Front jumping up and down- what to adjust?

[Hugo Stiglitz]

It's like a up/skip up stutter at the front. What do I need to adjust to tune that out? Forks have adjustment screws on both legs.

[dikkobat]

Very badly out of balance? Try lifting front end and might have to take calipers off, but spin the wheeel, mark the bottom with chalk, spin again, mark bottom, do this a few times and see if its aways stopping at same point (or just take it to tyre-fitters and get them to check it). I would start there then set all suspension settings to middle of adjustment range and take it out and see if issue remains? Deffo start with wheel balance tho, and also check it on a variety of roads, just incase its that bit of road thats causing it. Good luck!

[Steve Bass]

Rebound.

Wind it in a few clicks and see it it slows or stops the chatter

[Rick448]

Steve Bass said:

Rebound.

Wind it in a few clicks and see it it slows or stops the chatter

Agreed. If you press down on the front and let it extend, you should be aiming for it to fully extend and settle without 'bouncing.'

[dikkobat]

Also, what kind of bike, what speed does it happen etc?

[Hugo Stiglitz]

Vstrom 1000/1050 and generally any speed. It can be a smooth motorway or urban 40

[richhead]

Hugo Stiglitz said:

Vstrom 1000/1050 and generally any speed. It can be a smooth motorway or urban 40

it does sound like there is something abit more amiss that adjustment, but try winding up the rebound, this may help. but if you are avarage weight and its set about middle then it shouldnt be doing it, but it also may be also to much preload to or bump on the damper, basicly set everything to middle and see what happens, if its no different then you have a problem with something, and then adjust one thing at a time and have a ride to learn what difference things it make, do the same for front and rear. either that or go to a suspension specialist.

[2ndclasscitizen]

Is this new behaviour?

[Hungrymc]

From the initial description it kind of leads to damping (hence the rebound suggestions). But is it that the front end just feels loose ? check wheel and headstock bearings too?

[black-k1]

I think we need way more detail to be able to properly diagnose.

Is it more/less or consistent at different speeds?
How big are the "jumps"?
Are they a consistent frequency and amplitude or do they increase/decrease?
Does it happen on flat smooth tarmac or on bumpy roads? Or both?
Does it coincide with braking/acceleration?

"Jumping" is not a description I've ever heard in relation to a requirement for suspension adjustment. It could, however, be used for wheel balance or very shagged bearings.

[KTMsm]

Whilst I agree it sounds like a suspension setting issue - I'd start by sticking it back to factory settings and work from there

[SteveKTMer]

Does sound like too much rebound, or massively over pressure in the front tyre. Whatever adjustment you have, put it back to what the manual says is default and go from there is good advice if nothing is faulty.

[archie456]

KTMsm said:

Whilst I agree it sounds like a suspension setting issue - I'd start by sticking it back to factory settings and work from there

This is where I'd start, it's easy to mess up suspension settings.

[dikkobat]

If its happnenning on smooth roads (as stated by Hugo), i would first be looking at wheel-balance/tyre pressures - there would be little to cause suspension to be doing this on a smooth road. Then set all suspension settings to mid-range and take it from there on the same roads that it has been occurring on.

[Hugo Stiglitz]

Front/rear 32/39 (I always run 33/36)

Left fork was 7 more clicks than right. I've set both 5 in from -.

It's night and day.

I'll also still get the balancing checked.

[Steve_H80]

Hugo Stiglitz said:

Front/rear 32/39 (I always run 33/36)

Left fork was 7 more clicks than right. I've set both 5 in from -.

It's night and day.

I'll also still get the balancing checked.

That wouldn't have helped
It sound like the PO was the kind of random twiddler who shouldn't be allowed tools.
Set everything back to standard as per the handbook, the forks have preload, compression (at the bottom) and rebound (at the top), the shock has preload and rebound.
Tyres should be 36 & 42, the front rebound and compression is 8 clicks out from fully in, I can't remeber the preload or rear settings.
I've only had my vstrom for a few weeks and am still in the twiddle and untwiddle stage, although standard might actually be best for me.

[KTMsm]

I sold a lad a KTM with fully adjustable suspension a few weeks ago

He asked me if I'd set it up for him, I said I'd just set it to the factory settings that he should read the manual and have a play from there but I'd help if required

He bought it back and said he'd had a play with the forks and was much happier - on further discussion he'd only fiddled with the rebound and was unaware of the other two settings - he confessed he hadn't even opened the f****** manual

[Hugo Stiglitz]

KTMsm said:

I sold a lad a KTM with fully adjustable suspension a few weeks ago

He asked me if I'd set it up for him, I said I'd just set it to the factory settings that he should read the manual and have a play from there but I'd help if required

He bought it back and said he'd had a play with the forks and was much happier - on further discussion he'd only fiddled with the rebound and was unaware of the other two settings - he confessed he hadn't even opened the f****** manual

I can feel differences in tyre and psi but fork settings? Nope. Hence twiddle here twiddle there, get bored. Forget. Twiddle..

[dikkobat]

Im guessing the bike was OK, then this occurred suddenly?

What changes have been made that could cause this - im guessing that if the previous owner had mis-set the suspension, the issue would have been present the whole time, so something has changed during your ownership to cause this?

Simplest thing would be something like a balance-weight being knocked off whilst cleaning or something, causing wheel to be out-of-balance.

Like previous posters have said, if tyre pressure had been set way too high then that could contribute to being overly bouncy, but you have checked pressures and ruled that out.

I would think that adjusting the suspension settings might help, but deffo start with balance and work back from there.

Let us know how you get on.

[OutInTheShed]

Most of my bikes have been older, so the first thing I'd suspect might be the fork oil level.

Old-skool 'right way up' forks could also collect water after years of riding in the rain.