spokerider Posted March 15, 2009 Report Share Posted March 15, 2009 Wondering at what rpm the 348 makes it's power. In the manual, there is a graph that indicates speed vs rpm for each of the six gears, but no indication of the power band curve. Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted March 15, 2009 Report Share Posted March 15, 2009 Peak Torque is probably between 5-6000 rpm if it's like many other trials bikes of the period. Wayne.... Quote Link to comment Share on other sites More sharing options...
belldane Posted March 21, 2009 Report Share Posted March 21, 2009 I always thought that torque was low down power. The sort of stuff you need to get over obstacles at low revs with just a blip of the throttle. 5000 or 6000 rpm. Come on mate you have to be joking aren't you? Quote Link to comment Share on other sites More sharing options...
feetupfun Posted March 21, 2009 Report Share Posted March 21, 2009 Belldane, I think you are mixing up the terms "low down torque" and "torque". Torque is a moment about an axis. Units of torque are force times radius as in newton-metres or foot-pounds. Internal combustion engines produce a range of torque over the operating RPM range. Motors are designed to produce their torque peak (and how quickly it drops off on both sides of the peak) at an RPM range suitable for the purpose. If a motor generates good torque at low RPM, then it is comonly referred to as having good low-down torque. People commonly leave off the "low-down" bit and call it a torquey motor. Power is torque times RPM or newton-metres times radians per second, or Watts. The RPM where peak power is generated is usually higher than the RPM for peak torque. A Cota 348 produces its peak torque about where Wayne said and its peak power at slightly higher RPM. The important performance characteristic for any trials motor is that the torque curve is relatively flat, compared with a racing motor. Motors are commonly described as "peaky" if they have a sharply rising and falling torque curve. The Cota 348 has a lusciously flat torque curve. David Quote Link to comment Share on other sites More sharing options...
feetupfun Posted March 21, 2009 Report Share Posted March 21, 2009 Wondering at what rpm the 348 makes it's power. In the manual, there is a graph that indicates speed vs rpm for each of the six gears, but no indication of the power band curve. US bike magazines often ran trials bikes on a dyno as part of a testing for magazine articles so you may have luck getting torque and power curves by looking for old magazine tests. I remember the Aussie magazines had a thing for it in the 1970s too and one such comparison in Trail and Track mag put both the Suzuki RL250 and the Yamaha TY250A curves on the one chart for comparison. The RL250 motor performance was well above the Yamaha in the mid RPM range and was about the same at top and bottom. I don't actually remember ever seeing a curve for a Cota 348. If you are keen enough, just put yours on a motorbike dynomometer and get it tested. I'm sure we would all love to see the result. David Lahey Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted March 21, 2009 Report Share Posted March 21, 2009 Its Basic Physics. "Power" is a derived function. cannot really exist without torque or revs in the case of an IC engine. Wayne... Quote Link to comment Share on other sites More sharing options...
jse Posted March 21, 2009 Report Share Posted March 21, 2009 Its Basic Physics. "Power" is a derived function. cannot really exist without torque or revs in the case of an IC engine.Wayne... True, "power" ("horsepower" in some measurements) is a function of torque AND rpm. You can have a measurement of "torque" when trying to unscrew a peanut butter jar lid, as torque may or may not result in motion ("power" has a time/motion element involved and simple "torque" does not). When you look at a HP/Torque/RPM graph, where you see the torque curve peak is where the intake/exhaust system is losing it's ability to fill/evacuate the cylinder effectively. Jon Quote Link to comment Share on other sites More sharing options...
steve Posted March 22, 2009 Report Share Posted March 22, 2009 All sounds a bit over complicated to me! Twist the bit in your right hand and it makes more noise. Simple Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted March 22, 2009 Report Share Posted March 22, 2009 Sometimes that all you need to know I no longer have to and never want to spend another minute in a Dyno Cell if I can help it. It gets boring quickly. Wayne.... Quote Link to comment Share on other sites More sharing options...
copemech Posted March 23, 2009 Report Share Posted March 23, 2009 All sounds a bit over complicated to me! Twist the bit in your right hand and it makes more noise. Simple You may want to get that checked out! Quote Link to comment Share on other sites More sharing options...
thedktor Posted March 23, 2009 Report Share Posted March 23, 2009 Here you go: http://www.geocities.com/guanaco_es/motodelmescota348.html "Maximum power: 16 hp at 6000 rpm Torque: 2.9 mkg at 5100 rpm " But the point is that being a trials bike the power should "come in" from idle up! Steve Quote Link to comment Share on other sites More sharing options...
thedktor Posted March 23, 2009 Report Share Posted March 23, 2009 oh yes and for those of us 349 owners: http://www.motocra.com/motos/Montesa/cota349_1.html "Potencia: 20,5 CV a 5.500 r.p.m." Not bad .... Steve Quote Link to comment Share on other sites More sharing options...
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