2008 HM Fork Problems

[GCHyper]

I know the Front suspension on the Hyper is a much discussed topic , but i have an issue which only seems to be with my Hyper .
The problem i am having is that even with all the fork settings at full soft , the damping is still too stiff and rider sag is 34mm , my weight is 75kg without gear , i have checked with a couple of friends bikes and a new S today at the local dealer , all the other bikes on standard settings had 45mm rider sag and felt soft , actually all the other bikes rebound was too soft , when bouncing and releasing before the upstroke the fork would move past the static sag about 5-10 mm before settling .
I rode my friends bike and felt much more compliant over bumps, mine seems to get unsettled over most bumps, especially over ripples and sharp bumps mid corner where the bars wiggle and at times the front tyre washes out slightly .
My bike has 8k on the clock now and others new or 4k at most, does the fork oil get thicker as they get used more ? but then doesnt explain the low static sag 14mm or rider sag 34mm , any advice or other Riders suspension settings and values would be great , im thinking about trying to claim warranty as its quite dangerous at times and getting some body jarring through the arms and spine , honestly i have felt mountain bike suspension with better suspension operation

[Revelstoker]

One of the issues that have been posted about the forks is varying amounts of oil in the forks. I am not sure if this is an issue but maybe having your forks serviced, under warranty?, might solve the problem.

Just a thought.

[08hyper]

The least expensive way to check things out is to change your fork oil, after the oil & springs are out, stroke the tubes up & down to separately see if they "feel" about the same, and then make sure that both forks are filled the same level to factory spec, and I believe the stock fork oil weight is 7.5w.

And no, fork oil does not get thicker with use, it gets thinner & dirtier

If that does not work, then its something mechanical inside. Aloha Alex

[Decreasing Dave]

Originally Posted by 08hyper

The least expensive way to check things out is to change your fork oil, after the oil & springs are out, stroke the tubes up & down to separately see if they "feel" about the same, and then make sure that both forks are filled the same level to factory spec, and I believe the fork oil weight is 7.5w.
Aloha Alex

While I believe Alex is correct about the Fork Oil weight being 7.5w, I believe that others have posted that they had improved results by running 5w oil in its place, set to the proper level.

I am having a bit of the same problem and this is my next course of action before spending 4 figures on new cartridges.

Dave

[GMP]

My take on this is the primary problem is the springs are too soft, in addition to seeming progressive (bad), and have the preload jacked way up. What this does is makes the bike settle and sit in the stiff part of the travel and seem real harsh over road chop. There is also a lot of fore/aft weight transfer. The cartridge is overdamped as well, your correct. If you have not done so already, immediately loosen and retorque your triple clamp bolts. The lowers come way too tight and can affect the forks action. I do off road suspension work for myself and friends and have seen the annodizing worn off the inside of a 45mm marzocchi due to this. The oil and valving are then fouled with debri and all hell breaks loose.

Yeah, the real answer is a cartridge kit (too much $$), or doing some redesign and mods to an offroad cartridge and the fork cap to make it fit and work(too much time) which I have looked into a bit.

For a street only bike its just too much, $1K on a fork kit aint gonna happen. I have been running the 5W oil for a year and its better but the fork is still harsh. That said I'm going to install .85 - .90 kg/mm straight rate fork springs, much less preload, and drop the oil weight to something lighter than 5. This should be an acceptable improvement for street riders without the coin for a kit.

That said, who makes drop in springs? I see race tech lists a part# with a "will work with mod" clause. I know some guys have done it, what springs did you use?

[doon]

Originally Posted by Decreasing Dave

While I believe Alex is correct about the Fork Oil weight being 7.5w, I believe that others have posted that they had improved results by running 5w oil in its place, set to the proper level.

I am having a bit of the same problem and this is my next course of action before spending 4 figures on new cartridges.

Dave

You can try and make a silk purse out of a pigs ear but you are wasteing your time.
Andi and myself have changed oil to 5w, installed non progresive springs and tried different oil weights and levels.
It will help but in my opinion they are still a peice of shit.
When we drained my forks there was 650ml in one and 750ml in the other.
Also a huge boogy came out with the oil.
I am running with 5w 520ml at the moment.
Our dealer is complaining to NF Importers, I suggest you do the same.
The group fork buy is a good option, its sucks having to pay for the Marzshocking fark up but thats life.

[GCHyper]

Originally Posted by GMP

My take on this is the primary problem is the springs are too soft, The cartridge is overdamped as well, your correct. If you have not done so already, immediately loosen and retorque your triple clamp bolts. The lowers come way too tight and can affect the forks action. I do off road suspension work for myself and friends and have seen the annodizing worn off the inside of a 45mm marzocchi due to this. The oil and valving are then fouled with debri and all hell breaks loose.
That said, who makes drop in springs? I see race tech lists a part# with a "will work with mod" clause. I know some guys have done it, what springs did you use?

I will check the triple clamp bolts , although my springs ( standard) are way too stiff , not enough static and rider sag , i have a cable tie to mark where the suspension is operating at its most extreme , it wont compress more than 60mm from bottoming out , might need to check the oil level if some riders have had varying fork oil levels , cheers Michael .

[GCHyper]

Originally Posted by Revelstoker

One of the issues that have been posted about the forks is varying amounts of oil in the forks. I am not sure if this is an issue but maybe having your forks serviced, under warranty?, might solve the problem.

Just a thought.

Sounds like the most common problem so far , i will first contact the importer and see what my chances are , so what is the fork oil level supposed to be ?thanks Michael

[GMP]

I will check the triple clamp bolts , although my springs ( standard) are way too stiff , not enough static and rider sag , i have a cable tie to mark where the suspension is operating at its most extreme , it wont compress more than 60mm from bottoming out , might need to check the oil level if some riders have had varying fork oil levels , cheers Michael .

Do check the oil level, back off the preload and then make a call on the springs. A too soft spring with too much preload will seem too stiff, add too much oil and a tight T-clamp and you have a mess. Its a good idea to loosen everything up front and release any misalignment stress on the system, that will create stiction and poor action. I'm 190 lbs and mine are way soft for average street riding on mixed surfaces. You probably know this but the fork does not bottom when the slider (wiper) is in contact with the foot, its much sooner.

[GCHyper]

Originally Posted by GMP

Do check the oil level, back off the preload and then make a call on the springs. A too soft spring with too much preload will seem too stiff, add too much oil and a tight T-clamp and you have a mess. Its a good idea to loosen everything up front and release any misalignment stress on the system, that will create stiction and poor action. I'm 190 lbs and mine are way soft for average street riding on mixed surfaces. You probably know this but the fork does not bottom when the slider (wiper) is in contact with the foot, its much sooner.

All my settings inc preload are adjusted all the way out , i have since found a thread that mentioned some springs could be 0.66 or 0.86 , not specific with any model as i checked a new S at the local dealer and the Forks seemed plush , i acyually achieved more compression bouncing on the shop floor than i can on my bike riding over the most extreme bumps , have sent en email to NF Importers , will be interesting what they come up with , unfortunately the other susp thread in nov 2008 seemed to stop without a conclusion .