QuakerProf

Hi Folks,

I'm likely to buy a Jamis Ventura Race (JAMIS BICYCLES) from my LBS, which is matching the Evans Cycles price of 785, plus a small fee for assembly and initial tune up. Tiagra groupset, cheap but reliable wheelset, and good reviews where it has gotten any attention. In many ways similar to the Cannondale Synapse 105, but at a much lower price from a less well known company. The problem is fit. I'm willing to get a professional fitting once I have a bike, which runs about 100 bucks, but not the whole machine fit without a bike in hand, since that runs 350-400 in my area, almost half the price of my likely purchase. That seems like overkill. I'm in this for charity rides and distance rides 35 to 60 miles for fitness, maybe getting ready for a century ride in the near future. All to supplement my bike commute to work, about 60 to 100 miles per week depending on weather (I don't bike commute in hard rain or temps below 35F/above 90F). I ride at a slow, 17-19mph pace and don't want to be bent over too badly when I'm on the hoods.

Based on my short time with the Jamis Ventura Race at an LBS, the 51cm seems like a good fit, but I would appreciate an informed second opinion. Here are my numbers based on the fit calculator on Competitive Cyclist (Bike Fit Calculator | Find Your Bike Size | Competitive Cyclist).

Actual inseam: 30.25 in
Trunk: 24.5 in
Forearm: 13.5 in
Arm: 23.25 in
Thigh: 22 in
Lower leg: 20.25 in
Sternal notch: 53.25 in
Total height: 65.5 in

Here is the geometry of the Jamis Ventura Race in 51cm, but feel free to look at the 54cm's geometry in the link above:

SIZE 51
CENTER of BB to TOP of TT 18.19/462
ST ANGLE 74
HEADTUBE 5.51/140
HT ANGLE 71.5
EFFECTIVE TT LENGTH 20.67/525
FORK RAKE 1.97/50
BB DROP 2.87/73
CHAINSTAY 16.34/415
WHEELBASE 38.82/986
STANDOVER 29.37/746
REACH 14.45/367
STACK 21.77/553

Please understand that I'm not looking for a comprehensive fit from you folks online, just some guidance on whether I'm better off starting with the 51 or 54 given these numbers and my desire for a more upright geometry. I will then take the bike to a well-reviewed local guy for a basic professional fitting.

Many thanks. The most helpful response gets any Starbucks drink on the menu when passing through Richmond, VA, home of the western terminus of the Virginia Capital Trail.

FBinNY 

I can't help, but can't resist commenting how times have changed.

BITD when level top tubes were de rigeur, someone with an inseam like yours would be riding a 57mm or so frame, and had to be fitted carefully because seat posts weren't that long, and there was only enough for the top of the saddle to be about 6-7" above the top tube.

Nowadays there's vastly more margin of error in height, and top tube length (seat to stem distance) is more often the decider in frame sizing.

In your case, there's a benefit to modern designs because head tubes are higher compared to frame sizes, so factor that along with length to optimize the fit. Unless you use the bike off road, standover height is NOT going to factor.

Keep in mind that you only have to get close, the final adjustment will be made with stem angle and length.

oldbobcat

It's easier to make a slightly small bike fit larger than to make a large bike fit smaller. Even with accommodations like a forward set saddle and a short stem, you're going to feel stretched and out of balance on the 54. If the 51 isn't spot on for you, it will be with a little jiggling of the saddle and stem.

Two changes happened since the old days. First, top tubes, even on cheap bikes, became proportional to seat tube length and nominal sizes. This meant that you had to pay attention to top tube length instead of just buying the largest frame you could stand over. Second, starting around the early '90s, top tubes generally got longer relative to the nominal size of bikes. If you were paying attention, you sized down 2-3 cm to get a similar top tube length.

QuakerProf

Thanks, OldBobCat. This is helpful. You are currently in the yellow jersey for the free Starbucks drink. It's still early, though.