Go Back   Motorcycle Forum > Motorcycle.Com General Discussion > Motorcycle News > Old News > Yamaha News

Reply
 
Thread Tools
Old 03-07-2002, 02:08 PM   #31
granny
Founding Member
 
Join Date: Nov 2001
Posts: 149
Default Re: Questions......

I like the exposition of the content in this webpage and especially the conclusion which is: Repeat after me. "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*." . The discussion towards the end of the article concerning the water wheel explains in simple terms why four cylinder bikes with relatively little displacement and correspondingly little torque at high RPM typically accelerate better than bikes with mountain motors having mountains of torque at low RPM (no knock against bikes with big motors and low redlines, different designs are suitable for different purposes).
granny is offline   Reply With Quote

Sponsored Links Remove Advertisements
Motorcycle Forum
Advertisement
Old 03-07-2002, 02:42 PM   #32
granny
Founding Member
 
Join Date: Nov 2001
Posts: 149
Default VTX torque - Re: Check it out

The mass of the reciprocating assembly (or rotational inertia) certainly tends to resist changes in RPM but I don't see how the average torque that the engine can produce is dependent on high rotational inertia since the torque is function of how hard the pistons push on the rods. In fact, reducing flywheel weight of an engine will look like increased power on an inertial dyno (though a pony brake dyno would not show a similar change in power). The main advantage of high rotational inertia is to smooth the torque pulses (less variation between points of peak and minimum torque per revolution). The amount of rotational inertia can also have on effect on the usability of the torque. Since considerable kinetic energy can be stored in a engine with high rotational inertia, one might have the impression of the availability of large amounts of torque - one can dump the clutch with little throttle and not stall the engine immediately. But if the throttle is not opened, the kinetic energy stored in the rotational inertia of engine will eventually bleed off (though with those huge pistons a VTX may have enough oomph to just lurch along without stalling - the engines high rotational inertia would simply help smooth the lurching).
granny is offline   Reply With Quote
Old 03-07-2002, 02:49 PM   #33
granny
Founding Member
 
Join Date: Nov 2001
Posts: 149
Default Re: Year 2002 Yamaha R1 dyno run

These are the good old days...
granny is offline   Reply With Quote
Old 03-07-2002, 03:54 PM   #34
CBR1000F
Founding Member
 
Join Date: Nov 2001
Posts: 367
Default Re: Year 2002 Yamaha R1 dyno run

It's probably not the DYNO, but the location of the Dyno - MO is somewhere in the L.A. area, which means that their dyno probably has an optimal location for good dyno readings: Temperature, altitude/barometric pressure/humidity etc., being pretty ideal there. Makes me laugh every time I go down there and see the Los Angelenos wearing down jackets when it's '60 degrees out, LOL.
__________________
People are more violently opposed to fur than leather, because it\'s safer to harass rich women than bikers.
CBR1000F is offline   Reply With Quote
Old 03-08-2002, 06:13 AM   #35
shash_what
Founding Member
 
Join Date: Nov 2001
Posts: 20
Default Re: Questions......

That one was really good. Thanks. I guess I haven't got anymore doubts regarding this topic.
shash_what is offline   Reply With Quote
Old 03-09-2002, 05:35 AM   #36
roadscholar
Registered Member
 
Join Date: Jun 2007
Posts: 3
Default Re: Year 2002 Yamaha R1 dyno run

Good info on the new R1 but I still prefer the old styling. The new one is too origami-like for my taste. Honda is doing the same by copying Yamaha with the 954. GM is doing it with their cars so maybe it's a trend. I'll take a blue 2000 R1, my favorite look/color. And it's cheaper.
roadscholar is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off