Single drag washer vs Multi stack?

[Steelynorm]

When fixing my reel last night i was led to, https://www.reelschematic.com.. what a great resource..
I am also trying to find a 200 series round reel and starting looking at various Shimano Calcutta schematics.

Couple of observations, the newest Calcutta's have "*" stating that certain parts are only Dealer serviceable.
The second thing i have come across is that most 200 sized reels,  have only one drag washer, but the Calcutta 200D has 3 drag washers.

? of the day.. what are the pros and cons of 1 larger drag washer vs 3 smaller ones?

[Keta]

More contact surface = more and/or smoother drag.

I would never buy anything that is dealer service only.

[boon]

Do you have an example of the dealer serviceable thing?

Do you mean the note about the spool cross pin and the roller clutch?

[MarkT]

More contact surface = more and/or smoother drag.

I would never buy anything that is dealer service only.

Like Daiwa reels with mag sealed bearings!

[Steelynorm]

yes on clutch pin and roller bearing.

so three smaller drags washers are better the one larger one...if the 3 smaller drag washers cumulative surface area is greater?

[Brewcrafter]

Steelynorm - Yes, No, and It depends  We are getting into some pretty obtuse physics that you will find many posts on this site about (Jurelometer responding with detailed response in 3...2...1).  So, for what we are worried about, yes you are "mostly" right.  Where it gets tricky is what I will call "swept" area.  The brake pads on my Corvette C7 (NO I don't own one) are actually not a lot bigger that the brake pads on Bill's Z-28.  But the disks themselves are much larger, so a pad is covering a larger "swept area" and realistically this whole thing is about turning energy into heat.  For our fishing reels, yes, generally adding multiple quality friction surfaces will improve performance.  Easy to overthink it and go down the rabbit hole, you are on the right track but it's not all about surface area. - john

[jurelometer]

Just to make Mr Brewcrafter happy- here goes...

If the discs are of the same size, adding more braking surfaces will decrease the clamping force  required to achieve the same amount of drag.  Less clamping force helps to make the drag smoother. Most  star drag designs only engage a single side of each drag washer, but some use both sides, so counting washers is not enough.

If your comparison is of discs of different sizes, then it gets into a more complicated discussion that has been covered in other threads, but you have to take both the inner and outer diameter of the drag washers into account, and decide if you care more about braking power or smoothness. There will be tradeoffs. BTW, the amount of surface area plays only a small role.

If I understand correctly, the swept area concept is more about a small brake pad on a large drum or rotor in a vehicle. The larger the area that the pad temporarily comes in contact with,  the larger the area of heat convection. If you want to keep your car brakes from overheating, a larger rotor diameter helps. I don't think that this  applies to a star drag reel.  The drag washer is in full contact with the disc for the entire revolution, and the whole thing is crammed into a pocket in the main gear, trapping most of the heat.  Reel drags only operate for a short amount of time, so they can get away with this.
-J