Front preload adjustment

A new VFR owner registers with a question!

I bought a well kept 1992 VFR and was wondering about front spring preload adjustment.
Should the two screws be in identical position or like mirror images ?

My front end feels a bit soft and I tightened it a bit and it felt better. Before the screws were in mirror image like position, but after I adjusted I set them both to same position (3/9 o'clock).

I have a 1991 which does not have the preload adjustable forks. However, if you look in the "files" section of the site, you can download both the service manual and owners manual for your bike. The preload adjustments are covered in both. Gotta love the good information everyone provides here!

By the way, I just installed new Progressive springs and seals in my forks and they are much firmer and feel great.

Have fun on your new bike!

[image: View Post]thumper, on 04 June 2011 - 02:40 PM, said:

I have a 1991 which does not have the preload adjustable forks. However, if you look in the "files" section of the site, you can download both the service manual and owners manual for your bike. The preload adjustments are covered in both. Gotta love the good information everyone provides here!

By the way, I just installed new Progressive springs and seals in my forks and they are much firmer and feel great.

Have fun on your new bike!

Thanks for answering!
I already checked the manuals and the one that came with the bike, but it didn't actually help me out, cause there was no mention about position of the screws :(

I really love my VFR.
Even if it's old, it's a lot better than some of the more modern bikes. I've been riding a Kawasaki ER6-N and the VFR feels so much better even though its ~15 years older :)
The front end is still a bit soft, I think I'll adjust it a bit more tomorrow.

Start by adjusting them to the same height. No problem adjusting one or both to get them in the same or mirror positions just for looks.
Adjusting preload doesn't make the suspension any stiffer, for that you need other springs.

Don't do anything till you have finished reading this whole thing.

To adjust the preload either turn them all the way in(CW) , or all the way out (CCW). the slots may or may not look lined up the same(reason being the top part of the fork tubes aren't set to the screws when they are torqued to the thripple trees). What's important is that the number of turns are equal.

So knowing this; Count the turns from where it is now till you can't turn it any more, and write it down. Then you can play(sag adjust)with it to see what you want, and you'll have the original turns to go back to if you need them.

Same goes with the dampener set screw on the side of the rear shock(if your year has one).

Warning.... do not use a heavy hand to find out where these screws stop, don't want to damage the seats.

Read about about setting sag before you do anything else.

Like it was said, adjusting preload does not tighten or stiffen anything up.  Pre-load sets the point of travel within the suspension under a load.  In other words it is the amount that the springs "sag" under the weight of the bike and rider.  Too high and your suspension won't be able to "push down" into dips in the road, and too low and when you hit a big bump you'll run out of suspension travel and "bottom out" the forks.

After you've set the sag they should probably be in the same position.

[image: View Post]Monk, on 04 June 2011 - 06:23 PM, said:

Don't do anything till you have finished reading this whole thing.

To adjust the preload either turn them all the way in(CW) , or all the way out (CCW). the slots may or may not look lined up the same(reason being the top part of the fork tubes aren't set to the screws when they are torqued to the thripple trees). What's important is that the number of turns are equal.

So knowing this; Count the turns from where it is now till you can't turn it any more, and write it down. Then you can play(sag adjust)with it to see what you want, and you'll have the original turns to go back to if you need them.

Same goes with the dampener set screw on the side of the rear shock(if your year has one).

Warning.... do not use a heavy hand to find out where these screws stop, don't want to damage the seats.

Thanks for everyone for good advice!

I'll take a better look tomorrow to do this properly.
I'm not sure, if the front is supposed to be that soft. I really think, that it made a difference when I tightened them a bit, but it could be because they were so soft, that the movement of the front was so "long" ?
If I don't get the front to stiffen up, I have understod, that changing in thicker oil might make a difference ?

Thanks again!

[image: View Post]Xtreme, on 04 June 2011 - 01:49 PM, said:

A new VFR owner registers with a question!

I bought a well kept 1992 VFR and was wondering about front spring preload adjustment.
Should the two screws be in identical position or like mirror images ?

My front end feels a bit soft and I tightened it a bit and it felt better. Before the screws were in mirror image like position, but after I adjusted I set them both to same position (3/9 o'clock).


Thicker oil will make the forks take longer to extend after being compressed... speaking in really simple terms, it's easy to imagine thin oil going through a hole... and then imagine thick oil going through the same oil... the thinner oil will go through much faster/easier... this is how the damping controls the forks in their extension phase... you hit a bump, the fork compresses and the spring will then make the fork want to extend... but if there were no valves (holes) and no oil controlling this extension, the bike would pogo-stick, right??

Yes it is true that in a layman kind of way, thicker oil in your forks will make the forks seem stiffer... but that's not really true. What they are is slower to extend in order to receive the next bump... so if there are multiple bumps, one after the other in a short space of time, after each bump, the forks will not extend to their full run-out (absorbtion potential)... and so on each time... so the spring will be more compressed as you hit successive bumps... you run the risk of chattering taking place as the springs never get fully extended to meet the bumps.

The only real way to have properly stiffer springs is by putting stiffer spings in... the springs are what hold everything in suspension.

Tightening or increasing the preload just puts the springs under more load... compressing them, and thus they will try to extend to their position of equilibrium. The idea is to give a certain, range of usability for different riders' weights... it's not econommically feasibly for the manufacturers to put custom rated springs in according to each buyer... as different spring rates would require different valves and different oil weights/densities as well...

If you are out of the spring's range of tolerable weights then the best solution is new springs with the spring rate to suit you (your weight, your gear's weight, pillion or no, hardbags, agressive or relaxed riding style).

Adjusting preload will help within a certain range of rider weight/riding style. The thing is, in the front forks there is no damping adjustment... not like in the rear shock. So if you increase preload, making the spring want to extend more back to its original position of equilibrium... it will rebound with more gusto... and unless there is a rider/gear weight reason behind the increase in preload, the forks will want to extend more briskly/faster... changing the oil to a heavier weight oil will of course attend to this... but unfortunately with the trade off I mention earlier... and this is like putting the cart before the horse.

One should get the bike properly suspended for weight/riding style and then set up damping parameters accordingly.. not the other way around.

But play around with the settings... the bike probably won't high-side on you all of a sudden just making some conservative adjustments... oh and remember, front affects rear and rear affects front... they don't work in isolation...

There is always a trade off with suspension... softer gives more plush ride but less control/stability when pushing the bike to the limits...

As monk said, if seetings are lost, you can turn them all the way in or out counting turns. You then know where it was and how to adjust. The manual helps as you can go back to stock and then adjust.

I set my pre-load adjusters so they match when on the bike. It makes it easier to adjust and looks cleaner.

Dont force any screws.

Xtreme, on 05 June 2011 - 12:11 PM, said: Monk, on 04 June 2011 - 06:23 PM, said: Don't do anything till you have finished reading this whole thing. To adjust the preload either turn them all the way in(CW) , or all the way out (CCW). the slots may or may not look lined up the same(reason being the top part of the fork tubes aren't set to the screws when they are torqued to the thripple trees). What's important is that the number of turns are equal. So knowing this; Count the turns from where it is now till you can't turn it any more, and write it down. Then you can play(sag adjust)with it to see what you want, and you'll have the original turns to go back to if you need them. Same goes with the dampener set screw on the side of the rear shock(if your year has one). Warning.... do not use a heavy hand to find out where these screws stop, don't want to damage the seats. Thanks for everyone for good advice! I'll take a better look tomorrow to do this properly. I'm not sure, if the front is supposed to be that soft. I really think, that it made a difference when I tightened them a bit, but it could be because they were so soft, that the movement of the front was so "long" ? If I don't get the front to stiffen up, I have understod, that changing in thicker oil might make a difference ? Thanks again! This guy's the best , so watch this link:

If I don't get the front to stiffen up, I have understod, that changing in thicker oil might make a difference ?

Thanks again!
[/quote]

I did some reading here about forks since my '91's forks felt so squishy. Since I needed seals anyway, I went ahead with the springs. What I have found out, is that suspension is a real science with many variables contributing to performance. There are a lot of posters here that have great advise. If you are budget conscience, preload is a start, see how it feels for you. Fork oil is next but how will you know what weight oil is currently in the forks to make a change? Next would be springs and then rebound and dampening valve adjustments which can get expensive.

I can do fork work myself but did not have the time to do it, nor did I have an air impact to bust the dampening rod bolt loose at the bottom of the fork tube (inside the axle hole). That being said, I paid $70 for the Progressive Springs on ebay and $60 for a Seal and Bushing kit on ebay. I then took just the forks to a race shop near Infineon Raceway (professional suspension mechanics) and paid $100 to have them pull the forks apart, clean them and install the seals, bushings and springs. I ride the bike hard and the front suspension now outperfoms my ability (ie; it can be pushed harder but I can't).

Hope this helps!

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If I don't get the front to stiffen up, I have understod, that changing in thicker oil might make a difference ?

Thanks again!

Not to sound like a broken record, but the preload adjusters will NOT stiffen up the suspension in any way.

If I don't get the front to stiffen up, I have understod, that changing in thicker oil might make a difference ?

Thanks again!

Not to sound like a broken record, but the preload adjusters will NOT stiffen up the suspension in any way.

Thanks again everyone for answering.

I understand now, that preload is not the thing to adjust regarding the suspension softenss, thanks for Ryanme17 and others for punding that intop my head :)
English is not my native tonque, so be patient :)

Actually what I meen by front being soft is actually the amount of nosedive it does as soon as I even touch the front brake lever.
My old bike did not dive like that, although it was 50 kg lighter and a different kind of a bike.

I'm not that heavy guy, about 80 kg, so I don't think thats the problem.
Maybe its just a charasteristic of the bike ?

If I don't get the front to stiffen up, I have understod, that changing in thicker oil might make a difference ?

Thanks again!

Not to sound like a broken record, but the preload adjusters will NOT stiffen up the suspension in any way.

Thanks again everyone for answering.

I understand now, that preload is not the thing to adjust regarding the suspension softenss, thanks for Ryanme17 and others for punding that intop my head :)
English is not my native tonque, so be patient :)

Actually what I meen by front being soft is actually the amount of nosedive it does as soon as I even touch the front brake lever.
My old bike did not dive like that, although it was 50 kg lighter and a different kind of a bike.

I'm not that heavy guy, about 80 kg, so I don't think thats the problem.
Maybe its just a charasteristic of the bike ?

Actually it's a charasteristic of a spring being to light. If the spring is matched to your weight and the bikes, that will fix it. The fork oil weight can also be calculated for you and the bike, and the spring. There is a science that puts all of it together and with the limited adjustments of the VFR you need to get the springs and oil that's right for you, than have the sag adjusted.

The OEM springs on VFRs are quite soft.

The OEM springs on VFRs are quite soft.

Yep, this is what I thought might be the case.
I think I'll first try to learn and drive with these and if it still feels odd after couple of months, then I'll head to "spring store"

Thanks for everyone!
I'll be back with more questions after I get to know my new ride better!

Ride safe!

To decrease diving you can add some oil (stock weight) to the fork tubes. This will not influence damping but it will increase the total spring rate as the air chamber, that acts as a spring too, becomes more progressive spring.
Stock oil height is somewhere near 180mm. Going to 120mm will make a big difference.

Aren't the OEM springs progressive rate?

Aren't the OEM springs progressive rate?

Yes... but if you add a little (5mm height max??) more oil, they become "more" progressive... harder in the final stages of compression...

Aren't the OEM springs progressive rate?

Yes... but if you add a little (5mm height max??) more oil, they become "more" progressive... harder in the final stages of compression...

Should I check the current oil level before doing this ?
Because I have no idea whether the front suspension has been sercviced and if it is, have they added the correct amount of oil...

Aren't the OEM springs progressive rate?

Yes... but if you add a little (5mm height max??) more oil, they become "more" progressive... harder in the final stages of compression...

Should I check the current oil level before doing this ?
Because I have no idea whether the front suspension has been sercviced and if it is, have they added the correct amount of oil...

Just swap the oil out for new oil... It's dirt cheap.

Aren't the OEM springs progressive rate?

Yes... but if you add a little (5mm height max??) more oil, they become "more" progressive... harder in the final stages of compression...

Should I check the current oil level before doing this ?
Because I have no idea whether the front suspension has been sercviced and if it is, have they added the correct amount of oil...

Just swap the oil out for new oil... It's dirt cheap.

Ok, I'll do that.
First I have to get a front lifter/supporter of some sort, so I can get the forks out.


edit. Moved the other question to correct topic.