cbrown9064

Hey!

I have spent some time searching for this answer (perhaps there isnt one) and not sure what to do.

I just got back into riding last year on my 14 year old Rockhopper Comp (21.5"). I put Fatboy slicks on it and tried to get it as efficient as possible. It has both a hard front and tail. I kept looking at the road bikes last year thinking that is what I really needed/wanted, as they would be better for the longer haul. Longest ride last year was 40 miles and it killed my wrist.

So, I go to my favorite LBS yesterday and start looking at bikes. They had a closeout Roubaix in a 56CM. It just looked small to me, no idea why. I am looking to spend about $1500 on the bike.

We put the 56 on the trainer and it felt small. When I got out of the saddle (on the hoods) I felt like I was out way to far over the front wheel. Remember, this is my first road bike. I had about 4-6" on the standover. I liked the bike, but it felt "small". Again I don't know much about this.

Then we put a 58CM Tarmac on the stand. The Roubaix and Tarmac have the same top tube lengths in the same frame size, but the Tarmac has a bit longer seat tube (35CM longer than the 56 Roubaix). I had about 1-2" of standover. First glance on the trainer it felt more comfortable, but that is only for like 5 minutes.

After all this was over, I decided on a Sectuer Comp in 58.

But, here is what keeps playing over and over in my head. Is the 58 too big? The 58 Sectuer has the same geometry as the 58 Roubaix except the seat tube is 535 v. 540 (550 on the Tarmac). I am thinking that shorter seat tube will give me a bit more standover. How do I get the proper size? The guy at the shop thought initially the 56 would work, but thought the 58 looked better. I don't know anything about sizing. I am just worried that the 58 will be too big and then I am "stuck".

Also, I may just be lusting after that closeout Roubaix.

I am 6'1" with a 32.5 inseam (longer torso).

Thoughts?
Chris

10 Wheels

Fit is about feel not looks.

zoste

...and with sloping top tubes, standover height is not a great indicator of fit...

exile

If you feel better on the 58cm then that is probably the size you should get. Forget the closeout, get the size that's right for you. Get the bikes off the trainer and get them on the road to really see how they feel.

Mr. Beanz

I am zactly the same dimension as you, I ride a 58 Cannondale (straight top tube, 1 inch clearance) and a 57 Lemond (sloping top tube, much more standover clearance), both feel great.

I also have a 19.5 Trek 8000 MTB

A 21.5 would be waaaay big for me, 19.5 is PURRRFECT!

IMO, the 58 is right, the 56 would be too cramped.

10 Wheels

6 ft here, ride 60cm Felt F-85 and a Cannondale T-1 55cm.

magohn

I am 6'0" and my LBS had a 56 and 58 Robaix in stock when I was looking last week. I mentioned I thought a 58 would be more my size. However, he insisted the 56 was the way to go and boy was he correct. I have been riding the 56 for almost a week now and the fit is just awesome. The relaxed geometry of the Roubaix also allows a larger rider to ride a smaller frame. This is ideal for me because at 305lbs, when I tried a 58 my arm/wrists would go numb because of the extra stretch. The 56 is more compact for me and "forces" my elbows to slightly kink and not lock out. I rode the bike yesterday for 20 miles - I loved it. It was only 8 weeks ago I was gasping on a 1 mile loop. Im hoping to complete a 200 mile "fun-run" over 2 days in July - at least Im 10% of the way there.

10 Wheels

Happy Miles when you have a good fit.

Loose Chain

You need to get your cycling inseam. This si done by standing straight, back to a wall, take a book about one inch thick and have your wife jam it up so high your feet feel as if they are getting light. Place a mark on the wall at the top of the book. Measure it. Then, as a very close starting point, multiply that number by .883. The result is your optimal saddle height plus or minus a little bit depending on your exact body dimensions.

Measure up from the center of the crank along the seat tube and to the top of the saddle intersection. Adjust your saddle to that height. If then the saddle post is way out and your are crouched way down beyond your favored position, the bike is too small. If on the other hand, you are bolt upright and cannot get low enough, the frame is too big. Sloped top tube bikes will fool you, treat them as a straight top tube by projecting the top tube or effective top tube to the seat post.

Of course, I am going through this now and it sounds simpler that it actually is, lol.

Performance cyclist tend to prefer higher saddles and smaller frames and lower bars. Recreational/casual cyclists tend to prefer larger frames lower seats in relation to the bar top, at or only slightly below the saddle.

I am told that top tube length, effective top tube length is a better indicator of fit than going strictly on "frame size" as long as you can get your saddle into the position per the LeMond formula and the riding position is not too low or too high for your comfort. Obviously perfect fit can vary significantly for different riders who have different fit goals and riding styles.

I imagine you would prefer a frame to the larger side of "perfect" whatever that is.

cbrown9064

Thanks all for the thoughts. I am going back to check out the 56 again and take it for a ride.

Mr. Beanz

Just reading another thread in the road forum, one poster brought up a good point. The headtube is shorter on a smaller frame, if you're looking for a tall headtube for comfort vs a lower handlebar position (race set up), it wil be easier to get a more upright position on the larger frame.

Famous BF words "ALL THINGS EQUAL" a more level handlebar to saddle positon would be easier to achieve on a frame with a taller headtube.