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Please help choose first road bike!(13 posts)

Please help choose first road bike!jjdbike
Jul 28, 2002 5:41 AM
I know that this is an old wornout topic, but I'm loosing sleep over it and bike shopes have not helped. I am a former XC MTBer. I am switching to road for several reasons. 1. lower bike maintance. 2. Less bike breakage. Less body breakage. 3. Easier on my 37 yr old body. 4. A little bit more pure fitness than skill, finess and balls (I know that that does not apply to mass start races).
I am 5'7 1/2", inseam 29", 145lbs. I Spin 6 x a week (I am an instructor). I like to spin at 100 RPM. I like to climb, and I live in an area of rolling hills. I want the bike for fitness, social & training rides & for TT next YR.
I was sold on a Giant TCR-1. I thought it was the lightest, stiffest, best component/frame combo for the $. $1700 is streatching my budget to its max. Thats ok if this is THE bike for me. But I can't come to a definaive decision on a med or sm. I have been on booth . on the sm I need a size 4 seat post and long stem, on the med I need a size 2 post and a 120mm stem. I'm starting to think that this bike may just not fit me,. Perhaps I need a size in between sm & med. If so I have no idea what to buy. I want stiff,light, Ultegra, as aero as possible w/out being impractical for group rides. does anyone have any suggestions for which size TCR or another bike in my $ range that I should consider?
I would appreciate any help. I am desperate for a road biek to train on & ride w/ freinds, but can not afford to make the wrong choice.
Thanks so much in advance.
P.S. I know the common responce of ride them & see which feels best. The thing is its been a while since I've done much outdoor riding & I have never rode a road bike so I have no idea how its supposed to feel.I also know about measuring the distances & angles on my MTB. Unfortunatly I can't do that as I have sold it to enable me to buy a road bike.
Thanks again!
Medium too big for 29" cycling inseam.Eug
Jul 28, 2002 6:32 AM
I'm 5'7" with a 31" inch cycling inseam. My pants, which are probably a bit on the short side, have a 29" inseam. Are you talking cycling inseam or a pants inseam? I am assuming cycling inseam.

Anyways, when I was looking at Devinci (not Giant), the 48 cm medium seemed too big for me (and I have a longer inseam than you). A Devinci 43 cm small was a better fit, but I'm not sure how that corresponds to Giant's 44 cm sizing for their small. (Devinci also has a 38 cm extra small size.) I never tried a medium Giant, but the store fit me on a small.

Here are Devinci's geometry numbers:

Here are Giant's Geometry numbers:

I ended up getting a 54 cm Trek with a shortish stem. Trek calls their 52 and 54 cm frames small (whereas 56 cm is a medium). The 54 cm Trek is about 52 cm c-t, since Trek measures to the top of the seat collar, NOT to the top of the top tube.

Also note that Trek's 54 cm bikes have a top tube length of around 54.5-54.8 cm. As far as I can tell, Giant gives an effective top tube length of 55.5 cm for their medium frame, and 53.5 cm for their small. Devinci gives an effective top tube length of 56 cm for their medium, and 54 cm for their small.

(Even though 52 cm c-t is correct for my inseam size according to the formula (31 inch * 0.67 * 2.54 cm/inch = 52.8 cm c-t frame), strangely enough I only have a few inches of seatpost showing, and less than is usually expected, but that's another story.)
re: Please help choose first road bike!jjdbike
Jul 28, 2002 6:46 AM
I did read the post below on buying a new bike. I am, and have been an avid cyclist for several yrs (although all on a MTB) I have been riding on the road w/ my roadie friends w/ my MTB & am having trouble keeping up w/ them. I am quite fit (relitively speaking {VO2max 64). My mtb had road tires on it and it was quite light. So I think the differance was gearing & body position. I road my wife's road bike the other day & got my but kicked by some one (on a road bike) that I smoked on my mtb. It was not set up for me & I need to get comfortable w/ postion & shifting. I know I want a double. The cannondale w/ ulregra & decent/raceable wheels seem just a bit out of reach for me price wise. I road a Trek 5200 & loved it but it was too much $ for me. It was 52cm. I was told it was on the smallish side for me but it felt comfortabel. I like to be compact, I feel more powerful.I also road a LeMond 53cm & it felt huge to me. I wasn't fond of the feel. I guess I am just very used to a light stiff alum. frame.
Again I apoligise for the overkill of the tired topic, but I am desperate & stressing. I need one NOW, but am worried about buying the wrong one & having to try to sell it and spend more $ I don't have for a more appropriate bike.
Thanks again for any help in choosing THE right bike.
Anxious Obsesive compulsive!
You have a 29" inseam and rode a 52 cm Trek (29.7" standover)?Eug
Jul 28, 2002 7:07 AM
You rode a 52 cm Trek and have a 29" inseam? That's odd, considering a 52 cm Trek has a 29.7" standover.

By the way, a 52 cm Trek is probably about 50ish cm c-t.
Jul 28, 2002 6:52 AM
I find limited farme size offerings to be a sort of
annoying crapshoot. If you fall between sizes then don't settle. Try Klein Quantum, a 105 bike which nicely fits virtually all your criteria, and will almost certainly fit you too.
Compacts in a variety of sizes.Scot_Gore
Jul 28, 2002 7:55 AM
When I was looking for my bike I looked at Giants as well. I was a little dubious of the 3 sizes fit all philosphy. Like yourself I was leaning toward compact geometry. Take a look at the Specialized Allez line. Specialized makes compacts in a wide variety of sizes.

My LBS has a 2002 Allez E5 Comp on the floor tagged at 1799.99. It comes in these sizes:
Equivalent Size C-C 47 cm 50 cm 52 cm 54 cm 56 cm 58 cm 61 cm

It's full Ultegra and I think fairly equivalent to your Giant.

Jul 28, 2002 9:39 AM
I'm about the same size as you, not sure on the inseam but I venture that it is roughly the same as yours. I have a small tcr and after riding it for a year, and trying out my friends medium tcr I've come to the conclusion that I fall between their sizes. I've found that the the short headtube has placed the drop part of the bars to low for me, as my legs hit my torso when pedaling in the drops. But I've also found that the ride in the gives me roughly the same body position as with the others I ride with when they are in the drops. So I still have the same aeroness as them, but then I have the drops for extra stability when descending. Overall the bike isn't painful to ride, but it isn't optimal for my size. My $0.02
ABSOLUTELY the small!!!!JohnG
Jul 28, 2002 10:52 AM
I'm 5' 8 1/2" with a 32" inseam and the medium was too big for me....... still got it.

I've since recieved a small ONCE frameset and it will fit MUCHO better.

You will fit a small.
What about TT performance w/ aero barsjjdbike
Jul 28, 2002 11:30 AM
Thanks you guys. I thought that the small should fit me too, untill a pretty experienced mechanic/store manager told me otherwise. Now that I have been thinking about it, He may have been trying to sell me on a med, since he was out of smalls & this late in theseason, they may be difficult to get.
As afar as my inseam, The 29" was my pant inseam as opposed to cycling inseam. My inseam measured from a book tight up against my crotch to the floor in cycling shoes is 32". I measured 68.5 cm from the top of saddle rails to BB, & 66cm from center of bar to center of seat post, just like it says ti do on the Giant web site. According to that web site, ethier size fram would fit more or less. BUT MY CONCERN IS is how would have a smaller frame and longer stem/post affect handling vs. a larger frame & shorter post/stem, ESPECIALLY FOR TT PERFORMANCE W/ AERO BARS ADDED!!!!!!.
I know this is probably getting extraodinarily tirsome, but it is extremely inportant to me & I know alot of you guys have a lot of experience, and may have gone through this yourself.
Thanks again!
more info neededJohnG
Jul 28, 2002 11:45 AM
What is the KOP measurement when you have your bike setup with the aero stuff.

If your KOP is at or slightly behind the pedal axle, then absolutely the small is the right frame size. If you setup your bike with a 2+ cm forward KOP then you might (and I repeat might) want the medium. I'd still guess the small is the right choice though.

Basic point on handling and stem setup with drop bars. Short stems ==> fast and twitchy, long stems ==> slow and stable. I'm not sure how this gets modified when aero bars are used. I'd ask some tri geeks and see what they say. This should be pretty well figured out by now.

If you're bound a determined to try a medium let me know..... I've got a very lightly used 2001 ONCE frameset I might consider selling.

Measure Cycling Inseam WITHOUT shoesjtolleson
Jul 28, 2002 1:25 PM
for a more accurate figure. But a 120 stem isn't overly long, so it isn't like you are really making a mutant of the small frame at all.

I recently bought a new bike that was finally small enough for me, and the feeling of being balanced over the bike, rather than stretched with a small stem, felt like a huge improvement in handling.
Thanks TONS, What is KOP? 120 stem was on med frame.jjdbike
Jul 28, 2002 2:58 PM
Thanks you so much for all of your advice. You have more or less firmed up my feelings.
I need to be sure that my feet do not interfere w/ turning. As far as 120 stem, that was on a med frame.
But what is KOP?
Thanks again.
Jul 28, 2002 3:14 PM
You say you have a 120 stem on the medium TCR???? If that's so, then that's just about a perfect fit. I must surmise that your KOP is fairly forward to get this sort of stem legth.

KOP (Knee Over Pedal) is usually measured from the front edge of the bone just below the knee-cap. drop a plum line from this point and see where it falls relative to the pedal axle. My guess (given your body geometry #'s) is that your knee is forward of the pedal axle. I.e. @ 5' 7 1/2" and a 32" bike inseam length you would be WAY stretched out with a 120mm stem unless your body was positioned forward on the bike. That' makes sense IF you have a tri/time-trial forward setup.

I'd suggest again that you talk with some tri geeks about this. Isn't there a tri site somewhere on the web that has a usenet type board??? That's where I'd go if I were you. So forget everything I've said and find some good advice. ;)

good luck