New tires become suspension rebuild+...(Monza) FAC update!

[SED]

The Monza tires were very slippery in the wet.  Dot markings indicated 20 years old  :o   Ordered new Road Riders.


New tires means removing the wheels, and wheels were looking a little shabby, so took them to the powder coater.  Made an executive decision to eliminate the black.  They will be all silver like the LMIII (and the cooking V50).  Color is called "Silverstone".


The forks were leaking a bit of fork oil and seemed to lack some rebound damping so better rebuild those.  I've rebuilt girders and mtn bike forks - how hard can this be?   :BEER:  Pulled the fairing and loosened everything up:


Darn fork tubes were stuck in the triple clamps so used a rubber hammer to drive them out and got a little careless:  (ugh! this is the type of thing I hate doing and it's the second time on this bike  :'( )


Removed the instrument panel so I don't bash the speedo too:


Actually a good trick is to just put the axle through the lower fork leg and use the rubber mallet on the axle.  If only I'd thought of it earlier...

edit 3/29/2015
 :+=copcar  Stop!!!  A better method was just posted by JRT on another topic.  Take the pinch bolts out of the lower yoke and thread them in from the back then drop a washer or thin plate into the slot in the yoke and tighten the bolt against it.  It will spread the slot and loosen the clamp on the stanchions.  Nicer than either a wedge or a hammer.




 

[oldbike54]

 Ahh , the famous 30 minute repair job  :D

  Dusty

[SED]

Ordered seals, dust seals and FAC dampers from MotoInternational.   ;-T

To pull the fork lowers off the stanchions a hex bolt has to be removed from the bottom of the lowers.  It's accessible after the axle pinch bolt is removed.


Then the cartridge and spring assembly can be unscrewed from the stanchions.


Then the snapring at the bottom of the spring becomes accessible so that the spring can be removed from the cartridge assembly:


There is a little plastic spacer between the cartridge and the top of the spring:  


Seals arrived from MotoInt, chrome on the stanchions looks good, just waiting on the FAC dampers.

[SED]

Ahh , the famous 30 minute repair job  :D

  Dusty

Yes, there a bit of mission creep going on. 

[SED]

While waiting for the powder coater and the dampers, I check out the speedo drive.  Reportedly the small block speedo drives are very fragile and have a tendency to seize and break the drive tang off which renders them useless.

The brass receptacle for the speedo cable had slipped a cm or so out of the housing so I just pulled on it and the worm gear came out with it.
There was a retainer ring on the back so pulled it too to release the drive tang.  Haven't figured out how to pull the rest of it apart, but may not need to.  Will clean it and pack it with grease and hopefully it will last another 34 years.


Also had time to go to the friendly glass cutter and they cut a new lens for the tach:  (the rim is only a little bashed  :-[)

[SED]

The steering head bearings have a bad reputation so the triple tree yokes had to be pulled to check.  Until the late 1980s (I think!) small blocks ran loose ball bearings rather than tapered roller bearings like modern bikes.  These bearings have a reputation for early failure but these were not terrible.  Lower race in the head tube looks OK:


Strangely the upper race is in the worst condition because the track for the balls was chromed!  This picture shows chrome flaking from the bearing surface.  Why would they chrome plate a bearing surface?!  :P


Polished the inner races and bought 44 new balls.  I measured the balls at 0.1875" (3/16").  I expected them to be metric!


With the triple clamps out I decided to remove the steering lock because I didn't have a key for it.  Pry the brass rivet out using a strong knife blade as a wedge, pull the cover, then use a large punch the diameter of the lock cylinder to drive the lock cylinder in about 3/8".  The pin that holds the lock cylinder will be sheared and the lock removed by pushing it out - not in (good info here: http://w6rec.com/duane/bmw/lock/)


After the lock cylinder was removed I used a dremel to cut a slot in the sheared pin and removed it.  It was easy to replace with a short length of 3mm bolt.  I also pulled the cover off the lock pins (tumblers?) - they are tiny!  Much smaller than household lock pins. And the springs are tiny and fly everywhere.  There are 5 pins (the BMW site says 4) and I removed one, filed one and made another and was able to rekey the lock so that it uses the same key as my LMIII but with 4 instead of 5 pins.  I now have a key!   ;-T

[balvenie]

SED,
      Removing my fork tubes is accomplished by driving wedges into the gaps in the triple tree. The gaps are closed with pinch bolts to hold the tubes securely. With the gaps spread, twisting the tubes one way, then the other, liberates the tube quickly. That's my bike anyway.
      With your bike being 34 yo however, that might be asking a bit much if there was a chemical(?) reaction between the different metals in the tube and triple tree. glad you did not have to hammer the axle :o ;D   

[Chuck in Indiana]

Removed the instrument panel so I don't bash the speedo too:

;D ;D
And yeah the balls are 3/16". Surprised me, too.
Nice tutorial.. ;-T

[Tobit]

SED,
      Removing my fork tubes is accomplished by driving wedges into the gaps in the triple tree. The gaps are closed with pinch bolts to hold the tubes securely. With the gaps spread, twisting the tubes one way, then the other, liberates the tube quickly. That's my bike anyway.
      With your bike being 34 yo however, that might be asking a bit much if there was a chemical(?) reaction between the different metals in the tube and triple tree. glad you did not have to hammer the axle :o ;D    

 :+1

The condition is called Shipwright's disease.  Can't put a new part on a grungy old part.

Bashing the axle would be a good way to possibly damage the fork slider or the damper cartridges.  Brute force should be reserved for Caterpillar D9 maintenance.  Nice write up though.  I miss my Monza.

 ;-T

Tobit

[Groover]

Thanks for posting the steps on rebuilding the forks. It all makes sense now!

[kevdog3019]

Great post. These sort of DIY posts are priceless. Thanks.  ;-T

[Antietam Classic Cycle]

If the fork tubes don't come out willingly, I just leave them in the triple clamps. Sliders come off the bottom, damper spring units out the top. Less aggravation and achieves the same result.

[SED]

:+1

The condition is called Shipwright's disease.  Can't put a new part on a grungy old part.

Bashing the axle would be a good way to possibly damage the fork slider or the damper cartridges.  Brute force should be reserved for Caterpillar D9 maintenance.  Nice write up though.  I miss my Monza.

 ;-T

Tobit

(edit 3/29/2015)
 :+=copcar  Stop the presses!!!  Tobit's right.  A better method was just posted by JRT on another topic.  Take the pinch bolts out of the lower yoke and thread them in from the back then drop a washer or thin plate into the slot in the yoke and tighten the bolt against it.  It will spread the slot and loosen the clamp on the stanchions.  Nicer than either a wedge or a hammer.  Wish I'd read it a week ago. (end edit)

Apparently I did all the bashing on the tacho  :'(.  The stanchions were moving, but very tight so using a rubber mallet on the axle wasn't too bad - not trying to break anything loose and the axle fits well in its bore.  But Charlie's, right I could have left them in the triple clamps but I've never had motorcycle tele forks all the way apart before so I figured I better try to do it by the book.   :P

     Removing my fork tubes is accomplished by driving wedges into the gaps in the triple tree. The gaps are closed with pinch bolts to hold the tubes securely. With the gaps spread, twisting the tubes one way, then the other, liberates the tube quickly. That's my bike anyway.    

Balvene, I did however use a wedge to open the bore once the stanchions were out.  But the clamps in the Monza yokes are not split to the outside like some forks so couldn't get a wedge in with the yokes on the bike.  I knew I'd never be able to install the stanchions back in them without spreading them so used a cold chisel.  (More brute force and ignorance but it worked.  :BEER:)


Thanks for all the kind words all!  More soon!

[Matteo]

Great photo in front of Mt Shuksan, added to my screensaver. What road were you on?
Matt.

[SED]

Great photo in front of Mt Shuksan, added to my screensaver. What road were you on?
Matt.

Good eye Matt!

It's the road to Artist's Point above the Mt Baker ski area just one turn below the top.  Most years they try to get it open by the end of July, but this year it'll probably melt out by the end of May.  Going to be a dry summer...

[oldbike54]

If the fork tubes don't come out willingly, I just leave them in the triple clamps. Sliders come off the bottom, damper spring units out the top. Less aggravation and achieves the same result.
[/quote

 Kinda hard to get at the neck bearings that way Charlie  :D

  Dusty

[SED]

Need to clean up the fork lowers so pulled the top seal with a bent screw driver:


and made sure the "lower element" (brimstone? ;))came out of the bottom of the slider:


Soaked the sliders in hot water and powdered laundry detergent and scrubbed them all over.  Was wondering how to clean all the way down the inside of the slider.  Finally figured out that a threaded a loop of wire through a 12" tube would trap a rag and I could swab out the slider with it.  Worked great:


The bore of the slider after cleaning:


The "lower element" has a locating pin and the workshop manual says there is a detent to receive it and that you must make sure it is located correctly.  Dave Richardson suggests putting in in 180 out from the detent then rotating it with a long screwdrive so that you can feel the pin drop into place.  As the only detent is formed by the drain hole you can also mark the top of the lower element with a marker so you can look down and confirm that it is lined up with the fork drain plug:


Still need to paint the lowers.  

[SED]

 Kinda hard to get at the neck bearings that way Charlie  :D

  Dusty

;-T

[JPL]

If the fork tubes don't come out willingly, I just leave them in the triple clamps. Sliders come off the bottom, damper spring units out the top. Less aggravation and achieves the same result.

When I FACed my V50II I discovered that's how you have to assemble it. The integrated top nut of the FAC damper will not fit through the triple clamps; no pre-assembling the fork legs.

[SED]

When I FACed my V50II I discovered that's how you have to assemble it. The integrated top nut of the FAC damper will not fit through the triple clamps; no pre-assembling the fork legs.

Thanks for the tip JPL.  Looks like the FACs are still a week away.

[SED]

This started with wanting to put new tires on the Monza.  But first I had to get the wheels powder coated.

Picked them up Friday:


Tires on today:


The rear shocks were leaking so looked for a rebuild kit.  Marzocchi Stradas.  Got the rebuild kit here (for 12mm shafts only):
http://marzocchimoto.blogspot.com/p/ag-strada-kit-buy-it-now.html

Don't like having so many components in pieces.  Ugh!  It now looks like this:

[kevdog3019]

Coming along nicely.  ;-T  Once done you can rest assured things have been addressed.  Looking forward to hearing about your suspension upgrade.

[Antietam Classic Cycle]

If the fork tubes don't come out willingly, I just leave them in the triple clamps. Sliders come off the bottom, damper spring units out the top. Less aggravation and achieves the same result.

 Kinda hard to get at the neck bearings that way Charlie  :D

  Dusty

So, leave the tubes in the lower triple and just remove the top clamp. That usually comes off quite easily compared to removing the tubes completely.

[SED]

Progress!  Rebuilt the 'zocchs today and installed the rear wheel and tire.

Marzocchi Strada rebuild kit from http://marzocchimoto.blogspot.com/p/ag-strada-kit-buy-it-now.html
You can also find a Strada manual several places on line, but there's some things it doesn't have.



Got the spring off by compressing it all the way with the adjuster, tying it with wire loops and then loosening the adjuster.  The last 1/8" or so of clearance I got by prying with a screwdriver in the slot of the spring retainer.




Release air pressure through Schrader valve and then release hydraulic pressure through screw on air chamber.


Clamp in vice and remove large (32mm) "plug".


Once the plug is out, rock the piston back and forth to work the O-ring seal out of the shock body.  It's easier if pull toward you rather than up, but it will spill smelly oil all over.   ::)


The piston rides in a steel tube with a small hole at the bottom.  This tube ("sleeve" in the 'zocchi manual) will probably come out with the piston.  When it does the hole will leak smelly oil all over the workshop.  :P


Next disassemble the air chamber.  You will need a 30mm pin-wrench to do it.  Fortunately I have an old Sugino chainwheel pin-wrench.
The holes to insert the pins are under the sticker.  (Apparently you can buy sticker kits, but I don't need no stinking stickers!)



The cap has an O-ring, followed by a steel shim and the rubber air bladder.  Used a dental pick to pluck out the edge of the bladder.



At this point the shock bodies are bare except for the rubber in the lower mount.  I soaked them, springs and spring adjusters in hot water and powdered laundry detergent.

[SED]

The Laverda forum has a good thread on rebuilding these shocks with lots of pictures and info - very helpful.  ;-T

Clean the parts and reassemble the air chamber with new air bladder and new o-rings on cap and bleed screw.  I used some light synthetic grease on the o-rings and soaked or slathered other pieces with shock oil as assembly lube.



There isn't much info on the piston assembly in the Strada rebuild manual.  BTW, apparently the upper mounting eye is cast over the top the piston rod - it can't be unscrewed to be re-chromed or replaced (info from Laverda forum).

The picture shows from left to right - nut, aluminum piston with plastic ring and o-ring below it (this seals to the inside of the sleeve), 3 thin shims on the top of the piston, piston valve piece with another thin shim (looks like a wave washer) below it, spring and aluminum plug that has o-ring to seal top of sleeve and seal for piston rod (this entire piece comes with the kit), dust seal (fits into plug), threaded plug and rubber cushion.  There are at least 4 thin shims between the aluminum piston and the spring and the lower two are very similar and easy to mix up.



Picture of the piston shims:




A neat trick to removing o-rings is to stretch them by pinching around the outside so that it puckers out:




The piston has a plastic (teflon?) seal over an o-ring.  The o-ring is easy to install but the plastic ring isn't.  One guy on the Laverda forum just cut them at a 45 degree angle - and it looks like the originals were cut too:



At the risk of breaking or stretching the ring and ruining it, I decided to press it on with a block of wood in the vice.  It stretched over the wide part of the piston.  



Then I pushed the rest of the way over the o-ring with a screwdriver, but should have used something softer.  Photo shows that it sits tight enough over the o-ring to make contact, and it slid into the sleeve easily so apparently not stretched too much.



Installing the pieces on the piston rod.  Both rubber cushion and dust seal for the plug flare out toward the bottom.  

[SED]

I used solvent and compressed air to clean the valve at the bottom of the sleeve, then flushed with shock oil.  Some on the Laverda forum found that these valves would stick open so check that yours are OK.  The Marzocchi manual describes how to take them apart and change the shim order to change the compression damping. 

Clamp the shock body in the vice at an angle so that the air chamber is up and the bleed screw upper-most.  Insert clean sleeve.



Fill with shock oil until it dribbles out the bleeder hole.  Install the bleeder screw with its o-ring.



Tip the shock up in the vice so that it sits vertical.  The shock oil should be within 2-3 cm of the top of the threads.  Wrap a soon to be oily rag around the shock and vice and insert the piston in the sleeve, then slide the aluminum seal holder ("pilot boss" in the manual) and spring into the sleeve until the seal holder seats in the sleeve and the sleeve seated in the shock body.  The top of the seal holder should be just below the top of the shock body.  Leave the piston at its max extension and thread in the plug with its dust seal.  Marzocchi warns to watch that the dust seal doesn't push up too far - its top surface should be level with the top of the plug.  When I did this oil squeezed out when I put the plug indicating that there is no trapped air.



After everything was sealed up I cycled the shocks several times.  Compression damping was very light and rebound damping significant.  Felt smooth throughout the stroke after a couple of cycles.  Install the springs.  Air up with a bicycle suspension pump.  The air volume is so small that normal air pumps or compressors won't give you an accurate reading. 



Install the shocks, then the new tire on the powder coated rim!

[canuck750]

Great looking V50! and I can sure relate to where you are heading with this little bit of work :BEER: Nice work and keep at it, soon it will be brand new ;-T

[SED]

Thanks Canuck.  It sure is a fun little bike.  Hope to do many nice rides this summer.  ;D

[JPL]

SED, thank you for taking the time to document the Marzocchi Strada rebuild. ;-T  I've seen Marzocchi's document but was a little cloudy on a few points. I've have them on mine too; they're not leaking and still damping okay but probably overdue for a change of the smelly oil. What weight oil did you use?

[Chuck in Indiana]

Nice!  ;-T I have a set of those.. didn't even know you could get parts for them..