Ultima big round knob comes loose?

PLEASE HELP TO FUND ARCHERY INTERCHANGE

indegold

New member
Had my Shibuya Ultima mark 1 for about 10 years. Great bit of kit but within last few years the large round knob with the plastic domed-tip gradually works loose ( tightens bar to sight bracket on riser.)
I have tried adding rubber washers etc and my shooting/form hasn’t changed much.
I’m thinking the knob has become worn. Before investing in another thought I’d ask if anyone else has had this issue?

Cheers
 

Timid Toad

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Ironman
Idiot question: Over the last 10 years I'd guess you've changed arrows/string etc and retuned? So although it might not be a form issue it could be a set up/tune issue.
 

KidCurry

Well-known member
AIUK Saviour
If you have not changed anything as TT mentioned, the threads are probably worn. My first approach would be to clean both male and female treads with IPA to ensure no grease/dust in reducing the binding of the threads. If this doesn't work I would heli coil the block, but this option needs some experience. If the rest of the sight is fine you could always buy a new mounting block and screw, about £40 for the set or £25 for the block and £15 for the screw/knob, although that might be what you meant :)
 

Timid Toad

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Ironman
If you have not changed anything as TT mentioned, the threads are probably worn. My first approach would be to clean both male and female treads with IPA to ensure no grease/dust in reducing the binding of the threads. If this doesn't work I would heli coil the block, but this option needs some experience. If the rest of the sight is fine you could always buy a new mounting block and screw, about £40 for the set or £25 for the block and £15 for the screw/knob, although that might be what you meant :)
I prefer to drink my IPA ;)
 

ATH

New member
Had my Shibuya Ultima mark 1 for about 10 years. Great bit of kit but within last few years the large round knob with the plastic domed-tip gradually works loose ( tightens bar to sight bracket on riser.)
I have tried adding rubber washers etc and my shooting/form hasn’t changed much.
I’m thinking the knob has become worn. Before investing in another thought I’d ask if anyone else has had this issue?

Cheers
Hi, I've had a few shibuya sights and this part working loose is not an unusual problem. I've added tape around the knob on some to give extra grip so that I could clamp it down tighter. The other comments on checking bow set up to minimise vibration are also sound. You could try changing the extension you use on the sight in or out a little and see if its better like that too, I've often preferred to use them at about 3/4 of max extension rather than full out.
 

PFC

New member
Had my Shibuya Ultima mark 1 for about 10 years. Great bit of kit but within last few years the large round knob with the plastic domed-tip gradually works loose ( tightens bar to sight bracket on riser.)
I have tried adding rubber washers etc and my shooting/form hasn’t changed much.
I’m thinking the knob has become worn. Before investing in another thought I’d ask if anyone else has had this issue?

Cheers
Wrap some PTFE tape around the thread of the round knob, I have the same problem from time to time.
 
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