Okay, I’ve had an old 150cc Yamaha for about 2 months now and in general I’m really happy with it. The only problem is that whenever I ride over a bump in the road parallel to my tyres or brake (even gently) in the wet, the thing goes crazy on me and does a buckin’ bronco all over the road. I feel really comfortable at anything above 30-40km/h but at lower speeds I’m never quite sure what the hell it’s going to do.
Today was the second time in my life that I’ve ever come off a bike and by Gordon if I’m taking the blame. It was wet - but not even that wet - and I was doing maybe 5km/hr at an intersection when the front wheel went completely nuts and wrenched itself out from under me. I was slowing down very gently using just the front disc brake.
Should I give up and sell the thing back to a bike shop? Or could I perhaps try bigger/better wheels/tyres? It seems strange that the tyres are barely (if at all) bigger than my 125cc runaround, and this thing is at least twice the weight.
[quote=“llary”]I was slowing down very gently using just the front disc brake.
[/quote]
Here is part of the problem. Why in the world would you use just the front brake? Generally you’d be on the rear just before the front to keep the bike in a straight line (rear wheel dragging behind rather than coming up beside you or sailing over your head)
70-75%% of your stopping comes from the front brake but gnerally you’d expect to brake more with the rear as it is safer if there is oil on the road or whatever on the road.
How about having some maniac test ride the bike for you and give the front brake hell and see what happens.
Maybe nothing is wrong with your bike at all…You said that the road was a bit wet and you were slowing down coming up to an intersection…Well, did you notice if you went off while going over those fat white lines painted on the road? ( Like to call those things “suicide strips”)…Those lines are slippery as hell with a bit of water on them…
I would bet any money that you have one and maybe two problems. Low speed is not good, high speed is better and the bike doesn’t handle well. You can rule out the fork problem, high speed would be worse. Breakes either, speed wouldn’t matter. Your front wheel bearing is shot(possibly rear as well but less than likely, they last far longer than the front ones) and the bike leans from the front end against your will. It will cost you 250NT labour included.
You could possibly have a worn out swing-arm but from your description, it sure sounds like a bad wheel bearing. Put the bike on the double stand and see if you can feel any loose on the front wheel. I bet you will.
Rear brake? On a scooter? What’s that then? I’m no bike expert by any means but I’ve ridden enough of them including big’uns to know that this one doesn’t feel right.
While it was still wet I went to a safe-ish place and did just that. It stopped and I’m still alive. The mystery continues.
[quote=“Ironman”][quote=“llary”]I was slowing down very gently using just the front disc brake.
[/quote]
Here is part of the problem. Why in the world would you use just the front brake? Generally you’d be on the rear just before the front to keep the bike in a straight line (rear wheel dragging behind rather than coming up beside you or sailing over your head)
70-75%% of your stopping comes from the front brake but gnerally you’d expect to brake more with the rear as it is safer if there is oil on the road or whatever on the road.
How about having some maniac test ride the bike for you and give the front brake hell and see what happens.[/quote]
Hmm… if I ride at moderate speed I’ve noticed the bike keeps wanting to pull me to the left.
When you ask me to check for slack on the front wheel, are you talking about where the forks attack to the wheel?
[quote=“bobepine”]I would bet any money that you have one and maybe two problems. Low speed is not good, high speed is better and the bike doesn’t handle well. You can rule out the fork problem, high speed would be worse. Breakes either, speed wouldn’t matter. Your front wheel bearing is shot(possibly rear as well but less than likely, they last far longer than the front ones) and the bike leans from the front end against your will. It will cost you 250NT labour included.
You could possibly have a worn out swing-arm but from your description, it sure sounds like a bad wheel bearing. Put the bike on the double stand and see if you can feel any loose on the front wheel. I bet you will.
[quote=“llary”]Hmm… if I ride at moderate speed I’ve noticed the bike keeps wanting to pull me to the left.[/quote]You did not mention that earlier. In this case, Sandman may be right to point to your forks. A bad front wheel bearing will cause loss of balance on either side, not just to the left.
[quote]When you ask me to check for slack on the front wheel, are you talking about where the forks attack to the wheel?[/quote]Yes.
Think about it llary, if you drive a bike that pulls to the left, what’s likely to happen on a slippery surface?
Definitely take it in to Chen or somebody else you can trust. It sounds like bad bearings, swing arm bushings, suspension problems and possibly bent brake rotors or loose calipers. maybe the headset bearing is worn out ot loose as well. Some or all of the above, anyway.
Put the bike on the center stand. Get a friend to hold the back down and spin the front wheel. It should spin freely and not be obstructed by anything. Grab the wheel firmly when it stops spinning and shake it up and down. There should be no rattleing or play. shake it back and forth. No play. Get your friend to hod the front end down and grab the rear whel and shake it back and forth. should be no rattleing or play. Put the bike on the ground, sit on it, hold the front brake firmly and shake and twist the hell out of the handlebars in all directions. Should be no play or noises.
I’m assuming that you have a front disk on your old Yammy. Tell us more about the model.
I’m assuming your tire isn’t flat…
seriously, get it fixed; save your skin. Motorbikes are dangerous…
I just had another quick check on open ground and it must have just been my imagination… no real pull either way.
[quote=“bobepine”][quote=“llary”]Hmm… if I ride at moderate speed I’ve noticed the bike keeps wanting to pull me to the left.[/quote]You did not mention that earlier. In this case, Sandman may be right to point to your forks. A bad front wheel bearing will cause loss of balance on either side, not just to the left.
[quote]When you ask me to check for slack on the front wheel, are you talking about where the forks attack to the wheel?[/quote]Yes.
Think about it llary, if you drive a bike that pulls to the left, what’s likely to happen on a slippery surface?
Next time you’re stopped, point the front wheel dead ahead and wiggle the handlebars; if there’s play in them, that is, they move without moving the wheel, it’s your bearing.
As far as I know, they use Taiwanese/Japanese for bearing, so it’s just “Bay Neen”, sort of like Beijing with N replacing the J.
[quote=“plasmatron”]come on guys… the problem is obvious… Llary you didn’t go to the temple and get your little tie on “good luck” packet for your scooter did you?..
you foreigners just don’t understand Taiwanese engineering… [/quote]
Is this a scooter or a motorbike? Get those Battleaxes off and fire on a pair of Diablos. Far better in the wet. Oh they’ll laugh at me now, but he who laughs last laughts longes… laughs… the longest laugh, never been fooled again. Or something.
I’m no bike expert by any means but I’ve ridden enough of them including big’uns to know that this one doesn’t feel right.
