I'm not very good at downshifting :( - CBF 125

[shaungeo]

When I approach lights I down shift gear by gear like I was taught in the CBT(clutch in, throttle off, down shift and then release the clutch), the problem is everytime I downshift e.g. go from 3rd to 2nd gear (mostly at stop lights) and the light turns green again i give it some gas and the bike goes crazy. I also downshift at corners and when i give it some gas after downshifting the bike goes crazy.

Could you please advice me on what i'm doing wrong.

[Nobby the Bastard]

What do you mean by 'crazy' on the throttle?

I consider 'crazy' to mean the back wheel spinning and front end going light. I can't really square this sort of behaviour with the CGs lack of power...
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[shaungeo]

[misscrabstick]

You need gears to be appropriate to your speed and situation, if the bike is going "crazy" then I would think you have the wrong gear, stop trying to exactly do what they said on the CBT and try and develop some feel/empathy for your machine, try different gears, work out what feels right.

[Nobby the Bastard]

^

What she said. You are changing down too soon.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[misscrabstick]

[yampug]

doesn't sound like you matching engine speed to wheel speed before releasing the clutch.

just closing throttle kicking it down a gear and letting the clutch out will make the bike suddenly try to slow down with each down change, you want to try and match engine speed to wheel speed before releasing the clutch by increasing engine speed slightly matching the revs then releasing the clutch.

[Nobby the Bastard]

[yampug]

[shaungeo]

Ah alright thanks guys, I'll try and be more patient.

I guess it's only my 2nd day and i'll get it right eventually

[Rogerborg]

[dydey90]

When you downshift, the engine speed (on the rev counter) will go up. To do this, it has to get energy from somewhere to speed up. As you're not opening the throttle, it has no fuel to burn to achieve this and therefore uses the kinetic energy from the forward motion of the bike to speed up the engine, thus slowing down the bike as a whole.

By "going crazy" I assume you refer to the way it seems more responsive to the throttle. This is just down to how gear ratios work. Lower gears have higher acceleration and a lower top speed. Higher gears mean the bike struggles to accelerate but has a higher speed.
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This post is probably not serious and shouldn't be taken literally.
Past: CBR125,ER6f NINJA 650, ZZR600 Current: VFR750

[blurredman]

Until you get this technique right, don't down shift on a corner either, you could end up flying off if you don't have the proper control. Do it before the corner. Providing we're talking about town type corners.
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CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S, 1979 MZ TS150.
Current: 1973 MZ ES250/2 - 18k, 1979 Suzuki TS185ER - 10k, 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (295cc) - 40k, 1989 MZ ETZ251 - 51k.

[Nope.]

Much as above, you're likely selecting a gear which is too low for your current road speed resulting in the engine trying to catch up. Don't change down so far.
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Former: Derbi GP1 50, Sachs XTC 125, Suzuki GSXR 400 GK73A, Kawasaki ZX7R, Suzuki DR250, Yamaha RD350
Current: 2011 Yamaha XT660Z Ténéré, 2003 Yamaha YZR-R1 5PW (In Build), 2009 Kawasaki ZZR1400

[Rogerborg]

That's the obvious answer, but he says that whatever is happening is happening when he opens the throttle, not when he lets the clutch out.

On an 11bhp 125, you'd have to knock it into 1st and twist it full on to discombobulate it. OP says that it's happening in 2nd, which seems fairly unlikely.

Is the chain tensioned correctly? Do the tyres have tread on them?
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[dreamevil]

what about the posibility that hes been ridding around in a too high gear and when he lowers it he has more acceleration?

[CBFcarl]

I read this as when you release the clutch the engine revs up and the bike jerks forwards a bit? If so allow the bike to slow down a bit first, and maybe release the clutch a bit slower, I found the gear changes smoother when doing this.

[Rogerborg]

Several folk are making that very reasonable assumption, but that's not what he actually wrote.

Is probably dead now. We barely knew ye.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike