I have seen a lot of both and Im wondering what the benefits of one over the other is and vice versa!

 

Gear cams eliminate the tensioner problems that some twin cams have

 

The only down side(s) to gear drive that I can think of is they will not work if you have crank runout as it will negatively affect the backlash of the cam gears. I'm not certain as to the exact runout limit you can get by with, but I'd guess around .002 max. Maybe some engine builder can chime in to dispute or confirm that number.

One other down side that I've heard of is gear noise. While the slight gear whine may be annoying to some folks, it's music to others.

I put gear drive Andrews 26's in my Duece and the gear noise is an absolute non-issue to me. It's barely noticeable.

 

I think ill just stick with the chain cams and change out the tensioner every couple years. Looks easy enough to do. I wouldn't mind doing it every winter just to avoid problems

 

if you have an 07 or up twincam, they have the good cam plate and hydraulic tensioners, so they are not a big problem like the pre 07 twincams that had the spring loaded cam tensioners.

The harley spec for crank runout is 0.010, and the limit for gear cams is 0.004 if i remember correctly. So, swapping in may not be all that easy or it could be a direct bolt in if you are lucky.

With the new cam tensioners, going to gear drive does not really give you so much more like it used to with the old tensioners, even in terms of the horsepower robbing that the old tensioners did.

Oh and on a 12 model bike i believe you have the good compensator as well.

 

+1 - no advantage to post 06 bikes...

 

what about an 05 bike?

 

Read post #6

 

Upgrade to the new cam chain plates/tensioners that are used on 07+ TC's or install geared cams. Latter may need the crank welded and trued ...

 

I priced it out once. If you replace the original tensioners every 20K miles; the break even point for $ spent on parts, compared to upgrading to the hydraulic tensioners is 120K miles . . . didn't do the numbers for a gear drive conversion, but I assume that it'd be north or 120K miles. If you're paying someone to do the work, I suppose that'd be another story. For me? I just pull the cam chest once a year for a look-see and if/when I see any significant wear . . . then I'll replace them with the originals. From what I read on this forum upgrading to the hydraulic system without changing out both cam chains isn't a 100% for sure fix either. So all this can get a bit spendy pretty fast IMHO.

Heck, the tensioners are less $ and last longer than my tires . . . so if I look at it like routine maintenance . . .