Just how long, and what type of leader to use when spinning for trout.

This article is looking at leaders used while spinning, if you are interested in fly fishing tapered leaders, I suggest giving this video a view. It provides a very good overview of the importance of tapered leaders.

A reader recently wanted to know what the best leader setup was to use with his new ultralight spinning rod while trout fishing. Like most things in fishing, there is no easy answer and there are many competing setups which anglers use successfully.

Below, I will attempt to answer all frequently ask questions about trout spinning leaders and I will cover the main leader setups.

What are the advantages of a leader when spinning for trout?

  1. Leaders are less visible for trout compared with braid.
  2. Leaders are more abrasion resistant.
  3. Thicker leaders also helps reduce the chance of line cuts during the cast, or when handling the fish. A line cut is when a very thin mainline cuts into the skin of your finger, it is very common with braid but can at times happen with thin monofilaments.
  4. When landing a fish, it is possible to hold onto a stronger leader without worrying about the thin mainline breaking.
  5. If you are fishing braid, the leader is also a lot less visible in the water.
  6. A leader also absorbs most of the shocks when casting heavy lures. This reduces the chance of the line breaking during the cast. This is likely only an issue if you are powerfully casting heavy lures.

Do I need a leader when fishing monofilament mainline?

When fishing straight monofilament a leader is not really necessary. I personally never use a leader when fishing 4lb or 6lb monofilament.

There are a couple of exception, if your mainline is a bit too heavy, and the trout are line shy then using a thinner diameter leader is an option. Ideally, it is much better to use a low breaking strain mainline.

If you are fishing in a high abrasion environment, say around lots of weeds, sharp rocks, or submerged trees a thicker leader can reduce the chance of break-off. But keep in mind, the thicker the leader the easier it is for the trout to see.

If you are fishing a colored mainline, which you fear are scaring the trout. A clear leader can be used to be less visible.

What breaking strain should my trout fishing leader be?

The breaking strain of your leader depends on several variables. The breaking strain of your mainline, the size of the fish you are targeting, the clarity of the water and how line shy they are.

The cleaner, the water, and the more wary the trout the thinner your leader must be if you wish to consistently catch them. Secondarily, your leader must still be strong enough to land the fish, targeting strong, large fish in violent water full of snags will require a heavier leader.

I have caught wild brown and rainbow trout up to 10lb using a 2X leader (0.23mm, .009″) and a breaking strain of around 7lb-8lb. This might sound a bit thick, but keep in mind many ‘6lb’ mainlines are over 0.25mm in dimension (They are not really 6lb lines).

When the water is very clear, and the trout are spooky. I will drop down to a 3X line with a diameter of 0.20mm or .007”. This line typically breaks around 6lb.

When spinning, I have never had any need to go much lighter than this. But if you are fishing 2lb (0.12mm) mainline then there is no reason why a 0.15mm leader can not be used.

Matching line dimension with water clarity when trout fishing

Leader Dimension
Estimated True Breaking StrainWater Clarity
.011″0.28mm10lbNight fishing
.010″0.25mm8lbCloudy water
.009″0.23mm7lbStained water
.007″0.20mm5lbClear water
.006″0.18mm4lbVery clear
.005”0.15mm3lbGin clear
Quick reference chart for leader dimension for trout fishing. If the trout are wary, go thinner.

What breaking strain should my leader be when fishing braid?

I do not use different leaders when fishing with monofilament or braid. There is one difference to keep in mind, because braid normally massively over tests, there is a reasonable chance that 6lb braid is much stronger than even 8 or 10lb mono.

So when fishing braid, know that the mainline is probably stronger (But less abrasion resistant) than your leader.

How long should my leader be?

The leader length depends on the length of the rod you are fishing. I personally fish with a leader which is between 1.5 the length of my rod. This means I have several revolutions of leader on my spool when I am casting.

It also means I can have leader on my reel, when I bend over to net my fish. This provides a good buffer if trout has a last burst of energy in it.

How strong should my leader be to prevent lures breaking off during the cast?

Sometimes lures snap off during the cast, that happens when the weight we are casting generates too much forward inertia and the line snaps sending the lure flying towards the horizons. This normally happens when we are attempting to casts lures which are too heavy for our current setup.

But with a leader, we can cast lures full force, without risking them snapping off mid flight. . In the chart below I will provide a guide showing the breaking strain of line required to cast common weights of lures while minimizing the chance of a breakoff.

Leader DimensionLine WeightLure Weight
.005”2 lb test1/64–1/16 oz
.006”4 lb test1/16–1/4 oz
.007”6 lb test1/4–1/2 oz
.010”8lb test1 oz

What breaking strain should my steelhead leader be?

Steelheads, and large sea run brown trout can put up a much harder fight. When targeting them I use heavier line in general. I will go no lighter than a 0.25mm/0.07” leader.

If the water is big and fast then even heavier leaders can be beneficial.

Why do some people fish leaders weaker than the mainline?

Some fishermen use leaders which are weaker than their mainline. I personally struggle to understand their reasoning. In general, when fishing monofilament a leader should be stronger than the mainline.

Fishermen who fish weaker leaders are simply using a mainline which is too heavy. Forcing them to use a thinner leader not to scare the trout.

Think I am wrong, I am happy to hear any disagreements or justification in the comments below.

Is monofilament or flourocarbon better for leaders?

I fish monofilament leaders 90% of the time, and 98% of the time when spinning. In my experience monofilament is the superior line for both knot strength and abrasion resistance. If I fish the same dimension monofilament and fluorocarbon, I consistently find the mono to be the stronger, more durable line. This means, I can get away with fishing thinner lines if I use mono.

There is also a whole argument surrounding visibility in water. I have not found it matters much if at all. I agree, fluorocarbon is harder to see, but I have caught enough wary wild brown trout in crystal clear calm water on mono leaders to convince myself that it does not matter.

Why do I sometimes fish flourocarbon, this usually happens for two reasons. I have run out of my monofilament leader line, and only have floru in my vest, or if I decide to test my own bias and decide to fish floru for a while to see if it makes a difference.

I carry flourcarbon with me, because I use it while fly fishing. Floruocarbon sinks faster than monofilament, so I use it when fishing tiny nymphs which I want to sink quickly.

Can I use fly fishing tippet as a leader?

Yes, fly fishing tippet material makes for excellent leaders when spin fishing. It is what I use much of the time. The little spools are expensive, but they trend to be more accurately labelled and they fit nicely in my vest pocket.

Want to know my thoughts on tippets, check my overview here.

Tippet makes good leader material

Can I use mainline as a leader?

Yes, mainline also works fine as a leader. There is some arguments, that leader quality line is more consistent in diameter but I have not noticed much of a difference while out on the water. The biggest argument against mainline as a leader is that the spools are a bit too large to carry around when fishing from land.

Best knot to join my mainline to the leader?

If you have a joining knot which works well, I suggest sticking with it. No need to change what is not broken.

When trout fishing, I always use the Aussie Quickie knot to join my mainline to leader. This knot is very similar to the Bristol / No name knot but without doubling the line with a Bimini Twist. (There is no need for a Bimini twist, unsure why so many guides still exist on it).

The Aussie Quickie is also very similar to the Yucatan knot, but with the Yucatan the mainline gets wrapped around the leader, while with the Aussie quickie the leader gets wrapped around the mainline. No idea if it makes a difference.

The Aussie quickie works great when tying knots in very fine diameter lines. So is well suited for trout fishing. When tying monofilament to braid I do approximately 13 wraps, but I do fewer wraps when tying mono to mono. It takes a little trail and error to figure out the optimum number for every line weight combination.

I use fewer turns when joining monofilament to monofilament, and many more turns when joining monofilament to braid.

Can I use a swivel between my mainline and leader?

Yes, but it does remove many of the advantages of a leader. When you tie on a swivel, it means the entirety of the leader is outside of the rod guides. So the leader can no longer be used as a shock absorber during the casts or landing, and it also no longer protects against mainline cuts.

I personally will use a snap swivel and connect my spinner directly to it.

What colour line should my leader be?

I have only ever seen people fish clear leaders while spinning for trout.

If you are fishing surface presentations, and expecting the trout to strike from below, then high visibility lines do camouflage well against the bright sky.

When should I replace my leader?

Fishing for trout in freshwater is usually fairly gentle on leaders. But, I still inspect mine for damage quite frequently. Usually after a catch or when I am changing my spinning.

I trend to replace my leader if I notice abrasion occurring, this means the strength of the leader has been compromised. If the damage is near to the spinner, I usually will just cut away the damaged end.

If I notice damage on the mainline, then of course I will cut it away and tie on a new leader.

If the line has been under a lot of tension, such as freeing it from a snag. I will inspect the knot and consider tying a new knot.

I also replace the leader when it gets too short. Usually, I will replace the leader if it is not long enough to wrap around my spool during the cast. I do not want to be touching mainline while casting.

It is also a good idea to replace your leader every time you go fishing, overtime knots and line weaken. So retying them is a good idea.


Selecting and tying on the leader seems complicated, but it does not have to be. If you have any further questions or need clarification please comment below.

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