2014 Beta Evo 80 Full Size Adventure

Attended the Comanche 2-day trail SE of Amarillo TX last weekend and came away with a new Beta... for my wife. Here is what it looked like where we were:



A big surprise was my wife of 37 years, Claire, expressed interest in a trials bike and was attracted to a full size 2015 Beta 80 Ray Peters was riding around having fun testing Master lines. Tom Bachelor of Motortrialsport had new one for sale, a 2014. Ray let me ride his new looking 2015 and I was positively impressed. I later did some smart phone study and saw comments about how - as far as 80s go - the Beta is tops.

Anyway, it was there, and we bought it. Beta fans please don't cream yourselves :huh!

I later compared Ray's 2015 and the new 2014 side-by-side. The only difference I could find was cosmetics. The 2015 has a nicer looking white frame and different stickers - I think, but the 2014 otherwise is the same hardware.

I liked what I experienced riding Ray's 80. This is not some deeply compromised design just because it is small. in displacement. It's really quite the fine little machine!

One surprise was finding the steering super stable. Rake and trail on this bike result in steering which is way on the stable and lazy side of neutral. That's just right for persons learning. It'll still turns a tight line. There's no tendency toward oversteer and tuck-under in turns. My wife her artificial hip joint will appreciate an un intimidating 21st century trials experience.

Here's what it looks like:













Super compact 6-speed, case reed, hydraulic clutch motor. Good power. Very nice shifting. Zero clutch drag. You can shift into neutral stopped and idling easily. Starts very easily.

It's got that hyper lap-dog sound being a 2-stroke 80, but the modern large-volume exhaust and a decent muffler don't com across as loud-barky ring-ding.

Brakes and wheels are full size AJP. Not the latest in calipers, but they work quite strongly. Hard chrome on the fork stanchions in stead of fancy PVD coatings, but really, none of the hardware on this small bike is chintzy.

I see one of those substantial Paioli shocks to compensate for no linkage, and forks appear Paioli also. The rear brake master cylinder mounts sideways on the frame, which is atypical, but it works well. The footpegs are the older style plated steel type and too small. It looks like any full-size modern peg will fit. I could see some RQ forged aluminum pegs on there.

Tires, or should I say Tyres, are made by Golden Tyre, GT335 Trials Gecko model, front and rear. Likely Chinese, but they look good and the knobs are surprisingly soft.

The only flaw so far is a very obviously over rich main jet in the Dell'Orto PHBG 21 DS that serves as a blubbery rev limiter. Shut the gas off and ride until the float level drops, leaning the mixture out, and the little motor comes alive. I'll get into it and figure out which type of Dell'Orto jets this little 21 uses and what the specs are.

More later.

Do you think this would be enough bike for my wife [novice biker] at 5000 to 9000 foot altitude. She likes her 150 Honda but I am trying to edge her toward a trialer.

You did not give her weight, but I assume she's active.

We were at around 4,000 ft. yesterday and the bike did not feel weak. I know the 80, once that over rich main jet is tossed, and the right jet is fit for whatever altitude, that a full size adult could get around on it even at higher altitudes. These small bikes are geared so low and have such short stroke motors that a rider can really creep up stuff. But no bike can maintain running if the throttle is shut off and the bike stops. The limiting factor won't be the motor and altitude, but rather her skill level.

I just weighed the 80 at 144 pounds with oil and 2/3 tank of fuel. My Raga 300 is 152 with half a tank of fuel and some of yesterday's dirt still on it. They use some steel here and there like for the kick starter, the whole expansion chamber part of the exhaust, and maybe also the swing arm, so it's up in the 140s. The 80 feels more 130 pounds, however, due to the small center section and the low engine inertia.

I am all ears on what you find jetting wise as my daughters 06 Rev 80 needs some re-work and I would love to get it spot on.

FYI I have had my daughters bike over some intermediate obstacles with my 180lbs on it so they will do some rather impressive stuff if you are up to the task.

When it comes to jetting, there is no 'spot on' because of individual bike differences. I just re jetted a TXT300 near Amarillo, putting a 112 main jet in at just under 4,000 feet and it was still a bit rich on top (but not blubbering and fouling plugs as with the 118 stock jet).

I rode the thing a hour yesterday. Had to close the fuel screw down to 1/3 turn out so the pilot jet is too big. Still blubbery in the mid, so maybe dropping the needle might help. The main is a bit rich still too. I was surprised, however, that I could climb my hills with it when approaching at a bazillion rpm.

I plan to break into the carb today to find out what's in there. I don't think the jets are the same as those used in the PHBL 26 carbs common to the bigger bikes.

to clarify, my definition of "spot on" would be remove the blubbering and smooth it out. I am pretty sure I need to lean it out more, but when I cleaned it and adjusted without re-jetting it's better but still not as smooth as I was after.

I rode the bike more and am liking it more. It'd be fun to ride Senior AM on it no-comp.

It is running better as it breaks in, and as more of the fuel I use in the 300 takes over. The little tot seems to like my 50-50 blend of 110 racing fuel and E10.

I would have looked into the jetting today, but the 225 conversion job ate most of the day.

Got into the Dell'Orto PHBG 21 DS carburetor. The body is zinc, another common carburetor material, and thus it is a heavy carb for its size.



The bike is running better with break-in, needle clip change, and only my 50-50 mix of 110 racing fuel and E10. It is still on the rich side, bottom-to-middle, so I have ordered jets from the cool moped shop, https://www.treatland.tv/


Below is what the 2014 stock jetting is and where I intend to go in the first iteration. The jets are not the same as in the common trials application of the PHBL 26. The main jet in the PHBG is the same as the pilot or low-speed jets in a PHBL 26, but the much larger main jet-size orifice will mean fellow trials riders and dealers are not likely to have the type 1486 jet in the larger sizes. Treatland has lots of the jet sizes because the do dinky carbs. I saw no needles or nozzles on their web site. I don't know who might carry them.







The 100 main I will drop to 98. I also have a 91 and 93 and 95 coming for various higher altitudes. I'd start with the 93 to ride NM mountains, from 7,000 to 10,000 feet. No way to know for sure until I get there.

The 38 pilot will become a 35, and if that proves lean, a 37. With the 38, the fuel screw has to be turned almost all the way in (on this bike, anyway), so I know I can go leaner.

The needle clip was in second down of four slots from the factory. I moved it all the way up to the top slot (maximum lean). That helped reduce 4-stroking when backing off on the throttle. I leaner pilot jet might just round it out.

The atomizer-needle jet, is different where it intersects the venture, so different sizes may be hard to find. I'm OK with the stock nozzle and needle clip in the top position as long as the bike runs well.

The jet needle doesn't have many good alternatives, because of the unique B diameter of the W6 as seen below... so I'll live with it too.



When I get the jets I'll put them in and document the results.

Another update on the shifter, flywheel and gearing.

I had to remove the chain to move the shifter up. It was too low from the factory and the screw was too long, so it pinched the carburetor vents against the swing arm pivot tube. That was corrected.



This bike has a really long forged aluminum shifter. It's not a cheapo part.

I pulled the super-thick flywheel cover off and lacquered the virgin flywheel and stator, and found the ignition is made in Slovenia. I measured plenty of room between the cover and flywheel for an additional weight, should I so choose to machine one later. Flywheel inertia isn't obviously too light, but more could be better as the spool-up is pretty quick when on the gas. Reminds me of the power characteristics of my former 1974 Penton 125 MX with Sachs B motor.

Final drive gearing on the dinky 6-speed motor is pretty low, but it feels right. Very low 1st gear and 2nd and 3rd are close by and useable at lower speeds. It'll go about 30 on the loop in 6th gear, which is plenty.



Oh and a slotted stator plate means I can tweak timing easily, if I want to.

This is great, thanks!

Time to go a bit deeper into my daughters bike now.

Lets keep each other abreast of the jetting changes. My parts should be here any time now. The ranch altitude is 1,600 feet, BTW.

Also worth mention is I will be fitting a spark arrestor and leaving it on, so it's ready to go for western riding.

I will also fit a lanyard-style kill button so if wifey crashes, the billion-rpm thing won't happen.

Micah Hertrich was riding an 80 a few years ago as he was passing through the expert class. It was geared much lower, with a giant sized rear sprocket. I bet he weighed about 105 at the time. It went well through the sections. He is now on a 125 Gasser.

Yes, we are at about 2700 feet here so will keep track of my changes.

FYI. Ben sick all weekend and have to work next weekend so will be a few before I can dig all the way in.

You better get adjusting ! - Elberta is on the 28th. I am taking Friday off to play at the trials site if you want to come down and early and play. Mark

Stock rear is a 60 (1/2" pitch 428 chain). That's pretty giant. Was his more giant?

First gear is very low. It'll pull my 180 pounds around at absolute creeping speed no problem.

Be good to know what your stock jetting is. If the same as mine I bet it's rich at 1,100 feet over my altitude. We rode again yesterday. The needle all the way down got rid of the irritating 4 stroking when backing off on a barely-opened throttle, but it means we don't have any adjustment left on the needle to go to high altitude. That may not be a problem, as the reduced mass flow at high altitudes means a somewhat rich pilot is often fine, and the mid transition may also be fine with needle full down. That will leave the high altitude adjustments to a leaner main jet, raising idle, and tweaking via fuel screw, as is typical.

The next thing I will get into is gearbox oil. This little clutch is really fast-hitting and when the motor is hot, it will squawk the clutch on engagement during a high rpm clutch dump. From my past experience with oil viscosity, this typically means the oil viscosity is too low when the motor is warmed up.

I recall working with the clutch on my TY350 in the mid `80s. That was in Texas summer heat. I found then that clutch plates worn slick and thinner oils would cause the clutch to bark when slipping on faster loop riding. I don't suspect slick plates with the Beta, as it is new, but I think thinner oils are not ideal in these bikes.

I just asked Tom Bachelor, who sold me this bike, what oil is in there. He said the bike ships with a bottle of Motul Transmission Oil 10W30. The actual 40 degrees C viscosity is not provided (as is typical), so it could be anything inside of a wide range.

I've been putting hours on the bike for breaking before changing the tranny oil. I have in stock at the ranch Rotella 15W40 oil I use in my diesels and gas vehicles. That is a thicker non-synthetic oil. It'd be way too thick for a GasGas clutch, making that clutch drag too much and engage too slowly, but it might work well in the dinky, no-drag, and fast-engaging Beta 80 clutch.

I observed the amount of clutch throw relative to level throw by looking inside the open oil fill hole. The AJP 1405490 master cylinder may be larger in diameter than would be ideal (I don't know if it is 9, 10, or 11mm). Or, the slave cylinder diameter is smaller than ideal. The amount of clutch plate separation relative to lever throw is quite high, making the clutch disengage fast, release fully early, and also slams shut fast unless you are careful. The issue isn't as bad as, say, a 2005 4RT, but it is not optimal, so I'll work on improvement.

Interesting that you bring up the clutch, I was seeing the same with my daughters bike and went to a thicker oil (maybe 5%) over what was in the bike when I got it and it got better, however it will still bark when fully warm and I dump the clutch in 2nd/3rd.

Guess I need to go another 5 to 10% and see.

Working on that...