Raising the forks in the yokes?

[chris c]

Hi Guys

just wondered if there is a set amount to raise the forks through the yokes when fitting a 120/70/17 front tyre to a pointy SV650 or a good starting point?

Thanks

Chris

[jambo]

I personally wouldn't. These adjustments do different things, and will be additive, rather than cancelling out I suspect.

Taller tyre may raise the front end by a few mm when upright but will be more pointy, thus feeling like it drops into corners a little faster.

Raising the forks in the yokes will alter the geometry, making the bike turn a little faster.

I'd do one at a time, and I'd not raise the forks more than 5mm initially and 10mm total, as I think somewhere around there you run out of travel meaning at full compression the dust seals would start touching the bottom yoke. Not something they're designed for :)

Maybe pop a cable tie around the fork above the dust seal to see how close you're getting...

Jambo

[chris c]

Maybe pop a cable tie around the fork above the dust seal to see how close you're getting...

Jambo

Thanks

I already have a cable tie around the fork leg with the standard 120/60/17 and have about 15mm between the cable tie and yoke

[wideguy]

If you think the new tire is slowing down the handling, drop the front end a little. Adjust as necessary, in small increments, until you're happy.

[Mark-SV-UK]

I was thinking of putting the 120/70/17 on the front of mine as I need a new tyre they also seem to have more of a selection available is this a common thing people on here do or does it mess up handling and geometry???

[wideguy]

I was thinking of putting the 120/70/17 on the front of mine as I need a new tyre they also seem to have more of a selection available is this a common thing people on here do or does it mess up handling and geometry???
I think racers use the 120/70-17 fronts.
Lots of people change the entire front end, lots of others substitute rear shocks from a variety of bikes. They all seem to report good results.
It's possible to make a motorcycle unstable through geometry changes, but it isn't easy. You can change quite a lot of things, and the decision as to whether it's 'better' or not, is pretty subjective. If you like it, if it suits your riding style, it's better.
Try it. See what you think.

[Runako]

In reality a lot of it is subjective. What you really need is a good series of corners, or a track to play around with and then make incrimental changes as Jambo suggested and noting each change as you go along so you know what's needed to put it back to standard settings.

Personally, I would rather adjust the rear than play with front fork height. Unles you're gonna get better fork internals or an improved front end I'd leave it as is and get a good rear shock and sort that out instead.

[wideguy]

With some minor differences between tire manufacturers, the basic difference between a 120/60 and a 120/70 is that the 70 is 24mm larger in diameter, which means it will raise your front end roughly 12mm.
Depending on the tire profile, you may not notice any change in handling, or you might. The most probable result, if there is any noticeable change, is that the steering might feel a bit slower. If it does, and you don't like it, you can drop the front end 10mm and see if it's better.
You will notice a 4.2% change in your speedometer reading, since the SV takes its speed info from the front wheel.

[Mark-SV-UK]

Many thanks very usefull :-)))

[Biker Biggles]

I cant remember how much,but you can only drop the front through the yokes so far before you get fouling issues.

[wideguy]

Full fork travel on the curvey is 5.1", just under 130mm, so you're right, you can't drop it much.
I had mine dropped 10mm before I added the Penske shock , and I always have a zip tie around the fork tube. I never managed to mash the zip tie into the dust cover, even with a few screw ups on track that required braking at high speed and hard enough to lighten the rear end, nor did I ever squash it fully on some really bumpy, whoopy back roads at a fast pace.
How this works for you depends on the springs you have and how much compression damping you have to go with your springs. I've changed my springs and added emulators.

[chris c]

Ok after a few adjustments ive gone for a 10mm drop and running a 120/70/17 racetec on the front.

No clearance issues and the forks still have about 15mm travel before bottoming out.

Much happier with the front end feel now, next mod is GSXR forks