nuts

I was talking to a fellow who has a 96 Scorpa. He's been trying to bleed the clutch but tells me there is no bleed screw on the slave cylinder and he can't figure out how he's supposed to bleed the air out of this thing. I told him I was clueless (as if he didn't know), but I'd pass the question on to the Scorpa gods in cyberspace. Anyone had any experience with this?

When trials bikes go bad… Just in case you think this story is an isolated event, something similar happened to me some time ago. I had a brand new Scorpa sitting in the shop and my son took it out and was playing on it. One of his friends stopped by and my son let his friend ride it. His friend had very limited experience on motorcycles of any kind and I still question why my son offered the brand new bike and not the used one that had been sitting right beside it. However, this young man was very careful with the bike. No wheelies, no holeshots, no wheelies, no wheelies (why is it everyone investigating trials bikes has to try to wheelie the thing down the road?). In fact, I don’t think he even got it out of first gear. All was well until he was ready to quit. As he pulled up next to the cars he managed to crack the throttle open. I don’t know exactly what happened (I wasn’t there – this story was briefed to me by my wife, who witnessed the event), but I suspect he went to pull the front brake and opened the throttle at the same time. Being on pavement, the bike plowed forward, leaving the rider slightly behind but still holding on. This motion tends to increase the throttle opening, which it did in this case. The errant Scorpa wheelied into the rider’s own Chevy Blazer, bounced up and down a couple times on the back wheel, ripped the passenger mirror off the car, then parted company with the rider. Once he released the bike it calmed down and prostrated itself on the ground. The bike fared better than the Blazer and the rider, who managed to scrape himself up pretty good. It had a nice scratch on the rear fender and a very mangled footpeg – otherwise, no harm. Just another example of how a mild-mannered trials bike can surprise the unsuspecting victim. Here’s something else. In addition to trying to ride wheelies, why do folks on a trials bike for the first time tend to wick the throttle open when they grab the front brake? I’ve seen this happen several times. A case in point: These dudes stop by to check out a Rev-3 I had for sale. I get the same old story – they’ve been riding desert/MX/whatever for X number of years and they’re ready to slow down and take it easy (because we all know trials is slow and easy). Anyway, the first guy gets on and takes off. He’s got the thing wound tight in first gear, screaming down the road. Right then I’m wondering if this joker has ever actually been on a bike of any kind. He manages to locate the shifter at some point and clicks it up into second. Finding a handful of throttle he starts impressing me with his prowess in the art of second gear wheelies. A couple of passes up and down the road pulling 2-3 meter wheelies must have been sufficient to prove his reign as the wheelie king because he decided to come in for a landing at this point. He comes tooling up, standing impressively on the pegs, and slips it down into first gear. Then the master of disaster plants a foot and simultaneously grabs a handful of front brake and throttle. The front wheel stayed on the ground this time, and the front brake performed its function in spectacular fashion as the wheel skidded across the pavement and the expert motorbike rider did a one-foot hop trying to keep up with the Beta-from-hell. I stood there gaping as he squeezed harder on the brake and rolled the throttle on. To his credit, Mr. Motocross may have been able to shut ‘er down if he hadn’t skidded clear across the pavement and into the gravel. At this point the front wheel became a loose example of Newtonian Physics in that it was not experiencing any force to change its motion and therefore the bike became somewhat of a 2-stroke ballistic missile, in spite of the fact that is was only traveling a few meters an hour. Unfortunately this unguided missile was making a rather accurate trajectory for my daughter’s Nissan Pathfinder. I had a mental picture of the chrome on my forks mingling with the chrome on her bumper. Just about the time I would have soiled my knickers, and slightly after he’d already soiled his, Crash McDuck managed to shut the ol’ Beta down a meter or so shy of the Nissan. Needless to say, the rest of his crew were not allowed near the bike while the engine was running. Just one example of something I’ve seen quite frequently. Wonder why that is.

There are a couple of good posts here. One suggested using No-Toil filter kits. I've used this stuff and it's fantasmic. You use the No-Toil filter oil, and clean it in your sink with a scoop of the No-Toil cleaner. Your filter will look like new - it's amazing. My son sez the cleaner works on "regular" filter oil too, but I've not tried this. Someone mentioned PJ-1 Filter Cleaner. I've used this too. It's the best for cleaning filters that you've used filter oils other than No-Toil. Spray it on, let it soak for a minute or so, then hose it off. The reason you add oil to your filter is to trap the fine particles that can pass through the cells in the foam. You can put too much oil on the filter though, so be careful. You can seriously reduce your airflow and your bike will run like crap and you'll think it's a piece of crap and you'll have such a crappy time riding you'll think trials is crap and you'll trade in your crappy bike for a set of cheap crappy golf clubs. If there's a puddle of filter oil in your air box after you've cleaned & oiled your filter and let it sit overnight, you're using waaaaay too much erl.

Bikespace: Thanks for the laugh. The mental picture I got of a guy blasting through a quarry electrocuting himself while trying to yank the spark plug cap off his screaming bike almost caused me to snort Mt Dew through my nose. Awesome! FYI, if you ever encounter another situation where your throttle is stuck WFO, an effective way to shut ‘er down is to plug the exhaust. I know this from personal experience too. It’s amazing how fast this will shut your bike down. If you don’t believe me, give it a try. Have a buddy hold the throttle open on his bike while you plug his exhaust with a rag. Unless you have no feeling whatsoever, it’s impossible to do this with your bare hand. Personal experience told me this as well. Remember that Gestapo dude that grabbed that red-hot medallion in one of those Indiana Jones movies? Yeah, well. Fortunately reflex action took over for my rather slow noggin or I’d have a nice impression of the tail end of a Beta muffler branded into my hand. The gasses coming out of a screaming bike are HOT. Again, if you don’t believe me, have your buddy rev up his bike…

I was going to put this under the “if you were the engineer” heading, but my last response there was getting a bit lengthy already and I want to get myself into the rank of “advanced member” as quickly as possible so I can enjoy all the rights, honor, and privileges duly awarded members of that rank. Therefore I decided to start a new thread. There’s been a little banter about a programmable ignition. This is a cool thing, but is probably something only practical for very highly skilled riders. I can see myself trying to re-map the advance curve only to thoroughly honk up the performance of my bike. I suppose the manufacturer could provide 3 or 4 selectable pre-programmed maps which might give the choice a “soft” power up through a harder hitting advance. Kinda cool for those of us who take the time to play with anything that’s adjustable on the bike. But I’ll bet the majority of the riders would do like they do with the adjustable suspension – ride with whatever settings come out of the box. I think it would wind up being more of a sales gimmick. There was also mention of being able to switch the advance curve instantly (via a switch on the handlebar or something) depending on whether the terrain is slick, muddy, sandy, hard, rock, etc. I don’t know about anyone else, but once I get my bike set up to where the suspension matches my leg speed and riding style (it’s a timing thing), and I get used to the engine response, I DON’T want it to change depending on the terrain conditions. Rather than soften the power delivery by changing the advance curve in slick conditions, for instance, I think it’s better to modify my clutch and throttle technique to adapt to the situation. Maybe even use a higher gear. I want my bike to be the SAME every time I get on it. I want to know that if I do “this” the bike will respond by doing “that” every time. Man, it drives me crazy when there’s a change in atmospheric conditions and my carburetion doesn’t feel right. If it ain’t running right I can’t concentrate on my riding, as if I EVER do, but if I did I’d have to get that carb straightened out before I could. Anyway, my point is that all those adjustments for suspension, carburetion, ignition, etc., are there to adapt the bike to the rider, not to adapt the bike to the riding conditions. No?

There’s been some interesting ideas here. Some costly, some impractical, some quite good. Microprocessor controlled fuel injection is a beaut. Man, the thought of not having to dink around with jetting, float levels, etc. just makes my Spidey senses tingle. We may be on the brink of this concept becoming reality in the next few years. Cool. What about an electric motor? Not very practical with current affordable technology - it would need a lightweight power supply and the motor itself would have to be light as well - but as a dream... Dude, we could ride right past the enviro-nuts and they’d never know we were there. Couldn’t hear us, couldn’t smell us (other than B.O.!). Here’s something that’s a little more practical and, frankly, I don’t know why it hasn’t been adopted yet. How about moving the airbox up where the fuel tank is, then moving the fuel tank where the airbox used to be? Wouldn’t be much loss in fuel capacity, the stinkin’ things barely hold 3 liters as it is. Might need a small fuel pump if the carb sits higher than the lowest point on the fuel tank, but that’s no biggie – snowmobiles run a small, lightweight fuel pump that could be adapted. This gets the weight of the fuel much lower which will add stability by lowering the CG of the bike and actually make it feel lighter. It also gets the airbox up higher and makes it less prone to water and dirt contamination, especially the stuff the rear wheel kicks up. Oh, and HERE’s a revolutionary thought – how about providing a freakin’ SERVICE MANUAL with a bike. Yeah, something like Montesa hands out – but then Montesa is a Japanese company, right? You’re welcome to flame me on that, but before you do, know that I really don’t care where a bike is made – if they’re good, they’re good, and current trials machinery is very good. But, crap, since the beginning of time European manufacturers characteristically do not provide a detailed service manual, even to the bike shops. What’s up with that? What’s wrong with providing torque values for cylinder heads or fork pinch bolts? Why can’t they provide tech data on the ignition system, or instructions on replacing a bent kickstarter shaft? Ok, my truck doesn’t have a comprehensive service manual, but you can bet the shop I take it to does, and if I want one I can purchase one. See, improvements can be made without exotic materials and electronics!