rclugnut10

My Feedback: (1)

Okay, this is purely, an informational thread, i do NOT want any arguments or disagreements or comments even on other peoples posts. Not trying trying to be O.C.D. or tell you how to post, i simply want a thread to give people information on the Pro's and Con's of Plastic and Metal spur gears. So please Simply post the Pro's and the Con's in your opinion of each.

Plastic Pro's
1. Cheap
2. Lightweight

Cons.
1. Can Melt

Metal
Pro's
1. Durable
2. Won't Wear or Melt

Con's
1. Expensive
2. Heavy

the lug

MadManAndrew

If you purchase a vented Clutch bell, plastic spurs are less likely to melt.The combination of removing material from the clutch bell to vent it and using a lightweight plastic spur gives less rotating mass, increasing performance.

Just thought I'd add that little bit .

Andrew

twomanytoys

In reality I dont think any one of us can notice and power loss or gain from going to a metal or to a plastic spur. I dont think I can say I have ever had to replace a plastic spure on any of my trucks. If they are meshed right, slipper set right and they dont overheat you should be good for a long time.

black mamba

Steel is nice because you can beat on it without worry. Steel is much more resistant to rocks and hard dirt chunks too. I always run steel when given the choice between it and plastic.

Dale Gribble

My Feedback: (4)

FYI, steel spur will eatup stock clutchbells. I had to go to a RRP clutchbell after a steel spur.

MadManAndrew

Guys, he asked for no arguing, and here we are arguing...But yes, Dale is right, if you get a steel spur it will eat your clutch bells like cottage cheese...However, if you get a vented clutch bell, which is much harder, the spurs will no longer tear apart your clutch bells, but if you get a vented clutch bell, there's no point in getting a steel spur because the plastic ones will no longer melt...In the end, you're going to have to get a vented clutch bell no matter what, so get a vented clutch bell, and a $4 plastic spur, and all our problems will be solved.

black mamba

Haven't run into that problem. I only use HPI stuff....solid spurs with vented CBs offer a troublefree setup.[8D]

SAVAGEJIM

Yes, a good hardenened CB is a must with steel spurs.

I personally run steel spurs, but as everyone else says, something else foen in the drivertrain will break instead. In my daily basher Savage, the next thing to go was the diff teeth of the outer bevels and its pinion. I promptly chuched those and bought and adapted Cenchan Nemesis/Genesis/GST diffs; those have beefier teeth, and they look machined, not cast like the HPI outer bevels.

Inside the tranny, no promary gears have failed on me yet, but I have trashed way too many reverse modules. The HPI reverse modules are made for the older .21BB engines, not the power of an aftermarket, or a K5.9. (I would suggest you guys wait for HPI to redesign the reverse module with non-cast gears before your get one).

Dale Gribble

My Feedback: (4)

Ya, my CB was not vented. I am sure that makes a huge difference. I run plastic with one Savage and Steel with another. If changing the spur out wasn't such a pain, I wouldn't mind changing them as much. Plastic or Steel doesn't matter much to me.

twomanytoys

Who is arguing?

SAVAGEJIM

I dont think anyone is arguring. For me, I will run a plastic spur for stock engines up to a K4.6. But for the K5.9 or any of the e rest of the more powerful aftermarket engines, I prefer steel spurs, but of course, w/o reverse module, and with some upgrades in the drive train.

Each does have its advangates, and also downsides, its just knowing which sacrficies to make and to know how to best use those advantages.

PrjctStrtFrce

My Feedback: (10)

[sm=confused.gif] How is changing the SG a pain? Remove the roll-bar, take 7 screws out from the top half of the transmission and it's out. ..

MadManAndrew

I usually just take the engune out...That way I can examnine my clutch bell and get the spur out...

pythonfan

My Feedback: (1)

picco vs plastic spur

http://s241.photobucket.com/albums/f...t=M4V00441.flv

SAVAGEJIM

LOL, yeah, that is what happens everytime when you put a powerful aftermarket engine in, the plastic does not stand a chance, no matter how good of a mesh

BANKRUPTER

LMAO +1 with this

Argess

In tried the Robinson Spur/CB set and it wore out. Why? Because one of the machine screws that holds the engine mount plate down broke. Every time the engine torqued, the plate flexed and the gear mesh decreased to nothing.

This plate screw thing is fairly common.

Anyway, I fixed the plate with a stronger screw, switched back to plastic, and no more trouble. Am using a 30 VG and no problems with the plastic.

Previous to all this, I have stripped spur gears for two reasons:

1/ Improper mesh

2/ pebbles getting into the gear teeth

I have had a spur melt, but not at the teeth (i.e. not from the clutch bell). It was from the center out and it was because I had the slipper too loose.

Performance?

The power lost in rotating a metal spur gear is approximately the same as the power it takes to rotate all 4 tires. With a plastic spur gear, only about 10% of the power used to rotate the tires is required. (This is because the spur has to rotate much faster than the tires due to the gear reduction of the transmission).

Keeping this in perspective, we are only talking about the power lost in the rotating parts. For example, if we lose 0.5 HP rotating all those drivetrain parts (tires, wheels, spur, etc.), we still get 2 hp to the ground with a 2.5 hp engine. The % of the lost 0.5Hp due to the metal spur isn't all that high.

However, it should be noticeable to the discriminating driver, however me being "not-so-good"....well, .........er........I have to admit....I couldn't really notice it.......maybe a tiny bit "quicker" with the plastic, but it was hard for me to tell.

BudBud

I just ruined a vented 16 bell and a steel 52T spur, it was my fault. I lost a couple of engine mount screws and the engine rocked on the plate. It did not take long! Most of the plastic spurs I lost were due to broken engine plates. My STS fried a couple, from slipping clutches, I think. I fried a couple when the nearings in the clutch bell went bad. I got next to a fence when a throttle rod broke and melted one from both ends....the center out from the slipper and the teeth in from the super hot clutch shoes. I do not recall having one just torn up from a large engine... never had a problem with the plastics, but these metal Hpi spurs sure are nice! The Robinson spurs were always chipping the teeth off... a couple of gallons and they were so rough, they would ruin the bell. I still run both, I think I prefer the Hpi steel 47 or 52 though.

black mamba

Keep in mind the older, non X Savages do not have the split top trans case. So changing the spur on one of them requires pulling the engine. I have replaced my old trans case with a XSS case to make spur changes a snap.

-SomeGuy-

Well, not that I want to argue with anobody but I run only picco engines (.26.27.28) with stock non vented bells and plastic spurs (18/47) and have no problems. Some of you have seen what my trucks look like after a day of bashing and know I dont go easy on them. I do however run alloy shoes and that has made all the difference I've ever needed when it comes to melting/shredding gears.

On another note, I did try out the delrin spur gears and they did not hold up at all. Not even 2 tanks and the teeth were vaporised to a fine white dust, 2 gears in a row.

The steel RR gear I got way back when my meshing wasnt top notch started chipping its teeth so they are not a remedy to bad meshing IMO. Get the mesh right, use alloy shoes, set the spur right (in my case as tight as possible) and any problem you encounter after that is strictly user error, or maybe the engine shifted from a hard knock.

This is just my 2 cents worth, hope it helps.

rclugnut10

My Feedback: (1)

good info here, i'll definetly be saving a link to this, this is exactally what i was looking for no fights just good info for all


the lug

yakfish

My Feedback: (27)

I know this is an old thread but I think it is worth digging up. there is a lot of good info here. I have been running ST's for a long time and have just recently gotten a savage. I have been considering going with an RRP steel SG if and when the stock plastic one I have melts. but has anyone had any trouble differentials after switching to a steel SG? I have always looked at the SG as a good weak link in the drivetrain since they are fairly cheap and easy to fix compared to say a differential.

SportsFans

Well You mata trucker!!! I always go with steel spur and a hardened vented CB. Not only the clutch bell remain cooler but also the clutch shoes which I believe add to a longer lasting clutch shoes, and the clutch springs seem to keep their memory longer. My 2 cents

jbooker82

My Feedback: (4)

I have a Titanium Spur gear. It throws bight white sparks like a sparkler when you hammer on it.

rotzilla

titanium... who makes that? that would be stronger and have less rotating mass than steel.....