frame size for a fixed vs. regular road ride?
 

Hi,

I'd like to build up a fixed gear, and am scouring ebay for old frames. Is the sizing for a fixed about the same as a road bike? I'm looking at old roadbikes, and normally I ride a 60cm. For a fixed can I go with a 58? Is it OK to be smaller? Or is it better to go with the same size as your road frame?

Just wondering what those in the know think.

regards,
Francis

The size should be the same. If you are looking at cheaper old road bikes size doesn't matter as much though.

I would think that a frame size is a frame size. Unless you are looking for a specific use for the bike that requires something different. You would know that though if it is personalized.

I bought a size smaller than usual on my fix and I have been satisfied sofar.

if you're looking at doing a conversation, you are using a road frame, so you should use the road frame size that fits you. if you are getting a track frame, get one about 2 cm smaller.

some people do enjoy a bit smaller of a frame for a fixed gear. you aren't going to be able to change gears when the ***** gets hairy, so being able to muscle your frame around is kind of a nice feature. ultimately i think that's more a matter of personal preference rather than a hard and fast rule, if that's of any help. and ultimately, regardless of the size of your frame, when the ***** gets hairy, you're going to need to rely on your leg muscles.

is this because the top tube is a bit longer in relation to the seat tube on a track frame than on a road frame ?

no. generally speaking, the rear triangle is smaller, the fork has less rake, therefore the wheelbase is shorter. the seat tube and head tube angles tend to be steep, in the 74*-76* range. this allows for more manuverability, it also places the rider farther forward of the bottom bracket, which allows the rider to get a greater amount of leverage on the bars while retaining a low center of gravity and maintaining a position that maximizes aerodynamics and power output from the leg muscles. the bottom bracket is higher for clearance on banked velodrome tracks.

so is that why you need a (generally) 2cm smaller frame?
sounds to me like you just described the general differences in track vs. road frames. i'm thinking you probably answered the "why 2cm smaller?" question when you said that the bottom bracket is higher, but i'm wondering if this is right or not.

generally speaking, yes. take all of this with a grain of salt. fitting a unique body to a standardized frame for a particular application isn't cut and dry. The adjustments of the seatpost height, saddle angle, saddle fore-aft, stem height, stem rise and stem will likely allow you to obtain a good fit if you've narrowed down what top tube length and seat tube length will work for you. however, your chances of finding an ideal fit are a lot better if you enlist the help of someone who's experienced in..fitting. a lot of shops will apply the cost of fitting in part or in whole to the purchase of a bike there.

so should someone looking for a track frame be looking for a 2cm shorter seat tube AND top tube?
i usually check frames out based on the top tube length.

no, the top tube remains the same. don't forget that the head tube becomes more horizontally aligned as as well

/----------/ <- road bike

|----------| <- track bike


while your reach remains the same, the bars are farther ahead for more power.