F4i - Main Forum Main F4i discussion board

Rev-match downshifting

  #1  
Old 12-09-2009, 08:54 PM
raylee's Avatar
Senior Member
Thread Starter
Join Date: Feb 2009
Location: Dirty Jerz
Posts: 597
Default Rev-match downshifting

It may be a bad habit I've brought over from driving, but I tend to rev-match when I downshift and I've heard numerous reports of it being one of the contributing reasons my last bike died.

Anyways, anyone do it regularly on an F4i? These things don't have slipper clutches so I feel it would be a good way to compensate, but I'd like to know if anyone else has this habit and hasn't blown up trannies and clutches? I find it's particularly useful when it comes to having to change gears around a corner I misjudged as to not disrupt the bike's flow.
 
  #2  
Old 12-09-2009, 09:44 PM
Senior Member
Join Date: Oct 2007
Posts: 213
Default

How would it be a contributing reason to your last bike dying? If anything it will take much much less load and shock off of your transmission. Revving a bike will not kill it unless you have bad oil pressure (or the bike is cold and you're ripping on it), or the oil is dirty and stops its job of being a lubricant.

Exactly what do you mean by "Died"? spun a rod bearing, melted a piston, etc?
 
  #3  
Old 12-09-2009, 09:49 PM
raylee's Avatar
Senior Member
Thread Starter
Join Date: Feb 2009
Location: Dirty Jerz
Posts: 597
Default

I had a bunch of things in my tranny snap. Mind you, this wasn't a Japanese bike, so it might have been build quality. My next bike will be an F4i, I'm just asking for future reference.

And you're right, the reason I rev-match is to reduce load and shock, but several people have told me it's horrible to do it on a bike.
 
  #4  
Old 12-09-2009, 11:41 PM
Aken's Avatar
July 2008 ROTM
Join Date: Oct 2007
Location: Milwaukee
Posts: 3,002
Default

Those people are dumb. Rev matching is a normal procedure.
 
  #5  
Old 12-09-2009, 11:53 PM
Senior Member
Join Date: Oct 2007
Posts: 213
Default

Those people know nothing about how engine or a transmissions work. Now I have built numerous car engines and know a lot about transmissions, but not too familiar with bike transmissions. From what I know, coming from an engineering standpoint rev matching will not hurt a thing, this is what every rider SHOULD be doing. Especially on the street as it can reduce long term wear dramatically.
 
  #6  
Old 12-10-2009, 12:45 AM
Senior Member
Join Date: Dec 2008
Posts: 199
Default

how do u know when to rev match? at what rpm and miles u do it at?
 
  #7  
Old 12-10-2009, 01:27 AM
Senior Member
Join Date: Oct 2007
Posts: 213
Default

huh? you rev match when downshifting to match the revs of the next gear.
 
  #8  
Old 12-10-2009, 07:58 PM
Senior Member
Join Date: Jul 2008
Location: NOVA
Posts: 778
Default

Originally Posted by playb0i View Post
how do u know when to rev match? at what rpm and miles u do it at?
I'm not sure about everyone else but my "rev-matching" just consists of a little snap on the throttle when I shift before I let the clutch out...
 
  #9  
Old 12-11-2009, 02:59 AM
Member
Join Date: May 2007
Posts: 61
Default

To avoid confusion - you should blip the throttle when the clutch is pulled in, increasing the revs and more likely to match the revolutions of the rear wheel. This will be nicer on the bike all round, but most importantly will stop the rear wheel hopping if braking hard into a corner. This is a technique I think all test centres should instruct learners to do. Its far far safer practice than people image. Not only that, it sounds better and adds a little extra to the riding experience...
well thats my two cents worth anyway...
 
  #10  
Old 12-11-2009, 06:17 AM
Senior Member
Join Date: Aug 2008
Posts: 214
Default

Originally Posted by raylee View Post
It may be a bad habit I've brought over from driving, but I tend to rev-match when I downshift and I've heard numerous reports of it being one of the contributing reasons my last bike died.

Anyways, anyone do it regularly on an F4i? These things don't have slipper clutches so I feel it would be a good way to compensate, but I'd like to know if anyone else has this habit and hasn't blown up trannies and clutches? I find it's particularly useful when it comes to having to change gears around a corner I misjudged as to not disrupt the bike's flow.
Not a bad habit. Something we all do, probably, by force of habit. We had a big discussion on dowshifting a couple of weeks ago.

But if you break it down, how and when are you shifting? On a straight road, say approaching a distant stoplight where you know you have to stop and shift back into first, do you row down through the gears, declutching each time?

I don't. I roll off the throttle and slow down with brakes and with the clutch out. There's essentially no engine braking with the F4i. At some point, the clutch comes in and I snick down to either neutral or first without releasing the clutch with each shift.

Into a corner requiring a shift, I set up the line and the entry speed first, while simultaneously selecting the exit gear and releasing the clutch before the corner entry so I'm set for the exit. If you need to rev match, I guess that's the place.

But the thing is, if you select the right gear, the revs will more or less match because you've set the right speed already with front braking. You're not going to get much engine braking to spike the revs and if you do, you're one gear too low.

I read something a while ago written by one one of the GP racers, Rossi or Hayden or some such, that had this advice: On a four-cylinder bike, better to be in a gear slightly too low for the exit. On a twin, better to be slightly too high. Makes sense.
 

Thread Tools
Search this Thread
Quick Reply: Rev-match downshifting


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.