Arco Spigarelli Revolution riser bolts torque settings

whoosh

Member
Well - after I replaced all the riser bolts (due to one shearing) I emailed Arco Sport Spigarelli to ask what the torque settings should be . . .

This is the response :-

You have to turn the screw until the end of the thread at the end of the handle.
We hope we explain well
Regards
Arco Sport Spigarelli srl
Via Prenestina 252 /e 00177 Roma

I have a feeling that may be a "smidge" too tight as the bolt heads are at least 1/16" below the surface of the riser and are currently "hand tight" on a medium length Allen key

Any views on this?
 

lbp121

Member
Torque settings are not very accurate since they depend on the thread having a specifis level of friction. I can't speak for the ham fisted but I have never stripped a thread on a bow. Hand tight sounds good but if a watch maker were to hit it with a hammer he may use less force than a blacksmith tapping it!
The main reason to use torque settings is if there is are series of bolts which need to be tightened the same amount, like on a cylinder head or even a wheel. For a bow I wouldn't worry unduely, Arco won't have but if you are determined, look up torque setting for a whatever mm bolt and thread, you'll find there will be charts.
 

whoosh

Member
Thanks lbp121 - as the riser is made of three separate alloy bars bolted together with damping washers in between - I think the torque setting might be quite relevant to compress the damping washers the correct amount and keep the three bars parallel . .
 

robdav

New member
HI Whoosh,
it's your fellow member of the broken bolt club.
I got virtually the same response from Spigarelli:
You may use locktite and you have to turn the screw until it arrives to the end of the thread ( at the end of the handle).
We hope we explain well.


I'm guessing they don't use torque settings themselves.... relying on simple mechanical alignment. I noted that the factory installed bolts sat just a bit below the surface of the front of the riser, so I aligned the replacement bolt to the same position. I guess this is accurate enough.....
We'll see.
The bow is shooting fine now... so hopefully no more busted bolts!

Cheers,
Rob
 

whoosh

Member
Ah - thanks so that's about level with the internal chamfer then? That's about where mine are at, any tighter and it would deform the dampers
Cheers
 

whoosh

Member
Cheers Rob - one of ours turned up tonight with his recent eBay purchase of one and it's precisely that on his too, that's three already at our club and someone has just ordered a barebow one . . getting popular :)
 

robdav

New member
interesting.... no one around here (Toronto, Canada) had ever laid eyes on one until mine arrived. Now two more are shooting with it!

Everyone here shoots Win-Win or Hoyt, as they're the only brands available locally.

Happy shooting!
Rob
 

LAC Mark

Active member
Hi Guys

Sorry to drag up an old thread.

I've just had a bolt shear on my BB revolution, thanks to the posts on here I know the right size bolt and how much to screw them in.

I got my Rev second hand and it came with spare dampers, so I intend to fit them as I have no idea of how much use it's had.

The bolt that sheared on mine was the first countersunk closest to the top of the riser, I wonder if it was the same bolt as others have had.
 
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