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bikerpet

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About bikerpet

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  • Bike
    2020 Beta 300

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    Ozzie

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  1. It would be interesting to know how much difference your fins make. Most thermal conductivity stuff I've read makes a pretty big deal about getting really good contact between the surfaces - clean metal to metal, dead flat surfaces, conductive pastes where there is any chance of air gaps .... Obviously something has to do more than nothing but I'm not sure those fins would achieve a great deal. Do you have any before and after figures for the sort of temps you get? I'm not sure that the e-clutch will make any difference to the throttle lag on your MTB. It's just a second throttle, nothing more or less. The only difference is that the main throttle is 'normally open' while the "clutch" is 'normally closed'. Unless the lag is your ability to twist the throttle fast enough, which I very much doubt, then it's inherent in the controller. You could put an instantaneous switch as the throttle and it would make no difference to the delay. If you are trying to achieve a power chop rather than a power hit, maybe it might work. Or you might be able to hook onto the brake cutoff signal wire if it has one? Or some people have resorted to just chopping the main power with a contactor, although some controllers might not like that much. That is very likely exactly why Oset has gone with a brushed motor - they can get instant response without spending a lot of money on a fast brushless controller. If you want instant response on your MTB you probably need to get a new controller. If you haven't seen it, https://endless-sphere.com/ is well worth spending some time on (you might need a lot of time, there is so much info in there).
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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".
  8. 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!
  9. 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.
  10. 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.
  11. 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?
  12. 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.
  13. 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.
  14. 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.
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