Front Forks - Need advice.

Need advice on which oil to use or which tyre best suits you? Share your topic and get help here.
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Front Forks - Need advice.

Post by Tempest »

I'm not really very happy with the way the front forks on my VTR (was Tony's) are performing.
To the point of not actually enjoying cornering at all.

(not good for a bike eh?)

I think 2 people owned it prior to us to, and I guess I have a sneeky feeling (total guess) that perhaps someone in the past has perhaps tweaked the springs. Tony has not done anything to the forks, and I've not either.

Let me run over a few things (hope you can be bothered reading!) :)

When reading about the Firestorm, you keep hearing about soft front ends, and how you really need to turn up the settings to make it harder at the front end.
I mentioned this to Tony (when buying the bike from him) and he told me, he never found this, and found it best on SOFT setting.

I actually turned it up (to recommended settings on this forum) and it was like a block of concrete, so I backed them back down to soft/default settings again.

Let me TRY to describe what it feels like (as I'm no fork expert) and am quite a biking novice still really.

When you go round a corner, with even tiny lumps and bumps in the tarmac, it really feels to me like the front end is going to break away.
It may be my imagination, but it feels like the front wheel is bouncing off the road imperfections, rather than the forks soaking up the road.

I feel MUCH more secure cornering with my TDM850 Yamaha than on the Firestorm.

Yet, there is a LOT of movement when breaking.
The fork dive I guess you could say.

It's just (as I say) round round corners, it feels like the front tyre is bouncing up and down as you are leaning over and feels VERY disconcerting. To the point I'm actually worried about leaning it.

The front tyre still have molding stalks on it (not been over far enough to wear them off)

But (as I say) when you break in a straight line, the front end does dip down quite a bit.

Does this sound normal, or very odd?

This is on quite a soft setting as when I made it harder, if felt even worse :(

So as far as I know we have the springs (which may or may not have been changed by a previous owner)
The oil which may or may not have been changed.
and the two adjusters on each fork leg.

I need to nail something down here, but bit unsure quite where to start.

would appreciate some advice.

I could for example unscrew the top of the forks and take a look at the springs, but I have no idea what I'd be looking for anyway.

Thanks for reading :)

Oh yes, tyres on the bike are currenty Metzler ME Z4 which I'm not sure are really a cornering tyre as such (if that makes any difference?)
User avatar
Stormin Ben
Posts: 1234
Joined: Sun Dec 01, 2002 12:23 am
Location: Birmingham

Post by Stormin Ben »

The problem with totally stock Storm forks is they're too soft.
when you brake hardish they bottom out and the front chirps down the road like you've just run over a duckling

My guess is someone has changed the oil and/or the springs in an attempt to cure this. Possibly putting too long springs in without cutting down the spacer (easy mistaka to makea)

So, advice.
- Take the forks out, take the tops off and have a look see
- Check the weight of the spring (should be etched in the top of the spring)
- Check the length of the spring and the spacer
- With the spring removed nad the forks fully compressed, check the oil level from the top of the fork top (coz adding too much oil would definitely give you those symptoms)
- Check the oil condition
- Look at replacing the oil -at least then you KNOW what you're dealing with and its only £5

Then phone Roger at Revolution and listen to his words of wisdom regarding spring and spacer length, oil weight and amount of oil

In an ideal world you'd post the forks to him, pay £200 and get a fantastically sorted pair back in the post
Alternatively you can fit the right springs, some slightly stiffer oil and improve the ride considerably

Hope this helps
I've got an inferiority complex
But its not a very good one!
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Post by Tempest »

Great post Ben.

Many thanks for all that excellent advice.

Gives me something to fiddle with this weekend now :)

As you say, someone MAY have had a fiddle in the past, but I need to do something to find out.

Re the compress the forks without any springs in. When I have the fork tops off and the springs out, will the bike just fall down at the front and they bottom out without trying?

Is there ANY way I can suck/syphon out the oil (If I wish) as I Really don't want to have to dismantle the front end just so I can turn them upside down.

I like the sound of measuring the oil from the fork tops.

And (as you say) will make a note of any marks on the springs and overall length etc etc.
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Post by Tempest »

Oh, just re-read what you said, and the 1st thing:

"Take the forks out"

Can I do all you say WITHOUT doing this?
User avatar
Stormin Ben
Posts: 1234
Joined: Sun Dec 01, 2002 12:23 am
Location: Birmingham

Post by Stormin Ben »

You can do most of it without removing the forks but you're not gonna be able to get the oil out without turning them upside down and pumping them a few times (ooh-err! 8O )

If you do decide to do it with the forks in-situ, bear in mind that the springs are gonna be under a bit more load so be careful when you take the fork tops off

Personally I would be inclined to put the bike on a paddock stand and a jack under the bottom of the engine
NB put a bit of wood between the jack and the sump to spread the load and prevent damage
Then, with the weight off the front of the bike you can easily dismantle the front end

Provided you don't do anything daft like remove the rear wheel (yes, that IS the voice of experience :? ) the bike will be perfectly stable on the jack while you work on the front.
NB its worth loosening AND RETIGHTENING the spindle, fork pinch bolts, yoke clamp bolts etc before jacking up the front as you might need to put a bit of force on them which could upset the balance
I've got an inferiority complex
But its not a very good one!
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Post by Tempest »

Thanks Ben.

I'm a bit (very) nervous about putting a jack ender the engine.

Did look at it once, but nothing really looked like a nice large flat area to use.

I'm worried the whole thing may over balance, but I guess if I'm leaving the front wheel on and just lifting it a few mm off the ground (to take the load off the forks) not a lot can happen?
meintjiesj
Posts: 40
Joined: Mon Apr 24, 2006 12:29 am

Post by meintjiesj »

Tempest.
I bought my Firestorm earlier this year. Took it out and loved it, even the front end wasn't to bad the first few weeks. Then I was starting to push a bit harder and could feel the front wasn't up to it anymore. The rear was also starting to make me scared, throwing me out of the seat on B roads. The front was diving a lot when braking hard and every uneven spot on the road was being transfered thru the handle bars.
I went to Rodger and he has done magic with it. I think it was about 260 quid, but I would have paid more for the results. When I took it out the first time I went over some cat-eyes and that was the biggest difference, I didn't even feel them. I've been on the track also, grabbing handfulls of front break and it is rock solid. My advise is treat yourself to an early Chrismas present and go and see Rodger.
User avatar
Stormin Ben
Posts: 1234
Joined: Sun Dec 01, 2002 12:23 am
Location: Birmingham

Post by Stormin Ben »

Tempest wrote:Thanks Ben.

I'm a bit (very) nervous about putting a jack ender the engine.

Did look at it once, but nothing really looked like a nice large flat area to use.

I'm worried the whole thing may over balance, but I guess if I'm leaving the front wheel on and just lifting it a few mm off the ground (to take the load off the forks) not a lot can happen?
Don't be nervous, I've done mine LOADS of times -sometimes its been up like that most of the winter.
Get a small piece of wood (the one I use is 2" x 3" and 1/2" thick) and use this to spread the load. Put it at the very front of the sump next to the header pipe (NB you'll need to remove the little belly pan)

The only time mine's overbalanced was as I jacked it up without the rear wheel in. Every other time with the rear wheel in its been fine
If you're really worried you could cable tie the paddock stand to the swingarm -then its going nowhere
I've got an inferiority complex
But its not a very good one!
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Post by Tempest »

meintjiesj wrote:Tempest.
I bought my Firestorm earlier this year. Took it out and loved it, even the front end wasn't to bad the first few weeks. Then I was starting to push a bit harder and could feel the front wasn't up to it anymore. The rear was also starting to make me scared, throwing me out of the seat on B roads. The front was diving a lot when braking hard and every uneven spot on the road was being transfered thru the handle bars.
I went to Rodger and he has done magic with it. I think it was about 260 quid, but I would have paid more for the results. When I took it out the first time I went over some cat-eyes and that was the biggest difference, I didn't even feel them. I've been on the track also, grabbing handfulls of front break and it is rock solid. My advise is treat yourself to an early Chrismas present and go and see Rodger.
I've heard a lot about this "Rodger" but no idea where he actually is?
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Post by Tempest »

Stormin Ben wrote:
Tempest wrote:Thanks Ben.

I'm a bit (very) nervous about putting a jack ender the engine.

Did look at it once, but nothing really looked like a nice large flat area to use.

I'm worried the whole thing may over balance, but I guess if I'm leaving the front wheel on and just lifting it a few mm off the ground (to take the load off the forks) not a lot can happen?
Don't be nervous, I've done mine LOADS of times -sometimes its been up like that most of the winter.
Get a small piece of wood (the one I use is 2" x 3" and 1/2" thick) and use this to spread the load. Put it at the very front of the sump next to the header pipe (NB you'll need to remove the little belly pan)

The only time mine's overbalanced was as I jacked it up without the rear wheel in. Every other time with the rear wheel in its been fine
If you're really worried you could cable tie the paddock stand to the swingarm -then its going nowhere
Thanks for the advice.

I'm thinking I may do as you say, unscrew the fork tops, take springs out and do lots of measurments and photo's to post here.

Perhaps someone will be able to confirm if my springs are standard or someone had been making modifications in the past.
User avatar
Max
Posts: 878
Joined: Fri Mar 12, 2004 10:12 am
Location: Pembrokeshire

Post by Max »

Tempest wrote: I've heard a lot about this "Rodger" but no idea where he actually is?
http://www.revolutionuk.co.uk/

Roger is great, he did my front forks.
Max

Image
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Post by Tempest »

Max wrote:
Tempest wrote: I've heard a lot about this "Rodger" but no idea where he actually is?
http://www.revolutionuk.co.uk/

Roger is great, he did my front forks.
Thanks for that.

If I ever use Roger it's gonna be by post, he's 100's of miles away from me :(

Hoping with some tweaking, perhaps oil and springs (and advice) I can get somewhere :)
User avatar
Max
Posts: 878
Joined: Fri Mar 12, 2004 10:12 am
Location: Pembrokeshire

Post by Max »

It was over 500 mile round trip for me, done in a day.Probably about the same for you but the roads you'll use are much better than trapseing accross mid wales at 5 o'clock in the morning. It was worth the long ride as he set up everything on the suspension (had a new back shock as well).
Max

Image
User avatar
Tempest
Posts: 406
Joined: Sat Aug 05, 2006 6:02 pm
Location: Horley (Near Gatwick Airport)

Post by Tempest »

Sorry if this sounds a bit dim!

The adjusters on the top of the fork legs...............

the large one (with the grooves round the outside) The preload adjuster, and the small inner screw, the rebound damper.

I guess the Preload just screws the spring down tighter, basically putting a load onto the spring so it's harder to squash down (harder ride)?

wheras the middle (rebound) slows down the unnit from springing back to full height be restricting oil flow?

Is this all correct?

And could anyone summerise just how these 2 things affect handling?

Going along a bumpy road, I'd have thought youd want it to soak up all the bumps (soft) whilst returning to the full height as soon as possible?

But of course that's not right as hard is supposed to be good for fast riding, but I'd then have thought being hard it would not follow the road surface and would bounce over bumps.

All confusing (to someone who does not understand it!)
User avatar
Pete.L
Forum Health And Safety Officer
Posts: 7306
Joined: Fri Sep 26, 2003 5:09 pm
Location: Bristol

Post by Pete.L »

Its all about finding the right ballance tempest
You need to set the right amount of preload so the bike will stear properly but still have enough dip left to not bottome out. At the sametime you need to adust the the amount of rebound so the bike doesn't either go down too much and not return fast enough so you dont stick to the road when you brake or too little and it feels like a brick and doesn't stick to the road when you brake because it's boucing across ever little bump and ridge on the tarmac.

See, Simple :lol: :lol: :lol:
Post Reply