ClareQuilty Posted January 9, 2012 Share Posted January 9, 2012 I know very little about motorbikes, but in the course of owning a few Honda Waves, Yamaha Sparks and Freshs, Kawasaki Cheers, and driving a few Suzuki Smashs, I've noticed that I generally tend to prefer the Kawasakis and Suzukis over the Hondas and Yamahas. I did a little research and found that in the 100-125cc size which is normal for these bikes, the most notable difference between these brands is the Hondas and Yamahas go for long strokes and small bores ('oversquare?') and the Kawasakis and Suzukis tend to go for the short stroke and larger bore ('undersquare?') engine design. I'm sure there are many other differences in ride, handling, etc., which are effecting my preferences, but I'm curious if anyone else has any opinion on the bore/stroke aspect - what are the different characteristics and which do you guys like? Link to comment Share on other sites More sharing options...
ttakata Posted January 9, 2012 Share Posted January 9, 2012 Interesting and difficult to answer question. Your definitions are reversed. An oversquare engine is where one has a larger cylinder than the stroke it travels. This allows it to have bigger valves and rev higher as the mass has less distance to travel. More revs means more HP but maybe less torque. You guys can just google definitions and advantages of the designs but for scooting around Bangkok, I prefer more torque so I can get ahead of traffic quicker. Coincidentally my Nouvo 135 is undersquare which is the way I like it. yamaha-motor.co.th/Product/Product.aspx?ProductID=88 Link to comment Share on other sites More sharing options...
seedy Posted January 10, 2012 Share Posted January 10, 2012 In a nutshell - Torque = acceleration Horsepower = top speed Link to comment Share on other sites More sharing options...
seedy Posted January 10, 2012 Share Posted January 10, 2012 Long stroke favors torque, large bore - as stated - favors breathing which in the upper rev range makes horsepower. Posted with Thaivisa App http://apps.thaivisa.com Link to comment Share on other sites More sharing options...
Semper Posted January 10, 2012 Share Posted January 10, 2012 In a nutshell - Torque = acceleration Horsepower = top speed In a another nutshell- one will not notice any difference regarding bore/stroke on the bikes that are discussed here. 1 Link to comment Share on other sites More sharing options...
ClareQuilty Posted January 11, 2012 Author Share Posted January 11, 2012 In a nutshell - Torque = acceleration Horsepower = top speed In a another nutshell- one will not notice any difference regarding bore/stroke on the bikes that are discussed here. I was just waiting for this smug point to be made, but I disagree - I think you notice things like minor differences in power all the more in weaker, smaller machines than you would in your ultra-expensive ones, Semper. For example, for decades I used to drive big V-8 cars in the US. Some of them were 'big blocks' with long strokes, some were 'small blocks' with short strokes, some were 5 liters and some were 8, but they still were all generously powered and satisfying to drive. Nowadays I drive little four cylinder cars in Thailand and the difference between one that is seriously under-powered and one that is just-adequately powered is enormous in terms of feel. I think the same holds true with these small bikes. Link to comment Share on other sites More sharing options...
seedy Posted January 11, 2012 Share Posted January 11, 2012 Smug or not - facts are facts. Based on many hours running various engines on a dyno, both cars and bikes. Link to comment Share on other sites More sharing options...
ClareQuilty Posted January 11, 2012 Author Share Posted January 11, 2012 Smug or not - facts are facts. Based on many hours running various engines on a dyno, both cars and bikes. Actually the 'horsepower' and torque figures, as well as the RPMs at which they're delivered, are quite different between these small- bike engines, seedy, at least according to google... Link to comment Share on other sites More sharing options...
Semper Posted January 11, 2012 Share Posted January 11, 2012 (edited) In a nutshell - Torque = acceleration Horsepower = top speed In a another nutshell- one will not notice any difference regarding bore/stroke on the bikes that are discussed here. I was just waiting for this smug point to be made, but I disagree - I think you notice things like minor differences in power all the more in weaker, smaller machines than you would in your ultra-expensive ones, Semper. For example, for decades I used to drive big V-8 cars in the US. Some of them were 'big blocks' with long strokes, some were 'small blocks' with short strokes, some were 5 liters and some were 8, but they still were all generously powered and satisfying to drive. Nowadays I drive little four cylinder cars in Thailand and the difference between one that is seriously under-powered and one that is just-adequately powered is enormous in terms of feel. I think the same holds true with these small bikes. What would the bore- stroke ratio be in your examples? And regarding the underpowered versus the adequately powered cars you mention, has nothing to do with the bore-stroke ratio. It's about horsepower. Edited January 11, 2012 by Semper Link to comment Share on other sites More sharing options...
seedy Posted January 11, 2012 Share Posted January 11, 2012 "I know very little about motorbikes" - the first line in your topic. I gave you an answer which would have helped you, and was called by you 'smug' When you have an understanding of "duration, overlap, lift, lobe centers, rocker arm ratios, installed height, bore/stroke ratios, port shape and velocity, volumetric efficiency, ram effect, scavenging' among many others, then we can have a conversation. Link to comment Share on other sites More sharing options...
VocalNeal Posted January 12, 2012 Share Posted January 12, 2012 (edited) CQ, If you could find the Hp and toque figures you would probably find they are about the same just at different RPM. Then all the bikes will have different gearing to suit. So at "village' speeds the Suzuki and Kawasaki will be revving very slightly higher. I do know that if you put a Kawasaki Kaze piston in a Honda Wave you get 108cc. Done that before! So the differences can be exploit in a different way. You are correct though that as Carlo Abarth is quoted as saying " It is easy to get horsepower out of a large engine but it takes an artist to get horsepower out of a small engine". Edited January 12, 2012 by VocalNeal Link to comment Share on other sites More sharing options...
ttakata Posted January 12, 2012 Share Posted January 12, 2012 I agree, to me a noticeable difference in power is more percentage based, and it's easier to get a greater percentage change in a smaller engine. I had a 49cc Honda Ruckus and upped it to a 59cc. I could definitely feel those 10cc by the seat of my pants long before I quantified the increase in power. As expected the Veypor dash I had claimed ~1hp average increase over 15 test runs. Gearing is very key in these little bikes. I have a Nouvo135 and my friend has a Click110. 2 years ago when they were fairly new, stock condition, and broken in we raced repeatedly. We weigh about the same 95Kgs and the Click always beat the Nouvo for the first 50 meters no matter who's riding which scooter. The NE135 takes over after 50m and takes off from there and has a much higher top speed, but I felt shame losing out to a Click all the time. Link to comment Share on other sites More sharing options...
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