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  #1  
Old 01-31-2015, 05:23 PM
pdonk pdonk is offline
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Track Bike Fit

Is there a rule of thumb for sizing track bikes vs road bikes?

Reason I am asking is that I went to the track in milton today and the kid at the rental desk told me it was normal to ride a bike with a 3cm shorter top tube than my road bike. The bike felt really cramped.

On the good news, it was as fun as I remember. Now for them to get more xl bikes.

Last edited by pdonk; 02-01-2015 at 08:33 AM. Reason: grammar
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  #2  
Old 01-31-2015, 06:59 PM
aramis aramis is offline
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I don't know, but regardless of th top tube length a lot of track bikes seem to offer less setback in a similar size. So my "large" 56 cm giant omnium will barely let me set the seat how far back I want to with the supplied post and has a ton more drop than my van dessel rivet 56cm ( crit bike) even though I don't have my seat slammed back on the van dessel.

I just started ladt year but replicated the fit of my road bike and it seemed fine for me. I did my first season on a soma rush anyway and was able to get some points in cat4 omniums and even won a cat5 one. What I've read online says the whole downsizing thing is bs.
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  #3  
Old 01-31-2015, 09:59 PM
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eBAUMANN eBAUMANN is offline
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Originally Posted by aramis View Post
the whole downsizing thing is bs.
2nd this, for the most part.

I've noticed that it really depends more on you are a rider. a lot of guys with bmx/mtb backgrounds will feel more comfortable on smaller frames (relative to their ideal size) because they feel like it allows them a certain amount of control over the bike. Coming from a more road-centric background, you will tend to feel more comfortable on a larger frame that is the "correct" size for you. While a track bike should have a bit more aggressive fit (its made for going fast not going long) it ideally ends up fitting more or less like your road bike would.

Again, there is no real blanket rule of thumb for this, just gotta try out a few bikes and see what works for you. I would recommend starting as close to your road bike as possible (top tube length and head tube length) and going from there.
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  #4  
Old 01-31-2015, 11:39 PM
velotrack velotrack is offline
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No rule of thumb sizing, for sure. When you've got a steeper ST, you'll probably end up on a shorter TT, but each frame is different.

3cm seems pretty extreme.
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Old 02-01-2015, 07:12 AM
pdonk pdonk is offline
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I think the real issue was the rental shop justifying what it had in stock. Coming from mtb as my main ride it still felt small and less control as the stem and reach were short combined with a monster drop.

I really noticed the steeper seat tube angle.

When I go to buy a bike I'll be going for a similar fit as my road bike. I'm not looking to race. just want to be comfortable for winter laps.
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  #6  
Old 02-01-2015, 02:27 PM
aramis aramis is offline
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Originally Posted by pdonk View Post
I think the real issue was the rental shop justifying what it had in stock. Coming from mtb as my main ride it still felt small and less control as the stem and reach were short combined with a monster drop.

I really noticed the steeper seat tube angle.

When I go to buy a bike I'll be going for a similar fit as my road bike. I'm not looking to race. just want to be comfortable for winter laps.
What kind of banking? Is it an outdoor concrete track? I really liked my soma and it had a high bb, so something like that might work for you - and they are cheap. You probably don't need a 100% track bike for training sessions.
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  #7  
Old 02-01-2015, 02:45 PM
nooneline nooneline is offline
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Yeah, sizing down is crap.

Sometimes people ride a bit closer, lower, and more forward on the track; sometimes they don't.

More relevant, however, is that sometimes a track bike with the same reach and stack as a road bike will have nominal measurements that are smaller (higher BB, lower headtube, means a "shorter seat tube" even though sizes might be comparable; steeper seat tube means that the TT measurement will be "shorter" even though you'll gain some reach by putting the saddle further back in the seatpost). That's just how bike geometry works - it doesn't make the bike smaller. and it definitely doesn't mean you should buy a 52 if you really ride a 55.
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Old 02-01-2015, 05:57 PM
pdonk pdonk is offline
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Originally Posted by aramis View Post
What kind of banking? Is it an outdoor concrete track? I really liked my soma and it had a high bb, so something like that might work for you - and they are cheap. You probably don't need a 100% track bike for training sessions.
Its the brand new mattamy cycling centre in milton ontario. Its the track for the pan am games. Its an indoor siberian spruce track. Banking is in the low 40s. Its very easy to ride.
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  #9  
Old 02-02-2015, 09:53 AM
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The only thing worse than fitting schools trying to teach people how to fit clients in a weekend is people trying to explain fit in a sentence or two...
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  #10  
Old 02-02-2015, 10:59 AM
pdonk pdonk is offline
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Originally Posted by Ti Designs View Post
The only thing worse than fitting schools trying to teach people how to fit clients in a weekend is people trying to explain fit in a sentence or two...
I understand there is nuance and judgement in fit. Just trying to understand and gain insight before I start the process to buy a bike.
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  #11  
Old 02-12-2015, 08:48 PM
11.4 11.4 is offline
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Late to this discussion but here are a few thoughts.

1. You're presumably getting a stock frame, not a custom geometry, so you'll be dealing with whatever the manufacturer comes up with. That takes a lot of geometries out of the discussion.
2. When you're riding your bike on a track, your bottom bracket to top of saddle dimension should be pretty much the same as on your road bike. I'd do a lot of riding and fitting before I'd get into changing that dimension.
3. One of your most important dimensions on a track is how well you can ride the drop to the bars. On the track, you're riding on the drops all the time. That means your effective drop is greater than on the road, where most people are on the levers or the tops most of the time. It also means your reach is effectively a big greater. So ...
4. A little more reach is good because when you are riding down a banking (like in the launch of a 200m effort) your bike is under a bit better control with an extra cm or two on the stem. Your bars may be narrower as well, so the extra length compensates for the narrower stance. And,
5. You should expect to ride at higher cadence and probably with a good bit higher energy output, compared to the road. To do that, you can't be cramped on the bike. You need good hip rotation and very good hip flexibility, which also benefit your ability to get a lower position on the bars.
6. You are going to be riding faster -- track races are going to be 28-33 mph and sometimes faster, and you need the aerodynamics. You may have to ride with drop bars in an event, but you'll be trying for every last bit of aero performance and greater drop does help. This is one place where people come up with this "downsize" argument. It's inaccurate for the most part because people do ride lower on their bars already. It's accurate because you are riding shorter events and are perhaps more likely to be on aero bars, and a lot of track bikes can't get the bars low enough for efficient position. Riders resort to drop stems and bad bar setups to get low, simply because their front end is too high to begin with.
7. So this brings us to the real decision maker in bike sizing. Plan on sticking with your own seat tube length and your own top tube length, more or less. Plan on running a slightly longer stem. But when you measure your head tube (or more precisely, the distance from your front hub to the base of your stem, since bikes will have different headset stacks and different fork lengths), you have to be low enough. On some mass produced track bikes, that distance is pretty high to please the hipster fixie riders or those who first get on a track bike, grab the drops, and mutter "oh ииии." You'll have trouble getting one of those frames to fit you, at least in your normal size. So that's where you may want to go down a bit. Do so cautiously because smaller frames tend to get steeper seat tubes and shorter top tubes, both of which complicate your fit. You're better off sticking with your same frame size if you can, but the options for a drop threadless stem are pretty limited.
8. If anyone hasn't said so, standover height is meaningless. Your bottom bracket may be a bit higher on a track frame but that just lifts everything without necessarily changing any fit geometry. On a track bike, you just tilt it over a bit more when you put a foot down. End of story. If someone is selling you on size based on standover, go shop somewhere else.
9. You aren't going to be able to straddle a track bike in a shop and understand your correct frame size. Ride a bike, or several bikes, in different sizes and geometries, at your track before you buy. Tracks have rental bikes and you can usually borrow a bike from the store you're dealing with so you can try it out. And riders are usually pretty cool about letting you try a frame or aero bars or whatever they have that you may be interested in. But the important point is that you really need to ride a bike a fair amount on the track before you've figured out all the plethora of issues that determine your proper fit. It isn't just a simple translation from road position and it takes some experience. If you buy a frame right off, figure it's expendable and you'll be selling it at the end of the season. Buy used if you can and don't put a lot of money into it. You're just giving someone a very good deal next winter, someone who did more of the homework than you.
10. We're doing this for our enjoyment, not to make a living. You can spend exorbitant sums, and you're welcome to if you so desire. But your pleasure in your new bike will evaporate on your first serious track workout when everyone around you points out that your position isn't right or that you didn't pick a good frame. It's important that you make decisions that make your second, third, and tenth year of track racing enjoyable, and you don't need to get bummed out in your first season. There's a lot more to learn than any track newcomer thinks, and you'll get a lot more respect for winning on a rental bike or a junker than for showing up with a fancy carbon or NJS frame and not being able to use it properly.
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  #12  
Old 03-12-2019, 12:24 PM
pdonk pdonk is offline
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An update to this thread and a few more questions.

I have been riding weekly at the track and it is now time to get my own bike as they no longer swap cogs for the right gear and I have advanced in my skill and fitness enough that spinning a tiny gear is getting old, is not too much fun and is holding me back on workouts

Looking at getting an altruiste (https://altruistebikes.com/products/ http://www.2015.handmadebicycleshow....payerlafrance/) - he won at NAHBS last year for his mountain bike, is from a small town near my mother and seems like a nice guy, he has lots of fabricating experience having worked in a production shop so workmanship should not be an issue, plus his pricing is really good and I like the way his bikes look. There is no opportunity to ride one, and he is more of a fabricator than a fitter so can only answer very specific questions you get him to model for you.

So now the questions

The numbers for my speedvagen and the altruiste are as follows:

Speedvagen(road) altruiste(track)
Stack 57.2 vs 55.6
Reach 41.2 vs 42.5
headtube length 15 vs 15
toptube 58 vs 58.5
seat tube 73.75 vs 74
bar drop 10 vs 14 (with a 120x-20 stem)
bar reach 58.8 vs 60

Based on these numbers and using the stem calculator that was floated here a few times, it looks as though if I go with a 120 x -6 or 0 the bar drop can be made very close, if not a bit lower and the reach is slightly longer.

Do these numbers look close enough to take the leap?

Last edited by pdonk; 03-12-2019 at 03:33 PM.
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  #13  
Old 03-12-2019, 03:02 PM
woodworker woodworker is offline
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I tend to run longer in the torso and lower (with more drop) on my track bike. Better for sprints and staying low. Durations tend to be shorter, so I don't mind the lower position. Seems like it should work for you.

P.S. Didn't see 11.4's post, but it's a good analysis. I didn't go through all of that--I just find that lower is better on the track, particularly since most of the sprints are of pretty short duration compared to the amount of time that you spend on the road. On the track, the lower position tends to help with sprinting and with holding speed.

Last edited by woodworker; 03-12-2019 at 03:06 PM.
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  #14  
Old 03-13-2019, 03:22 AM
ceya ceya is offline
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Where are you located?

Have you figure by riding what size you feel comfortable on?
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  #15  
Old 03-13-2019, 07:48 AM
pdonk pdonk is offline
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Originally Posted by ceya View Post
Where are you located?

Have you figure by riding what size you feel comfortable on?
In Toronto, riding at Milton.

I've been riding an argon 18 XL from the rental fleet. They have them set up with too many spacers, it seems high and a bit short. The XXL are set up way too tall, but about the right length.

Unfortunately, I can't find the geometry for them on line. Going to take a tape measure and check a few things on them as well for sizing.
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