Another no-Monster build thread

[MonsterHPD]

No problems, Speeddog, I trust you 100% :-)

I´ve never checked max travel of the Showa SBK cartridges, and beeing not the tallest of persons I´ve tended more towards keeping my bikes low. Having said that, I do know that some of the steel cartridges used on Monsters etc, and also on earlier SBK´s, do not have any excess travel. I once had to do a lot of minor machining to avoid the cartridge bottoming before the forks when installing a K-tech piston / shim kit in a monster fork. In the end I got about 118 mm and fork tubes bottoming first, if memory serves. 

I´m also slightly surprised the stanchion does not bottom against the top nut until 140+ mm. Are the fork legs stock components?

[koko64]

Some advice to folk reading this (once again). Although quite capable of learning the dark art of suspension tuning and quite adept at setting up suspension for a rider, I pull the forks/shock out and send them to people like speeddog and hpd, Traction Dynamics, or whoever specializes in this area. If youre time poor or busy specializing somewhere else it makes sense.

My local guy is brilliant (Dave and Co at Kroozetune, Melbourne) and he will machine up and implant whatever is required to turn manky old oem Marzocchi's into functioning forks. It will cost me a grand for plug and play, perfect fit, outwardly oem forks for my M750, but that's reasonable here like a 500-600 buck job in the States. SBK forks alone here in Australia could cost 500+ before any work, let alone triple clamp, wheel, brake and axel compatability issues. It is definitely worth paying a specialist as it usually saves time and money in the long run.

[Dadouzzu]

When you change 1 step springs or add/remove one shims can be better or worst, but when you do a big change or swap entire fork or shocks is more a start of a project that will require time and money to be completed  
Obvusly the help of an expert is essential to start near as possible to the end of the project

When a ohlins broker tell that the shocks will be tailored to the driver wheight it mean that ohlins shim and spring it or that simply the broker change the spring?

Did you reshim the shocks yoursef? There are some instruction manual or at last a part list with the internal component drawings?

Edit: monster >2002 inner and outer tube are about 30mm short than <2001 and sbk, so if you put a sbk cartridge iside you endup with about correct fork lenght but longer travel unless the rebound valve hit the compression one first

Edit2: in this configuration you alse reduce the bushings overlap. Is possible thay you increase the already horrible sticktion and outer tube anodizing wear?

[Speeddog]

~~~SNIP~~~

I´m also slightly surprised the stanchion does not bottom against the top nut until 140+ mm. Are the fork legs stock components?

The uppers are the ones that came on my '02 S4, which I bought brand new straight from a dealer.
I hard-black anodized them in 2010 (which BTW still looks great, no fading at all, and they've seen a lot of sun).
The lowers are from a customer S4R that I bought after he yardsaled it, no evidence of anyone being inside them prior.
SBK cartridges from '01 748 forks bought here on the DMF from EEL, IIRC they were virgin internally as I had to drill the peen marks to get the base valves out.

All of the extra travel comes from the SBK cartridges, they're longer overall than the S4/S4R yet have barely enough travel to work with the shorter upper and lower.
So it's just that they're extended further.
I had no idea of it until I did a dry fit, I was very concerned until I confirmed the cartridges weren't a bottoming stop, then I was super chuffed! 
I spent the late 70's early 80's on MX bikes, ~last half of which was on 12" travel suspension, and I'm about 185cm tall, so even 140mm+ feels quite stingy. 

[Speeddog]

When you change 1 step springs or add/remove one shims can be better or worst, but when you do a big change or swap entire fork or shocks is more a start of a project that will require time and money to be completed  
Obvusly the help of an expert is essential to start near as possible to the end of the project

When a ohlins broker tell that the shocks will be tailored to the driver wheight it mean that ohlins shim and spring it or that simply the broker change the spring?

Did you reshim the shocks yoursef? There are some instruction manual or at last a part list with the internal component drawings?

Edit: monster >2002 inner and outer tube are about 30mm short than <2001 and sbk, so if you put a sbk cartridge iside you endup with about correct fork lenght but longer travel unless the rebound valve hit the compression one first

Edit2: in this configuration you alse reduce the bushings overlap. Is possible thay you increase the already horrible sticktion and outer tube anodizing wear?

IME, when they say 'tailored to your weight', yes, it's only that they fit a spring that they think is appropriate for your weight.
I think some Ohlins vendors will revalve, but that's at added cost, not within the normal 'retail' price.

Also, IME, aftermarket and even OEM Ohlins shocks have too much damping, especially on high speed compression.
I think partly due to it being slightly safer than too little damping, and for aftermarket shocks they've got no idea what folks will do with them.
The aftermarket Ohlins for my S4 and the OEM M900s Ohlins I've run on my M750 were both really stiff as delivered.
Customer's S4Rs same way.
One can adjust the knobs, but those are low speed only (unless it's a top shelf one that has hi/lo compression adjusters).
That results in a bouncy/sloppy ride that's still too harsh on sharp-edged bumps, and that's not much of a solution.
I've reshimmed Ohlins and dramatically improved the response to sharp bumps.

There are parts diagrams floating around, searching for 'ohlins shock manual' or similar and then examining the results will get you those.

I've got a set of 2001 Monster forks off a M900s, and they're the long outer/long inner/short travel version Showas.
They've only got 113mm of travel.
Really pissed me off, as I hard black anodized the outers and assembled them with the best RaceTech gold valves before I realized that shortcoming. 


The long travel forks I concocted have TiN coated lowers that had 32k miles on them when I fitted them, and I've put 22k miles on them since.
Will confirm today, but the TiN still looks good from memory.

I use the SKF seals that are not sticky and are long wearing, they don't seem to have any catchy trade name.
The rubber compound was developed to survive in oilfield drilling application, which is about the nastiest environment possible short of some saltwater beach hell.
The motocross boys love em, and they usually favor the natural green color (personally I think it's awful  ).
Be sure to specify the black version when buying, unless you REALLY like all shades of green.

[Dadouzzu]

Yes, i am a big fan of skf, black version, since about 2 years.
I am on my third fork outer tube (40kkm) because of anodizing wear, no problem with the inners.
https://www.dropbox.com/s/jstj8crxyw2yjo1/20190602_182320.jpg?dl=0
Last time i rework the bushing lands like modern mx forks to try to get better mileage and less sticktion.
https://www.dropbox.com/s/hfrpgd8k28a4l3l/20190616_135945.jpg?dl=0

I agree with the sloppy bouncy than harsh on bumps settings on both ohlins and andreani.
The last one suggested me to remove one of the 3 0.15mm compression shims.
After that i will look at the shocks (feel bad to open a new shocks that take 2 month and half to arrive directly from ohlins set to my weight )

[koko64]

Appreciate all the contributions to this thread. Good reading and the information really assists potential decisions about suspension tuning.

[MonsterHPD]

Hello,
back home again after a few days of vacation with wife, daughter and dog :-)

As mentioned, lots of interesting info available from the contributors in this thread (as in many others, of course). I would like to know more about this (from Dadouzzous post):

Last time i rework the bushing lands like modern mx forks to try to get better mileage bang head and less sticktion.

Exact what is this rework? I may have an idea, but some more details would be much appreciated.

Anyway, to comment on some of the above:

I do my shock work myself, but only started doing that after I´d attended the suspension seminars at reaction Suspension (York, UK).
Even so, some time ago I noticed a small oil puddle under the bike. I was worried this might come from my new motor, and spent some time looking for the source (in vain, which was a good thing, at least as far as the motor is concerned).  Then, at one of the track days, Hanna (member of the track day committee) pointed out it actually came from the shock.  Back home again, I disassembled the shock, changed the seal etc in the seal head of the shock,and put everything back together. All nice and clean, also during (and after) the next track day. However, arriving at the next track for the next track day a week later, I was greeted by this sight:

20190728_204358 by torbjörn bergström, on Flickr

Much worse than the previous leak ….. The shock is now apart again, no obvious problem visible, so I suppose I manage to mangle the seal ring when I put it all together. Since this shock has been apart many times, and the object of much procedure experimentation on my part, I´ve ordered a pre-assembled seal head from Öhlins; seal, support ring, bushing, the lot, so that´s one variable removed. Shaft polished, and extreme care on assembly, fingers crossed …. Knowing roughly what you´re doing does not help if you don´t do it well. Good thing it was my own shock, and not on someone elses bike at  track day in Spain. Doing this kind of work on a spare-time basis does have it´s risks.

Anyway, all the experimentation has resulted in a shim set-up much softer than the stock 749R; I´ve removed 3pcs 38x0.2 (out of 5) and one 36x0.20 (from 2), and reduced clamp shim diameter (the shim at the bottom of the stack, defining the ”bending diameter” of all the other shims) from 19 to 18 mm.
The shock on the M800 has also been softened, by removing one each od 38 and 36 x 0.20 mm shim, and reducing clamp shim from 18 mm to 16 mm.
From this you may deduce I agree on the view that the Öhlins shocks are on the stiff side as they come …    

For my needs, this shock (and fork along the same lines) work well enough on track, I never worry about bumps when I ride this bike on track.

67882104_10220237295433533_8103222915127836672_o by torbjörn bergström, on Flickr

Old man, doing his best to look like a track rider. It´s the fun you have that counts :-)
  
 

[Speeddog]

~~~SNIP~~~

Last time i rework the bushing lands like modern mx forks to try to get better mileage bang head and less sticktion.

Exact what is this rework? I may have an idea, but some more details would be much appreciated.

~~~SNIP~~~

I think he's 'barrel-shaped' the surface under the bushing to avoid tube flex induced cocking of the bushing.

[MonsterHPD]

I think he's 'barrel-shaped' the surface under the bushing to avoid tube flex induced cocking of the bushing.

Sounds plausible.

I think Gareth (of Reactive Suspension) showed a fork leg where the buhing recess had a higher, rather narro center band on which the bushing was supposedly "swivelling"; I suppose that would be the same basic idea.

[MonsterHPD]

BTW,
I´ve also used the SKF seals since 2013, don´t think I´ve had to change one due to leakage.

[Speeddog]

The M900s OEM Ohlins had 3 of 38x0.20 and 2 of 38x0.25.
I think someone grabbed a setup sheet from Iveco or DAF.

[MonsterHPD]

The M900s OEM Ohlins had 3 of 38x0.20 and 2 of 38x0.25.
I think someone grabbed a setup sheet from Iveco or DAF.

That´s really stiff. One 0.25 shim equals 1.96 0.20 shims, so that would equal almost 7 pcs. 0.20 shims. Pretty stiff ... my DU5034 (for the Monster RS, I think) had 2x38x0.20, and 2x36x0.20, not nearly as stiff as what you had (also depending on the rest of the stack, and particularly the clamp shim), but still too stiff for me.   

It´s almost 2 years ago now that I attendedd the suspension dyno semainar at Reactive Suspension; it was very enlightening to actually get numbers on whatever change you made. The dynos have become more "affordable", but still beyond my means ....

[Dadouzzu]

Hi, i'am also in vacation with my family so i write now that my son is sleeping 

Yes, i reshaped the bushing land in a barrel shape instead of stock cilindrical.
The idea is to leave the bushing free to rock in the land to tolerate fork flex and freeplay.
I read some advice in a forum long time ago, maybe from an australian guy (terry hay?).
When i see the worn outertube and a perfect bushing with only minor worn on the edge i decided to try.
He write to do an interference plug on a lathe and cut the land at 1' degree leaving 8mm flat portion in the center.
My lathe was probably build before the II world war  and is not very accurate so i build a conical plug and rounded the land with a hand file, slowly and continuosly cecking with a dial gauge:)
https://www.dropbox.com/s/ol8z22orea20j7o/20190605_194604.jpg?dl=0
I removed up to 0.07mm of radius on the external part of the land and that finished it with sandpaper.
https://www.dropbox.com/s/j9hect2a0ek8pui/20190616_114206.jpg?dl=0
The stiction became 4-5mm instead of 15-20mm (but i also swap springs and cartridge and regreased the seals..), for the anodizing wear i have to wait this winter to see if is better.

I'm the only one that have found this type of wear/sticktion (on a sraight and aligned fork)?
Here most of the service change oil and don't even take a look inside

The shocks has about 500km so i don't have to remove the seal head but i haven't found any manual so i don't know the level of separator (du321 is a monotube) and the proper filling procedure

[Speeddog]

Very general manual:
http://www.smartperformanceinc.com/ohlinsttxshockservice