What type of rubbers?

[daveduvet]

Hi there,
Spring is approaching and I have started getting my kit ready for the new season This year I have decided to start using bulk rubber and tying my own dyneema wishbones.
I would like to know what is the differences between the the varities of 'bulk rubber' I see available? What is the best type of rubber to go for?
Many thanks!

 

[spaghetti]

It depends on type of gun, gun length, type of shaft, single or double set up et cetera.
If it's a normal gun in the 90'ish size, you can't go wrong either way with H. Dessault 16 or Cressi S45 Plus. They're both "nervous" but still enough progressive, a compromise between smart and strong.
The Cressi S45+ are easy to avail, not so the Dessault.
Cressi Slings per Meter. Fucili Accessori, Scubastore.com, Comprare, Offerta, immersione

 

[Old Man Dave]

I bought some bulk rubber from Apnea in Jersey last year, via the Net. They just list "bulk rubber" without a makers tag in different colours and diameters. I bought some 16mm black and it seemed very good quality.

One of the issues with this type of deal is it was priced by the metre. Not sure if you can by it by smaller sizes. That meant although I wanted 60cm I bought a metre. In retrospect I should have bought 2 metres and made 3 bands, but then I didn't know if it was any good!

Dave.

 

[foxfish]

I bought 4 mtrs of 16mm natural coulour, they seem very stretchy & pretty easy to pull back ...great for me.

 

[HEDS]

It's a matter of trying out - im in pretty much the same situation as you now!! i need rubber but dont know what to go for.. Last year i bought bulk natural colour from US - ok stuff but very stretchy and easy to pull even if the length was reduced - this meant less power , to the point where i wouldnt entertain using it again. The year before i bought bulk from greece , it was like wire rope to pull - a real bugger , but the power was great. so two rubbers , same colour , same 16mm, same price roughly per M , same description -two completely different outcomes! its a bit of a lottery. I think that this is my next buy RobAllen - Λάστιχα Χύμα --- diveshop.gr
Ill try it out - thats the only way to do it!

 

[Old Man Dave]

Check out the cornwall thread http://forums.deeperblue.com/cornwall/85292-cornwall-2010-a-12.html#post798999 as shipping from Greece might be too much unless you are spending a lot. Foxfish quotes £30 shipping for small items.

I think I would recommend the 16mm black bulk from Apnea as it seemed powerfull but loadable. However don't blame me if I'm proven wrong as that's only my opinion.

Dave

PS Had a quick look and they offer bulk in black or amber in 16, 18 and 20mm plus Omer branded bulk black in all 3 sizes. Prices seem to be around £11 per metre average.

 

[foxfish]

You guys need a mamba then you dont need bands at all.

 

[spaghetti]

Most of it depends on the shaft. It brings no good to mix a regular 6mm euroshaft with the explosive southafrican rubbers, or, say, with the monstre Picasso 21mm.

If it's a normal euro in the <90 size, I wouldn't try anything more than a 18mm.

Apart of the clever physics disquisitions about elongation ratios, work and energy where I'm no good at, I bear in mind the very simple example given by Valerio Grassi (founder of Omer and now chief engineer at Seatec) about the shaft/band combo. I'll let Valerio speak for me:

"It's no different than preparing ammo for your hunting rifle: keep a balance between powder and leadshot. Overload with powder, and the shot will go out of control. Overload with lead, and your shot will go feeble". Simple as that.

 

[daveduvet]

i have two types here, one is made from the same material throughout but other has a black coating and a clear core. The stuff with the core seems better quality than the other. What is the difference?

 

[daveduvet]

They're both "nervous"

what do you mean by this?

 

[foxfish]

Jumpy, not smooth - Dave nothing you see for sale from a well known brand will let you down.
Buy the same make that are on your gun now?

 

[spaghetti]

The 2 colour bands (co-extrusion process) are meant for better protection from salt and sun. Both layers are usually made of latex both for in and out.

Nervous means, in poor words, that they output the energy with a jerky, immediate
elastic return when compared with different types of rubbers, whose action is more progressive.

But what gun is it for? What shaft?

 

[daveduvet]

i have a snake 90 and 1 x 6.5 seatec and 1 x 6.3 omer shaft.

I want bands for each of them.

 

[GreekDiver]

I think more natural the bands are, the smoother and easier they pull back. All black seems to be more powerful and snappy. If you are shooting a railgun (less mass), i would suggest black over amber. If you are shooting a wooden gun (more mass), i would suggest all black.

 

[Don Paul]

Getting into a discussion about rubber is like talking about the making of fine wine except modulus of elasticity is a lot less fun.

I'm with GreekDiver's recommendation for simplicity of use.
Cheers, Don Paul

 

[foxfish]

But dont you Americans use those little 14mm worm like things :t

 

[Don Paul]

But dont you Americans use those little 14mm worm like things :t

I use 5/8 to 3/4 elongated 300% of specimen length, when I hit 70 years
old I going to cut back to 9/16ths.
Cheers, Don

 

[Bill McIntyre]

I use 5/8 to 3/4 elongated 300% of specimen length, when I hit 70 years
old I going to cut back to 9/16ths.
Cheers, Don

Hang in there and eat your Wheaties Don. I'm 71, and I'm still using ⅝" rubber stretched to 350%.

Of course I'm faithfully doing seated rows too.

 

[Don Paul]

Hang in there and eat your Wheaties Don. I'm 71, and I'm still using ⅝" rubber stretched to 350%.

Of course I'm faithfully doing seated rows too.

I'm turning 58 on March 7th. I can't run with my knees, but I do like to mountain bike and fin swim a lot. You and I are going to make it to 100 years
old, my kid is only 10, so I need to stick around if I want to see grand kids.
Cheers, Don

 

[GreekDiver]

Hang in there and eat your Wheaties Don. I'm 71, and I'm still using ⅝" rubber stretched to 350%.

Of course I'm faithfully doing seated rows too.

Bill your 350% is probably 250% stretch! Most people make that wrong assumption. Don't count the length of the band when you talk about %.

350% would lose so much power when its loaded over time. Over 300% true stretch and you really damage the bands and you don't get much more out of them.

You could be stretching them 3.5 times but i'm guessing you aren't and not because you physically cant load them. Measure the distance from them laying on the stock of gun plus the wishbone length pinched, then to the distance to each notch.