wierd noise near top speed - cg125

[Eas85]

So, went out for a ride yesterday and noticed that when i started getting up to top speed, around 50+ in fifth gear I started getting an, as best as I can describe... shrrr'ing sound, which continues while im at this speed until I slow down and it completely stopped when I dropped it into third.
So it starts in fifth and continues if I drop to fourth but stops in third. The noise is quite disconcerting, however, I couldn't really try and pinpoint it as there's so much other noise at that speed, but it definately wasn't the wind before anyone points that out.

To try and clarify some more on the noise, its more of a windy kind of shrrr'ing noise and sounds obviosuly different to the hum of the engine but its definately coming from the bike and its not the wind as it completely stopped at the same time as I dropped it into third.

Any help on this would be appreciated, I've only been riding 3 weeks so am pretty noobish.

The bike itself: 05 plate cg125, 6000 miles, serviced every year and serviced 3 weeks ago when I bought it.
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Currently riding a Honda Deauville NT650

[unitynotsocri...]

on small bikes,especially single four strokes there's loads of noises.
remember that its a push rod design with ONE cam and not designed to 'cruise' above 50mph.
vibration rattles and whines travel through the tank and footpegs and headlamp fairings.then it could also be your oil changing thickness as it boils up at high revs.
Make sure it's got clean oil and the cycleparts are bolted down thoroughly,after all its a cg!!!The later ones were designed to carry fat brazillian couples to work everyday ,not to do crisp high speed pushrod cruising.
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nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS

[Drake]

wind noise? or my solution put some ear plugs in sorts allsorts of random noises
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was: derbi senda, aprilia sx125, nsr250 mc16, cagiva mito, cb600 hornet now: mk1 bandit, KR1S, landrover series 3 light weight 2.5 petrol, 5speed box

[rumppole]

Its nothing to worry about. Its just air accoustics as you near the sound barrier.
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Sermo datur cunctis; animi sapientia paucis.

[cb1rocket]

just check it does at least have oil in the sump! Serviced 3 weeks ago? By yourself? If not you better check the service has been done

[jimbothe]

Chain whirr.
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[BigGeeking]

mine dose the same just keep an eye on the oil level as when i do my oil change every 700 miles (i use cheep o oil) i have a look at the leve every week and it stays the same then at around 800 miles it starts to drop quits fast thats why i do oil every 700 miles
but i ride alot i do about 600miles every 4 weeks more if i go out on my days off work and average 50/60mph
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Bendy "Flip front. I can filter down the M4 while shoving a Twix in my face."
honda CG 125 2001 SOLD-- current Bandit 400--SOLD. current SV650s 2000
MOD 1 ON 20/7/2011**passed** MOD 2 ON 17/10/2011***passed***,,

[MattJ]

[jpderv]

i wouldn't say its nothing to worry about but with that amount of miles chances are its nothing serious i have a hartford vr 125 which has the same engine as the cg a noise come into mine at high speed turned out to be the gudgeon pin that broke although no shame for the bike it has 43k miles 15quid later and as good as new again.
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1st bike= skyjet 125 2nd bike= suzuki ts 50 x 3rd bike= peugeot speedfight 2 100cc 4th bike= suzuki katana 50cc 5th bike honda cg125 6th bike = yamaha dt125 r 7th bike honda rebel 125cc 8th bike hartford vr 125cc current bike = honda mtx 125

[tahrey]