|What is better?||Fez|
Nov 22, 2002 10:03 AM
|I have 2 identically equipeed Litespeeds (long story). All components are identical except seatpost (more later). One is a size 55, the other is a 53. However, due to different seat angles, they have an almost identical reach. The main difference is in the standover and head tube height. I need help determining which is a better fit. My inseam is 80.6cm, or 31.75 inches. Here are the details:
1) The 55cm frame has ZERO spacers on the steerer, 80 degree/100mm stem. I have an approx 70cm saddle height, so that leaves approx 15cm distance from top of saddle to top of top tube? Standover is 79.3cm, so it is a tad bit tight for my 80.6cm inseam.
Top tube is 55.5cm, with 73 degree STA and a Thomson straight post.
2) The 53cm frame has 1.5 cm steerer spacers (lower headtube), the same 80 degree/100mm stem, and approx 17 cm distance from top of saddle to top of top tube (shorter seat tube). Standover is 77.6cm.
Top tube is 54cm, but since it has a 74 degree STA I use a Thomson setback post. This gives me the identical KOPS distance as I did with the 73 degree angle. Therefore, the reach is NEARLY identical (or within 1/2 cm) to the larger 55cm frame with the 73STA.
Isn't it odd that the reach is nearly identical on both bikes? The ride is nearly identical between the 2, except the 53cm exhibits the possibility of a little TOE RUB on very sharp turns, and the 55cm does not.
In summary, the smaller frame's drawbacks are toe rub and 1.5cm of steerer spacers. The larger frame's only drawback is the slightly small (approx 1.3cm) standover.
Thanks for the input.
|you tell us||Steve_0|
Nov 22, 2002 10:25 AM
|i'm sure some expert here can espouse theoretical mathematical benefits of one bike vs the other, but the bottom line is you cant tell the difference, so why do you 'need help in determining the better fit' ?
Not trying to ruffle feathers, i just dont think theory will provide you benefit over empiricism.
|you tell us||Fez|
Nov 22, 2002 10:31 AM
|That's the problem. I can't really tell a difference, even while climbing.
Is the toe overlap issue enough to choose the larger one?
Does the taller head tube protect the carbon steerer better than a shorter one with 1.5cm of spacer?
Is a 73 STA preferable, since the 74 necessitates a setback seatpost?
It may have to come down to a flip of the coin.
|always get the smallest rame that fits||str8dum1|
Nov 22, 2002 10:39 AM
|the 53 fits you perfect. you will NEVER toe rub when you are actually riding. tooling around in the parking lot of track standing at a stop light maybe, but when you are really riding, most of the turn is from body lean.
i'd stick with the 53
Nov 22, 2002 11:14 AM
|This is one of those cycling proverbs that makes you (or rather me) ask: why? I agree that a smaller frame, for somebody who's racing, or riding aggresively in general, is the better idea. A bigger frame gives a more upright position- which is more comfortable for the vast majority of people. The longer wheelbase will also make the ride more stable (in all else being equal).
However, in this case, both frames' contact points are equally dimensioned (as I understand it), so there's not much to gain from having more spacers and seatpost showing.
|If your not racing..||koala|
Nov 22, 2002 1:45 PM
|why not go with the slack seat tube for a touch more comfort
and not have any unsightly spacers? Standover is way overrated anyway. Just one opinion.
|my bad- 90% forum users = non racers||str8dum1|
Nov 25, 2002 1:42 PM
|or low cat racers where you could get by on anything. I guess if i was touring, nah i'd still want the smallest frame the fit me with a 120/130 stem|
|Trade both for a 54!||dzrider|
Nov 22, 2002 11:13 AM
|Just kidding. I'd put them both up for sale and keep the one that brings less in the market. Most people can be fit comfortably on a small range of sizes.|
Nov 22, 2002 2:01 PM
|The 53cm has an appropriate saddle height. 17cm above the top tube is just about perfect. You're also using a modest stem length. Most, if not all of the spacers can be eliminated by switching to a Ritchey WCS stem. It has a taller clamp height and 4 degrees more rise.
The 55cm frame is on the big side, producing a low saddle and minimal standover clearance.
Next time you get a frame, I'd carefully measure the front-center dimension to try to eliminate the overlap. Colnago's standard geometry might do it. They use a more relaxed head tube angle (around 72 degrees) with a 43mm rake. According to the geometry charts, Colnago's front center dimension on a 53cm frame is 1cm longer than a Litespeed.