bikerpet

I use a Troy Lee Designs MTB padded vest for that same reason. I like that it gives all around protection, not just back. My rib bruises have been on the front/side rather than back. It also covers the shoulders so I hope it gives a bit of protection against shoulder and clavicle injuries. It's very light, and ventilated so not too hot. It seems from this thread that there isn't any particularly common specific injury, which is probably encouraging.

I just had a quick look at the Oset wiring diagram (if in doubt read the b****y instructions). There is a temp sensor in the motor that feeds back to the controller, which in turn shuts down the output if the motor gets hot. So there's little risk that the motor is getting damaged in any significant way. There is also an Oset Technical Bulletin which says the sensor has had some failures on some 2017 bikes, is not needed and can be safely disconnected. I leave it to you to find, read and decide if you want to act on it. I don't know that I'd consider a bit of extra brush wear "much more" damage. Brushes wear - faster if they are are worked harder. Brushes are also cheap and usually pretty straightforward to replace. Not such a big deal I'd have thought. I don't know how often Oset owners have to replace brushes? Also it may not be the motor that is overheating, it could be the controller. In which case there is probably little if any damage occurring anywhere. If it's the controller then presumably it's a self-protection function kicking in. Just an annoyance. Try adding some cooling to the controller (more/better heatsinking or a small fan perhaps?). My understanding is that the main issue with excessive heat in any motor is The winding insulation breaks down Magnets can be demagnetised by excess heat, particularly when combined with high currents. Solder joints can melt Brushless motors also have electronic components within the casing (hall effect sensors), these can be damaged by excessive heat. So bottom line is that too much heat is bad for any motor, I'm not sure it makes a great deal of difference if it's brushed or brushless in the real world.

I don't believe there's any significant difference between the two motor types when comparing apples to apples. Motor heat is simply the result of the amount of current you stuff through the copper windings less the the heat shed through the motor body. There would be a very slight contribution via the friction and arcing of the brushes, but I don't think it would be significant. So overheating is basically a result of a (possibly deliberate) mismatch between the power output of the controller and the ability of the motor to shed that heat. Oset probably decided that it was a better trade-off to use a lighter, cheaper, smaller motor and drive it hard, given the target is trials where the duty cycle is typically very low so the motor has time to shed the heat from the short bursts of full power. Your MTB motor/controller was probably designed with a far higher duty cycle in mind, the motor just isn't driven as hard so it can shed the heat adequately. Throw a controller on it that can push more current and it'll overheat just as quick. I'd be interested to hear how the e-clutch works out on the Oset. My expectation is that it will be fairly underwhelming. It won't change the peak torque at the back wheel one iota, only very slightly speed up how quickly it builds - assuming the controller can ramp up as fast as the lever can move. It will give a nice cutout against whiskey throttle and possibly the alternative throttle control via the clutch finger could be more controllable in some situations. The e-clutch is really only a "finger throttle", it's not at all the same as a "real" clutch. On most controllers it's relatively easy to hook up a "reverse throttle" in series with the normal one, which is all the e-clutch is. FYI my dob e-trials bike doesn't overheat pretty much whatever I do to it and it's a brushless motor too. It certainly gets too hot to touch if I work it hard up a long steep hill but it's never missed a beat.

No worries. It gets quicker and easier. I find it's getting the long bolt through the bones and linkage that's the trickiest. But with a systematic approach it becomes quick and easy.

Without some degree of programmability in the controller I think you'll struggle to get the feel you need. There are cheap brushed controllers with basic programming for max power, acceleration and throttle start/end points. They work just fine although you need a USB to serial dongle and windows PC to adjust settings. Yes, it's a small but sightly annoying feature. On the plus side it does offer a little rollback resistance when you lose it on a hill :-) A clutch is almost pointless without some significant flywheel mass. With a lightweight brushless rotor the motor simply stalls instantly if you don't have enough power on, and with too much the bike either spins or takes off. It's flywheel inertia that makes a clutch work, one without the other is at best pointless and at worst a nightmare. Hence EM having adjustable flywheels on e-pure bikes with clutches.

I think changing the carby to a bigger one will make a substantial difference to the low speed response - there is so little air flowing through at low revs already, and a bigger carby will slow the flow even more and become harder to get the low speed mixture and response right. I think you're on the right path now - change as little as possible on the bike to get it to be barely acceptable on your commutes, then just ride it. You used to be able to buy (or make) two speed rear sprockets - a normal smaller sprocket and a "ring" which slipped over that and located with a few bolts in the tooth gaps. You cable tied (or wired) the ring to the spokes when on the road, then when you went off-road you added a few links to the chain, slipped the ring over the main sprocket and away you went in "low range".

As far as I'm aware it doesn't make any difference. I tend to swap the directions each time I grease them on the theory it will spread the wear more evenly. I also try to mark the loaded direction (rotation) when I dismantle and put them back rotated from that for the same reason. Probably totally over the top, but I can, so I do. I only do the main pivots every second dismantle of the linkages as they seem to stay better lubed and cleaner (and are more of a pain to do anyway). If you had to undo the engine mounts to re-assemble the main pivot (pretty normal in my experience) then be careful of that lower rear mount bolt - it's dear as poison (titanium they claim) and I've had one snap when undoing it, let alone tightening it. I've had a squeak develop in the suspension a couple of times which is actually that bolt coming slightly loose and the frame moving relative to the engine when the suspension is loaded, took me ages to figure it out the first time!

Exactly my thought too!

I hope you've taken notice of what Totty79 said. By the time you've geared it up that much it might also be very "interesting" for riding trials, especially with badly worn tyres from the road riding. Even mores so if you swap to a 30mm carby! It sounds as if you're almost trying to reinvent a light enduro bike to me. Go for it if that's what you want to do, it could make the perfect bike for you. Just be well aware that every step away from it's standard form is probably going to make it less fun for trials.

300A is at or close to the point the fuse blows. I doubt the controller would be setup to be pulling close to the ragged edge of the fuse, so I'd think closer to 12kW would be more realistic.

I come from a skiing background where ACL injuries have been common. Years ago there was research done into the specific mechanisms that caused the injuries and out of that some falling techniques to reduce the risk. Similarly snowboarding has a high incidence of wrist fractures and shoulder dislocations, and people are taught (or should be) specific falling techniques to minimise the risk. What are the common trials injuries, and are there techniques or practices that can reduce the chance of injuring yourself? I'm guessing ankle injuries are probably fairly common? Are ACL injuries common? Shoulders? Clavicle? Shoulder AC joints? Facial injuries?

Just a follow up. I got in some Forma soles and had my Sidi's resoled by a highly reputable cobbler (previous resole was falling off so not using that cobbler again). Excellent result. Only 30 hours or so currently but they are working well and showing no sign of wear from the pegs. I'd say this is a good way to go when your Sidi soles wear out. The Forma soles feel like a harder rubber but have a more aggressive tread, so grip is probably better in some conditions, worse in others. The red patch for the peg feels harder again but absolutely no issues with peg grip.

I've got a couple of hundred hours on my trials bikes (sherco & beta) with my Fox mtb pants and no burns - maybe lucky but they have stood up better than my actual moto pants which have several melt marks. Almost no-one wears any upper body protection where I am - plenty of people in short sleeves or T-shirts (against the rules but no-one seems to care). I'm usually the odd one out wearing a vest of any sort. I'm sure the time will come when protection is required.

MTB/BMX trousers are an excellent option - not skin tight lycra and designed for knee pads underneath. Also usually have some ventilation and often handy zip pockets too. They tend to be a bit pricey for what you get, but on sale they can be had for a decent price. I like the Fox stretch version, they are fairly expensive (unless you find a really good sale) but last extremely well I've found. Fly Racing make some that I know others have found good. I use MTB knee pads and also an MTB (Troy Lee Designs) padded vest. I've only ever had minor injuries, but nearly all have involved bruised and painful ribs which I got thoroughly sick of, the vest seems to have solved that.

Brushed motor controllers are inexpensive and one of the key features is that the throttle response from even the most basic brushed controller/motor combo is virtually instant, even from stalled. The same cannot be said for a lot of brushless controllers, many of them are perfectly fine for 99% of uses, but the tiny bit of lag, particularly as they first spin the motor or from very low RPM, can be a problem in trials. I'm guessing, but I'd also expect that as most brushed controllers are fundamentally analog rather than digital, then it was far easier to find a controller that could use easy to understand twist knobs to adjust settings. Digital brushless controllers have to read the rotor position from sensors, then calculate & send the appropriate AC power to the correct motor windings, that happens fast, but depending on the software and hardware there can be delays. An analog brushed controller just ramps up the voltage and the motor spins. My guess is that Oset found that for the money there wasn't much out there that had the same response & control inputs in brushless designs. Brushed motors are slightly less efficient, but really in trials is it going to be even measurable or significant? Brushes are going to last nigh on forever in trials use and are cheap and simple to replace anyway (I don't know the detail of Oset motors, this is a generalisation). Yes, a good brushless setup will be a bit more efficient, probably lighter and maybe more tuneable, but you'll likely be paying a pretty decent premium to get one that actually rides as well as a sorted brushed setup. I've got an analog brushed controller here that costs around US$15 and works really nicely for trials. I've also got a $500 brushless controller that does pretty much the same job. I've certainly heard of people spending well over $100 on a controller and getting something that is perfect for golf carts, scooters etc but is almost useless for trials because of the throttle lag. No question a quality brushless setup is the gold standard, but in the real commercial world there's a lot to be said for the older tech.

This. Absolutely for sure! I've been getting coaching online (there's no-one coaching within many hours & hundreds of kilometres of me) and my progress & understanding has leapt ahead. Face to face coaching would be even better in so many ways, but good online coaching can be amazingly effective. As someone else said, just videoing yourself regularly can be such an eye opener too.

One of the attractions of the Beta to me is that they have just chipped away at the same basic machine for a long time so they're well sorted. The clutch is really the only thing that I'd like to see updated. The air filter is a non-issue for me, but I don't live in the soggy UK. I did start putting a thin sheet of (oiled) filter foam over the top as a pre-filter which works really well to keep the main filter clean longer and is super quick and easy to swap regularly.

Pretty late to the party, but I made a pit bike based seat which works very well and was quick and simple. Cut off the lumpy bits underneath, cover the bike with a rubbish bag, sit the seat on top then squirt spray expanding foam in the gap. Once the foam hardens (it takes a while with a big bulk of foam), peel off the plastic, cut and sand foam shape and job's done. I just used a 3mm bungy over the top to hold it in place - because it fits the bike so snugly it doesn't really move. I did end up gluing a bit of non-slip silicone to the bottom for extra grip. Quick, simple, cheap and worked well.

I've been using Fox MTB DH pants (probably the same as their BMX by the look of it) for several years. They are perfect as far as I'm concerned. Light, tough, slightly stretchy, not form fitting but not at all baggy, slightly ventilated. I'd have 3-400 hours on them and besides being grubby they are basically good as new. Amazing really. Just make sure you get the stretch version, the cheaper ones tend to be non-stretch which I don't think would be as comfy. I use Dainese MTB knee pads and a TLD MTB vest with shoulders for protection (I'm getting older and more fragile, so relatively minor bumps put me out of action pretty easily). They are also ideal I reckon.

For some time now I've been getting professional coaching (do it!) which has changed my perspective on the double blip. Now I see 3 fundamental techniques for obstacles: Ride up, Zap, Splatter. Ride is anything where the rear tyre drives all the way up. It doesn't matter if the front wheel clears, glances or hits the obstacle, it's all still the same basic technique. So a double blip is just a minor variation of the Ride. With this idea in your head it all becomes much simpler and puts more focus on where the real action is, the back wheel. I think @lineaway said something along these lines ages ago, that the DBL blip was a historical technique, a hangover from twinshock era. Don't get me wrong, there's still a call for DBL blip, and the ability to accurately place the front is important but the whole DBL blip is only as important as lofting the front clear or letting it skim the obstacle. Actually getting over the obstacle depends entirely on how you drive the rear into and up the obstacle, not what the front wheel does. If you take a look for "Neil Price Mind over Matter" you'll get the pro explanation rather than my amateur interpretation.

@ken_hosking I think I disagree that the clutch can't move in the basket when it's engaged. The plates all bind up together but the whole cluster of plates and pressure plates is still somewhat free from the the basket. Any tolerance (slop) between plate splines and basket splines still exists. The plates are bound up with the hub because it's all part of the pressure plates, but the basket isn't part of the pressure plate system. The basket is just sitting on the bearings free to do it's thing. It's only when the bike is in gear that the output gear exerts significant resistance to the hub and therefore drags it all back against the fingers of the plates.So I still think the noise is just the whole mass of plates, pressure plates, springs etc clattering about inside the basket (or the basket bouncing around over the plate assembly). At higher RPM either oil and bearing drag etc provides enough drag that it all sits tight against the basket fingers or the mass of plates etc. simply can't resonate at the higher frequency, or both. Also at idle a single cylinder two stroke RPM is bouncing around like nobody's business, so the basket is always being accelerated and decelerated as the engine pulses and surges, while the plates etc are acting like a flywheel inside the basket. Constantly a different speed between the two. Take a look at the pic here to see the exploded clutch assembly - the only bit missing is the output shaft which runs through the middle into the hub. You can see that the two pressure plates and all clutch plates are completely free from the basket except for the splines, and the splines have bucket loads of free play in them (in the scheme of manufacturing tolerances), I'm guessing there's probably something in the order of 0.2mm free play between basket and plate splines - that's more than enough slop to cause a ruckus! It's presumably not a big deal - the driven side of the basket fingers are always the ones that wear and cause issues, if it was caused by the plates banging about at idle I'd expect both sides of the fingers to be similarly knocked about, which they never are.

I've always figured the noise comes from the engaged "block" of plates slopping back and forth in the basket, which pulses with the piston. When you pull the lever the plates have less combined inertia (they then effectively form two blocks with a degree of slip) so the rattle is reduced. When you give it a few revs the frequency of the piston pulse is simply way higher than the frequency the block of plates can move at, so the rattle disappears. Probably viscous drag from the oil and other friction also works to keep the plates anchored against the basket fingers at higher revs. No empirical data to back that up though. A wrap of tape on the basket fingers would probably be a quick and dirty way to prove it out, if only for a very short time! If it's the fingers then it should go quiet, if it's the gears it will remain.

I too have terminal DIY, however sometimes I just have to relent and roll over. Most rubber contact adhesives work best if you apply pressure, hence why I used to build resole presses. I've yet to find a consumer grade cement that really works for the job, and have to admit that even some of the cobblers I've used in the past don't seem to use anything much better. One adhesive which I find pretty close to miraculous is Aqua-Seal, it's a urethane adhesive used for sealing wetsuits, tents etc. Similar in appearance to ShoeGoo but vastly superior in my experience. There's another brand sold as Seam-Grip which seems similar but I've less experience with it. One of those might do the trick? Whatever you use I think it needs to remain highly flexible after it cures. Good luck.

That would explain it. Certainly makes a big difference. Looking at the parts list numbers it appears the cylinder changed in 2019. Thanks, I'm happy to have that mystery solved. You'd think Beta would have talked it up a bit more really.

I just made a little video comparing turning over the two bikes. Big difference! But I'm not really sure how either of them compare to other people's Evo's. The '17 had the head & cylinder off about 100 hours ago and was in perfect condition. It doesn't seem to have changed in compression or performance since then. Vimeo kicking over video