My inspiration and my first build

[gereonb]

Hello Vsalonistas,
I am an electronics geek at heart, i like analog photography as bit of a balance to work life. I only recently got back into biking, i find it helps keep fit while enjoying oneself. I ride some nice retro steeds but about a year ago got inspired to try building my own bike, there is no off the shelf version of what i wanted.

The butt-kick that really got me hooked like heroin was the Chris Bishop Raw NAHBS Track bike, seen here:
IMG_47931-970x646.jpg

I spent a lot of time on the internet in the next weeks and days, i was walking in Antwerp and found a great book called cyclepedia about a guy called Michael Embacher with a huge collection of awesomely rare bikes, the one which caught my eye was a stripped down messenger bike, this one:
messenger1.jpg

I figured i wanted to actually build my own frame now as the brazing and process involved awakened the inner OCD in me, i soon found bike cad and transferred what i had seen in pictures to a basic cad version, here:

Commandment 11th 75-Parallel.png

Top tube 25,4 Down tube 28,6 Seat tube 28,6 with 75degree angles on both seat and head tube.
I have now acquired the tubing and lugs and other materials need to start practicing brazing, i would be very interested in anyones views on my bike cad creation, does it look like something that could work ?.

[Too Tall]

I am not a framebuilder. What you are doing is great and the idea to create and ride your own vision is pretty cool.
My brutal opinion is that almost anything is "rideable" if that matters or not I do not know?
If you want my opinion it would be desirable to build a bike with better road manners and is not going to buck you off into a ditch while still achieving the "look" you dig. Dig me?

[ToddFarr]

You found lugs with a reverse sloping top tube like that?? From my limited experience lugs are great but can't be changed more that a few degrees in either direction. Even then it can be a real pain.

[afwalker]

I'm just wondering what the handling will be like. Should have very little wheel flop, maybe too little that the handling will be sluggish? Trail looks like 59mm ish.
I haven't build enough bikes to have a handle on this so others please chime in:)
cheers
andy walker

[veryredbike]

Yeah, I wouldn't build that for your first frame if you're going lugged. It's a pretty big shift for the angles, and while experienced framebuilders do it all the time, it's pretty hard when you're just starting (take it from someone just starting).

[gereonb]

The 75º Parallel Seat and Head tubes are quite a standard track geo, it will certainly be a twitchy ride (bad straight ahead tracking on flat road, requiring more corrections) but thats expected and wanted in this case.
The only real strange part is the -5º forward sloping top tube, this makes the top head lug a little more extreme in angle but i had a cheap pressed lug i hammered a bit and it seems to be fine when i slip the tubes in, haven't brazed or tacked them up yet. I am going to see if i can get a cast lug to do the same.

Interestingly, the Orange frame (2 pic) out of Cyclepedia seems to have been a conversion, the Track Dropouts point upwards to the rear, this makes me think someone had a road frame and either brazed in new dropouts and/or changed the Headtube lugs/length.

[ToddFarr]

You have to remember if you are changing the lug angles you are also changing the gaps between the lugs and the tubes. If you are planning on using silver, large gaps are a lot harder to fill especially if you have limited brazing experience. Silver likes to flat out and run rather than stack and fillet. I remember my first frame struggling to get the silver to stay put on my SS - ST joints (this was my largest gap).

[MiWi]

does it look like something that could work

It works. Quite common track geometry. Built some similar bikes for friends.
If you like tight rearends and are running max 28mm tires: You can shorten the chainstays 10mm easily.

Toros_01.jpg

On the left 75°/75°, 30mm offset fork, 969mm wheelbase
On the right 75°/73°, 45mm offset fork, 995mm wheelbase
both 385mm chainstays.

The left is crazy agile, but not twitchy.
The right one (73° HTA) handles a little more relaxed, quite like a roadracing bike.

[gereonb]

Thanks michael, especially for the details. I checked your site and the rear wishbone on that blue one is damn hot.

I am not ready for Filets yet, i am going to start off with lugs until i have a proper workshop, i have been hammering the pressed lugs into shape around some test tubes and it looks like i can get the gaps down really tight just by taking some time. I guess the ultimate goal would be to create my own lugs (some day).

[randonneur]

If I'm not mistaken, this eisho lugset is a bit closer to track geometry than most lugs.

[gereonb]

Those are indeed ideal lugsets for track geo, there is also paul wyganowski Bicycle Frame Building Supplies For Sale | Wyganowski Frames he has lugs in various angles to order.

[gereonb]

1372685214010.bcad.zip

If possible could anyone with BikeCad Pro kindly export this as DXF or SVG, thanks much !.