Mazzo forks damper rod allen head bolt torque spec

78jotadave

78jotadave

Hero member
Location
Palm Desert, California. (near Palm Springs)
Does any knowledgeable person have this spec handy or at least tell me where to find it on the Forum. Torque spec for the allen heads on the triple clamps and front axle nut too. I have always done it by feel, I need to work smarter and tap into the Forums knowledge, thanks in advance
 
Below from the RGS Factory Workshop Manual. Can't see why any other model triple would be different:

Triple clamp: 10x1.5, 4 off, 30-33b/ft
Axle nut: 16x1.5, 52-59 lb/ft.
 

Attachments

  • Torque settings.jpg
    Torque settings.jpg
    140.9 KB · Views: 28
78jotadave said:
Hey Ventodue, thanks for the spec chart, down loaded and copied. No damper rod spec so I called RaceTech shop and asked Doug in the suspension shop, he returned my call within 10 minutes=30ft/lbs.
This Forum works, thanks again.
Click to expand...
30ft/lbs. sounds like a helluva lot for a, IIRC, 6mm allen bolt in the damper rod.
I'd go with the 6-9, as in the list above.
Just sayin'
 
The Sock said:
Still a very high torque setting for an 8mm.
Click to expand...
You don't want them coming loose - ask Dennis Neill, Australian superbike rider from the 70s-80s who had a career ending accident at Bathurst when the entire front end (sliders and wheel) dropped off the staunchions of His 900 Bol d'Or Honda when the front end got light at about 200kph.
 
Sorry, but some wrong info going about here I think. All Marzocchis I have come across have an M12 bottom bolt, it is a 'socket low head' type, so the inhex is one size smaller than a standard cap screw at 8mm. It should have a 12mm ID 'dowty' type rubber-sealed solid washer. These are often stuck in the fork slider counterbore, sometimes then doubled up with more washers and sealant and god knows what. Dig it out and replace it.
The damper rod into which it screws is steel and there is good thread engagement, so for a torque I don't see much wrong with the standard M12 tightening torque of 30-37ft-lbs per the RGS manual (and similar to that mentioned much earlier).
You need a pretty long inhex socket to reach them.

The thing with Denis Niel's bike was weird. Surely if those bolts were not installed you'd have no fork oil and a pro rider would notice straight away. If they came loose they'd dump all the fork oil over the tyres and engine and again the rider would crash on his own oil or otherwise notice before lofting the front wheel. At least in the Marzo's I doubt there is enough room for them to unscrew all the way to let the lowers drop off, the front axle would prevent them from unscrewing all the way (the lack of available space determines the need for the socket low head bolts). Well weird indeed.
 
I must be confusing Marzo with Ceriani.
Dennis Neil's crash was apparently caused by the front wheel coming out from the sliders. As it was a superbike it could well have had those fancy quick release hinged type axle retainers. Had one of those loosened the wheel would have been torn out of the other side. At the 8 hour at Oran Park the year before he pulled in to the pits on his CB1100R on one of the first laps, furiously waggling his RH clip-on which had loose pinch bolts, hmmm.
 
Cerianis are my experience base, too, never had anything to do with the Marzocchis.
M12s will take that kind of torque but, since it seemed to high, to me, better to ask, than wait till something shears and then say "I thought that was too high".
 
Dennis Neil’s crash was caused by the fork axle cap not being done up correctly and therefore when the wheel got light over the hump the axle caps dropped off causing the wheel to part company. I believe that he successfully sued the Honda team later on. A powerful piece of evidence was a photo of the bike on the grid and apparently they could see that the caps were loose 😧 Almost finished him and his career 🙁
Tom
 
breganzane said:
I doubt there is enough room for them to unscrew all the way to let the lowers drop off, the front axle would prevent them from unscrewing all the way ...
Click to expand...
It's possible in theory for the bolt to unscrew all the way if the if the damper rod rotates rather than the bolt. Any scenario of the bolt coming unscrewed seems pretty unlikely though, for the reasons you mention.
 
I stand corrected - a piece of info that went sideways with the retelling of the tale - it was a long time ago and an axle retaining cap coming adrift makes far more sense than the damper rod bolts coming out. Either way it was a terrible accident. As a mechanic I absolutely double check essential stuff like that - as a race mechanic it's unbelievable that they would miss something like that - can't believe they weren't lock-wired anyway.
 
And to top it off a proper Honda team to boot. O yer didn't something similar happen to Casey Stoner a couple of years back on a Suzuka 8hr ride. His first competitive ride in Donkey's years, he had just broken the lap record and then something broke, don't remember what but it came from poor Spannering. This resulted in a horrible crash and a heartfelt apology from the team. That was the end of any riding comeback.
www.autosport.com

Former MotoGP star Casey Stoner injured in Suzuka 8 Hours crash

Casey Stoner suffered a broken right shoulder blade and fractured tibia in his left leg after crashing out of the Suzuka 8 Hours when his throttle stuck open.
www.autosport.com www.autosport.com
 
You must log in or register to reply here.
Back
Top