Front End Bounce / Hop

[Highwayman]

..:: Update ::..

Front brake discs and pad changed to oem.
Calipers serviced (new caliper seals, cleaned pistons, reassemble)
Front & rear brakes flushed, abs module cycled.

Issue not solved.
Oem fork bushings are not in stock, takes 2 months to arrive.
I can't say what when down during the fork servicing, as I was not around.
FYI, I fail to mention that the fork servicing was done by another shop, and I'm back at where I usually am to resolve this.
Bad mistake not staying to see the fork servicing done and/or going to another store for a try-out.

Guess I will update this thread in 2 month's time?

Check with Race Tech..... I just went with a rebuild on my S10 because of leaky seals. They had everything, bushings and seals in stock. Good friend and local MC shop owner said Race Tech sells OEM stuff.

 

[mran]

I just used race tech bushings on a rebuild i did on my own forks. Had a bit of slop extended and compressed. I would only use oem next time. Id high suspect your suspension. Could be wrong fluid or level, rebound shims or valve. More than likely your fluud or level if it happened after it was rebuilt.. wait you mentioned high stiction after? Time for a complete tear down id bet they messed up

 

[Doodlefadd]

I just used race tech bushings on a rebuild i did on my own forks. Had a bit of slop extended and compressed. I would only use oem next time. Id high suspect your suspension. Could be wrong fluid or level, rebound shims or valve. More than likely your fluud or level if it happened after it was rebuilt.. wait you mentioned high stiction after? Time for a complete tear down id bet they messed up

Still sourcing out oem parts for the fork rebuild, that reaches to my country.

When I said high stiction, this is what I did (I wish to believe the way I tested it out is true to my understanding, but hey, I'm a dumbass who looses a screw or two everytime I work on my bike anyway)
-loosen compression to max
-loosen rebound to max
- sit on bike
-have a friend push the front down mimicking compression, it stays and doesn't come back up.
-have a friend pull the front up mimicking rebound, it stays and doesnt go back down.
-both ways, the fork doesn't even budge after my friend releases his hands from my bike.

Is this supposed to be normal?
(I label this as stiction, but hey, what do I know)

 

[Johnwesley]

What’s the difference in the sag numbers when he does this? This will tell you the stiction zone and let us know how server it is.

 

[Doodlefadd]

What’s the difference in the sag numbers when he does this? This will tell you the stiction zone and let us know how server it is.

Bike on mainstand, we measure exposed chrome part of forks is 207mm

Bike down, I sat down, fork compressed and stays at 135mm
Bike down, I sat down, fork raised and stays at 165mm

Stiction is 30mm (is this correctly calculated? And if yes, yeps I know stiction should be 5-15mm max)

207mm - [(135+165)÷2] = 57mm (30% of our 190mm travel) so sag is correctly measured.

 

[jrusell]

Bike on mainstand, we measure exposed chrome part of forks is 207mm

Bike down, I sat down, fork compressed and stays at 135mm
Bike down, I sat down, fork raised and stays at 165mm

Stiction is 30mm (is this correctly calculated? And if yes, yeps I know stiction should be 5-15mm max)

207mm - [(135+165)÷2] = 57mm (30% of our 190mm travel) so sag is correctly measured.

I think you have something installed incorrectly in those forks.
You said the forks were serviced, but what was actually done? Just an oil change, or did they replace seals and wipers? Was the cartridge taken out?
207mm does not seem right to me. Here is a pic of my fork lower with the bike on the centre stand..
Right around 195mm. Tire is on the ground, so if you lifted the tire clear you might get another 2-3mm , but there is no way I could get 207mm.

Is your 207mm exposed chrome or from the seam between the wiper and the gold fork?
If it is actually 207mm of chrome I have some thoughts but will wait for your answer.

 

[Fordf350]

do you feel any vibration in the seat or pegs or only in the bars?

 

[~TABASCO~]

Still sourcing out oem parts for the fork rebuild, that reaches to my country.

When I said high stiction, this is what I did (I wish to believe the way I tested it out is true to my understanding, but hey, I'm a dumbass who looses a screw or two everytime I work on my bike anyway)
-loosen compression to max
-loosen rebound to max
- sit on bike
-have a friend push the front down mimicking compression, it stays and doesn't come back up.
-have a friend pull the front up mimicking rebound, it stays and doesnt go back down.
-both ways, the fork doesn't even budge after my friend releases his hands from my bike.

Is this supposed to be normal?
(I label this as stiction, but hey, what do I know)

Normal- NO !!!!
I now would suggest not riding the bike at all until this is fixed. Something is WRONG !!!!!!
“ literally broken”

 

[ballisticexchris]

Normal- NO !!!!
I now would suggest not riding the bike at all until this is fixed. Something is WRONG !!!!!!
“ literally broken”

Plus one!! Something is binding and not assembled or tightened correctly. Check the simple stuff first like the lower pinch bolts. Those should be no more than 15Nm or so.

 

[Doodlefadd]

do you feel any vibration in the seat or pegs or only in the bars?

No to this question.
But if ur wondering if the engine has anything to do with it, like prolly engine not balanced will and cause a shake that translate to front handling, I ruled that out.
I rode the bike at slow speed where the problem is most prominent, put it in neutral and killed the switch, let the bike roll, and it still bounces/hops.

Normal- NO !!!!
I now would suggest not riding the bike at all until this is fixed. Something is WRONG !!!!!!
“ literally broken”

I would have guessed so too.
Loosening compression and rebound fully out,
To my understanding should make the fork bounces happily when it's either pulled down or pushed up. Not stay at where it is when the hands providing the force, is released.

I think you have something installed incorrectly in those forks.
You said the forks were serviced, but what was actually done? Just an oil change, or did they replace seals and wipers? Was the cartridge taken out?
207mm does not seem right to me. Here is a pic of my fork lower with the bike on the centre stand..
Right around 195mm. Tire is on the ground, so if you lifted the tire clear you might get another 2-3mm , but there is no way I could get 207mm.

Is your 207mm exposed chrome or from the seam between the wiper and the gold fork?
If it is actually 207mm of chrome I have some thoughts but will wait for your answer.

Problem is, I left the bike overnight to collect it the next day. When asked what was done, it was dismissed with 'fork service, all internals changed. Seals, oils'
This issue right now, is the only reason that got me to understand the whole mechanics of forks.
From the components, to the measurements, to signs of bad forks.
I will measure my forks again with pictures and edit this post at a later time, to countercheck with u guys if I'm measuring right.. Gmt+8 here haha.

I do have plans to get the forks opened again and closely looked upon what was previously done by the other shop. Hence the current search for parts online and getting them shipped.

I've also told the shop I frequent for years, to keep any tyres that is changed out by another customer, to fix it to mine and rule out tyre manufacturing defects. Tbh, I'm not ready to buy a new set just to rule this aspect out, when the ones I have are less than 2 weeks / 500km old.

Would be amazed if it wasn't done properly tho, as the primary reason me visiting that shop was coz he was notorious for suspension works with certificates pasted all over his office walls from race techs/ohlins/ktm/sbk from tuning to suspension courses. Guys who do track days all go to him for susp setups.

But then again, hey what do I know right?
It could be a shady turnaround for a quick buck over a customer that's easily decievable.
Don't wish to ill think, but Can't rule that out.

I reckon u see me using the word 'shop' alot in my post and nothing about 'yea, I'll troubleshoot it myself / work on it'. Here in sg, it's downright illegal to be repairing ur vehicles by urself. Many still practice it, but behind the authorities. Almost any advise here on this forum translate to cash going out. Lols not complaining tho. But Ive spent close to 2 grand SGD just eliminating the possibilities.

Thanks for keeping up tho. Would be so clueless without your support and responses. Regret not being part of this forum earlier tbh

 

[nondairycreamer]

Why not remove the forks and shock and send to Stoltec, Race Tech, Northwest Suspension or someone that rebuilds and properly modifies components every day and have them serviced? Not only will the components be corrected for problems but you will have suspension tuned to your weight and riding parameters.

 

[holligl]

Here in sg, it's downright illegal to be repairing ur vehicles by urself.

Did not see your location in your profile. Where are you?

Sent from my SM-N950U using Tapatalk

 

[jrusell]

Why not remove the forks and shock and send to Stoltec, Race Tech, Northwest Suspension or someone that rebuilds and properly modifies components every day and have them serviced? Not only will the components be corrected for problems but you will have suspension tuned to your weight and riding parameters.

Because he is in Singapore.

 

[Cycledude]

wish I could actually take your bike for a short ride just to experience the problem

 

[Johnwesley]

I wouldn’t be surprised if the bushing slipped and they just didn’t catch it. its binding for sure and if it is bushing related then you can certainly do damage.

 

[~TABASCO~]

I’m going to take stab at this- Someone tried to remove the top cap after unscrewing the top cap. Maybe to measure the oil with out the spring. There is a shim that sits under the top cap. If it gets side ways it will jam the cartridge rod. Most people can experience this when the fork / cartridge are in there ‘spring remover’ tool. It’s easy to get this shim sideways and experience the cartridge rod getting in a bind.
If someone took apart the top, got that shim turned out of the ‘seat’ it’s supposed to sit in, I’m guess this scenario ’might’ happen I suppose.
Sounds like the cartridge rod is bound up and this is an easy “look-see” and check it out.

FYI- if people don’t know how to work on forks and they don’t fallow the ‘rules’ your going to have even more issues with rebound and compression. The rebound must be set properly before someone reinstalls the top cap and you tighten the jam nut, otherwise you will not have all the “clicks” your supposed to. Also,if It’s not done properly you might not be starting at “full open or closed”. You might be starting 6 clicks in or 14 clicks in. (Made up numbers for example, might be ‘in’ or ‘out’.
Call around. Find an expert. The expert might not be at a big fancy expensive shop. But when talking to this person you will feel like the person has a “clue”.

This is the area im referring to... This is just a **GUESS** with such little info... I think something is binding the cartridge tube.

 

[Fordf350]

So if am reading this correctly, the issue was not corrected by the initial fork service and maybe even worse after. Seems like whatever the initial problem was must have been missed on rebuild.. Such a shame to have spend all that money not to mention the frustration. Good luck..

 

[Doodlefadd]

Why not remove the forks and shock and send to Stoltec, Race Tech, Northwest Suspension or someone that rebuilds and properly modifies components every day and have them serviced? Not only will the components be corrected for problems but you will have suspension tuned to your weight and riding parameters.

Yeps because I'm in Singapore.
Just 2 weeks ago, when I was swapping my windshields (I have a few in hand) a patrol car was doing their rounds and decided to check on me. Reminded me any form of meddling with the bike must be done at an authorised shop. Yeps.. Its that lame.

I’m going to take stab at this- Someone tried to remove the top cap after unscrewing the top cap. Maybe to measure the oil with out the spring. There is a shim that sits under the top cap. If it gets side ways it will jam the cartridge rod. Most people can experience this when the fork / cartridge are in there ‘spring remover’ tool. It’s easy to get this shim sideways and experience the cartridge rod getting in a bind.
If someone took apart the top, got that shim turned out of the ‘seat’ it’s supposed to sit in, I’m guess this scenario ’might’ happen I suppose.
Sounds like the cartridge rod is bound up and this is an easy “look-see” and check it out.

FYI- if people don’t know how to work on forks and they don’t fallow the ‘rules’ your going to have even more issues with rebound and compression. The rebound must be set properly before someone reinstalls the top cap and you tighten the jam nut, otherwise you will not have all the “clicks” your supposed to. Also,if It’s not done properly you might not be starting at “full open or closed”. You might be starting 6 clicks in or 14 clicks in. (Made up numbers for example, might be ‘in’ or ‘out’.
Call around. Find an expert. The expert might not be at a big fancy expensive shop. But when talking to this person you will feel like the person has a “clue”.

Am looking at this too. Tryna find someone who is reliable/dependable enough to do susp works that is not out to slit my throat for cash. Last I did that, I end up here with this thread. Haha
So if I get this right Jaxon, the potential problem is probably something that's darn obvious to someone whose done forks yea?
Noted on that.
Just for comparison, a full fork service would run me about sgd$400/usd300/£220 here. Not sure if that's pricey to u guys.

So if am reading this correctly, the issue was not corrected by the initial fork service and maybe even worse after. Seems like whatever the initial problem was must have been missed on rebuild.. Such a shame to have spend all that money not to mention the frustration. Good luck..

Yea tell me about it. Well then again the forks are not investigated for the 2nd time, and i ain't gonna be to quick to shoot my bullets at his direction. Let's just be nice and open it when the parts comes.

Will update again.
Sorry this post is not showing any signs of progress and merely a rant.

 

[Fordf350]

Also ,slightly off topic, could you elaborate on the law about not being able to work on your own vehicle. Sounds so unbelievable to us do it yourselfers..thanks

 

[nondairycreamer]

Have you tried looking for a you tube video doing a detailed fork rebuild? Be necessity you might become the local expert on forks., if you can source the tools and a proper manual.