dan williams

I've seen several opinions on here by knowledgeable people about what the proper relationship of the taper of the flywheel vs. crankshaft is. Since I don

The lapping thing is a bit over rated. It means polishing the flywheel and shaft to a perfect fit. Many theories on what the perfect fit is. Usually the problem is the flywheel nut wasn't tightened properly. Forget the rear brake,jamming something in the wheel,rope in the cylinder methods. Make yourself a proper holding tool and torque to the right setting with a torque wrench and it'll stay put. http://www.trialscentral.com/forums/topic/27287-flywheel-holding-tool-sheared-woodruff/page__view__findpost__p__214657

The drilling is not necessary. Just set the floats properly and nip a hole in the two vent hoses about halfway up the carb body. That will stop the leak. The leak happens because fuel gets splashed up into the vent tubes and if it is enough to fill the tube it acts like a siphon because the tubes end below the float bowl. If you cut a little hole in the tubes above the level of the float bowl the fuel in the tubes just goes back into the float bowl. Simple solution. Try it before going through all the fooforaw of drilling out the carb body.

The resistors don't have much effect on the initial spark as the gap has giga-Ohms of resistance before the initial pulse breaks down the resistance. In series with a 5k Ohm resistor the effect is negligible. What it does affect is the rise time of the current after the initial spark is made. This is the reason for the resistor. After the spark is started the resistance of the gap essentially goes to 0 and the current from the ignition coil is dumped across the gap. How fast this current level rises determines the amount of radio frequency harmonics generated by the electro-magnetic field emitted by the coil/wire/plug. Same as a lightning bolt on your radio. Unfortunately with all the computers in cars these days that radio noise gets into the electronics and wreaks havok. From a practical ignition standpoint the slower risetime of the current means the spark will last a little longer but will be less hot as it limits the peak current the coil can deliver. As far as damaging the ignition system going resistor/non-resistor it's extremely unlikely to have any significant effect on a trials bike unless it has a poorly shielded computer sitting next to the plug wire. Now having said that most of your ignition systems since the early 90's have microcontrollers in the CDI box so....

The V-Force reeds are made out of carbon fiber so they have less mass which means they will open and close faster. At high engine speeds all reed valves are essentially stuck open as there is constant high velocity airflow through the intake. In this situation the design of the reedcage is the limiting factor as it acts as an obstruction to the airflow. At mid engine speeds the reeds really don't serve much purpose. They will actually pulse without fully closing and this is where the spring tension of the reed comes into play as there is some spring to help them close but too much leaves them partially obstructing the airflow. Reed valves are really all about performance at low RPM. A piston port engine is stuck with fixed port timing. The transfer and intake ports have to be open for an extended part of the crank rotation to not starve the engine for air at high RPM but at low RPM mixture will escape back out the inlet tract. The dreaded "Four Stroking". The reed valve is intended to cure this by replacing the intake port with a pressure sensitive valve that closes when there is back pressure in the intake of the engine which at low RPM happens every stroke. As with any piece of material flapping back and forth its mass is going to determine how much force is required to change its direction. Since the carbon fiber is extremely light weight it will respond to smaller changes in air pressure faster than a comparable fiberglass or steel reed. OK end of diatribe. In short lighter weight reeds react faster so the bike will have more torque at low RPM. This translates to grunt like an old fashioned trials engine while still maintaining the shoulder ripping burst of a handful of throttle on a new bike. Boyesen multistage reeds accomplish the same thing in fiberglass by having a smaller light weight reed along with a larger heavier reed for big throttle moments. Great for MX but not really enough room or need for that much complexity in a trials engine. If you put in a set of V-Force you won't immediately go WOW what a difference. But the first time you blow a shift before a tricky uphill and crawl up it in third and the bike just keeps chugging you'll appreciate them no end.

Good example of a badly written rule. If it's like here in New England the original rule was written to be clear and some eager beaver decided it was too complex and reworded it changing the meaning.

Proper heat range of plug and jetting will accomplish that. Iridium is extremely hard so it doesn't erode from the spark the way a conventional electrode will. They were developed for automotive applications where plugs are now expected to last for 100,000 miles. No real benefit for a trials bike short of the pointy electrode slightly reducing the tendancy to foul. A platinum plug has the same advantage for a lot less money.

NETA schedule/form/rulebook for 2011 now posted to the newenglandtrials.org website. Not sure I like the way the sub forum header abbreviates this.

Battery tech is advancing rapidly. Much of what is in research today won't hit mainstream production for 5 years but there is plenty of money behind it and we will all benefit. As for the power characteristics of an electric just program a memory chip for anything you want. Want it to feel like a two stroke, four stroke, tubine? No problem. You can still have a clutch lever. Pull it and it will just decrease the drive current to the motor. The advantage of the electric motor is the torque output is decoupled from the speed of the engine. Want full acceleration from zero RPM? No problem just use the clutch lever as an on/off switch. No gears to change. Traction control? Again easy to acheive. Swapping out batteries every loop shouldn't be difficult when the price comes down from mass production. I'm looking forward to the electric bike. It will change everything and it will change nothing. The best riders will still be the best and us duffers will still have fun. And yes, the ECO nazis will still find a way to close down access. It's never been about the environment. It's about control.

V-force reeds are the first mod I do for a new Beta but they don't really "perk it up". They do make it pull much better in the lower RPM like when I'm in the wrong gear because of mid-section brain fart.

Time to pull the sidecover off. Sounds like you may have a gear with hockey teeth. i.e. missing. Only way to know for sure is to have a look.

You'll spend more time worrying about it then it will take to just drop the skidplate. Big 'ol channel locks work for me to get it all back together.

I found dropping the countershaft 1 tooth helped on my '08. From a post in 2004 by someone named Viking. This should probably be a sticky too. Tightening torque Rev3: Shock absorber-Swingarm 45Nm Shock absorber-Frame 45Nm Connecting frame rod-frame 23 Nm Cylinder-Crankcase 20-23 Nm Primary drive gear 120 Nm Handlebar 25 Nm Engine-frame 50 Nm Swingarm bolt 90 Nm Front wheel axle 65 Nm Rear wheel axle 65 Nm Steering stern bracket 25 Nm Rear fender bracket 10-15 Nm Front brake pad 20-23 Nm Rear brake pad 20-23 Nm Engine Head-Cylinder nuts 15-16 Nm Front axle fixing nuts 10 Nm Flywheel 140 Nm 1 Nm=0,1 kgm

Preston Petty where art thou? Hey at this rate Duggan you could have bought two carbon fiber fenders. They still can snap but you would have been stylin' Oh yeah I noticed on my '08 one of the fender screws had pulled clean through but the fender is not even cracked.

The external bolt on parts are nice goodies but in the "factory" bikes my experiance has been the difference is attention to detail. Only Honda can afford to do wacky one-off things like titanium transmission shafts or custom frames. The simple truth is there isn't enough money in trials to be worth building million dollar machines. What I've seen is more like custom ignition curves, higher compression heads, smoothed/blue printed ports, perfect jetting, properly torqued bolts and basically anything that happens when somebody's full time job is to work on the bike. The reality is you can get within spitting distance of the factory bike for a thousand worth of trick parts and careful tuning. Then again an extra 5 hours of practice a week would probably do more for your riding then all the titanium you can afford.

Hmmm like years of crappy clutch plates? It's important that Beta get lot's of feedback that this is unacceptable so they can take it back to their supplier. Maybe this is the start of the Chinese parts invasion. Maybe not. You'd hope Beta learned the lesson from snapped frames on the 2009 Evo that there are places you can save money and places that you had better get right or profit goes to zero. Right now fenders look to the factory to be a revenue generator. They need to hear right now that this will hurt them in the long run and they better get it sorted "muy pronto" or it's going to cost them bike sales. All you guys who've snapped fenders should contact them through their website info@betamotor.com.

Understood. I've taken to shooting mostly RAW to get more dynamic range. Then again I built a beast of a system to do the conversion and get the most out of the highly threaded Bibble software. It does help recover usable stuff when I completely Melvin a shoot with the wrong settings. Not that that happens, er alot.

Yup bend the tang the needle valve attaches to to set the float level. Bend the little tab that points up at a right angle along the pylon that holds the float pivot to set the float travel. Don't be afraid, it's not as scary as it sounds. It'll be pretty obvious once you pull the float bowl off.

You guys have to realize it's not as simple as throwing your bike in a transit and showing up at the event. There's much more involved and it takes money. Money that wasn't there from the sponsor and money that Ossa can't afford to spend just yet. A factory has to answer to the sponsors or there is no team. Riding Sheffield without the sponsor could have blown a deal that I would guess took months to negotiate. I'm sure they were more frustrated then any spectator or organizer could be but it's a business first and a sport second or they won't be a business very long.

Yeah the Billy T article opened my eyes. Nippering a small hole in each of the vent tubes halfway up the carb body stopped the fuel leak siphon problem on all the bikes I've done it to (~10). Works like a charm, costs $0. The extreme angle the Beta carb sits at helps it run strong on steep ups but requires the float level be correct or slightly low or it will stall on downhills. I've found this to be true on the Mikuni and the Keihin.

You gotta love Fuji, he's a one man highlight reel. Andy are you shooting raw or doing JPGs out of the camera?

Maybe Jeroni should borrow Billy T's kilt.

I hope they'll be posted soon.

Heh heh, you're forgetting the factory makes more money selling the riding gear then the bike. From that perspective the excuse makes sense.

Yeah that's just the way experts like them. Trials brakes don't "chase themselves" into engagement so they're unlikely to be malfunctioning just that you haven't got the feel for them. You can try letting the lever adjustment out further so they engage nearer to the bar or moving the perch closer to the end of the bar to reduce your finger's leverage. You could try filing grooves in the pads to reduce the surface area of the pad. My guess is you're just not used to them. Remember more then one finger on the brake is too many. If you're throwing two or a handful at the front brake like it's an old drum brake Bultaco any modern bike will put you on your head.