Need Advice On 2500C Main Drive Gear: Aluminum Versus Brass

[Walleye Guy]

I'm building two nice 2500C reels (vintage 1975 and 1976 per the lot numbers) and also have acquired two complete...but very rough (so very affordable)...2500C reels (vintage 1975 per the lot numbers) for parts.  So I have four reels.  All four have brass pinion gears but three of the four have aluminum main gears and one has a brass main gear.

Was this a design revision by Abu or is the brass gear an aftermarket part?  What are everyone's thoughts on the durability of an aluminum main gear? 

I know certain aluminum alloys can be heat treated but it seems to me that brass is a better choice for durability.

Looking at the Abu schematics I only see one P/N for the main gear: 10213

Thanks in advance for any thoughts & advice.

[JasonGotaProblem]

Check the gear ratio. All the aftermarket aluminum gears I'm familiar with have a faster gear ratio than any stock offering. That would tell you a lot.

Also every Abu baitcaster I've ever been in has a brass main. Even my modern cheapo blackmax

[Walleye Guy]

Good point, I'll do that.

If the aluminum is an early version then I wonder if Abu had failures of the aluminum gears.

[DougK]

aluminum were all aftermarket I believe, and mostly not made anymore because of those durability concerns..

see,
https://www.hedgehog-studio.co.jp/phone/product/647
"The pinion gear is still made of brass.
Due to wear resistance, we will not manufacture extra super duralumin pinion gears in the future."

I'd fish the aluminum until they wear out, then replace with the Avail brand brass.

All my small ABUs have the original brass gear, I don't need high-speed so the stock gearing works fine for me.
ereplacementparts still has the original brass gears for the 3500, which theoretically should fit the 2500 also. I bought one of these for a 3500 rebuild, have not started it yet tho.

https://www.ereplacementparts.com/parts/conventional-reels/abu-garcia/erp18322331/drive-gear-975493/?SourceCode=45

[drumbum]

ABU used a lot of aluminum gears through the `70's.

Still aluminum in some of my `83-84 reels.

[jurelometer]

The Hedgehog statement on their site about wear was on the high speed pinion gears.  It looks to me like they are still selling their aluminum main gears. Pinions tend to be more vulnerable. And the type of aluminum on the main matters too.  A aluminum/copper alloy gear (e.g., the Avail Duralumin mains) is a whole different animal than something made from cast aluminum.  It could be stronger than brass, but maybe more brittle and noisy.  And a  brass pinion/Duralumin main could be superior in strength and wear resistance than an all brass set.

High speed vs standard gear ratio also makes a difference in durability for drop-in gear set replacements on these type of reels.  What gives you the increase  in gear ratios is the increase in pitch circle (roughly at the center of tooth depth) diameter ratios.

Since they can't move the gears farther apart without moving the gear shaft, they have to somehow decrease the pinion pitch diameter, but the overall pinion diameter is usually pretty small already, so they use shallower (which also means smaller) teeth to help drop the pitch diameters bit more.  Smaller teeth require better alignment to avoid wear and failure, but alignment degrades under load with this class of reel design- not just ABUs, but any star drag with a post style main gear support.

Additionally, the greater the gear ratio the more load on components on the main gear shaft.  Remember that a gear set is essentially a rotating form of a lever.

All of this should matter much less on an ABU 2500 when it is used within the limits that it is designed for, compared to something like a high speed 505 Penn Jigmaster someone plans to crank on yellowtail with.  If you need a high load 2500, it is probably the wrong reel for the job.

I'm with DougK.  Might be better to wait and see if you get any wear that requires replacement.  You might be better off with what you already have.

-J