A bit curious: If I'm correct, the conventional wisdom is that one ought to usethe 1st guide in half the diameter of a spin reel's diameter.

Thus, if a Reel is 35mm, one ought to use a guide about of about size 20 with ID of

Questions:
1. How did this rule of thumb come about?

2. I know this is a 'general rule' and not exact but wouldone look at the ID? For example, size 20 in Fuji has 13.9 ID while 25 has 18.3 ID. By right, size 25's inner ID is about 1/2 of the 35mm.

3. Does it really choke the line down significantly if one is using a 50mm reel, and still the same size 20 1st guide?

Just wondering how 'hard and fast' the rule is for spin reels.

4. Would it also depend on the line? Examined some spincasters where the line is also on a reel, but the line is choked down IMMEDIATELY but a very small opening. Some of these spin casters can cast a remarkable distance using UL lines so I'm wondering if that 'choking down' action really makes a big difference with UL lines.

The questions above are relevant because I'm building for a specific UL reel with a very small spool but would be nice to know that with UL braided (we're talking about 1 lb diameter equivalent to mono), one can use larger reels down the road without much detrimental affect. Of course, it if is wishful thinking, would like to know now.

Thanks!
Mo

The "rule" came about because people kept asking me what size butt guide to use on their spinning rods, so I came up with something that is a reasonable starting point - that's about it. It's not hard and fast and the height of the frame can mean as much or more than ring size. Often you are only using a larger ring size as a means to get more overall guide height.

For what you're proposing above, I'd think that you could get by very well with a ring no larger than a 20. Check the online library here for the article on the New Guide Concept System set-up.

.........

On some of my spin/fly combo rods, I've used much smaller and lower guides than "normal" to keep the weight down and also because I want it to fit in a travel tube (the whole point of the spin/fly combo). Typically, I'm not just satisfied by the casting performance as a spinning rod, but left scratching my head and thinking that I should make all my spinning rods with much smaller guides. They're cheaper and lighter and require less thread and epoxy and aren't as prone to getting snagged and bent out of shape as the small guides.

Tom and Steve, THANKS for taking time.

Steve, yes I was wondering that too with the modern very light lines. We ourselves use a 1 lb test diameter line on our reels (4-8 lb break strength) so it is extremely light and thin. One way to get around the height of the issue is to slot the tennesse grip so that the reel foot sits almost on top of the blank, thus lowering the spool height from the blank/rod, and thus, go though the short small guides in a more straight line.

My son has a tiny reelcast where the line is choked down to a size 12 or so right at the spool and the casting distance constantly suprises me given all that I'm told about having a large enough 1st guide, and far enough out away from the reel.

Would appreciate any more comments.

Thanks,
Mo