I just watched a Fuji video that stated that running guides should be 4 or 4.5mm at the largest for best performance when using the new KR concept guides. Assuming the butt guide and reduction train are properly placed, are 5mm running guides too large? A couple examples would be trains that go, 20-10-5.5- then 5mm runners, or 25, 10, 6 then the 5mm runners on medium action rods 6-71/2 ft in length.

What do you more experienced builders who have built lots of these rods say? 5mm too big? Too much or any line slap? Oscillation coils?

Thanks for your input!

5mm is fine.

I agree with Lynn, 5 mm guides are just fine and will work well. Fuji KR setups give you a lot of options to fit your individual needs, which include reel size, line type and size, knots used, and your fishing style. Set it up and test cast it, I think you will be very happy with the performance.
Norm

We've been using 4 mm guides for many decades, nothing new, use what you like and passes any knots you use. If like me you have lots of uses for a rod that doesn't use any knots that pass through the guides, there is no downside to the smaller guides unless you fish some seriously low temps that freeze line guides to the fishing line.

One of the best things i ever did was to go to size 5 KT running guides on my 8 foot inshore rod , what an amazing difference they make , i was so impressed i scrapped the KT size 8 guides in favor of KT 6's on my heaviest surf rod . Fuji says size 4 or 4.5 is the smallest they recommend for any size rod.

I love the size 5 and 5.5 's though , you won't be disappointed and i admit when viewing them in hand for the first time i was like " You got to be kidding me " lol. I looked at an Avid Inshore rod i had sitting around and realized it's running guides looked like strippers compared to the KB and KT 5 mm.

Rod,
Remember, every situation is unique.
If you fish waters that have a lot of junk on the surface that tends to gather on the line you may want to go larger to say a 6,7 or even 8 running guide.

The same thing is true for folks who use their rods in freezing conditions where there is a situation with icing on the line. Then, you will be very happy with larger running guides to minimize the issue.

Remember, this avocation is called "custom rod building".

It is custom, because every situation is unique and you - as the builder - can make the decisions that make sense for both you as a builder as well as any client who might be using the rod.

Good luck

My experience indicates that 5mm running guides will work fine. I believe that sizes below that offer little or no advantage, and can have problems like Roger mentions. As is often the case when something new comes out, we tend to go overboard with it which at times can be counterproductive, as in the smaller micros.

Thanks for the input guys.

Last few rods I have built have 5mm runners. The Fuji video recommended 4 and 4.5 but think I will stick with the 5mm. They seem to work fine, just wanted your guys opinions on the even smaller ones.

Once again, great source for resources and information, especially for us less seasoned builders.

Does the type of line used, its diameter or its stiffness have any bearing on choice of ideal guide I.D.?

On most of my rods I use size 4.5 KB/KT guides, I have some with size 4 and others with size 5 runners. They all work great, it is your choice. When the micro guides were first becoming popular, running guide were as small as size 2 and 3. I tried just about every size and settled on 4.5 and 5 for most of my rods, personal preference. For some people micro guides are not their thing and a size 6 is as small as they will ever go. Different strokes for different folks.
Norm

Of course line size and type, as well as the inline knots used, play a role in guide selection. In my opinion microguides really shine when using braid, and I always use the FG knot when attaching a leader. If using big bulky leader knots it might be better to use larger guides, or learn how to tie the FG knot.
Norm

Fuji may suggest that the 4 or 4.5 is the smallest guide they would recommend for the KR Concept but I don't think they say it "should" be used. They provide layouts with the 6L and 7L as the third guide in the KR reduction train for situations where a size 6 or 7 runner might be most appropriate. With no knots the 4-4.5 recommendation is probably spot on but the saltwater crowd will often opt for the 5 or 5.5 runner. Many times when trying to ease a customer into smaller runners (when he's had size 8 runners on all his rods all his life) it's easier to "step him down" with a size 6 on his first rod - and then when he's blown away by the performance use 5.5 runners on the second, etc. The leap is just too mind-boggling for some. ;)

Norman: I have successfully used the "Slim Beauty Knot" to join braid to heavy mono leader for several years. Like the FG Knot the Slim beauty relies upon multiple points of contact between the two lines and the friction each point provides. Do you know of any remotely scientific comparison tests which could be used to compare these two knots, particularly tests of knot strength when the knots are subject to a lengthy series of strong, short jerks?

I'm not sure if any hard research has been done but this guy obviously spent some time making a good attempt at "hard" science. It's the only thing I've seen and Norm has likely seen it too. This is also the best tutorial I have seen on how to quickly tie the knot. I have finally reached the point where I can put a rod in a rod-holder and tie this while on the boat - I wouldn't recommend it if it's your first try, however. Similar to a Bimini Twist, it takes both hands, good teeth and a little tension.

[www.saltstrong.com]

If the 5.5s throw them, don't show them a rod inspired by Mr. Vinzant.

The slim beauty is a good knot but it is bulkier and not as strong as the FG knot. There have been a number of tests comparing various knots with each other and the FG knot comes out on top in all of the tests I’ve seen. The testing site Jim gave demonstrates clearly that the FG is stronger than the slim beauty. Once you tie the FG knot a few times it’s not that difficult and can be tied quickly and consistently. I’m sort of a knot geek and I used to tie many different braid to leader knots, including the slim beauty, but once I tried the FG I stop using all of the others. The nice thing about the FG knot (as well as the slim beauty) is that there is no line tag in the leading end of the knot so it passes smoothly through the guides without ever catching, so it seems like there is no knot present at all.
Norm

The girl who sat in the desk in front of me in public school had her hair tied in TWO FG knots. Why, I don't know.

That's an easy one!

Manmade polymer fishing lines PVDF [aka "flouro"] and Nylon 6,6 [aka "mono"] lose strength VERY quickly when they are heated, which happens when under tension they rub against guides in a guide train. No big deal in freshwater fishing where long runs against tension (drag) is not a problem. Problems arise in [relatively] light-tackle saltwater angling with unexpected hookups on BIG fish that run but don't hide. The water quenches the heat generated sequentially by a polymer line passing through six or eight guides, but by then the line is weakened by increasing friction-generated heat by each guide and the line will not regain strength. Roller guides are not practical for light saltwater tackle. Which fixed metal or ceramic ring guides dissipate heat most quickly?

SiC, Phil.