Vibration problem

[xww10]

Hi,

I just bought myself a Honda CD250U as a present after getting my learners and have been enjoying riding my first proper bike! Before that I had a Honda C50 for 3 years. Man what a difference. Anyways, I have a possible vibration issue which I can't seem to find the cause of. I've had the front wheel balanced, the wheel bearings look good, and all the fork bolts have been tightened up but I still get this vibration up and down on the handlebars at speeds of around 40-50kph. At 80kph, the vibration disappears. Can anyone suggest where else to look for the cause of the problem?

Thanks!

[cs363]

Hi,

I just bought myself a Honda CD250U as a present after getting my learners and have been enjoying riding my first proper bike! Before that I had a Honda C50 for 3 years. Man what a difference. Anyways, I have a possible vibration issue which I can't seem to find the cause of. I've had the front wheel balanced, the wheel bearings look good, and all the fork bolts have been tightened up but I still get this vibration up and down on the handlebars at speeds of around 40-50kph. At 80kph, the vibration disappears. Can anyone suggest where else to look for the cause of the problem?

Thanks!

Have you had the tyre checked? It may be blistered, flat spotted or not fitted properly.

[YellowDog]

Getting the wheel balanced is a good start however do also get the bearings checked out properly.

I'd also work from the ground up tightening all the bolts.

Why don't you give the guy you bought it from a call.

He'll know what's wrong.

[xww10]

I brought the bike to Pit Lane Motorcycles (next to Street n Sport) here in Christchurch and the guys there (Don and Grant) were great! They checked the tyre (which is newish) and balanced the wheel so I'm inclined to think its not the wheel/tyre combo that is the problem. I would think a wheel bearing/tyre issue would become increasingly worse with speed but does the fact that it goes away at higher speeds point at some other vibration issue? The vibration is quite slight so I'm not sure if its actually a problem or maybe something inherent in the characteristics of the bike.

I had an old biker friend ride it and he said that the vibration is too little to be bothered with. I don't know. This is the first big bike I've ridden and it feels a bit weird to me. I just don't have a gauge for these sort of things.

Thanks!

[The Pastor]

I just bought myself a Honda CD250U

This is the first big bike I've ridden

[xww10]

I just bought myself a Honda CD250U

This is the first big bike I've ridden

OK sensei I get it... I'll just ride it like it is :Oops:

[The Pastor]

OK sensei I get it... I'll just ride it like it is :Oops:
take it to a mechanic and ask them mate, dont piss around with bike shops

[AllanB]

Could just be a characteristic of the engine - they usually have a vibe spot in the rev range and yours may be right at that annoying speed.

Is it just a tingle through the bars not a wobble?

Easy to check if it is a engine vibe as it will appear at the same revs in any gear - but you may not have a rev counter?

Run it through the gears fairly slowly and smoothly from 2nd to 4th and keep an eye out for the same tingle. If the vibe is at say 3,000 rpm it will appear at a low speed in second and a higher speed in 3rd & 4th (or the same revs if you have a rev counter).

Also check the engine mounts are tight.

If you are cheeky ring your local Honda dealers and see if they have a demo model ....... try it out and see if it is the same. :whistle:

[xww10]

Thanks AllanB, probably not engine as I pulled the clutch in today and the vibration was still there. I would say it is more than a tingle, quite high frequency but the amplitude is small, say a few mm of movement at the grips. The vibration was pretty bad to begin with when I first picked up the bike. Then the got the wheel balanced. This cut out about 90% of the vibration. Then, I went over the forks and tightened the bolts on the triple clamp etc. turned out one was much looser than the rest.

Does the fact that the vibration disappears at high speed mean anything?

[jubilant]

mate it may or may not help but i found my exhaust needed the bolts tightening and that has fixed but also been told that vibration in the bars can be sorted with bar weights!!

[MSTRS]

We had one of those bikes, and it had the exact same low-ish speed wobble, which you describe as a vibration. It was most noticeable at about 45kph, and quickly disappeared as the speed crept up. I topped it out at about 130 (closed road, of course) and the bike was as steady as a rock.
Perhaps you have the same bike (it was sold to an old guy in Nelson)?
I had checked all the bearings, etc and had the front wheel balanced too. The bike did have a slight buckle in the rim. Not bad enough to bother with. I would have tweaked the spokes to straighten it, if I could have been certain I wouldn't break any...some were a little rusty.

[xww10]

Hmnn, actually do u remember the rego number? PM me the rego and we could certainly find out but yeah, that sounds exactly like my bike. I wonder if any other CD250Us out there have the same issue?

[EJK]

Could be loose chain riding on low revs?

[xww10]

Could be loose chain riding on low revs?

Thanks EJK, I was following up on ur loose chain theory but I found out another thing. The rear sprocket is a bit loose. Has a bout 1-2mm of side to side movement. Is that normal? Wheel looks good.

[MSTRS]

The sprocket on the rear wheel shouldn't really move. the front sprocket may, however, be allowed some sideways play on it's shaft. Depends...some bikes do, some don't. As long as the nut/bolted plate/fixing system is designed to allow that play.

[EJK]

Where about chch are you? If you can, you can bring it to our Chch Wednesday Maintenance Evening and we can take a closer look at it for you :)

Here's the link: http://www.kiwibiker.co.nz/forums/showthread.php?t=97587

I'm preety sure there will be atleast SOMEONE that will ike to help you out :)

[merv]

Sprocket thing depends on whether its got a cush drive or not. If its like some bikes I've owned they just have a bloody big circlip or something doing a similar job holding the back sprocket in place. Can be a bit disconcerting to see the back sprocket move a little bit, but if its meant to be then fine, if not figure out why and get it tightened.

[xww10]

Sprocket thing depends on whether its got a cush drive or not. If its like some bikes I've owned they just have a bloody big circlip or something doing a similar job holding the back sprocket in place. Can be a bit disconcerting to see the back sprocket move a little bit, but if its meant to be then fine, if not figure out why and get it tightened.

Cheers Merv,

My Honda also has a big circlip holding the sprocket in. I had a look at the manual for the bike and everything is installed properly, i.e., no spacers missing etc. So I guess it's meant to be like that. OK, back to the original problem!

[CookMySock]

At around 5,000rpm my bike blurs its mirrors and the windscreen nearly pops out, so you are small-time yet. ;-)

While you were there getting them to balance the wheels, did it occur to you to ask them to ride it and offer you their diagnosis or opinion?

Steve

[xww10]

At around 5,000rpm my bike blurs its mirrors and the windscreen nearly pops out, so you are small-time yet. ;-)

While you were there getting them to balance the wheels, did it occur to you to ask them to ride it and offer you their diagnosis or opinion?

Steve

Nope. Not at the time :bash:. However, T.W.R. has offered to have a look at it and I was hoping to make it to the maintenance night tomorrow but didn't know I had plans beforehand. As soon as I get a day off I'll have T.W.R. have a look at it.