I've been riding a Centurion Sport DLX with Exage Motion components recently, but came across a Diamond Back "Master" with a RX100 components and was wondering how much of an upgrade the Diamond Back would be? I also would like to figure out what Centurion frame it would be most similar to, i.e. Iron Man or Lemans?

Big jump. The DB Master is quicker, probably lighter, and should be better equipped.

Some say the Master compares to the Ironman, but my guess is it compares more to the Schwinn PDG Series 3.

The Masters I've seen that were not OS-tubed were nearly identical to the Lemans RS by Centurion. The yen was climbing so fast, they had to drop a level or two of components to stay in a decent price range, but I'd still say the Sport DLX was probably a step down from a DB Master.

It's not a Diamondback, it's a Diamond Back. Huh...

Slight diversion

Master looks a lot like tigged Trek/Lemond True Temper OS offerings before 853 took over the lineup. My '97 Tourmalet/Unicrown is a reponsive and comfy ride with a 230 lb rider. Even with 28 mm Gatorskins.

Having ridden with both Exage Motion and RX100 components, I can't say I noticed much difference. Both are pretty solid in performance, but the Motion stuff has more plastic in it IIRC (which may make it the cheaper-but-lighter group?)

The two frames may be quite different. I've never ridden one of those OS tubed Diamond Backs.

That's a nice bike. Toned down quite a lot from my 1991. 1992? 1990 I believe was the grey/white fade, 1991 was the pink with black splatter paint, and 1992... may have been that one. Not sure if there were other color choices for the first two years. I think they only did these 1990 - 1994.

I haven't actually had much of a chance to ride mine.

The Diamond Back Master has more aggressive geometry than the Sport DLX. It will be nimbler, more responsive and stiffer, though that may not be apparent to all cyclists. The Diamond Back Master and earlier Master TG were the evolutionary development of the Ironman Master. The major change was moving to a TIG welded frame allowing the use of oversized tubes with shorter butts and thinner walls for increased stiffness and weight reduction.

While the Shimano RX100 components were officially a couple of steps lower than the New 600EX and 600 Ultegra used on the earlier Ironman Masters and occupied a position roughly equivalent to Exage Motion, technical progress made RX100 superior in performance to these groups. Most notable was Hyperglide which added ramps to the cogs and permitted shifting under high loads and Super SLR with better performing dual pivot brakes. Unfortunately, it doesn't have the STI brifters which were OEM spec.

This subject Master would be a notable upgrade over a Sport DLX. It appears to be a circa 1994-1995 model. It's definitely no earlier than 1994, as the Master TG was 1990-1993.

What I said, only a lot lot smarter and better informed.

I used to own a DB Master TG(so ’90 or ’91) and currently own a Centurion Ironman frame from ’89.

They are extremely similar in general geometry in that both are quick to steer. Not in a bad way, mind you.
The DB had oversized tubing and felt stiffer/less flexy than the Ironman. This is how it should be, given the tubing diameters.

The DB is an upgrade to your Centurion Sport DLX only if you want a more aggressive riding position.

Its been stylized both ways thru the years. Actually there have been 3 ways.


Diamond Back
DiamondBack
Diamondback

When there is no agreement on how to spell the companies name, that's usually not a good sign. Thanks for the clarification; I thought I'd seen it spelled like the snake (aka Diamondback) as the going thought was that mountain bikes ruled the market (back in the early 90's) and the name gave the brand the outdoorsy/wilderness feel that the bigheads were looking for.