What size, and how many should guides should I use on say a 7 or 6 foot casting rod and how much for the same on a spinning rod?

Check the library page on the Concept guide placement. Should answer your questions

CASTING rod - Use as many guides as it takes to keep the "bridge" of the line ABOVE the rod blank when is is deeply flexed. For a 6'- 7' casting rod, that will probably take 7-9 guides, depending on the flexibility of your blank and the ring-height of the guides you select. The stripper guide may be as large as a 16mm ring, then 12mm, 10mm, 8mm's, on down to a 7mm or 6mm if you really have a lite tip.

SPINNING rod - With a cone-of-flight type layout, you may use 5-7 guides for a 6' - 7' spinning rod. Sizes probably being a 30mm choker, followed by a 20mm or 16mm, then 12mm, 10mm, 8mm. With a CONCEPT layout, and high-frame / Y-frame guides, it's more likely to be 6-8 guides: 25mm, 16mm, 10mm, then 8, 7, 6mm on out.

That's a range of choices that would cover 80% of the scenarios.
Best Wishes, -Cliff Hall, Gainesville, FL-

And how about a fly rod? What is the relation between line weight and guide sizes? OK, the bigger the line the bigger the guides, but in numbers? Any rules of thumb?

Karel

Every blank/reel combination may be different. The reel will tell you where-how many and size of guides to use. There is no across the board "best" setup. You need to do a static defection test and let that tell you what to do. I have build rods on the exact same blank and ended up with the guide layout differen on each one. Any "guide chart" should only be used as a starting point.

If you are going to go through the work (play) of building a rod you should try to get the most performance that you can out of it. Check out the articles in the library at the top of the page on Concept System and static distribution test. A great investment would be $15 for Rodbuilding Guide by Tom Kirkman.

Mike

Hello Mike,

I have the book, and guide spacing is quite clear, but i can't find a guideline for the guide sizes. Is there any formulae for guide sizing, perhaps last guide same size as tip top, even distribution of guide sizes until you reach the stripper guide? More tip action, more smaller guides on the top?

Karel