I ride older bikes and expect a certain level of knowledge to have slipped through the cracks over the years.
But that? I'd be looking for another bike shop. If that's not an option I'd seek out a better-informed person within the shop at the very least.
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A race bike in any era is a highly personal choice that at its "best" balances the requirements of fit, weight, handling, durability and cost tempered by the willingness to toss it and oneself down the pavement at considerable speed. ~Bandera