[Twilly]

I'm making a track frame for a school project and have finished four models in order to recieve constructive criticism from the general public.
Please leave any general comments, which ones you like, which ones you dislike, what you like about them, etc etc etc.

Cheers

[The BikeForums Team]

This is an archived thread, you can find the full version of this thread, with images, links and more content here.

Ready to buy? Check out these two online bike stores:
- http://www.nashbar.com (you can find the latest bike nashbar coupons in this thread)
- http://www.performancebike.com (you can find the latest performance bike coupons in this thread)

Cya on the forums,
- The BikeForums Team
- http://www.bikeforums.net

[zzzwillzzz]

what type of class?
these are models?
it looks like some are kinda of copying designs that exist already. those frames are designed/studied in the wind tunnel and simulations on computers too be actually aerodynamic, your frames look similar but without real engineering and just making them look aero seems to miss the point of how and why they are designed the way that they are.

[steel-is-real]

Attached photographs of a carbon fibre frame built at high school in 1990. Contructed around a Divinycell foam core with titanium inserts (for headset/bottom bracket/seat post/dropouts). Various different layers of uni-directional carbon fibre were laid up around the core & vacuum bagged, using West System resins.

Raced it for a couple of years after constructing, was something different at the time.

Divinycell:- a rigid PVC foam with a closed, inert gas filled cellular structure. Produced in a range of densities and thicknesses.


Twilly just go for it, explore the design process and come up with some different.

[sfcrossrider]

^^^ Very cool. I like your stuff Twilly. Looks like a great starting place.

[Twilly]

Oh yup, forgot all that stuff. They are 1:5 scale models made out of MDF and then coated with filler, and spray painted. This year I'm making a mold and then using Fibreglass (will hopefully work) to get the shape, and then If i like it I can take it to a guy I know to do it properly with Carbon Fibre. But am hopefully taking the models to a wind tunnel to just check out some figures and probably end up with some unrealistic figures but still..... better than nothing. Is there any frame design that you prefer?

[zzzwillzzz]

as a track racer, which ever one is faster.

do you know how much windtunnel time costs??? and you can't just test the frames. you need forks, wheels, components and rider. a frame needs to be tested with all the other parts and their interactions. a frame that's low drag by itself is meaningless. it has to be fast as a complete system.

[Twilly]

I'm getting it done at the University for free (hopefully) on the basis that I do Mechanical engineering next year :rolleyes: And I am going to fit a basic Disc wheel and forks on the front and back.

Which frames do you like Aesthetically though?

[hotbike]

I'm making a track frame for a school project and have finished four models in order to recieve constructive criticism from the general public.
Please leave any general comments, which ones you like, which ones you dislike, what you like about them, etc etc etc.

Cheers

I don't like the frames you offered.
Mainly because you didn't make a step-thru frame.
With the versatility of composites , ( I don't know if these frames are carbon or fiberglass) , you could make a step-thru frame, with an oversize monotube, so that the market for a traditional Ladies Bicycle would be satisfied.
Here's a photo of the Fiberglass Ladies Bicycle my Daughter designed:
http://i134.photobucket.com/albums/q119/hotbike/00000024-1.jpg

Make a step-thru ladies bike. Better yet, make two identical ladies bikes. Women who jog together will bike together, if they can find a matching pair of bikes.

[Twilly]

I'm making a high performance Track racing bicycle to be used by top athletes...... not a woman's cruising bike used to go to the corner store and buy some milk. They are pure racing bikes.

[ong]

I guess I'm a little confused about your design goals for the project -- if you have a primarily aesthetic goal, that's one thing, but if you're designing for specific parameters, I'm not sure you're going about it properly. If you're primarily looking for aerodynamics and other utilitarian features, then testing four radically different shapes won't tell you all that much -- seems like you would have a basic design, and then test iterative, incremental changes, like ovalizing the tubing more, and evaluating aerodynamic gains vs. stiffness vs. total weight, etc...


I know it's a student project, not a commercial venture, but it just seems like you're saying two different things... if it's an art project, then just go with aesthetic concerns (after making sure it's ridable!). Nothing wrong with that -- there have been whole movements around making stuff *look* aerodynamic! But if it's a design project, then I'd start by doing a wireframe fit drawing around your target cyclist (you?) to get all your dimensions and angles down -- you don't want to leave the rider out of the overall picture! And define some goals and metrics for evaluating success.... just my two cents.

[Twilly]

As Part of the design fase we have to test the frames in different areas. One of my tests is to check that the frame is aesthetically pleasing by handing the frames to the general public for constructive criticism on the frames, merely aesthetically. As aesthetics are important in order to sell bikes.

[ong]

Yes, aesthetics definitely sell a lot more bikes than aerodynamics!

From a pure "eye candy" standpoint, I think straying too far from the double diamond design starts to look a little big cartoonish -- the old Kestrels (pre-2000) had a nice swoopy, sculpted look without looking too dorky (like the current ones). I would think your model with the drastically curved seat cluster might look a little odd with a seatpost jutting up from that (at least, that interface would pose a real design challenge). Carbon frames often use a wishbone to avoid having too many tubes join right at the seat cluster -- did you toy with that idea at all? The shark fin looks a little derivative, although I can't think who it is that does that -- Cervelo?

For no particular reason, I tend to like the overall look of the sharkfin-y one, and the top left one... probably because they're the most bicycle-y of the models you've got.

Good luck with your project!

[zzzwillzzz]

. As aesthetics are important in order to sell bikes.
not in the very small world of track bikes. they will buy the ugliest bike in the world if it is the fastest.

i like the last one best with the curved seat tube. the other black one with the fin is not integrated the way the fin doesn't connect to the brake bridge area. also you don't necessarily need the brake bridge since it is a track bike (you might need it structurally, but since the frame would be carbon fiber you should be able to go with out it)