|
Enduro Suspension Tuning & maintenance of Enduro forks, shocks, etc |
|
Thread Tools | Display Modes |
|
#1
|
||||
|
||||
Putting a radius on the tubes to allow the upper bushing to float to prevent binding and prevent wearing the hard coating off the inside of the tubes was suggested by Terry Hay. Here is a picture of the tubes after I ground them. Not as pretty as turning them in a lathe but still gets the job done. Dave
|
#2
|
|||
|
|||
It's amzing they STILL haven't fixed the bushing land?
|
#3
|
|||
|
|||
Quote:
You felt it was worth the effort? |
#4
|
|||
|
|||
Quote:
Just measured a 89 RM 46mm fork tube as it was handy. Bushing width measures 19.79mm--Bushing land 20.09 = clearance of .30mm or .012" this allows the bushing to float some and not get bound up. Land dia at center 44.90. Center area is 16.59mm wide--At edges dia is 44.69= .31mm/.012" of clearance for the bushing to rock on the tube. Reduced dia area is about 1.50mm wide per side. I can take pictures if it will help anyone. |
#5
|
|||
|
|||
Very nice elaborations on this subject, Lew. Now i finally see what Terry meant with the upper bushing problem.
Although i can see the picture now I surely like to see some pictures. I feel that more people wld appreciate that. Dave, when do you plan on yr test ride? Hopefully soon?! Ohh, and how did you find out about the bind up. Riding with a ty-strap around the fork and hitting that brick several times? |
#6
|
|||
|
|||
Dave, again... how wld i investigate binding with my marzocchies? Is it something you learn by experience or is there a trick that can address binding?
I am very light on mine compressions valving, midvalve aswell bottomvalve, but still i feel some spike on 2" roots. Is this reshaping of the land of the bushes helping me in this situation? I once ridden this showa Honda fork... i never felt any spike..... This is what i like to accomplish with mine marzochies |
#7
|
|||
|
|||
Ok, here a report about the marzocchies 45mm.
First i disassembled the forks completely and went step by step to measure and look at the various parts. One upper bushing was very thight on its land. The other was so so. With the outer legs in the triple clamps i cld feel some binding at the last part of travel. This is the upper clamp area. Both legs have a freebleed hole in the legs at 17cm of the upper bushing. So i felt no need for extra holes at 20cm. I started working. I did the bushing land as per Pobit pictures. Now both bushing have some room to flex and turn on the land. With everything assembled this gave some free play(more than was before offcourse). I checked binding by putting the outer legs in the triple clamps, torqued the bolts to specs and when shoving the inner legs tru felt no binding at all at the triple clamp area. What i did notice was quite some drag/binding caused by the seals. I sure feel that slippery oil will benefit some forks with thight seals. Today i went for a little ride, and first thing i noticed was that with slap down landing of the front forks(you get these with ending a wheely) there is a softer cushion. I address this to the more free play of the bushings. Correct me if i am wrong in my thinking. I surely felt the whole travel was more compliant, but i did not do a real high speed spike test. I also felt that the rebound was better?! The fork was less dribbling over smaller impacts, at speed. And i had even less rebound than before. I did nothing to my valving, so the only thing i did was the bushing land. What i did do was running less oil volume than ever before. Terry Hay gave me his advice to run oil height of 130mm, where i normally use around 90mm. I use ATF II type, which shld read 7,5 sae of forkoil. Well, so far my experience with the year 99 marzochies and i feel that everyone can benefit as they are not changed for over 8 years now. Maybe the valves are a little different but all dimensions are still the same. I have a very light midvalve, with around 1.0mm of lift, and a very light basevalve. Rebound is rather heavy simmed since it is such a small cartridge. Because of the small cartridge the basevalve sees rather much oil. Maybe my midvalve is too light but i rather have no spike with an occasionally bottom out than otherwise. When i did some more riding i will report back. |
#8
|
|||
|
|||
|
#9
|
|||
|
|||
I'm assuming everyone knows the numbers in my other post won't match the Zoch's? They are just for reference. An X wide bushing on a Jap bike tube has Y clearance.
|
#10
|
|||
|
|||
Ktmlew, Pobit, and Terry Hay, your guys experience really opened my eyes regarding the need of clearence at these bushings.
It is funny though, that a fork can be too rigid. |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
05 De 300 Specs | VORMAN | Enduro Electrical & Wiring | 9 | 11-14-2010 06:36 PM |
Top End Clearances/Specs | SpeedyManiac | Enduro Engine - 2 stroke | 4 | 09-24-2009 09:53 PM |
Torque Specs | steve | Enduro Engine - 2 stroke | 8 | 02-26-2008 09:30 PM |