After being off the road for nigh on ten months the Ossa Explorer has finally been returned to Ossa following a refund of the purchase price. Last May, after numerous relatively minor but very inconvenient problems the bike suffered main bearing failure which Ossa, to their credit, repaired quite promptly.
Unfortunately the bike then suffered a catastrophic rear suspension failure at which point I decided I’d had enough. It’s regrettable because I feel the Explorer had great potential but the bike highlighted the problems faced by small, specialist manufacturers trying to bring technically advanced products to market whilst having limited development resources available.
Based on Ossa’s successful TR280i trials bike the Explorer should in theory be a great bike. Unfortunately the conditions a trail bike operates in are very different than a trials bike and bolting on a dual seat, an extra tank and set of lights to a competition trials bike simply isn’t enough to effect a transition from hard core trials iron to a credible all day cross country machine. My experiences with the bike left me feeling Ossa failed to appreciate the wider implications of building a bike which targeted customers outside their core customer base of club trials riders . One which would bring the company into contact with customers with potentially higher expectations of sales and service support…
For a start trail bikes are more likely to cover more miles at higher revs for longer periods . Buzzing along at 6000rpm in top gear on a stretch of dual carriageway is a world away from plonking around a disused quarry using short busts of throttle to climb over a trials section. I’m sure the premature main bearing failure suffered by my bike can be at least partly attributed to sustained high rpm on the road in conjunction with the very meagre 100 to 1 pre mix ratio stipulated by Ossa.
The 280i trials gearbox ratios fitted to the Explorer [ie five ultra close ratios topped off by a very tall sixth] made keeping up with the customer Pamperas on the road sections very hard work . The Ossa never seemed to have the right gear available for the job in hand. When climbing hills on the road it was either falling off the torque curve in top or screaming its nuts off in fifth. Not pleasant. I even tried gearing it up so I didn’t actually have to use sixth but to no avail. It was never happy. When Gas Gas developed the Pampera they had the good sense [and presumably the development budget] to build it with a proper wide ratio set of gears. It makes a huge difference.
The rear suspension failure is a very different and potentially very dangerous ball game. For some reason Ossa equip the 280i/Explorer with plain bushes in the connecting linkages. Why Ossa chose to plough this lonely furrow whilst almost every other manufacturer uses needle rollers in this application is anybody’s guess. It could be down to weight saving, cost or simply limited space but whatever the reason it’s a potentially flawed concept. As far as I could tell the bushes in my dog bone linkages seized causing the dog bones to shear under stress resulting in complete rear suspension collapse. This trashed the expensive silencer and the rear tyre, not to mention dumping me on my backside in the middle of nowhere.
A quick trawl of the web revealed sheared dog bones is a more common fault than Ossa would care to admit. I’ve even seen the dog bones being sold on an Ossa dealer’s website alongside consumables such as bushes and bearings. Now if that isn’t an admission something is fundamentally wrong with Ossa’s suspension design I don’t know what is. The problem is , if the Explorer’s suspension unexpectedly fails on a busy road [by no means an unlikely scenario on a trail bike] the results could be potentially fatal. Given the Explorer is being sold as a dual purpose road/off road bike this could have very serious implications for a small company like Ossa . A larger manufacturer would have done a product recall long before the law suits started piling up.
In summary, I rode the Explorer on seventeen trail rides. It broke down on four of them and suffered numerous minor component failures before snapping its rear suspension. It became completely non-viable to operate as part of a trail riding business. In stark contrast, doing exactly the same work, the trusty Pamperas kept plonking on, day in day out. So what next? Well, having now made some space in the workshop hitherto occupied by a dead Ossa I’ve resurrected my old ’98 MK2 Pampera . I suspect these early Pamperas [which are more trials orientated than the later MK3s on the hire fleet] probably provided the initial inspiration to Ossa’s engineers when they created the Explorer concept. The Pampera is 18 kg heavier than the Explorer but, like the MK3s they’re a tough old bus with an excellent reliability record. I used this bike for long distance trials and it was the machine I used to do all the initial exploration of the AdventureRide routes. It’ll do for me.