TJtheWrecker

I am choosing between the Jamis Renegade S3, S4, and Expat, for either size 58 or 61.

Unfortunately my LBS doesn’t have one to try and will place an order for me. Not all models are available in both sizes so you see my issue. Can you help fit me so I can pick one of these lovely machines? Thanks!!

Height: 6"3
Inseam: 35.5 inches.

duckhuntr

58cm would probably work if you like a road-bike aero position, and the 61 if you prefer a more upright position. I prefer a slightly smaller frame because you get a smaller wheelbase and can run longer stems or handlebars that have additional reach. Also you get the benefit of having maximum bar drop although it might take awhile to drop the bars all the way if you're not in shape or have a beer belly obstruction. So on the smaller frame you can have a 130mm stem initially at +6 degrees, and about a year later flip a shorter stem so it runs -6 degrees x 110mm and a year after that drop it to -17 using a new 90mm stem. You need pretty good core strength to run the bars lower but the benefit is shock dampening. You don't get that jack-hammer effect while riding over rough surfaces because most of your weight is suspended by your spine instead of supporting your weight by leaning on the bars. It's counter intuitive but sometimes lowering the bars makes the ride more comfortable.

The longer headtube on the larger frame effectively limits how far you can drop the bars. Having low bars is helpful on really steep off-road climbs although initially if you're a newbie it's easier to have the bars somewhat high, like 4 inches below the saddle. As you get stronger you have the option of dropping them maybe 6 or 7 inches below the saddle. Tall people often benefit from a lot of bar drop. Not always but often. Many of the taller pro riders have 6 or 7 inches of bar drop these days. Those guys are young and in excellent shape though, 6'3" but only weighing 160-170lbs. You can google "pro bike gallery 190cm height" to see how their race bikes look and read over their specs.

Maybe go somewhere else to test ride other bikes of those two sizes, for example REI carries a large stock of bikes. Ride both sizes of the same model around the parking lot a few times.

TJtheWrecker

Thank you for the detailed response. I'm 6"3 and about 200lbs from a few years of bodybuilding, not fat. I'm definitely aiming to get toward a more road aero type position. So a 58cm won't be too difficult for me to ride?

A friend made the concern that I have longer legs so should go with the 58cm over 61cm because I may have reach issues.

duckhuntr

Yeah if you have a relatively short torso to leg proportion it makes sense to go 58cm. A bike even slightly too big in one dimension drives me nuts whereas a slightly too small frame in every dimension can be fitted with aftermarket stems, cranks, seatpost, or handlebar to adjust fit. Smaller frame = more adaptability. On the other hand if you lift maybe the bulk in your upper body requires a larger frame, but I doubt it. Pro cyclists are rail-thin and run frames that are one or two sizes smaller than typical cyclists. They're on bikes for hours every day so they know how to be comfortable.