2019 Beta 390 (350-430-500) RR-S - Engineering & Experiences

Discussion in 'Thumpers' started by motobene, Apr 8, 2019.

  1. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    The purpose of this thread is to document a wide array of the technical and experiential aspects of the 2019 (and many years) of Beta off road and street legal off road motorcycles.

    I typically do multiple edits on posts, so when a new addition pops up and looks unfinished, it will get updated usually within a day.

    Some ideas presented will be 'different', arising from many decades of riding and competition with a heavy technical and technique component. I hope whatever dribbles out below will do some good or at least be entertaining :dukegirl

    Why did I choose Beta?
    2019 Beta 430 RR-S Left.JPG

    Why not KTM or Husqvarna or Sherco or GasGas? Certainly they all have great bikes with the latest technology. Lots of followers. Why not one of the very solid Japanese brands? I've much experience with Japanese bikes, particularly Kawasaki, and Yamaha. I have nothing but respect for them. Beta got my business for several reasons.

    There are lots of reasons that can get complicated, but basically I needed a street legal 4 stroke, which knocked out Sherco and GasGas, and I determined after much thought and demo-ing that I wanted 350-400cc displacement. I also wanted to directly experience machines and various displacements, and Beta was the only one to make that easier for me early in the year.

    Thirty-five years of trials competition after motocross, enduro, and cross country racing years was critical. Trials altered my preferences and techniques greatly! Beta, being one of the top trials bikes manufacturers has had some trials influence cross over into their off-road bikes. So I'm a Sherco trials guy and wanted a Sherco. But 300 was a bit small and I learned through demos that I definitely did NOT want a 450. The street legal part could have been forced with Sherco, but they did not offer the size I wanted.

    Beta had a tour of demos going on and I signed up for one in January. I could feel and appreciate some attributes of Beta's trials connection in the demo rides.

    A Beta RR or RR-S is NOT a trials bike by any stretch! If anything, less aggressive power and more total rotational inertia (more flywheel effect), even lower seat height, a r e a l l y w i d e ratio transmission... all would suit me better. The Beta design I found worthy and refined. Great quality, stability, and proven reliability.

    The engine design is top notch. The top end is DOHC, dual overhead cam, and a little larger than KTM/Husqvarna, Honda, and others. The design stresses the valve train less than SOHC or compact Uni-cam designs. The bottom end is robust and very well made. Frame and suspension components, and finally, the plastic are top notch. Beta gets some criticism in wiring and connectors, and while that has some justification, some easy setup steps can reduce potential problems to being a non issue.

    Stability & Reliability
    The basic design has been improved in many details, evolving to better and lighter. It is now into 9th year after the intro of the Beta-designed-and-made engine. Mature means stable and reliable.

    Engine Size
    It is significant that Beta is the only manufacturer left that offers a 400-size bike in the 390, which is a stroked 350. The crank stroke on the 390 is the longest of all the sizes:

    350: 57.4mm
    390: 63.4mm
    430/480/500: 60.8mm

    The 350s were my favorite for single track and technical riding. It just has power everywhere, including right off the bottom. I did the least amount of short shifting with the 350.

    The 390 pulled the head strings, however, offering more torque for more relaxed mid- and high-speed riding than the 350, and is not as insanely powerful or torqy as a 430-500cc bike. The 390 feels a little heavier and less 'flickable' than the 350, but it feels lighter than any bike over 400cc, including the 430.

    But of course so much depends on the loose nut behind the handlebars, you and me. Each size has its fans and justifications.

    Why a street-legal version of an off-road bike? For $11,000 I don't want to be limited to off-road! There is so little difference between an RR and an RR-S. The RR-S just adds some nice-to-haves, like a fan kit and street legal hardware. In a blindfold test it's hard to tell the two models apart. I had several people insist it isn't a big deal to street-legalize an off-road bike. I've spent a lifetime doing stuff like that. If I was going to spend the big bucks, I decided that though I could, I did not want to.

    And why a 4 stroke? Though I prefer 2-stroke trials bikes by a wide margin, I prefer the power characteristics of 4 strokes for everything else. Of particular benefit is not having to use the rear brake much. Long story, but given some right-foot issues, the added engine braking I do not see as a negative. I did a number of test rides on 4 strokes and found I could haul butt and hardly ever touch the rear brake. Then I'd try a 2 stroke and HAD to use the rear brake a lot to not blow through corners.

    Though the BYOB (build your own Beta program) is highly successful and I did investigate and choose a number of expen$ive options, when it came time to order the bike BYOB, delivery was 6 weeks out. I needed a significant setup period before a scheduled ride, so I changed my order to no options and outside of BYOB. That cut off four weeks of wait time.

    I picked my 390 up April 5, 2019. Very pleased! The bike has a great personality and no major flaws like excessive vibration or weird noises.

    Now I am deep into my usual very detailed setup, with modifications, which usually exceeds a hundred hours of work with frequent test rides. I've made a long string of changes already, some of which are documented in a larger thread on the Betas, starting about page 208:


    My propensity for technical detail in a more general subject matter forum was not welcome by a few so I decided to shifting the greater level of detail here.

    Stay tuned!
    MacG, kj7687, Kiharaikido and 5 others like this.
  2. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    Just a dinky mod last night. Took about an hour to fabricate a new rear brake lever tip. Very convenient to have a steel tip affixed to the forged aluminum lever via 2X M5 fasteners. I did not need to remove the lever to do the swap.

    The fasteners I changed from flange hex head to socket head so they were easier to install under the clutch cover bulge.

    The stock tip is dinky and slick, and sometimes hard for me to find quickly.

    The new tip I made from 1/8" stainless, 304 I think. A little bigger platform and big grippy teeth!

    The forward positional bias warrants some explanation, as that is not what I would normally do for more ideal ergonomics. I have 'special needs' ankle-wise, and will step on a brake pedal that is closer to the peg when I don't intend to.

    Here are the stock and modified tips:
    Here is the tip in relation to the KTM Rally pegs I fit (much yummier on the feet!):

    There is a whole other way for me to do rear brakes. On my competiton trials bikes fabricate a custom modular setup for the left side of the bike for activation by live body parts. It's a lot of work to pull of a custom setup and have it work very well and stay reliable in the first iteration.
    160602 Sherco Factory 250 Left-Side Brake Lever-640x360.jpg
    I might do something like the setup on my Sherco trials bike later on my Beta. For now the one little mod will suffice.
    ACR, jonnyc21, overtone and 1 other person like this.
  3. mac20

    mac20 AVL OG

    Dec 27, 2016
    Johnson City,TN
    Motobene-i am trying to decide between the 430 rr-s and 390. i went to a Beta Demo day at Durhamtown last month, loved the 2 strokes, but they were to vibey for me. Felt super comfortable on the 430, but the trail we used was not tight or technical. Soooo, my question is how much better is the 390 than the 430 for woods riding??
  4. Cycle_Path

    Cycle_Path Been here awhile

    Jan 1, 2012
    North Idaho
    Run a cable on the brake pedal. I learned my lesson 7DC83A85-D58B-40B5-9941-8ED27FB37E96.jpeg
  5. Harry Potter

    Harry Potter Been here awhile

    Oct 27, 2010
    Motobene are you making the Mrs. do all the work with calving this year while you fine tune that 390?
    Hair and motobene like this.
  6. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    mac20, really simple questions can have quite complex answers! One can duck and say it depends. Another out is, "It's just personal preference." A lot of riders don't care about the fine details of design and just pick one and are happy.

    I am picky, being an engineer, and have MY reasons for preferring the 390 over the 430. The 430 has fun power, and a lot of it, but a bunch of power comes at the price of reduced confidence in extreme situations, and an uptick in risk.

    A BIG overlooked attribute in bikes is inertia. But it's not obvious because all the sizes almost exactly the same in weight, but at each step up in engine size takes you a step up in inertia and that impacts great the perception of weight and move physical input required to change directions quickly. It's why the 350 feels more 'flickable' than the 390 though it's the same bike except for the crank stroke which ups displacement a mere 40cc.

    If you want the big cruiser feel and dripping torque, get a 500. If you want adequate power and very flickable, get a 350. If you want exciting power, get a 430 (it will ride smooth and the rainy map helps). The 390 is an oddball, displacement-wise. I sure as heck like it.

    If I have any doubts about the 390, and a little voice in the back of my head says, what other size would you stable? The answer at this point would be the 350. Plenty of power. Then again 35 years of trials has biased me to preferring lower perception of weight and lower intimidation factor.

    The 430 and 500 are nice. They obviously can be ridden in the woods well. For me they they take a bit more work and concentration to stay on an accurate line.

    In the big open it's a lot of fun to ride the bigger displacements. But today the smaller machines are surprisingly powerful.

    What is too powerful? That's very subjective as well as terrain dependent. At what point is too much enough? You must decide:-)
  7. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    firecrotch, I was pondering that same thing last night because of the large gap between the tip and primary case. Your photo is a good reminder, thanks. I'll work on putting something there.

    I'm usually pretty good at avoiding banging up levers and such, but all it takes is the one odd hit to pull that brake lever right out.
  8. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    I found out today during more setup that Beta uses a lot of small fasteners that have loose step washers (of varying thicknesses) and many thread into brass inserts over molded into plastic.

    The fasteners are the Dacromet (a zinc compound) plated steel typical to Euro bikes. They are of course assembled dry, and at under 10 hours some of mine already came out squeaky and with white corrosion.

    Brass and Dacromet form a galvanic couple for a mini battery when moisture gets in. Failure to grease fasteners like these WILL lead to corrosion because water WILL get in the thread interface. Then they dry out. Wet, dry, wet, dry. Corroded fasteners are irritating and result in cursing.

    The factory greases the triple clamp fasteners because when those are assembled dry they really get stuck! They even get somewhat stuck greased, so they've learned their lesson. They don't do them all, however. That's way too labor intensive. But we users can. On my bikes every thread I can get to gets grease, and a few pesky ones that like to loosen get grease on a first install and blue Loktite on a second install.

    This process is very labor intensive, but I've done so many bikes I've gotten very fast at it. I can do a whole bike in a couple of hours.

    I do the project section by section, like front end, mid section, subframe, and I'll do a section when doing other things like full packing of the always under greased suspension linkage, wheel bearings, or steering stem. Engine mounts and axles and the swingarm pivot get grease too. I even pull the brake rotor screws and grease them, so way down the road if I bend a disc, I won't be braking off any disc fasteners replacing the disc.

    I do one fastener at a time in assemblies having multiple fasteners.

    As for the large number of step washers Beta uses, they prevent plastic from getting mashed by ham-fisted mechanics. But they are not affixed to the fasteners like some washers are on Japanese machines. If you take a faster out in the boonies, the step washer can drop out and disappear into another universe. There's like four different ones so I don't want to lose even one! So I added to the process running a small ring of silicone adhesive (silicone 1 clear) around the step of the step washer so after reassembly the washers have a good chance of staying adhered to the plastic. That doesn't always work and the washer will come loose anyway, but it helps a little to keep from losing washers.

    Loktite? I use it sometimes with grease. Some fasteners, like the ones affixing the subframe to the frame, have Loktite from the factory. I just leave the residual on the threads and grease over it. When I do add Loktite I do it on a second insertion after the grease is spread out.

    Why no anti-seize? Some types are just a grease base with messy metal powders like copper, aluminum, or nickel. Anti seize is fine stuff, but the metal powder stuff can get quite messy. The non-metallic versions are usually a grease base and moly (molybdenum disulfide) and black.

    I had a couple of side panel screws disappear on me in two rides, so I decided to do all the side panel screws with grease plus Loktite.
    Junglejeff1, chasejj and jonnyc21 like this.
  9. DBM

    DBM Let's Just Ride!!

    Feb 4, 2007
    Champa Bay, Fla
    I use a quick squirt of silicone garage door lube into the female side of the connector works great.
  10. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    Absolutely right DBM about the solution of lubrication. Don't know if by "connector" you mean electrical connector. If so, I will next post about the silicone grease solution as prophylaxis against corrosion-related electrical issues.
  11. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    A very important set-up step I started on yesterday was addressing the tendency for dry-assembled electrical connectors to corrode.

    I have read of complaints about the Euro electrical connectors being not sealed enough. Some of the connectors are not as well sealed, perhaps, as some modern automotive connectors, but they really are good enough and won't cause you problems IF you do the following to prevent corrosion!

    IF you don't, you can waste more time later on than it takes to do the following by being driven crazy by one open or intermittent connection.

    Moisture WILL get into connectors from humidity, rain, stream crossings and cleaning. Once moisture is in it acts as an electrolyte, setting up rapid corrosion. Oxides are produced and they are not conductive. Eventually terminals in the connector will go open, even when connected firmly together. When you see blue or white at the connection, corrosion has started in.

    I've been doing something for many years on all bikes I set up to prevent corrosion and to recover corroded connectors on customer bikes: I pack electrical connectors and coat all terminals in connectors, battery terminals, and grounding points with grease. Anything that connects one thing to another and carries a current should be greased, terminals, screws, posts, etc.

    Any grease is better than no grease, just as any oil, drip or spray is better than no oil. Anything is better than a dry connection! The best and most enduring protection is grease, and if you can't get grease into something like copper cable that has a crimp connection, a drop of oil to sit in the among the squashed copper wires plus a coating of grease at the junction, goes a long way to preventing future issues.

    Silicone grease is considered so-called "dielectric" grease. That's like saying "wet" water because grease bases are dielectric. You can use any grease. For decades I stuffed Vaseline in electrical connectors. If you don't have silicone grease use any grease. Avoid antiseize-type greases because they contain metal powders.

    I cannot drive the point home hard enough: connectors that are assembled dry are an invitation to having them corrode and/or get stuck together!

    I started in the subframe area, doing the battery, ECM, and the fuse links, and tilt sensor, and will move forward to under the tank. On the high-amperage connectors, I pumped a little ATF into the crimp, then coated with silicone grease, then pulled the boot back over, which slides nicely on grease instead of getting stuck.

    The technique for connectors is simple. Smear a layer of grease over the end of connector with female terminals such that when you slide the connector with male terminal home they will coat with grease and drag more grease into the female terminals. Do them all, including all grounding points and their screws and washers, fuses, battery terminals.

    Takes as long time to do them all, but then you can just forget about it. Your connectors will also come apart much easier!
    No grease is shown on the ECM make connector (female terminals) to show just how many terminals there are. I coated the flat face thick, pushed grease in, then re coated with an added 1mm layer before pushing the connector back in. When there are multi-lip seals I give them a light coat too.

    THERE ARE A LOT of additional connectors under the fuel tank, headlight, and steering stem area!

    A connector that defeated me was on a module on the throttle body. It's the one with the gray collar in the middle, to the right of my fingers. Despite strong light and a shop mirror it balked at unlatching and un plugging:

    Connectors near the frame backbone:
    There are more on the other side associated with the fan.

    There's a real gaggle of connectors behind the headlight:

    The turn signal connectors defeated me. They are really stuck together and I did not want to pull wires out of terminals. Maybe later....

    There are four tiny indicator lights that plug into white tubes via silicone rubber plugs. I worked those out carefully one by one and greased the plug. They were already pretty stuck in there and it will get worse later.

    The white indicator light bodies are affixed vertically by an o-ring and snap ring that doesn't really go home in a groove. Take care not to allow the white body to push up, which will drop the snap ring down. It's tight in there so keep the snap ring pushed up when you work on each indicator light.
    Twenty9, chasejj, JCascarano and 7 others like this.
  12. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    Beta (@ my dealer, anyway) fit an AGM (absorbed glass mat) lead-acid battery to my bike. Looks like a good battery, but being lead acid, it's a real porker at 2.06 kg (4.5 lbs.)
    My Stock Battery
    Motobatt MBTZ7S, 100 CCA, 6.5 Ah 2,062 grams, 112 X 107 X 70

    Lithium Equivalent
    Shorai LFX14L2-BS12, 210 CCA, 14 Ah, 763 grams, 113 X 89 X 58

    I've found the new technology to be cost effective in motorcycles because they last much longer. They also tend to be smaller in size.

    Shorai ships batteries with a number of gray foam pads with peel-off sticky side to make up for the smaller battery body size. There are so many extra pads I keep them around to use for all sorts of things, like cutting squares to stick to the back of bed headboards so the don't bump walls hard.

    The cost of a lithium battery is higher, in this case $150. I have so far had FAR better performance and FAR better life from the Shorai lithium as a primary motorcycle battery. I haven't tried other lithium brands yet. Lithium batteries start the bike with more authority and don't lose as much voltage when stored. And there's the big benefit of chopping out 1.3 kg in this case! It's tough for Beta to lose weight of that magnitude from one model year to another. Getting rid of the kick starter, for example. But you can do it just ditching the lead-acid battery.

    Tipmethewink reported in this thread that his UK Beta came with a lithium battery. Wish American Beta did.

    My lead-acid battery can be a backup unit on those rides where I trailer the bike. What about a dead battery on the trail? Some carry "jump starters" as backups, for about $100. I make a 5S battery pack which is more compact.

    I've never had a battery go poof during a ride. My wife had a lead-acid battery suddenly die on a trip, but that's it. Maybe I will carry a jumper, maybe not.

    The biggest risk is usually someone using the red button to kill the engine and leaving the key on. The tungsten headlight will drop the voltage pretty quickly. I don't touch the wicked red death button! :-)

    Helpful is to wire up a DPDT headlight switch (one side for the low beam and the other side for the high) so when doing offroad one can switch off the headlight. Shutting the headlight off can help if you are powering an accessory via a DIN Hella (BMW-style or Powerlet) outlet, and need tom extra oomph. Like running a heated vest for a bit because you are freezing to death on a road stretch, and you can't run the headlight and the vest as long as needed without dropping voltage. I always wire at least one of these power outlets on a plate on the bar clamps on my bikes:
    DIN Hella Outlet.JPG

    If the rubber o-ring strap fails with a lead-acid battery there will be a literal lead weight bouncing up and down back there. Luke said that his o-ring strap failed very soon and revealed this optional strap from American Beta:
    Beta HD Battery Strap.JPG

    Update: I received and fit the Shorai battery. The little guy is so light and compact, yet it has more cranking amps and a bit higher voltage, which you can hear in the speed of the fuel pump being higher when you turn the key on.

    I used a thin pad on the bottom of the battery and a medium pad in two contact strips on the back. By sticking the pads on the battery instead of in the box, if the Shorai poops out I can just drop in the lead mongo battery.

    The Shorai sits lower and farther back, so the tension on the o-ring is less. Maybe that way it will be fine and last?
    chasejj and jonnyc21 like this.
  13. Tipmethewink

    Tipmethewink Adventurer

    Mar 24, 2017
    Fyi: Lithium battery came as standard here in the UK.
    motobene likes this.
  14. Luke

    Luke GPoET&P

    Aug 25, 2004
    Beaverton, OR
    BTW, there's an upgraded battery strap available from the beta accesories store
    It's a thick moulded rubber strap, much better than the stock oring. I'd want the upgraded strap even with the lighter battery. It's a shame the good strap isn't stock....my oring lasted a couple of rides.
    motobene likes this.
  15. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    Beta has a sensor that is reported to kill the engine in a tipover. It sits up and behind the battery. It's tilted forward about 20 degrees. Written on the top surface is TOP.

    Mine was interfering with the battery so I drilled two new holes to move it away from the battery. That meant shifting it left a bit too.

    I'm not sure how it actually works with the ECM, but it has 3 wires. Here is what I found:
    Tilt means I had it upside down.
    chasejj, jonnyc21 and Dao1 like this.
  16. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    Thanks. I'll get one.
  17. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    Beautiful piece by Beta! Stouter than it looks in pix. Narrow tip though (why do they do that?)

    I wanted a bigger foot on the kick stand and wanted the bike not to lean as much on the stand, so I made a foot out of 1/4" 6061 and TIG welded it on a slight angle such that the new foot sits flat on concrete:pynd
  18. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    I find the bar bends on off-road bikes to kind of suck. Different ergonomics are used on trials bikes. I don't like flat bar bends and don't like the usual position most riders put the bars in. The bars feel like they are in my lap sitting, an I can't balance over the pegs when standing.

    I fit Sherco trials Factory bars (RYPUSA). The standard bars are black, and the Factory bars are white paint over the same black bars. Being trials bars they feel really good rotated forward and further ergonomic improvement is had moving the clutch and brake levers inboard and not having them angled way down. It's hard to explain, but suffice to say such details have justification.

    The Sherco bars are probably too tall for shorter riders, but they work for me very well.

    Interesting side note. The Euro clutch master cylinder is 'new world', having the lever and reservoir on the same angle. Perfect for a trials guy who likes his levers not angled way down.

    The Japanese Nissin brake master cylinder is 'old world' having a big angle difference between the lever and reservoir. With the lever angle more up there is a swept back angle to the reservoir (boo). Doesn't affect function, but it's goofy looking. The irritating thing about this old-world angle is the mirror mount on the right is angled too far back. I later had to make an adapter for the right side to fix the mirror angle problem. no doing so with trials type lever ergonomics will cause the mirror stem or RAM mount (depending on mirror type) to hit your right forearm when standing, and it will impair rear visibility.

    BTW, master cylinders should be filled with brake fluid 100% if possible. The idea of needing a big bubble in the reservoir to prevent brake lockup is a myth.

    Big air in the reservoir can leave you without brakes temporarily after a crash, or sucking air into a master cylinder from pad wear fluid displacement. The give in the system is from the bladder in the cap, so you don't need or want any air below the bladder.

    For master cylinders having the goofy angles at whatever your ergonomic preferences are, cock the steering and even rotate the master cylinder on the bars to make the top plane of the reservoir nearer to level so you can fully fill them. Don't be bashful. just hold an old T shirt under them when you fit the cap and let the excess pour over the sides of the reservoir. Put the screws in while holding the cap down.

    Another technique to know is you can avoid having to bleed the whole system by doing a simple trick every year: Mop out all the fluid in the reservoir with paper towel. Don't touch the lever! Refill fully with fresh fluid. The fresh fluid will over time slowly exchange with the old, all the way into the pucks. The heat in the slave cylinders causes a little convection flow.
  19. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    The most beneficial and critical set of mods I have done so far to the bike involve the clutch.

    The standard clutch in the Beta 4 strokes from the first engine until 2017 is seen in the video panel below. Clutch lever pull was pretty stiff, so some came up with ways to lighten lever pull and tweak performance. To understand some of where I am going below in my mods, watch this interesting video by some Aussie trials riders turned devoted Beta off road freaks. Lots of practical tech info in there:

    For 2018-on Beta fit as standard a clutch that looks like this:
    2018 Beta RR Clutch No Cover.jpg
    2018 Beta RR Clutch.jpg

    This new clutch is the former Beta option of 2014 Factory clutch (6 springs), which used a larger slave cylinder as well, at 28.5mm instead of 27mm. In 2018 a 6-springs clutch and that same larger slave cylinder became standard.

    The new (or new-old) clutch is definitely well designed and made example of a 6-helical-coils-springs clutch! When a clutch releases fully early into the pull with no drag, that allows room to do things to make the clutch more controllable. Stiff clutch lever pull and having the lever way out promotes what trials riders call whiskey clutch. You'll see poor clutch technique too. Lots of throttle, multiple fingers on clutches, and the lever going way in and out. The rider loses traction and stops on a steep hill, then goes bug nuts tearing up the hillside, spinning the rear wheel.

    I'm used to exceptionally good clutches with light lever pull and a very predictable and broader slip-zone. Also full release half way into lever pull without drag.

    The best examples of clutches in my opinion are the Belleville-spring clutches on most trials bikes. KTM has a clutch like that, but the benefits are lost somewhat from a stiffer lever pull (at least on the `16 500 I rode).

    I use one finger on the clutch lever, the index finger. On my new Beta, lever pull allowed that but was high, and the lever slip/engage point could not be adjusted far enough in to the grip.

    I transformed my clutch with a few simple mods. The result was excellent!! It's the best fast-bike-type clutch I have yet to experience on any non-trials bike, and it behave a lot like the Belleville spring clutches I'm used to on my Sherco trials bike.
    I tweaked ergonomics and alteration of pressure plate net spring force:

    I slid the master cylinder inboard. You can pretty much count on master cylinders being too far outboard on the bars as that is considered normal. It's much better for brake and clutch control when the master cylinders are more inboard than the norm.

    I rolled the bars forward into a more trials-like position (I hate when the grips are in my lap).

    I brought the levers up so my wrists aren't cocked down

    That looks like this on the left hand:

    I shortened the master cylinder push pin to being the slip-engage zone closer to the grip.

    The 3mm range of adjustment is off, as in too far from the grip. Here's the Brembo lever setup:
    Interesting floating stop design via the small bias spring. It gives a wide adjustment range to lever angle.

    Here is the push pin sticking out of its rubber bootie (Gaak! Someone before me buggered one of the master cylinder cap screws :-(

    ...and the stock length push pin by itself:

    I shortened my push pin from 40.7mm to 37.5mm (3.2mm) by grinding the right end which contacts the hydraulic piston shorter, then re rounding the end using a drill and belt sander. A safe bet is 38mm, or if you aren't sure, try 38.5mm first. Not everyone's hands are the same.

    I pulled the push pin out of the bootie without removing the pressed in bootie. Getting it back in was a pain. I used electrical tape and dental tools to get the pin back into the bootie (you'll see what I mean). If the bootie will pull out without ripping that would be easier. I didn't try removing it without a spare on hand.

    The clutch is fortunately so good that even with the lever pulled back there is no drag or sticky shifting or difficulty snicking into neutral at a stop when the lever is pulled against my fingers.

    I reduced net pressure plate spring force by about a third.

    This is the most critical mod. It can be done inside of 10 minutes, and reverse inside of 10 minutes. It tends to weird some folks out, but I've done this mod many times on bikes I owned a long time and rode aggressively. Clutches have a BUNCH of overkill in holding capacity. Knowing that is liberating because you can back off on net spring force and derive control benefits.

    How? Remove the clutch cover. Leave the rear brake spring on the cover and rotate the cover out of the way. Remove 2 of the six springs, washers, and screws on opposite sides of the clutch and put them in a sandwich bag. Here I am in the process of removing the two sets of springs, washers, and screws:

    Stroke the clutch lever and observe the lift of the pressure plate. If it lifts evenly (mine did with 6 and then 4 springs), you're good to go, butting it back up. If one side lifts slightly early, just move springs around until you get even lift.

    The lever pull with 4 springs is still a little stiffer than I prefer, which tells me Beta sprung the clutch quite stiffly. Same clutch for all the sizes. I have yet to have a clutch modified like this start to slip and wear under heavy load in the higher gears. Any squid can burn a clutch up:jive no matter how heavily sprung but poor energy management, turning too much chemical energy into kinetic energy then into heat energy into the clutch, over running the ability of the clutch to get rid of heat by conduction and oil cooling.

    Below is a video of the action of the lever after all the mods were done. As you can see, the pull is easier, and the lever position at the now-wider slip zone is changed to closer to the grip. The second finger bone of the index finger rocking about vertical from the ground plane at the slip zone is better ergonomics for control.


    After many months and rides, the modified clutch is solidly proven. It's the best off road bike clutch I've ever experienced.

    While the modified clutch was for me a huge improvement, I eventually went Rekluse auto clutch (read on) to keep from injuring myself with the rare stall in very scary places because I'm a trials rider and it's almost unprogrammable for me to stop nuancing the clutch at low rpm. While a trials bike will rarely stall because of nuancing - and the implications on a not-tall and not-heavy bike are much less from a stall - the hyper-motor off-road bikes can be killer stallers!
  20. motobene

    motobene Motoing for 51 years Supporter

    Mar 9, 2013
    ABQ NM & Wichita Mountains OK
    I don't like small foot pegs! I'm old enough to remember when they were tiny and deadly. Even the modern pegs are on the small side for me. I want stand - a lot and don't like the outside edges of pegs pushing in on my boot soles.

    How big is big? Check out this extreme custom peg design I used to make in the `90s. I made these Monster Pegs in the from skinny Spanish stock pegs and adding custom laser cut stainless steel parts.

    I found the last remaining set in a box two years ago and it was celebration:clap and no going back! Competition on them ever since.
    160602 Sherco Factory 250 Left-Side Brake-640x360.jpg
    (I also made and still use the custom left-side brake (long story)).

    Unfortunately, I've been out of the stainless steel parts so I could not mod my stock Beta pegs. I really liked the looks of the $150 KTM 60103940000 Rally Pegs, however. Nice and long! A little less wide than I like, but WAY better than the stock pegs.
    KTM Rally Pegs 60103940000 Beth Sides.JPG

    Very comfortable and secure feeling. The tooth profile is about as good as it gets. Large, grippy teeth that don't tear up boots.

    The only thing I had to do was drill the holes in the pegs out a tiny bit because the Beta pins on my bike were oddly over 10mm nominal at 10.3mm. I used an X (0.397") drill.

    The rally pegs are about 270g heavier per pair than stock, but worth every gram.

    These pegs have proved out nicely. I ride with my legs away from the bike (trials technique). I love being able to do that without feeling like I'm standing half off an edge. Being investment cast steel the reliability has been 100% too. They haven't creep-angled down at all.
    chasejj, jonnyc21 and theailer like this.