Thank God for locking tabs and a bit of technical advice requested ...

jotajoe

jotajoe

Hero member
Location
Warwickshire UK
Sometimes " Good n tight" just isn't " good enough"

I was just checking my Jota over ready for the weekend's run and noticed a couple of the rear wheel sprocket bolts were loose. Kind of shocked  :o and embarrassed  :-[ but relieved the the locking tabs had kept them in.

So, Now I prostrate myself before the Laverda Gods and humbly ask the question, " What is a sensible torque figure for the rear sprocket bolts on my Jota 180,  630 Chain and should I use a bit of Loctite medium thread lock on the bolts. 

Then I shall go and do it properly !

Joe
 
I've heard of properly torqued bolts being loose when the tab washer (or lockwire) is removed.
Caused by fretting of the 2 thread surfaces due to vibration, not by the bolt backing off (tab washer), or possibly by bolt stretching.
I would have though new tab washers and Loctite on reassembly would sort it out.
 
Thanks Grant.That is interesting .

Thankfully the sprocket wasn't loose itself....I can't see a torque value in the manual so I'll look up a generic figure for the bolt size and keep a close eye on it in future. A fair bit of vibration on these bikes and it just shows the benefit of a detailed clean from time to time.

I guess it could be deemed unfair to ask a torque figure if there isn't one published in the manual.

cheers

joe
 
2 beads of sweat on the forehead. That's a BSI-calibrated forehead by the way...
 
That sounds reasonable Rob..Thank you.

It's only a guide I guess as adding thread lock will lubricate it a bit and then the torque figure will be a bit tighter than dry threads.

Joe
 
Joe,

The torque figures in the RGS manual take into account the following (I quote):

"NOTE - We recommend the application of molybdenum grease on the threads and underside of the nuts."

Craig
 
We recommend the application of molybdenum grease on the threads and underside of the nuts."

Craig
Click to expand...

  Must be a throwback to the drum rear hub - as the sprocket carrier is tapped - no nuts!! - Joe - not too difficult to strip threads if you overdue it!! Regards - Phil
 
Hi Phil...Yes that is the issue ..I used to work with green timber all day and every day and arms are a bit too strong for my comfort at times..Handy when hauling a Jota around and the clutch lever is a non- event but.. :o...

.I'm ok with very light tasks as I like to build model aeroplanes on the dark winter nights. However if the brain gets a signal to put in a load of torque then a load of torque gets delivered !

Thank you for your input Craig,,

I'll be careful...

Joe
 
When it's time is up if not before think about ditching the 630? Mine used to wear away the crankcase quite well!
 
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