Originally Posted by vomitron
Listen man, I'm a physicist, and I'll tell you, they put that extra material there to absorb the stresses of a fixed gear. A track BB shell is not designed to take those loads, and thus you HAVE TO USE TRACK CRANKS ON A TRACK FRAME.
Now, as for the wheelset, you can get away with formula hubs, but really, track bikes are designed to use tubular tires. See, tubular tires have lower rolling resistance, and track bikes are designed to use them, so the added forces of a tire with a very HIGH rolling resistance (remember, resistance = load = forces), such as a clincher tire designed for the road, will put undue stresses on your fork and rear stays.
Listen man, you can build it however you want, but if you don't want to face plant in the middle of the street because YOU put components the bike was NOT DESIGNED TO USE, that's your decision.
Hehe, you're silly.
Alright, so you say they put extra material in the cranks (I'm assuming, you never really specified, but since you said the BB can't handle the load you must mean it's weak, therefore has less material) to handle the load, but as a physicist you must also know force balancing. That is, if he puts 180 pounds on a track crank that flexes little, or a road crank that flexes more, once the material is done flexing that 180 pounds is still placed directly onto the bottom bracket. Now, it doesn't matter if it is applied in forward motion or rear, as the BB shell doesn't get much torque from the crankset, only the forces.
The frame must then have extra material? Well, no, as track bikes are designed to take very specifically meted forces, not including being ridden roughly on the street, although they can be used for such. And the force a track rider places on the bike is no more than that of the same racer on a road frame, as if they're on the same ratio there is no difference when accelerating except for slightly higher drivetrain resistance on the road bike.
Now, tubulars. They actually have a higher rolling resistance, but the lower weight of both the tubular and tubular-specific rim decreases the rotational inertia of the wheelset, making accelerating, such in track sprints, far easier. However, due to the greater flexes in tubular tires, they have a tiny amount MORE rolling resistance.
So therefore, if you have tubulars on your bike, due to THEIR higher rolling resistance, they must be putting undue stress on YOUR bike, which is liable to fail at any moment apparently! AND you're putting more stress on the BB shell by allowing for less flex in the crank, making a more drastic application of load possible! You better just give your bike(s) to me so they can be safeguarded and made suitable for track application...
[/thinks he knows it all Junior in Mechanical Engineering who hates ignorance rant over]
As for your bike, I'd go with mattface's suggestion. Wait for deals, wait for the right part, don't just throw money at companies until you get something that's ok.