Overlining grain weight by +25?

Would overlining a 11' 5/6 switch rod with a Rio Skagit Max Short by +25 grain suggestion have a negative impact or would this more so be determined on a rod by rod basis?

I believe the recommendation is 375 grain but I currently have a 400 grain Max Short. I am just trying to determine if the gear I already have will work for the setup. Any help is appreciated. Thank you.

It depends on the rod, but most have a 150-200 grain window. Of course, with a Skagit you're adding a heavy tip as well , so you're more like 500 grains +/-. That would be towards the upper end of the range on my 13' 5/6/7, but again, it depends on the rod. Check the specs and see if you can get grain window rather than just a specific grain weight.

There are plenty of bigger line nerds than I am on this forum - they can probably give more specific answers than I can.

I would try to get down on the water with Andy Guibord who can see if it is over loaded or under loaded.

You need water, head, tip and fly to be able to check out your setup.

You also need a good two handed / Spey fly caster

I am not sure of the grain window as it is not on the rod nor on the rod manufacturer's website.

It's a Fenwick Aetos 11'1" 5/6 Switch that my friend owns. He currently has a switch line on it but felt that it was underlined so he asked me about trying my 400 Grain Rio Skagit Max Short head on it.

Thanks for the input. And yes Andy could probably help in this situation.

Heck, just string it up and throw it! If he’s underlined with a 375 grain, a 400 skagit with a tip might be ideal. Easy enough to head down to the American and test it out...

Should work but each rod is different. I use a 400 Skagit max short on my 6119 TCX and 6110 Z-Axis. Andy showed me that 25 grains is about the same weight as a single business card using a digital scale.

I would agree that 400 grain Skagit short should probably work fine. Best way to find out is to take it out and cast it. Try it with a light (T8 )tip and a smaller fly first, then slowly move to a bit bigger fly and see how it feels. Just a guess, but I would think you might be right in the sweet spot?
JB

Thanks for the info guys. It seems like it is time for some “trial and error.”

25 gr is about the minimum increment where most casters will notice a difference in performance. FWIW, when I am fine-tuning lines I cut in increments of about 15gr. So if 375gr is well in the grain window, 400gr should also be fine.

But, I notice elsewhere on the thread, you are talking about comparing a 375gr "switch line" to a 400gr skagit. Skagit lines are some what standardized as the tapers are all fairly similar and the length variation is not large. If you know the grain weight for one you are pretty close for all. "switch lines", on the other hand, are not a well standardized category, so you can't compare precisely to a skagit. Which line exactly are we talking about? 375 gr spread over say the 55ft of the Rio "switch line" is pretty different from 375 over 20ft in the skagit max short. So you can't necessarily compare these lines. That's before we get into the loading differences in typical sustained anchor/CM casting styles.

Aside from that, I agree with the previous comments. Start with light tips as Jason suggests, and try it out. 400gr skagit is in the ballpark for a 5/6 rated switch rod, maybe a tad heavy.