I have an Earle's Fork front end with 15" car type wheel ( on a BMW R100 ). After haveing a new front tyre put on I'm experiencing alot of vibration at around 65 mph. Below this speed everything is fine.
Before putting the new tyre on, I replaced the front swingarm bearing's and the steering head bearing's appeared to be okay as are the wheel bearing's. All sidecar attachment's are okay.
I have messed around with the front suspension (soft/hard), but this has done nothing to rid the vibration.
So would I be right in thinking that an out of balance wheel would induce this vibration at a certain speed? I cant get the wheel balanced on a machine because being modified for the bike it wont fit on one.
When I look down at the wheel whilst on the move, it dont half look to be pattering a fair old whack and to hold onto the bar's at 65/70 mph is real annoying.
Or have I missed something else?
Safe riding Karl.
I cant understand how you got a car tire on the earles fork. it has a limit of a 4.00 wide tire.
There are static balancers that will accept the small center of a motorcycle wheel. I have an old one that I got from J.C.Whitney years ago. Have you tried any bike shops?
Lonnie
Northwest Sidecars
Bob in Wis - Look on my user profile there's a photo. The tyre is a 125/15.
Lonnie - Thank's for that, but where I live there's no bike shop's and I'm surrounded by sea. Anyway after today's ride I'm begining to think that it's the suspension that's at fault (too hard).
Safe riding Karl.
certainly sounds like a balance issue,however; I have heard no mention of the ever critical tire presure, a couple of pounds makes a world of difference,...I run 26lbs on the bike rear (car rubber), and 8lbs in the car tire on the hack,. cause that's what works best for my bike's ride....just a thought...
Originally written by outfit on 5/11/2008 5:55 PM
Bob in Wis - Look on my user profile there's a photo. The tyre is a 125/15.
Lonnie - Thank's for that, but where I live there's no bike shop's and I'm surrounded by sea. Anyway after today's ride I'm begining to think that it's the suspension that's at fault (too hard).
Safe riding Karl.
karl, the pic is too small to really make out anything.
If it really is an Earles fork [BMW] and not a different brand LL, try putting the original shocks back on..that might help the wobble problem.I put an earles on my /5 and it is steady all the way up to 95MPH {my limit not the bike's]
Crawf - Jezerbell's, that's one low pressure on the tub tyre. Reckon I could blow that ( 8 lbs ) into the tyre.
Bob in Wis - It's definatly a BMW Earle's Fork set-up, adapted for disc brake's. It's not a wobble, but a vibration and a heck of a one at that, but only when I reach 65 mph and it does'nt go away at a higher speed. When I look down at the wheel, it's pattering quite a lot as if the damping is too hard. I also notice that when I take it off the centre stand, there is very little suspension movement, infact there is none. Also when I brake hard there is no upward movement of the fork's. I have ordered home some different shock's, so will let you know how that work's out.
Safe riding Karl.
Unhook the shocks and make sure the swingarm moves easily. Then when you hook the shocks back up make sure the mounting points are not so thight theat they do not allow movement. If the mounting points for the shock are rubber there shoudl be a metal sleeve in the middle of the hole that controls how much the rubber is compressed when the mounting bolt is tightened.
AY LADDY!,..but I be carry'n only a wee one, and need all the comfort I can find!. save the blowin' for the pipes! .hehe..the car tire has no trouble at the lower preasures and it greatly improves the ride and softenes the tilt-away while riding, 155/60/13 car rubber. ..when working on local hard-tailed choppers, I found the owners did this also for a better ride. I'm running nice road here also,..no cobble stone or rough country roads.Is the pre-sprung weight on the shock set correctly for ya????can you soften the setting?? say AY! to me clan, cheers crawf ord
Claude - I put new bearing's in there. I have just put a pair of new suspension unit's on and although the ride is better, the vibration is still there. So I'm now thinking that it's the wheel that's out of balance. Being a car wheel with a bike hub I cannot get it balanced on a machine, so I'm looking at the possability of staticaly balanceing the wheel. Has anyone any advice on this please?
Crawf - I be resting a bit noo tha wind is doon. Aye had a nip to doon tha pleasas? I have tried different suspension setting's and it dont work. I even put the front tyre down to 20psi and that did'nt work either.
Thank's for you're replies.
Safe riding Karl.
soft tires and stiff suspension can be tough to muscle through...assuming all is tight and correct in the frame neck,..I still have to look at wheel/tire balance or a missalignment somewhere....wheel balance will certainly make it tough to keep from hopping off the road at a"peticular speed"..good luck, crawf.
Outfit wrote:
>>>I'm now thinking that it's the wheel that's out of balance. Being a car wheel with a bike hub I cannot get it balanced on a machine, so I'm looking at the possability of staticaly balanceing the wheel. Has anyone any advice on this please?<<<
Well to get an idea you could unhook the brakes so there is no potential of drag from them. Jack up the front end and spin the wheel. See is one part comes up at the bottom all the time. If so stick on some weight across from it repeat the process etc etc. This may nto be THE high road to balaning but it could detect and even get rid of your problems.
Another thought would be to "let your fingers do the walking" and call around to see if any of the area tire shops have a static "bubble" balancer. Most shops use a spin balancer but, if you work on them, will admit to having a bubble balancer buried away somewhere in the back room.
FWIW, Claude's balancing method was specified as the factory-approved method by BSA for their bikes.
Sarge
Thank's guy's. I've had one of those portable wheel balancer's brought home, but have not had time to use it yet due to some consistantly sunny day's (almost un-heard of in my neck o the wood's). I'm having to put some new window frame's in the old house. I'll let you know how I get on when I get fed-up of going up and down ladder's.
Safe riding Karl.
Just an up-date. Fed up of going up and down ladder's, so after tea I took front wheel off and put it on my new wheel balancer. It needed a load of weight's, but hey it's worked (no vibration). So after all it was an un-balanced wheel (I'll get round to doing the other two wheel's soon). Did'nt realise that an un-balanced front wheel would cause so much vibration through the handlebar's.
Thank's again.
Safe riding Karl.
