Originally Posted by Digdeep
I think you hit the nail on the head. ASV builds their machines around an undercarriage to match weight, balance and hp to weight ratios. CAT takes an existing undercarriage and bolts it to an existing skid chassis. CAT's 247, 277 and 287s performed relatively well concerning their operating weights with the exception of their weight oriented significantly to the rear on their vertical lift machines. IMO the 257 should never have happened because it is just plain too heavy and has too much weight on the A$$ of the machine.
The PT60 has the exact same undercarriage and it only weighs about 6300lbs compared to the 257 coming in at just over 8000lbs. That's a 20%+ weight difference not to mention that a lot of that extra weight is toward the rear of the machine over that small rear idler.
I agree the asv's seem better balanced, but I think the weight still is a factor on some of the heavier asv's like the 80 and 100. The ones I bought to resell had about 2000hrs on the undercarriage and they needed a rebuild.
The asv 30s 50s and 60s undercarriage seem to last past 2000 hrs before a rebuild. It might need a few bogies or rear idlers at 2000hrs but not a complete undercarriage.
I have bought and sold a few 257s and they chew up those rear idler wheels fast.
And I have pretty good luck with the bobcat undercarriage. Most of them time, I just have to buy sprockets and maybe a rear idler.