M1100/Evo Showa/Marzocchi Forks

Started by koko64, September 09, 2020, 08:07:45 PM

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Speeddog

Quote from: MonsterHPD on September 21, 2020, 12:59:35 PM
The Ducati forks with top-out springs that I have encountered have pretty soft top-outs, so If I want to measure sag from fully and surely extended forks I do so by screwing the pre-load all the way in. As you say, that will completely squash the top-outs.

The aggro with non-parallell front axle bores .... extremely annoying. Would probably not be half as annoying, if only one had 3 hands ....

I have managed to slightly improve oval front axles by mounting them 90° (no wheel ...) and give them a good tightening. I think part reason they get oval is that they always sit in the same position on the Showas with fork-bottom adjuster. I did not measure anything, but I think it got sligtly better .... :-\   

Ducati axles are a bit too thin honestly I'd not mind hauling around another mm of thickness for much improved ruggedness.

Ducati's not great but it's heaps better than many other bikes where I need to use all 5 of my hands.
Very annoying as that means someone has to hold my beverage.

I've done dozens of Duc axles that way.
Check 'em for burrs first, and eyeball em to look for bends.
Then pinch on the 25mm diameter 90 degrees out they can be rounded up so they'll slide through the bearings.
Then do the fat end, confirm it'll slide through all.

The pinch bolts are easy to overtighten.
I've often thought that setup could do with some thin-shank bolts or M6's or something for some springiness.
Not much benefit being stronger than the axle it just crushes it.

I unwittingly dolled up a set of SS forks (I think) with black ano and SKF seals and nice valves for my S4 then realized they're short travel and they're pretty sucky.
I've got the springs and sag set good so it sits right and won't bottom.
But it's just stiff so it rides crappy.
[bang]

I forget what the forks on my 750 had, it was a lot.
The SBK cartridges and Monster legs squeezed the last mm out of it, I had to check carefully that I wasn't going to use the damper rod as a bottoming stopper.
I'll fit those to the S4 see if it'll calm it down a little.

- - - - - Valley Desmo Service - - - - -
Reseda, CA

(951) 640-8908


~~~ "We've rearranged the deck chairs, refilled the champagne glasses, and the band sounds great. This is fine." - Alberto Puig ~~~

koko64

Good stuff to know. It makes for a more meaningful conversation with my suspension guy. I often refer back to these posts when a suspension situation arises. It's very useful contextual knowledge and promotes informed rather than annoying questions when we discuss a job. [laugh]
2015 Scrambler 800

MonsterHPD

Quote

Ducati's not great but it's heaps better than many other bikes where I need to use all 5 of my hands.
Very annoying as that means someone has to hold my beverage.

;D

When I tighten the pinch bolts, I sort of don't tighten them, I do them alternately a little at a time until the second in the sequence does not move more that the first one and both feel sort of nice and tight; I hope that makes sense.

Any fork with an SBK (or gsxr) cartridge will be better than a supersport fork with the crappy cartridge, but you already know my view on those ...

All Showa and Öhlins forks from the road / track bikes I've worked on have between 118m and 123 mm travel (with no hydralic stops). I suppose they have the same travel with the stops, but the last maybe 10 mm will be compronised by the stops.     
Monster 900-2002 (sold, alive and well in the UK), 749R / 1100 HYM combo for track days, wifes / my Monster Dark 800-2003 (not entirely "Dark" anymore and a personal favourite) , 50% of 900SSie -2000 track bike for rainy days-now with tuned ST2 motor and Microtec ECU. Also parked due to having been T-boned on track.

koko64

Forks needed a re-chrome after only 4000 miles.  [bang].
The hard chrome was not hard enough and in bad shape with deep stone chips that no amount of polishing could fix. My suspension guy diagnosed a poor batch of hard chroming which led to the decision to have high quality and durable hard chroming done by a respected local firm. Rechroming was half the price of new tubes. Premium seals, oil and the Ohlins 0.9kg Gixxer springs round out the package. I'm glad the Gixxer springs fit as they save $220.

Now to consider the shock.
2015 Scrambler 800

Speeddog

That's disappointing about the hard chrome.
Nice to have a re-chromer that is set up for forks.

I got a set rechromed for about the same cost as an aftermarket set outright.
It was a bit of an adventure but it closed the book on a refurbishment job that saw 2 sets of aftermarket tubes get rust barnacles in months.
- - - - - Valley Desmo Service - - - - -
Reseda, CA

(951) 640-8908


~~~ "We've rearranged the deck chairs, refilled the champagne glasses, and the band sounds great. This is fine." - Alberto Puig ~~~

koko64

Wow, two pair. I think the companies that handle industrial level hard chroming (for heavy hydraulic equipment, for example) are the go. I'm pretty sure the company here handles nation wide demand. They also did the 750 forks, for which I'm glad since it frequents dirt roads.
2015 Scrambler 800

MonsterHPD

If the hard  cromers do a good job, there's a good chance your fork legs will be better than new. A friends fork had the chrome worn through, and when I asked my pro friends about it, I was told that the OE hard chrome is the thinnest they can get away with. Every reason to treat your fork legs gently ....
Monster 900-2002 (sold, alive and well in the UK), 749R / 1100 HYM combo for track days, wifes / my Monster Dark 800-2003 (not entirely "Dark" anymore and a personal favourite) , 50% of 900SSie -2000 track bike for rainy days-now with tuned ST2 motor and Microtec ECU. Also parked due to having been T-boned on track.

Speeddog

In my head I wrote the cost off as R&D but losing real money still hurts.

Fork leg refurbishment will become more common, hopefully the heavy equipment industry can continue to underwrite the repair infrastructure.

Pitted nonadjustables get replaced with good adjustables if at all possible.
- - - - - Valley Desmo Service - - - - -
Reseda, CA

(951) 640-8908


~~~ "We've rearranged the deck chairs, refilled the champagne glasses, and the band sounds great. This is fine." - Alberto Puig ~~~

koko64

Quote from: Speeddog on October 01, 2020, 04:50:14 PM
In my head I wrote the cost off as R&D but losing real money still hurts.

Fork leg refurbishment will become more common, hopefully the heavy equipment industry can continue to underwrite the repair infrastructure.

Pitted nonadjustables get replaced with good adjustables if at all possible.
Note to self, rechroming will be better than brand new oem.
If I ever do a scrambler type fork mod again it'll be with Showa and not Marzocchi, that's for sure.
2015 Scrambler 800

booger

I sent my forks out ;D

Do NOT want to fuss with the rebuilding, shim stack this fluid level that. I rebuilt my mtn bike forks once and hated every minute of it. I have the grey S4R Testa which came with Showa adjustable forks.

Traxxion has them right now, installing an AK20 cartridge and anodizing the outer tubes grey. Inner tubes are getting TiN. I asked if I could get red TiN and never heard back. So I might assume they are going to be gold.

I tried for years to find some factory Ohlins or even some road & track forks they used to make. Nope and nope. 50% on the bay are S2R800 forks that people are asking $600 for. They cite the new part price from Ducati to justify their used price knowing full well the forks are garbage to begin with. Thusly there are forks on the bay that have been there for years unsold with zero watchers.

Question for Speeddog - are the M1100 Showa forks the same as what was used on the S4RT from the factory? They look the same.
Everybody got a plan 'till they get punched in the mouth - Mike Tyson

2001 M900Sie - sold
2006 S2R1000 - sold
2008 HM1100S - sold
2004 998 FE - $old
2007 S4RT
2007 Vespa LX50 aka "Slowey"
2008 BMW R1200 GSA

koko64

Quote from: koko64 on October 01, 2020, 07:32:25 PM
Note to self, rechroming will be better than brand new oem.
If I ever do a scrambler type fork mod again it'll be with Showa and not Marzocchi, that's for sure.
Purely because the Showas are easy to pull apart and reassemble while the M forks are often staked in place. Showas are much cheaper to work on labour wise.
2015 Scrambler 800

koko64

Forks are back and fitted. A turn less preload and a 1/2 turn more rebound damping feels good. Of course whenever you do work at one end the other end feels like crap.
2015 Scrambler 800

koko64

#27
Update.

The fork builder, Dontune, got the inner preload so close with the spacer length that I only used one turn of preload on the external adjusters, Edit: make that no turns out, the internal preload is spot on. With 0.92 springs for my 200lbs sans gear I ended up with rebound 1/4 turn out from max and compression damping 2 1/4 out. Oem damping was rebound 1 turn out and compression 1&1/2 turns out. The heavier spring gave me support with little preload and minimal comp damping for bumpy roads but needed more rebound to keep things tied down.

Very happy.

I can feel the budget nature of the Sachs shock and I'm running just one extra click of damping with 20mm spring preload from fully unloaded spring. Oem damping is 8 clicks out. I like 6 but it's harsh so have compromised at 7. I so want to seperate the rebound from the compression damping.

What I love about this bike is it's tiny, weighs nothing, has razor sharp steering, has 916 hp and 1098 torque.
2015 Scrambler 800