Chain Drive vs Gear Drive

[les]

My vote is for gear drive cams...all the way. I picked up a set of new Andrews/S&S inner & outer gears off E-Bay for $200.00 when I switch over from the chain drive on my 117"er.
But like previously stated...you need no more than .003 runout on your crank for gear drives. Gear drive cams will have dead on accurate timing events vs a set of chain drive cams that will stretch and not to mention wear the shoes over time. This will change your timing events as the chain stretchs and shoes wear.
I still think the Moco is kicking their self in the butt for losing their patent on gear drive setups.

No Cents

If you're able to get a set of gears for $200 then that changes my opinion.  For that money I would go with gears.  Although the cams are additional money, gears for $200 is a really great price.

[prodrag1320]

no luck,gear drives are the way to go,we`ve installed WAY to many to count,not one failure

[War Horse]

Another  for gear drives. Hands down a better set up.

[cherryseeg2]

  After seeing a few sets of new style tensioners with a lot of wear I don't regret going gears at all.

[02FYRFTR]

I will not build a motor over 95" w/o gear drives and reworked flywheels !!!  gears are the way to go......................

[Boe Cole]

Went with S&S510G's when I did my 88 to a 95 on an 06RG.  Used the gear set up for peace of mind only - just did not want to deal with chains and tensioners.  Did not care to have to go back in to the cam chest again - once was enough.  As to horse power, etc., I was happy but for the 510's to really come on, you had to be doing 3k rpm for them to wake up.  When they did - life was great:-)

[harleywood]

Dang, I guess I'm the odd man out. I upgraded to the SE Hyd Plate so I could keep the OE style cams on my 05, 95". No complaints. The gears were just too darned expensive.

[cycleman11]

Not against gear drives but wonder what happens as the engine gets the miles with relation to run out affecting the matting of the gears.  The reason I ask it that I know in some models of early BMW airheads they actually changed the diameters of the alternators ( they run off the end of the cranks on these bikes ) because they where worried about the movement of the crank end in relation to the case.

One thing with chains is that they will compensate for any run out.  Gears are much more critical on fitment.

[wolf_59]

I run both gears and chain drive
Gears in my 04 Fatboy as a 88" @ 13k mi. upgraded to 95" @21k mi. just upgraded to 98" @ 49k mi.
Stock chain and tensioners in my 06 Ultra upgraded to 95" @ 31k mi. replaced stock tensioners, inner was worn about half way through, upgraded cams @ 42k tensioners were hardly worn after 10k.
No issues with either in my opinion
your $ spend it where it makes you happy, Why not spend the extra money it would cost to go gear drive on a good street port on the heads and set up compression to work with your cam choice

[Eglider05]

As much as I like gear drive cams keep in mind if you slip a crank it can have disastrous results. It completely trashed this motor. Based on this experience I will never again run gear drive without a welded crank.  With that said, I still prefer gear drive and still run them in my 120r....with a plugged/welded crank and left side Timken.

Rick

[Ohio HD]

As much as I like gear drive cams keep in mind if you slip a crank it can have disastrous results. It completely trashed this motor. Based on this experience I will never again run gear drive without a welded crank.  With that said, I still prefer gear drive and still run them in my 120r....with a plugged/welded crank and left side Timken.

Rick


I would agree with that, gears are the bomb, but I wouldn't use them without a welded crank myself.

[05FLHTC]

Thanks for posting that picture 

Nothing like a visual aid

[maggy]

  gear drives

[No Cents]

As much as I like gear drive cams keep in mind if you slip a crank it can have disastrous results. It completely trashed this motor. Based on this experience I will never again run gear drive without a welded crank.  With that said, I still prefer gear drive and still run them in my 120r....with a plugged/welded crank and left side Timken.

Rick

Did you miss a shift at some high rpms?



No Cents

[Admiral Akbar]

And have the rev limiter set to 8500?

What was the runout?  What did the cam plate look like?  Cams still spun free?  In the upper left the gasket surface looks like it was knurled.. What's up with that??  Could something have gone through the gear?  What was the lash?

Max

[mrmike]

I have to agree with Cycleman11 chains are more forgiving, my bike had .002 runout but we still put the new style chain setup in when the BB was done money was not an issue and it was my builders choice, I had no problem with it.

Just because it was .002 when the build was done what says it's going to stay there?

Just to be clear I'm not against gears at all but in the end they rely on a good solid platform with little to no runout and that is a description I rarely hear used in refrence to a Harley motor,lol.

As far as catastrophic failure lets be real here if it's going to "Potty mouth" the bed gears or chains it's heading south, jmho.

Mike

[Eglider05]

Did you miss a shift at some high rpms?



No Cents

How did you guess?

Rick

[djl]

I run gears in my 95" with .0025" runout; no issues and less noise than the OEM chains. BTW, the outer tensioner was cracked at 12K miles.  I run the SE Hybrid plate/pump setup on my 107" simply because I like to change cams and that is so much easier with the later chain drive setup.  Lots of different reasons for making different choices.

[Eglider05]

And have the rev limiter set to 8500?

What was the runout?  What did the cam plate look like?  Cams still spun free?  In the upper left the gasket surface looks like it was knurled.. What's up with that??  Could something have gone through the gear?  What was the lash?

Max

Rev limiter was set at 6200 rpm. The cam plate was cracked around the pinion bushing (.034 runout) and the cams still spun free. I don't recall the lash measurements but the pinion runout was less than .0015 when originally installed and there was no binding, smooth as butter. The gears were in the bike for better than 20K miles and quieter than stock.

As many times as I've posted this pic I never noticed the gasket surface that looks like it was knurled. I wonder if it is some kind of aberration with the camera and the lighting, maybe a reflection. I'm going to go back through some other pics and see if it's there. These are the same cases as I'm currently running with my 120r.

Rick

[harleytoprock]

Gears  is what the twin cams should have originaly came with. The epa noise issue is a bunch of bull. Harley knew how to make silent gears with the Evo. They accomplished  quiet by offer many different size pinion gears for proper backlash. And besides, look how many gears are in a Sportster motor. I feel the real reason Harley doesn't use gears is because of the crappy crankshafts that slip and slide and have to much runout. Another thing Harley did because of excessive pinion runout was to make the oil feed hole in the pinion end bushing very small. In this way, even with much runout and pinion bushing clearance wear, it will still maintain oil pressure. Band aids all over the place. I would only  use gears if the crank is trued and welded with less than .002 or .003 runout. I have gears with only .0002 pinion runout ( decimal is correct) and they are sweet. Thats they way it shoud have come from the factory.

[05FLHTC]

  $$$ GREED is the root cause

[prodrag1320]

as far as "catastrphic" damage if the F/W`s shift over .004-up,the damage isnt catastropic,youll take a couple teeth off,maybe.but THE REAL PROBLEM IS A F/W ASSY THATS OUT .004-up!!!whatever cam set up your running,THAT NEEDS TO REPAIRED!!

[cycleman11]

With respect to run out?  As the engine ages with miles does this increase? 

[Mother]

I will always run gear drives AND trued & welded cranks, period!

[prodrag1320]

With respect to run out?  As the engine ages with miles does this increase?

not really,but if your going to do a hi-po build,its a real good idea to pin & weld the F/W ass`y