2006 Roketa 125, chain & transmission question.

Desp · 12-10-2009, 11:47 PM

I've recently started getting into pit bikes and purchased one for my wife to teach her how to ride a motorcycle. Of course I had to get one for myself. We each ended up with used Roketa 125s. Hers is a 2006 and I'm not sure what mine is, 2006 or 2005. I want to change out my front sprocket for a larger one to make first gear more usable and gain some top end speed, but I'm not sure if it's a 420, or 428, I can't find any info on it. Anyone that has one know of a good tooth sprocket to use up front? I weigh around 220...

On my wife's bike for some reason we're having transmission issues, its really really hard to find neutral, while standing still but very easy to find it while moving. If it is stopped in neutral and you lean it over it'll pop into first gear sometimes. I'm also getting a lot of false neutrals between gears and we're having issues shifting. Any advice on what to look for on fixing it? I have a donor motor to take apart if I need pieces for it.

Weldangrind · 12-11-2009, 01:48 AM

Welcome to the forums! Please take a moment to post in the Introduce Yourself section.

Your chain is likely a 428. If you provide a photo of your bikes, I can likely give you specifics on the sprockets, but this will be a good start: http://www.jtsprockets.com/52.0.html...el_uid=4367&p= This link will probably guide you towards the front sprocket (definitely not the rear), but you should remove your sprocket and measure the shaft teeth and width.

Start by counting the number of teeth on the front and rear sprockets and applying them to the ratio chart. You'll quickly get an idea of how the ratio will change by increasing the tooth count.

Have you changed the oil in your wife's bike? If not, change it right away and use synthetic motorcycle oil. It'll likely improve the shifts and help with neutral selection.

Cheers!

katoranger · 12-11-2009, 08:32 AM

I second the 428 chain and also the recommended oil change. You will be surprised as to how much difference an oil change can make.

You only need a qt. Less than that actually. I think they are 800-900ml.

Allen

12-10-2009, 11:47 PM	#1
Desp Join Date: Dec 2009 Posts: 1	2006 Roketa 125, chain & transmission question. I've recently started getting into pit bikes and purchased one for my wife to teach her how to ride a motorcycle. Of course I had to get one for myself. We each ended up with used Roketa 125s. Hers is a 2006 and I'm not sure what mine is, 2006 or 2005. I want to change out my front sprocket for a larger one to make first gear more usable and gain some top end speed, but I'm not sure if it's a 420, or 428, I can't find any info on it. Anyone that has one know of a good tooth sprocket to use up front? I weigh around 220... On my wife's bike for some reason we're having transmission issues, its really really hard to find neutral, while standing still but very easy to find it while moving. If it is stopped in neutral and you lean it over it'll pop into first gear sometimes. I'm also getting a lot of false neutrals between gears and we're having issues shifting. Any advice on what to look for on fixing it? I have a donor motor to take apart if I need pieces for it.
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12-11-2009, 01:48 AM	#2
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Welcome to the forums! Please take a moment to post in the Introduce Yourself section. Your chain is likely a 428. If you provide a photo of your bikes, I can likely give you specifics on the sprockets, but this will be a good start: http://www.jtsprockets.com/52.0.html...el_uid=4367&p= This link will probably guide you towards the front sprocket (definitely not the rear), but you should remove your sprocket and measure the shaft teeth and width. Start by counting the number of teeth on the front and rear sprockets and applying them to the ratio chart. You'll quickly get an idea of how the ratio will change by increasing the tooth count. Have you changed the oil in your wife's bike? If not, change it right away and use synthetic motorcycle oil. It'll likely improve the shifts and help with neutral selection. Cheers! __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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12-11-2009, 08:32 AM	#3
katoranger Join Date: May 2007 Location: Altamont, Kansas Posts: 15,103	I second the 428 chain and also the recommended oil change. You will be surprised as to how much difference an oil change can make. You only need a qt. Less than that actually. I think they are 800-900ml. Allen __________________ You meet the nicest people on a Honda Clone.
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