front wheel lock-up when downshifting ? pls help !
 

good day,


I`m a pretty new rider (for about 4 months). So far I had the chance to test some bike models, like a Yamaha R1 for about 3 weeks and a Buell 1200 for the same time, and a Daytona.

Now I own a Honda CBR 600 from 2008, and I love this bike, looks and feel :), but lately when i was trying to improve my downshifting and braking riding skills I started to notice some very strange noise and manifestations.

Every time I downshift fast (at high speeds, like going into first gear at about 65 km/h) and use the read brake/ front brake at the same time, the bike makes a very very strange noise, like bonking, and in the meantime the fork bonks up and down pretty hard and fast (like a swift tremble) – it gives the feeling that the front wheel may lock-up any second.
Ok, so i know that if i don`t blip, the rear wheel may skid or lock, and that would be understandable and ok, but the problem is that this bonking noise it comes from the FRONT wheel (or so it seems, because it may come from the rear or anything else, but I can`t pinpoint it that well)
I have brand new Meltzer M5 tires and brake pods (changed all of them about 2 weeks ago) but the situation remained.

What I noticed is, the bonking noise comes especially if I use the rear brake at the same time as downshifting (also at this time I’m on the front brake pretty hard also). Also the noise it reduced if i blip the throttle a little harder when i downshift.
The bonking and the front fork tremble only happens when I downshift into first gear at pretty high speeds and if i let out the clutch fast (not so gradually) – while braking at the same time.

What I would love to understand is what is going on... because this happens in the worst moments like when i have to do an emergency stop, and while this happens the breaks don`t work that well and also the noise and tremble are scary and I tend to loosen the brakes (front and back) and thus increasing the chance i will not stop in time.


Thank you in advance !

Mate , I approved your thread ....


All the symptoms that you are experiencing are caused by not quite matching the engine revs with your down shifting ....


The harder and the higher speed that you try to down shift , the higher the engine revs you have to keep up " or match " ....


Practice makes perfect !! keep trying it out on a quiet piece of road some where .... and you will get it right ...

Major Axel hop will be the next thing you strike !!! and that can bring you unstuck !!! .... practice all this stuff as I said , on a quiet piece of back road till you figure it all out ....:icon_beerchug:







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i wouldnt be downshifting into first for any reason......motorcycles have amazing brakes and its pretty much unnecessary to be downshifting past 2nd

Unless you are coming to a complete stop.... You need to be in first to be able to get away fast in case someone behind you doesn't stop in time.

Now while downshifting to 1st during this stop, I wouldn't let out the clutch.

this was all very useful information indeed, thank you !

I was downshifting into first to practice emergency stops, and i read that it helps to learn to downshift into first. Not sure if what I`m doing was ok.

I still find it strange that none of the CBR 600 users had this tremble+bonking noise, even when testing.
I can make it happen even in second gear sometimes if I let go of the clutch really fast at higher speeds. And the noise especially comes out when rear breaking also.

Anyway thank you for approving my post :) but your advice was not so clear, regarding what I should do or not, or even this is a common problem or if there is something wrong with my bike,

I still get the feeling that the front wheel is locking up and I really do not understand the reason for this (like i said I’m kind of a newb and this may not be the case)

and 1 more thing :)
what is a "Major Axel hop" ? :))

Noob question: If you're worried about panic stops, should you even be downshifting? Just brake and roll off the throttle?

I know what your talking about. Can't really explain ATM as I'm at work. Its not coming from the front end. Its coming from the drivetrain.

You're goin too fast for the gear you downshifted into.

when you downshift into a gear and your rpms are too high the tire wont go as fast as your moving and it will hop like the wheel is actually locked up, then eventually start rolling again. DO NOT ever downshift like that in a turn or you WILL end up on the ground pretty quickly

Your engine is high in the RPM's, you release the clutch(not slowly let it out) correct??? your clutch plate reengages the gears when it is not spinning as fast, thus one has to slow down, one has to speed up to match in the middle or parts would go flying. The noise you are hearing is your transmission/gears catching up/slowing down to match. That is the noise you are hearing. If your forks are "trembling" I take that as they are shaking back and forth really fast, buy a steering damper, or take it to be inspeected.