RE. Enclosed tracks
@foxfish is the man to talk enclosed tracks with. It used to seem like an unnecessary complication to me e.g. what if you bend your spear - I guess that would be a problem with any speargun though. Plus expense and friction. But there is another thread where some forum members showed us their wooden, Italian made double roller speargun and they are beautiful, impressively accurate even at distance and very powerful of course. They have enclosed tracks. I forget the makers name - anybody recognise my description?
I used to be into rails and figured that was good enough but I now consider them unnecessary and possibly even a hindrance below 90cm (increased mass, inertia, drag and expense). Above 90 probably a good idea still though.
RE. 14mm bands
This is another recent fashion/fad - but, again, that doesn't mean it's bad or won't last. Twin 14mm bands has long been a popular option in Hawaii but not much elsewhere. Perhaps suiting the youngsters with clear water and big fish possibilities. Perhaps the rest of us are just slow learners? I think there are lots of reasons why it has become popular recently:
1. Much easier to load, especially if you have poor loading technique - but slower.
2. More research (like your video link perhaps?). Is the energy release more evenly/smoothly? Less recoil perhaps?
3. Fashion: quite a few of us are trying twin rubbers in the UK now (Foxfish observed the fashion change from rollers to twin 14mm bands at their annual get together in Guernsey) but I think most of us suspect, perhaps know, that a single band (or pneumatic) will always be optimal for UK conditions. But perhaps a roller speargun might have a place? - TBD
4. A longer term trend towards SA-style configurations with bulk rubbers (cheaper, more powerful and offering more options) and, often, dyneema wishbones by European makers. This facilitates multi-band configurations more naturally than screw-in band configurations. But much of the market for European brands, perhaps, don't need the power of 2x16mm that the South Africans and Australians often do (160cm barrel, 2x20mm bands anyone?). And for those that do need the power, the Invicta, Omer's replacement for the Cayman, comes with 2x14mm bands but the muzzle can support a third 14mm band!
*
5. Rollers and reverse trigger mechanisms have increased the power available for many, perhaps we now feel ok about sacrificing a little of the potential power to improve overall usability and balance? E.g. making loading and firing more pleasant.
*I believe Mako and others have also offered triple (perhaps even quadruple?) muzzles for SA-style railguns for sometime and I wouldn't be surprised if they can all be 20mm rubber if that's your preference and the trigger mech. can handle it.
