Quite serious vibrations/bouncing

[kelena]

hi everyone.. i'm not sure if this section is suitable for posting tech issues, if it aint, please help me move this to the right section..

 

here goes: i just got my bike, a Rieju RS3 on Monday.

Been taking it out for rides just to get acquainted with it. however, i realised something about my bike which is quite unnerving.

at speeds approaching 70kph, my bike hops and bounces like a bunny..and i'm not very sure what's happening, so i thought i could seek some advices from the techies and gurus

 

i'd like to have some idea first, before heading back to the motorshop..as this bike is still relatively new, some issues may, at this point of time remain undetected..

 

thanks!

[kelena]

To add, the jumping and bobbing comes intermittently, like every 3-5 seconds.. As a new rider, I don't feel really safe when that happens, so um going slow..by the way, my bike's a Rieju RS3 125..

Any insights will be appreciated..

[stsoh]

cant really tell wats ur problem is?

check ur tire pressure, pump 29 psi or 2 bars for both tires when cold (this mean let tire cool off first. dun pump after a long ride).

best is to let the motorshop troubleshoot since it is new.

[kelena]

Thanks! I did that earlier.. Pumped to the psi recommended by the manufacturer, but it didn't help. I'm just worried it's got something to do with engine harmonics.. Like resonance and stuff.. Then it'd be tricky. Perhaps I can only go back to the shop and get them to troubleshoot..

Anyone any idea besides tire pressure?

[CSV]

wow! a new rieju rs3! thats a very very nice looking bike. meet up and show me sometime.

 

bring it back to distributor and demand they get it sorted out. its a new bike, so warranty should cover it. could be your suspension also which i strongly believe it is.

[kelena]

wow! a new rieju rs3! thats a very very nice looking bike. meet up and show me sometime.

 

bring it back to distributor and demand they get it sorted out. its a new bike, so warranty should cover it. could be your suspension also which i strongly believe it is.

 

oh, thank you very much! of course, we can arrange for a teh session =)

i also was thinking about the front suspension, but heck! what do i know about bikes? lol

but first, i gotta get it sorted out. lol, a myriad of problems..squeaking sound coming from the swing arm, etc.. but it still doesnt dampen my spirits! will bring it down to the distributor, and will only budge when everything's fixed!

 

and thanks for all who chipped in!

[Chatterbox]

I once has a similar issue on my scrambler, it could be either the valve or the clutch plates itself.

 

To add, the jumping and bobbing comes intermittently, like every 3-5 seconds.. As a new rider, I don't feel really safe when that happens, so um going slow..by the way, my bike's a Rieju RS3 125..

Any insights will be appreciated..

[three]

Try a lower gear.

[kelena]

I once has a similar issue on my scrambler, it could be either the valve or the clutch plates itself.

 

thanks! but i'm thinking the possibility of valve clearance or clutch plates pretty low, as my bike's new..

it feels like some form of resonance or something..the vibrations arent hand-numbing types, it's more of the handlebars coming up and down..

[kelena]

Try a lower gear.

 

i thought it might be an inappropriate gear..but the vibrations are different from that of a wrong gear, rather it's more of speed-oriented; at a precise speed of 61kph..the bouncing appears. up to that speed, it's smooth though..

[stsoh]

check front brake disc rotor might have a high spot.

like a warp disc rotor will gallop when braking.

[Jehuty]

Maybe something wrong with the EFI or carburettor. Warped brake disc got this scraping sound at low speed.

[kelena]

check front brake disc rotor might have a high spot.

like a warp disc rotor will gallop when braking.

 

good point..but i'm guessing if it's a case of warped rotors, the effects would be more pronounced during braking? but i dont recall any vibes coming in during braking..

 

but nevertheless, i'll still check it, in an elimination process.

[Jehuty]

good point..but i'm guessing if it's a case of warped rotors, the effects would be more pronounced during braking? but i dont recall any vibes coming in during braking..

 

but nevertheless, i'll still check it, in an elimination process.

 

Hold down the brakes, if your brake lever pushes up and down while you're braking = warped rotors.

[kelena]

Hold down the brakes, if your brake lever pushes up and down while you're braking = warped rotors.

 

i remember braking was a pretty smooth affair..

 

but thanks for all the suggestions! you guys were a great help..

 

but funny only one person spoke about suspension..could the suspension be too soft?

[Zeth0la]

i remember braking was a pretty smooth affair..

 

but thanks for all the suggestions! you guys were a great help..

 

but funny only one person spoke about suspension..could the suspension be too soft?

 

If ur traveling on straight road and ur bike does what u described, should not be due to the suspension. if ur taking corners, then prolly it's a tad soft.

 

I'm guessing the brakes may be the cause too... Cause the calipers may be touching the disc thus causing a reduction in speed then when the warped disc clears the calipers it's back to normal speed.

 

Hmm... But I'm no expert. Does it happen on all gears? Or specific gears?

[Jehuty]

If ur traveling on straight road and ur bike does what u described, should not be due to the suspension. if ur taking corners, then prolly it's a tad soft.

 

I'm guessing the brakes may be the cause too... Cause the calipers may be touching the disc thus causing a reduction in speed then when the warped disc clears the calipers it's back to normal speed.

 

Hmm... But I'm no expert. Does it happen on all gears? Or specific gears?

 

All gears. If suspension soft then when cornering, you'll feel the bike sway up and down, more apparent in hard cornerning.