[Techmaven]

Just curious, I heard/read that the iron barrel Enfields used an aluminum connecting rod..True? How about the UCE? AVL?

[ace.cafe]

The AVL and the UCE have a steel connecting rod and roller big-end bearing.
The Iron Barrel has an alloy con-rod and floating bush big end.

[Techmaven]

The AVL and the UCE have a steel connecting rod and roller big-end bearing.
The Iron Barrel has an alloy con-rod and floating bush big end.

That clears up why people say you shouldn't push an Iron barrel too fast..the fatigue limit of aluminum...a lot lower than a nice, steel forging.

[ace.cafe]

That clears up why people say you shouldn't push an Iron barrel too fast..the fatigue limit of aluminum...a lot lower than a nice, steel forging.

Yes, well that's one of the reasons. There are even more reasons for not pushing an Iron Barrel too fast.

[Ice]

 Like the Iron Barrel itself.

 The iron barrel does have lovely expansion characteristics but It does not shed heat as well as aluminum.

 Push too fast for too long, I.E. make more heat than can be ejected, and the piston and rings suffer. The exhaust valve and seat suffer also sometime far worse than the piston.

 Piston seizures can be catastrophic.

 If the piston seizes at any sort of speed often times the rod will stretch and break in half.
 The fly wheels still having rotational inertia propel the connecting rod stub, at best beating things up and at worst punching a hole in the crank cases.

Heat and high revs are the enemies of the Iron Barrel engine in stock form.


 
 

[Techmaven]

Would I be safe in assuming an Iron Barrel would be fine for a lazy Sunday morning rider and a 50mph commuter? Are they good on gas also?

[ace.cafe]

Would I be safe in assuming an Iron Barrel would be fine for a lazy Sunday morning rider and a 50mph commuter? Are they good on gas also?

Yes.
They are fine for riding on roads with speed limits up to 55mph. They just can't handle the Interstate highways.
They are very good on gas, with the typical stock Iron Barrel Bullet 500 getting about 70-75 mpg while cruising. Around town or riding hard will bring the fuel mileage down a bit, but it's still good.
I personally think they are very nice vintage machines, and with a bit of upgrading inside the engine, they are very capable of good performance such as over 100mph top speed, and ability to cruise the Interstate highways at 75mph, and ability to accelerate as quickly as most vintage 650-750 British twins of the 1960s, while retaining that 70mpg fuel economy.
So, there is a lot of potential, but it takes a rebuild with the right stuff to get it there.
In stock form, they are a bit fragile, and under-powered, but still plenty of fun, and really a nice 1950s-era vintage ride.

[Ice]

Would I be safe in assuming an Iron Barrel would be fine for a lazy Sunday morning rider and a 50mph commuter? Are they good on gas also?

An emphatic yes to all the above.

 With proper break in and maintenance and when ridden within its envelope the Iron Barrel can be very economical and reliable transportation if one heads the aforementioned caveats.

 The cost savings of riding compared to driving can be very substantial depending on your particular commuting and usage habits and needs.
 
 I live where I can and do ride year round. In the first two years of ownership my Bullet saved me enough gas money to essentially pay for itself.
 
 

[Ice]

Yes.
They are fine for riding on roads with speed limits up to 55mph. They just can't handle the Interstate highways.

Ace,,please let me expound on this just a bit.

 Techmaven, by highways the majority of us most often mean today's high speed multi lane super-slabs.

 The lesser usage of the term applies to the old style two lane black top style of highways that sees less traffic and have speed limits of 55 or often less.

 These second definition "highways" are one of the Bullets three favorite playgrounds and it REaly shines there.

[barenekd]

"B" roads as they are known as in Jolly Olde.  Hwy 66 in its former glory!
Bare

[Ducati Scotty]

When I followed Ice and a few other cats on iron barrels and AVLs they all clocked right along at 50-60mph for a good stretch.  I was impressed given the reputation of the older bikes.  They held their own very well.

Scott