Downshifting Concept Question

[Tripwire]

Ok. If I recall correctly, I've read in numerous posts that you can possibly lock up your rear tire while downshifting, if you dont match the revs for the next gear. Here is the question: What are the reasons why the rear tire could lock up? I know about engine breaking, and I understand how you will slow down, but I dont understand what could cause it to actually lock up. Any thoughts?

[BobKat2002]

Engine Braking pretty much sums it up.

'Course most of the current line of SS bikes have slipper clutches to minimize rea wheel lock up while down shifting.

[Black_peter]

No thoughts.. Only facts..
The rear tire doesn't lock up..
What can happen is that it will chirp and
lose traction.

Say you are going 50 MPH
at 5000 RPM in 4th gear..
That means you are traveling with a surface speed of 4400 feet /min.
If your tire is say 6 feet around,
that means your wheel is spinning at 700 RPM (or so)
Now you downshift.
In 3rd gear at 5000 RPM your rear tire is only going
to spin at say 500 RPM a surface speed
of 3000 feet/ min.. However the motorcycle
is still moving at 50 MPH (4400 feet/min)
Sure the reves will rise and the bike will slow down
but in the instant you release the clutch the rear
tire needs to deal with the 1400 feet / min difference.
Unless its sticky as snot and your engine is willing to rev up fast it's going to break it's grip with the road.
Not locking up but skidding and potentally giving you a lot of heart burn..

[Tripwire]

Wow. Thanks alot for that explanation BP. Putting it into scientific form like that helps a nerd like me understand!

[iwannadie]

do they make slipper clutches for the kat? be kinda cool to have that setup ha.

[StevieB]

I just bought an 83 Honda Magna V45, got it cheap at a garage sale. Not trying to hijack this thread, but seller gave me a 83 edition of a mc mag, and the article on the V65 says it has a clutch that will disengage if you downshift too far, thus preventing the rear wheel from churping/ loosing traction. Sounds like a slipper clutch to me! Are they that old??

[md86]

do they make slipper clutches for the kat? be kinda cool to have that setup ha.

Just learn to blip . Kinda fun anyway .

[DreKat]

droping from 6th to 5th is not a big deal but if you drop from 6th to 4th or 3rd then you are asking for it.

[gpggnnn]

do they make slipper clutches for the kat? be kinda cool to have that setup ha.

Just learn to blip . Kinda fun anyway .

I heard of bliping, but what exactly is it?

[BarMatt80]

do they make slipper clutches for the kat? be kinda cool to have that setup ha.

Just learn to blip . Kinda fun anyway .

I heard of bliping, but what exactly is it?

it is just like driving a car, basically matching revs when you downshift. So you don't have that throwing you forward or clunk into gear when you let the clutch out. basically just blip or give gas so say if you are in 6th gear at about 7k, you would downshift to 5th and the rpms are going to go to 8 or 8.5k you "blip" it so the engine doesn't meet the trans with a 1.5k rpm difference. hope that helps. also saves and prolongs the life of the clutch in car and bike if done right.

[gpggnnn]

Thanks barmatt80
I'll start working on that.

[md86]

But you HAD to know that was coming !