frame builders, how's this layout??

[learlove]

I was messing around with bikecad from the bikeforest.com site and came up with this design. Would it work? I'm going for something stiff (either OS steel or AL) and fast handleing.

[learlove]

the headtube diameter is 45mm and I set the top/down and seat tubes at 36mm diameter. off the top of my head i though that would be a aprox representation of OS steel or AL tubes. The fork is generic straight blade 45mm.

I basically took the demensions from my aluminum Merckx Leader and "tightened" it up to make it feel alittle more "sporty" or crit like instead of Belgium Cobbles stable.

Thanks for the input.

[Tom Kellogg]

of course, but I'd suggest two small changes that will make a BIG difference. First, make that head angle 73 degrees, or go with 73.5 with a 43 rake. If you don't the front end will push and understeer in fast corners. The other related thing is that your chain stays are too short. Add about 5mm and your weight blaance will make it much easier to corner and especially descend. have fun.

[mister]

you probably want your trail to be more around 55-58mm. 50 is kinda low which is what Tom is getting at with the different head angle and rake.

[thejen12]

I'm not a frame builder, but it looks like a high potential for toe clip overlap with those dimensions, too.

Jenn

[michael white]

I was going to say it looked needlessly tight in front, but was hoping a framebuilder would comment. One did, so I didn't need to. :cool:

[musgravecycles]

I'm with Tom, your F-C (and rear for that matter) is too short bro...

[cpg]

I'll third the suggestions. The current design while not unrideable would never be something that I would design.

[abqhudson]

Best advice available anywhere - and, it's free! This is a great forum.

[learlove]

thanks for the advise guys. not to sound like a know-it-all, but I had a feeling that the front end was going to get comments. Pete Dreesens said the same thing when I met him a 2 weeks ago to biuld a track bike for me. I caved and am also having him do a road bike also.

We measured my current merckx plus another corsa extra frame I brought along. Funny thing is the advice you guys give here and what Pete said all come out very close if not spot on to the merckx numbers (road bike wise).

If I apply the suggestions Tom gave above to the design the numbers come out almost exactly to my current AL Merckx Leader.

Thanks

now its off to t-town to watch the races.

[learlove]

hey tom does this bike look familiar to you:

[learlove]

here it is alittle larger:

[mister]

whoa, that thing has ten pitch on it.

[learlove]

whoa, that thing has ten pitch on it.

yes I used to get lots of comments about the 10 pitch when i raced that bike at t-town as a junior back in 1991 to 1993.

I sold it durring college to fund my commercial pilots license - regret it to this day.

[learlove]

how about these numbers for a road bike (steel lugged):

seat tube: 52cm ctc
tt: 54cm ctc
drop: 70mm
rake: 50mm
front center 584
seat angle: 73
head angle: 72
chain stay: 410mm
trail: 56.9

[learlove]

tweeking alittle from above to "quicken" the handeling some the way I like it (alittle quicker/snappier than average)

seat tube: 52cm ctc
tt: 54cm ctc
drop: 70mm
rake: 45mm change from above
front center 570 resulting change from above (automatic with head angle)
seat angle: 73
head angle: 73 - change from above
chain stay: 410mm

resulting trail - 56mm

[learlove]

track bike numbers:

st:51.5 ctc
tt:53.5 ctc
head and seat angles 74
rake: 34mm
bb drop: 55
front center 557
cs 390mm
trail: 61.3

[learlove]

road bike 1

st-52
tt-54
head angle 72
seat angle 73
rake 50
front center 583.6
trail-56.9
cs-41
bb drop - 70

[learlove]

road bike 2 ("quickened up")

st-53
tt-54
cs-41
drop-70
rake-45
trail-56
head and seat angle - 73
front center - 570

[Peter P.]

Now you're on overload. Your specs keep changing. You will drive a framebuilder to lose patience with you. You need to pick a builder you can have a dialog with who's frame design you trust because frankly, you're not too sure what you want.

I don't intend to sound harsh but you're gonna have to settle down with your geometry or let the builder make the decisions for you because you don't seem sure of what specs you want or what direction you want to go in, especially with that front end.

[EnginCycle]

Just curious why the first photo says Engin? i did not design that bike and would not design that bike since the HA and fork rake do not work out. just curious?

-Drew (designer and builder of Engin Cycles)

[learlove]

Now you're on overload. Your specs keep changing. You will drive a framebuilder to lose patience with you. You need to pick a builder you can have a dialog with who's frame design you trust because frankly, you're not too sure what you want.

I don't intend to sound harsh but you're gonna have to settle down with your geometry or let the builder make the decisions for you because you don't seem sure of what specs you want or what direction you want to go in, especially with that front end.

maybe i should have been alittle more clear - first pete thanks and i can see by my post how you could get the wrong idea. I'm just playing around with the bikecad software.

Pete D is currently building me 2 bikes ( a road and track). the numbers/bik in post 17 (red track) and 18 (blue road) are the ones pete came up with after we met, talked about what i wanted and then took some measurements from me and my current merckx road bike. i would not go against the builder nore tell him/her this is what i want the numbers to be.

As a pilot I wouldn't expect you guys to tell me how to fly the plane from point a to b, so I use the same judgement here. Sorry I should have pointed that out in the begining. I really just playing with number to help me better understand the process.

[learlove]

Just curious why the first photo says Engin? i did not design that bike and would not design that bike since the HA and fork rake do not work out. just curious?

-Drew (designer and builder of Engin Cycles)

Drew - the bike with engin on the tubes were from a file (with diff numbers) a riding buddy gave me. he has one of your bikes bought second hand and had modeled it in the cad program for his use. I did not discover in the bike cad program how to change the frame text until a day or so ago.

I could not find the file but copied the bike with your logo on it to a paint program then covered up the name if it makes it better. sorry didn't even think of it at the time.

[palincss]

track bike numbers:

st:51.5 ctc
tt:53.5 ctc
head and seat angles 74
rake: 34mm
bb drop: 55
front center 557
cs 390mm
trail: 61.3

What do you win by having only 2 mm clearance between the tire and the seat tube?

[learlove]

What do you win by having only 2 mm clearance between the tire and the seat tube?

I think the cad program is/was set at 23c or 25c tires and the 390mm cs is typical track. you usually have more clearance because of pulling the cain snug when positioning the wheel. I think that 2mm is from the cad program assuming the wheel is slammed all the way in on the dropouts which is not typical (in my exp. with track bikes). my generic bianchi pista track bike has a 38cm cs but with a 48X17 gear the wheel more than 10mm from the seat tube.

[Samster]

sign the check, close your eyes, and let him build you a great bike, imo. but, de gustibus non est disputandum applies here as it does almost everywhere else.