Help needed for mechanically dyslexic Scotsman

Hiya
Happy New Year.

My bike has developed a clunking sound from the front end when going over humps and bumps in the road. Not every bump, about 10% of the time.

Any help would be greatly appreciated.

Cheers

Jock

Miles on scoot? a lot of rough roads? serviced regularly ( head bearings ) ?  So many sounds can travel, where you think it is may not be where it is.


Side note, that beastie ( photo ) what is the breed? there is a farm nearby that has 4 of them out to pasture, impressive looking animals.

HNY Jock

My tuppence worth, firstly loose body panels/fairing or glove boxes. Mine clunk over certain road faults (hard to find a good road UK side nowadays & the New Forest has it's share of humps, the New Forest pixies have tried killing me twice)

Second would be front forks (push down sat astride are they noticeabley softer.

Finally head stock bearing (put scoot on centre stand so front wheel off the ground and turn gentley from side to side on full lock, you may notice a 'drop' which is the worn bearing collapsed)

but as stated noises travel and once we believe we have a fault the mind plays awful tricks

As for the beastie I believe it's a Scottish long horn and def' not native to the New Forest (unlike the horses)

oldwingguy wrote:

Miles on scoot? a lot of rough roads? serviced regularly ( head bearings ) ?  So many sounds can travel, where you think it is may not be where it is.


Side note, that beastie ( photo ) what is the breed? there is a farm nearby that has 4 of them out to pasture, impressive looking animals.

Hiya Oldwingguy

Thanks for taking the time to reply to my post.

The scooter has done 40,000 miles.
The roads in the UK are terrible, pot holes & sunken drain covers.
Serviced regularly.

The beastie in the photo is a Highland cow.

Scootypuff Snr wrote:

HNY Jock

My tuppence worth, firstly loose body panels/fairing or glove boxes. Mine clunk over certain road faults (hard to find a good road UK side nowadays & the New Forest has it's share of humps, the New Forest pixies have tried killing me twice)

Second would be front forks (push down sat astride are they noticeabley softer.

Finally head stock bearing (put scoot on centre stand so front wheel off the ground and turn gentley from side to side on full lock, you may notice a 'drop' which is the worn bearing collapsed)

but as stated noises travel and once we believe we have a fault the mind plays awful tricks

As for the beastie I believe it's a Scottish long horn and def' not native to the New Forest (unlike the horses)

Hiya Scootypuff Snr

Thanks for taking the time to reply to my post.

I'll try your suggestions about the forks and bearings in the morning. You're right about the state of the roads in the UK.

The beastie is a Highland cow and there actually are 5 or 6 of them roaming the New Forest!

The Highland cow or 'coo' as we used to say was a familiar sight to school kids of my generation, as it was on the wrapper of McCowan's Highland Toffee. As nice as it tasted, chewing it was similar to super glueing your teeth together and kept NHS Dentists in regular employment filling Baby Boomer children's tooth cavities.

No milk n' cookies for we Brits of the bread and jam generation, and even now the word flossing will be met with blank looks by a lot of people.

First check that the fender is securely bolted to the fork legs. 

Secondly take all your "stuff" out of both cubbies and under the seat. Then go for a ride to see whether those same clunks & rattles go away.

Now for the serious stuff. There's not a lot of travel on either the front or rear suspension. You might want to consider replacing the fork oil with something heavier --say 15 wt, but not more than 20 wt.

But before you get too far into the woods, you should check the steering head (head stock) bearings. As OWG and Scootypuff mention, jack up the front end (scissors jack under the engine area) with the center stand supporting the rear. Remove the the front wheel, fender and secure the brake caliper off and away from the fork tube and check the head stock bearings for play and dead spot.

At that point you are just 4 bolts away from removing the fork tubes. If you decide to go with heavier fork oil you might also consider adding a 10mm shim (PVC pipe) to the existing fork springs as well. That'll slightly reduce the suspension travel but stiffen & preload the springs. 

Tim

[Afterthought] Before you jack up the front end you should break loose the four bolts holding the fork legs to the "triple tree". They are torqued pretty tight and you'll only succeed in toppling the scoot if you try to loosen those bolts with out the scoot being firmly secured.

I hear similar clunks with potholes, manhole covers, etc. but as long as the bike is behaving okay after such mishaps I don't get concerned. However, if you have handling problems or persistent clunking you should take a closer look as suggested.

Jay.

An easy, quick check of the head bearings is with the bike shut off, hold the front brake on firmly astride of the bike and rock it forward and back. If you hear or feel a noise it could be the head bearing loose or possibly the fork tube bushings worn.

With only the rear brake held try rocking the bike. Any slop in the rear suspension will make itself more noticeable in this manner.

As already mentioned the tupperware can make odd noises. One way I chase it down is to put masking tape or such like over the joints of plastic. Then take the bike out on a bumpy road. If the noise is gone you have identified the cause. After that it's a matter of removing tape a joint at a time until the noise comes back, when it does you have your culprit.-

Update:

I have tried to identify the mysterious sound using the advice given. Everything appears to be normal!

I rode slowly over some pretty high & wide speed bumps and the noise occurs when I go down the other side.

I'm flummoxed.

Cosmic_Jumper wrote:

First check that the fender is securely bolted to the fork legs. 

Secondly take all your "stuff" out of both cubbies and under the seat. Then go for a ride to see whether those same clunks & rattles go away.

Now for the serious stuff. There's not a lot of travel on either the front or rear suspension. You might want to consider replacing the fork oil with something heavier --say 15 wt, but not more than 20 wt.

But before you get too far into the woods, you should check the steering head (head stock) bearings. As OWG and Scootypuff mention, jack up the front end (scissors jack under the engine area) with the center stand supporting the rear. Remove the the front wheel, fender and secure the brake caliper off and away from the fork tube and check the head stock bearings for play and dead spot.

At that point you are just 4 bolts away from removing the fork tubes. If you decide to go with heavier fork oil you might also consider adding a 10mm shim (PVC pipe) to the existing fork springs as well. That'll slightly reduce the suspension travel but stiffen & preload the springs. 

Tim

[Afterthought] Before you jack up the front end you should break loose the four bolts holding the fork legs to the "triple tree". They are torqued pretty tight and you'll only succeed in toppling the scoot if you try to loosen those bolts with out the scoot being firmly secured.

Hiya Tim

Thanks for taking the time to reply to my post.

After reading your post my mechanical knowledge has probably increased 10 fold.

Thanks again.

cotetoi wrote:

I hear similar clunks with potholes, manhole covers, etc. but as long as the bike is behaving okay after such mishaps I don't get concerned. However, if you have handling problems or persistent clunking you should take a closer look as suggested.

Jay.

Hiya Jay

Thanks for taking the time to reply to my post.

The bike behaves as normal.

exavid wrote:

An easy, quick check of the head bearings is with the bike shut off, hold the front brake on firmly astride of the bike and rock it forward and back. If you hear or feel a noise it could be the head bearing loose or possibly the fork tube bushings worn.

With only the rear brake held try rocking the bike. Any slop in the rear suspension will make itself more noticeable in this manner.

As already mentioned the tupperware can make odd noises. One way I chase it down is to put masking tape or such like over the joints of plastic. Then take the bike out on a bumpy road. If the noise is gone you have identified the cause. After that it's a matter of removing tape a joint at a time until the noise comes back, when it does you have your culprit.-

Hiya Paul

Thanks for taking the time to reply to my post.

Does the ABS apply both brakes, even if you only apply one?

Tried your masking tape trick, still heard the noise.

Tried your masking tape trick, still heard the noise.<<>> so it's not body panels. Noise, now comes the hard part, tink / click like two pieces of metal touching, say like the blades of two screwdrivers? Thunk . clunk, heavier metal like a worn shock grommet letting shock eyes touching the bike frame? Noises are such fun trying to figure out

Don''t forget the easiest testing, tapping and jiggling all the plastic pieces which are about 75% of SW noises. Mechanical noises in the suspension usually tend to sound a bit more "heavy" than the smaller parts. Brakes can rattle at times, when on a rough road where rattliing is occuring try very lightly apply first one brake then the other to see if the noise changes.

Also you might check what you have in your pockets and give your helmet a shake. (just kidding)

Sound like your steering head bearings are worn. Place the bike on the center stand and raise the front wheel off the ground with a jack under the bike just behind the radiator. Grab the handle bar and push forward and backward. There should be no play. Now turn the wheel lock-to-lock feeling for bumps and/or dips. The steering should be smooth as glass. Replacement of your head bearings is needed if either of the two for mentioned occurs. Honda use ball bearings for head bearing. These bearing tend to wear a spot in the straight forward position because that is the most common position we travel. I would recommend using roller bearings if you have to replace the head bearing.

There is a procedure in the service manual the check if the head bearing needs to be tightened using a weighing scale.

40,000 miles =64,000 km. Not overly high, but if it is ridden on bad roads all the time then you could easily add a third of that mileage for wear and tear on the components. My SWings were both low mileage and ridden on good roads 90% of the time. I still hear and feel that clunk going over bumps. Bike recovers and proceeds without a hiccup.
Given the mileage on your bike, I'd say take a closer look as suggested and proceed according to what you find. If you are not mechanically inclined, make friends with a good mechanic or a rider in your friendly neighbourhood.

Jay.

Try backing off and re-torquing the front axle pinch bolts and axle nut. My front axle spacer would occasionally knock until I tightened the front axle up.