[rtillery02]

The longer I have my iron barrel, the more I love ridin it, I ride it more than my Boulevard. Though it runs & rides perfect right now, the lingering thoughts of the inevitable bottom end failure is really uncomfortable.  What specific parts are the weak spots in this bottom end? Is there any advantage to upgrading them BEFORE they fail? If so, which parts are they? "Ollie" has almost 4000 miles on him & has most upgrades available already installed from elect. ign. to 5 disc clutch, H/V oil pumps w/alloy barrel & piston/rings upgrade(std.500cc). BUT, I've been hesitant to open up the bottom end, 1) for no real reason to, &2) I don't really know what I'm going after to replace & upgrade or what a "proper" upgrade would be (brand,quality wise). Anybody been down this road yet? I'd like to start stocking up on the "proper" parts for the bottom end in advance if I could, thanks in advance for any insights to my dilemma, R.Tillery

[fxrskrsa]

The longer I have my iron barrel, the more I love ridin it, I ride it more than my Boulevard. Though it runs & rides perfect right now, the lingering thoughts of the inevitable bottom end failure is really uncomfortable.  What specific parts are the weak spots in this bottom end? Is there any advantage to upgrading them BEFORE they fail? If so, which parts are they? "Ollie" has almost 4000 miles on him & has most upgrades available already installed from elect. ign. to 5 disc clutch, H/V oil pumps w/alloy barrel & piston/rings upgrade(std.500cc). BUT, I've been hesitant to open up the bottom end, 1) for no real reason to, &2) I don't really know what I'm going after to replace & upgrade or what a "proper" upgrade would be (brand,quality wise). Anybody been down this road yet? I'd like to start stocking up on the "proper" parts for the bottom end in advance if I could, thanks in advance for any insights to my dilemma, R.Tillery

Hi Rtillery02

Your post echoes some of the thoughts that go through my mind when riding my trusty 2004 Iron Barrel. I will look forward to the responses from the learned ones in the community.

The post also brought to mind one of my favourite quotes from The Hitchhikers Guide to the Galaxy around 'lingering thoughts':

“All through my life I've had this strange unaccountable feeling that something was going on in the world, something big, even sinister, and no one would tell me what it was."
"No," said the old man, "that's just perfectly normal paranoia. Everyone in the Universe has that.”
― Douglas Adams, The Hitchhiker's Guide to the Galaxy

[ace.cafe]

 We have been down this road a couple hundred times.
 
It needs a crank rebuild with a Carrillo con-rod, and either an Alpha roller big end bearing, or an Ace bronze floating bush big end, with a proper assembly and truing to near zero run-out.
Main bearings from FAG or NTN, preferably ones with brass cages in the roller bearing mains, and a good quality FAG or NTN ball bearing drive side bearing.

I don't know what piston you have, but I don't know of any "good ones" in 500 cc size.
The rest of the stuff you listed appears to be good enough. Probably about $1000-$1500 job for the bottom end, if you remove, disassemble, reassemble, re-fit.

[fxrskrsa]

“Don't Panic.”
― Douglas Adams, The Hitchhiker's Guide to the Galaxy

[Mr.Mazza]

We have been down this road a couple hundred times.
 
It needs a crank rebuild with a Carrillo con-rod, and either an Alpha roller big end bearing, or an Ace bronze floating bush big end, with a proper assembly and truing to near zero run-out.
Main bearings from FAG or NTN, preferably ones with brass cages in the roller bearing mains, and a good quality FAG or NTN ball bearing drive side bearing.

I don't know what piston you have, but I don't know of any "good ones" in 500 cc size.
The rest of the stuff you listed appears to be good enough. Probably about $1000-$1500 job for the bottom end, if you remove, disassemble, reassemble, re-fit.

I can back up aces products, I have just started running in my 2007 Iron Barrell with corillo rod, bronze floating bush ace piston and properaly balanced crank.
Tidy the head alittle and its a little rocketship! Ace also offers head overhaul that makes these bikes kinda nuts.

[rtillery02]

Thank you, sounds like solid info. I've been "eyeballin" these flywheel/crankshaft/rod/bearing "assemblies" that our host offers, haven't found many main bearing options though. Any thoughts or experiences with those assemblies?
 

[Adrian II]

Is there any advantage to upgrading them BEFORE they fail? If so, which parts are they?

If you get the bearings before they go, that's a load of metal fragments in the oil you that don't have to worry about.

If you swap the conrod for a steel version before the original snaps, you won't have to worry about finding a set of replacement crankcases, either. 

So there you have two advantages.

A.

[rtillery02]

Yup, The more I research Aces' Carillo rods with the Bronze bush upgrade, the more practical it sounds, haven't read of any bad experiences concerning that set-up. No, not panicking about the job, just wanna do it once, "properly". The plan is to upgrade "before" a failure. 

[dginfw]

Yup, The more I research Aces' Carillo rods with the Bronze bush upgrade, the more practical it sounds, haven't read of any bad experiences concerning that set-up. No, not panicking about the job, just wanna do it once, "properly". The plan is to upgrade "before" a failure.

A "swap" job is always cheaper than a "repair" job...
I have done the build on mine and it CAN be done with basic tools by a non-professional if you are careful and take notes/pics. If need be you could probably do it two stages since you already have an alloy barrel:  stage one would be crank/rod/bearings, which would give you quality and safety. Stage two would be the headwork, 535 piston/barrel bore&hone, and cams, which would give you a HUGE bump in performance

[Kevin Mahoney]

Bottom end failure is not inevitable by any means. Depends on how you ride the bike, how well your oiling system works (like checking the worm nut and oil pump shaft for wear etc. Not saying it can't fail just saying stories of it's demise are greatly exaggerated. I have done warranty claims for 16 years and can base that statement on fact. We have run a stock bottom end at Bonneville some years ago with no ill effect. Having said that if you push the engine with RPM's (6,500 is pushing it) and speed equipment you are increasing the odds (not in your favor). You might also have just plain bad luck but they don't fail for no reason. If you want to push the engine a better bottom end is a good idea. IMHO one of the most important things  you can do is the alloy barrel. I have seen more of these damaged by heat than anything else.