIP’R is the high pressure range – over 300psi. The VIP’R uses a very large volume to help on end stroke ramp up and still be very progressive. Bos say that this works really well even in long eye-to-eye shock (i.e. 222mm) and due to its large volume this helps the progressivity. Essentially what BOS has done is try to match the Stoy spring shock characteristics into an air can.

Running double air amounts to what we would in a similar Fox shock ITS otherwise business as usual externally with compression and rebound adjusters consistent with other air shocks right now. We were interested in the usable range rather than the amount, something we have found on other Bos products and whether the characteristic control gene that runs through the range continues here. Nothing seems to panic the French shockers, monitoring the terrain and consistency through the range.

Heading out onto the trails it was interesting to compare this out of the box Bos to a custom tuned Monarch built for the Zesty and hard dry conditions similar to what we were riding. Having the benefit of a Deville fork up front is a clear advantage when attempting bike set up and instantly there is familiarity front and rear.

It’s easy to get carried away. Taking a 140mm bike onto a track which is in patches beaten up downhill root territory obviously rides the edge of what the bike is made for – we rode it but used as a comparison the newer red route that’s about to open up in the Forest of Dean.

Working alongside Roger Estrada of R53 engineering highlighted the time needed to get near to comfort. On that blown out root tracks we quickly found a good setting in terms of grip yet experienced that more extreme high speed hit support needed work. An instant call to Toulouse confirmed that the Zesty was similar to a couple of other bikes and an evolution of this shock will follow in the next week or so. In terms of traction on shallower root however the Bos is better than what we have ridden on this particular bike.

The Bos has superb consistency and an ability to manage terrain. We ran rebound quite open – about seventeen clicks – this appears similar with other Bos units we have tried in the past. The most noticeable and positive experience came on the recently made trail in the Dean about to open. Although still pretty fresh, the coarse rock material yet to be weathered still produces a grip challenge in isolated places and it was here that we found small changes in the dials transferred to subtle yet definite grip improvements on the bike very, very quickly. And it’s on that type of terrain that many people will be using the VIP’R.

First impressions? In terms of numbers sold like I said it’s probably here on man made forest trails that riders will most use the new Bos damper although I’m sure there will be keen followers in the 160mm range of enduro bikes in the competitive environment. We found it a very easy item to work with in terms of dials. Trying to quantify its value? Very difficult in the short space of time we had. It’s definitely a different feel, the range is more in the middle rather than at the extremes on many air shocks, particularly rebound, and it’s always miserly in the use of inches. In this respect it offers a balance advantage but you really need to spend time on it to extract the real benefit.

SPECIFICATION
– Air compression adjuster
– Rebound adjuster
– compression adjuster (2 position. soft is normal and hard to help pedalling)
– Shim stack valve piston
– Customized Tune for each bike
– Available in 190, 200, 216, 222mm eye to eye
– bushings (needle bearing is an option)
– weight: 250grs (190×51)
– Price: £479

CONTACT: www.r53engineering.com

Roger Estrada (left) got out riding too, well I guess he was a former top Spanish trials rider! On the right Shinny – SR racing was on hand to help out. Thanks to both.