YBR125 Strange Sound

[sparkywilliam...]

Hi
I think i have a problem with my YBR 125.
I bought it secondhand,a one owner 2007 with 13,000miles.
When i change up the gears there's what sounds like a whiney\whistling noise like something's not oiled/greased.
Its almost like its low on oil but it was fine when i emptied it and ive used expensive castrol to re-fill it.
I was told it had a recent new chain and sprockets and i regularly lube the chain,visually it looks fine.
In top gear doing 50 plus its fine and she sounds smooth.I just can't stand slow traffic with this gearbox!
This is the first YBR i've had an am used to an old CG125 and i found the gears alot smoother on that an sounded much smoother transmission.
Can anyone suggest anything obvious to check? Could it be the previous owner has ragged the gears or could it be the chain?
Any help much appreciated.
My last question is i've been quoted ?130 all in to have fittted a pair of Michelin Pilot Sporty tyres,is this competitive?
Thank You

[Frost]

Does the sound change according to your speed, or according to the engine rev's?

Possibly causes:
wheel bearing
chain & sprockets
Brake disc warp
Brake pads sticking
Suspension too soft and something touching
rubbing plastics
wind whistle through a hole.

[sparkywilliam...]

its when the engine is in low revs.at high speed i cant detect it.
It feels more like a transmission problem,like chain,or gears.
what can i check? All i know about chains is they should be fairly tight and that sprockets can wear,is it worth me takin off the front sprocket cover and checking for wear?

[Mark65]

Hi
Yes the gearbox can make a sound when riding in 4-5th on a quitish road, similair to the big bikes dont let it worry you its a kinda cruising noise ive heard it on many big bikes as they have gone past, i got the 2 michilin sportys fitted and balanced for around ?90 from an online firm and a national tyre centre outlet fitted them, i will try and find receipt.

www.Tyre-shopper.co.uk

Mark
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07 Yamaha YBR125, 07 Honda CG125 , 15 CBR300R (Chocolate Crank, Deaded), 16 CB500FA, 19 Honda Forza 300, 70 Suzuki SV650