Anvil Bikes

[Archibald]

Hi,

As others have stated, this Smoked Out thread is a great read. Makes me want to build a bike and ride it across a continent, and then start all over again!
Don, your life experiences, and knowledge and mastery of the various skills involved in framebuilding are quite inspiring.

Thanks for sharing.
Jim

You're welcome, Jim and thank you for your kind comments!

[Archibald]

we have PAUL components.

how 'bout we have DON components?

a DON Derailleur?

a new day has Don'd

It'd be cool as hell, but it's not realistic. I just don't want my biz to grow/expand/fracture past what it is. Maybe one more guy so I have more time to design stuff or build, but that's it. I wish Paul would get back into it though. I'd love to rock a full US group!

[Curt Goodrich]

Good question. My answer: it just made sense to me and keeps the fixtures simpler & more compact. Having worked with all kinds of jigs & fixtures in machine & fab shops, I knew how important it was that the fixtures could be easily checked by eyeball for setup & I try to include that wherever it's practical. That criteria can/does drive design. What I like best about it is that slight changes in head tube angle does not affect head tube height meaning you can divorce one setting from another when making adjustments. Does that answer your question?

Yes and that totally makes sense. What I found interesting to your approach was that it basically ignored the way the Italian and French frame fixtures arrive at that point in space. Probably because your experience at that time outside the industry was greater than your time in. IMO your fixture design is parallel to what I think is the "new" way of building. People now talk about building from CAD drawings and your fixture is designed around that philosophy. The older style fixtures predate the current trend of building off CAD drawings. In saying this I'm not placing a value judgment on either CAD vs. no CAD. There's pros and cons to both methods. I just find it interesting how people solve the same problems in many different and valid ways.

[Archibald]

Yes and that totally makes sense. What I found interesting to your approach was that it basically ignored the way the Italian and French frame fixtures arrive at that point in space. Probably because your experience at that time outside the industry was greater than your time in. IMO your fixture design is parallel to what I think is the "new" way of building. People now talk about building from CAD drawings and your fixture is designed around that philosophy. The older style fixtures predate the current trend of building off CAD drawings. In saying this I'm not placing a value judgment on either CAD vs. no CAD. There's pros and cons to both methods. I just find it interesting how people solve the same problems in many different and valid ways.

I never considered it from a drawing perspective, but yeah, you're probably right. Remember that mad painful spreadsheet I had for a while for folks that didn't draw their frames? Damn how I hated that thing! Folks would call/email/passengerpigeon me about it when they/I blew some formula or how come I couldn't add all the stuff found on BikeCad to it....so glad I/Brent Curry/ weaned folks of that. Damn I hate even thinking about it. Now & again somebody will ask me about it and I always throw up in my mouth a little bit and have to take a Zantac afterwords.

[Archibald]

...and Matt says there's too many words and not enough pictures in this thread so here:



If you look close you can see it's still all wet up and there are nice little radii everywhere!

[e-RICHIE]

Well, we don't use cones on the bottom any more, but yeah, the bottom center of the headtube is your "head tube height" on the fixture and that's set using the scale on the main base plate of the fixture. That dimension is a product of your fork length, HTA, and BB drop. BB drop is set separately from head tube height and since both the Type 3 Journeyman and the Super Journeyman use the same configuration it's just an adjustment made via the chainstay tower scale. On Type 2 & older JMan's, BB drop was set via chainstay angle for the rear axle (head tube height settings are the same as current models). Does that answer your question?

so - you can set the frame drop, dial in a fork length (and rake too?) and then the "bottom center of the head is my head tube height..."?
cool atmo.
what do you mean "bottom center"?

[Archibald]

so - you can set the frame drop, dial in a fork length (and rake too?) and then the "bottom center of the head is my head tube height..."?
cool atmo.
what do you mean "bottom center"?

No, you can't do that, at least not in the fixture directly. There is no measurement on the fixture that is directly related to fork length or offset. Head tube height is a product of fork length, head tube angle, & BB drop. Head tube height on the fixture is the true vertical distance the bottom center of the head tube is above the center of the bottom bracket. Savvy? Here, I'll post a pic....

Frame Fixture Variables.jpg

clear now?

[e-RICHIE]

No, you can't do that, at least not in the fixture directly. There is no measurement on the fixture that is directly related to fork length or offset. Head tube height is a product of fork length, head tube angle, & BB drop. Head tube height on the fixture is the true vertical distance the bottom center of the head tube is above the center of the bottom bracket. Savvy? Here, I'll post a pic....



clear now?

so - what numbers do you set on the fixture so that the bottom arrives here atmo?
or did you just tell me atmo?

[Archibald]

so - what numbers do you set on the fixture so that the bottom arrives here atmo?
or did you just tell me atmo?

Bottom of what? Head tube, bracket, or rider?

I set my head tube and seat tube angle first. Then I set my head tube height. Then my bottom bracket drop for the rear dropouts. Everything else sets itself or does as the build progresses.

[e-RICHIE]

Bottom of what? Head tube, bracket, or rider?

I set my head tube and seat tube angle first. Then I set my head tube height. Then my bottom bracket drop for the rear dropouts. Everything else sets itself or does as the build progresses.

set the bottom of the head tube atmo.
i am dialed into using the fixture to find that point for me, and it compensates for HS stack as well.
i adjust the frame drop and also the fork length, and the lower head tube landing spot is right there.

[e-RICHIE]

ps i guess i should have written atmo - "...then you set the head tube height? how?"

[ron l edmiston]

sorry for my interruption ---- this fasinates the shit out of me .... i ride a "maserati birdcage.."
not in my wildest dream did i preceive the skill / insight to build a steel lugged frame / fork..

thanks for smoked out

ronnie

[Archibald]

set the bottom of the head tube atmo.
i am dialed into using the fixture to find that point for me, and it compensates for HS stack as well.
i adjust the frame drop and also the fork length, and the lower head tube landing spot is right there.

Right. My fixtures won't tell you fork length or offset or headset stack height. You tell it via head tube height as derived from those dimensions. You gotta' show it who's boss, yo!

[Archibald]

sorry for my interruption ---- this fasinates the shit out of me .... i ride a "maserati birdcage.."
not in my wildest dream did i preceive the skill / insight to build a steel lugged frame / fork..

thanks for smoked out

ronnie

Thank you, Ronnie, for both your interest and your patronage of made to order frame builders!

[Human Epic Jolt]

ps i guess i should have written atmo - "...then you set the head tube height? how?"

i guess the dia. of the headtube is a factor too. at least when reading back to the scale.

[Archibald]

i guess the dia. of the headtube is a factor too. at least when reading back to the scale.

Could be on a cone, but we don't use cones any longer.

[e-RICHIE]

Right. My fixtures won't tell you fork length or offset or headset stack height. You tell it via head tube height as derived from those dimensions. You gotta' show it who's boss, yo!

ya i got that it doesn't tell me fork length, so how do you know those, and what parts on
your fixture are manipulated so that the bottom of the head tube is in the right spot atmo?

[Archibald]

ya i got that it doesn't tell me fork length, so how do you know those, and what parts on
your fixture are manipulated so that the bottom of the head tube is in the right spot atmo?

The only part manipulated on the fixture is the head tube height. The rest are divorced from that setting. The bottom center of the head tube is always directly over the center of the pivot, so changing head tube angle does not affect your head tube height on the fixture itself. BB drop, fork length, head tube angle, and headset stack height are how you determine the head tube height and those dimensions come from your design. If you go back and look at the drawing I posted, you can see that the head tube height is the only dimension the fixture requires/uses.

[Archibald]

More to go with the drawing:

*********
Anvil Frame Fixtures 101

Frame fixtures or jigs are designed with a basic build process logic and the Anvil fixtures are no different. This document will explain the logic behind Anvil frame fixtures so you can better understand how they’re designed to work.

Home Is Where the Bottom Bracket Is
All Anvil frame fixtures are designed with the center of the bottom bracket tower as the reference or home dimension (XY zero). With the exception of the head tube angle witness marks, all scales on the fixture are referenced relative to this position. Our fixtures place the non-drive side of the bike towards the fixture’s base plate which mandates that the head tube be on your right hand side as you’re looking at the fixture. The reason for this is that this leaves the drive side (the important side) of the bike facing you. Most bottom brackets are longer than their nominal dimension, for example, a 68mm English BB shell is normally supplied 69mm long. On Anvil fixtures you can let the drive side run long and then face to tolerance after the build process. On the Super Journeyman you can center the BB shell to the shell’s exact centerline or a lug port centerline without prefacing. That said, it’s our position that all builders, regardless of the fixturing they’re using, should start their frame construction with a properly faced and blueprinted bottom bracket shell.*

Head Tube Height
All Anvil frame fixtures locate the head tube’s vertical placement by a measurement we call the “head tube height.” This is the vertical dimension from the center of the bottom bracket to the bottom center of the head tube. This dimension can be taken from your design drawing. Again, this the vertical dimension from the center of the bottom bracket to the bottom center of the head tube. Head tube height is directly read from the bottom of the top tube length arm on the vertical scale which is permanently placed on the fixture’s base plate. A change in head tube angle will not affect the head tube height.

Chainstay Length & Bottom Bracket Drop
The Super Journeyman, Type 3 Journeyman, and the Journeyman Type 2 approach chainstay length and bottom bracket drop in different ways, but the results are the same.

The Super Journeyman and the Type 3 Journeyman have a direct reading scale for the “Effective Chainstay Length” (read from the front edge of the Chainstay Tower Assembly’s sliding base) and an independent adjustment to establish bottom bracket drop using a direct reading scale integrated into the chain stay length base and a pointer on the chain stay tower. For example, to set the fixture up for 70mm of BB drop, you’d just align the BB drop pointer with 70mm on the scale. Easy as cake.

The Journeyman Type 2 and older Journeyman have a direct reading scale for “Actual Chainstay Length” and bottom bracket drop is set by adjusting the chainstay length arm to the design “Chainstay Angle.” The Chainstay Angle scale on the Type 2 and older Journeyman is integrated with the fixture and the back purge valve. The scale reads from -10 to +16 degrees with 1/8th-degree resolution. The chainstay angle pointer has three distinct witness marks on it which are used like a vernier caliper to give you 1/16th-degree resolution. 1/16th-degree resolution equals 1mm of BB drop at a 400mm chainstay length

“Effective Chainstay Length” (ECL) is the horizontal distance the rear axle is behind the bottom bracket as opposed to “Actual Chainstay Length” (ACL) which is the parallel or bee-line distance between the bottom bracket and axle centers normally provided when discussing bicycle geometry. To be clear:

• Effective Chainstay Length (ECL): The horizontal distance the center of the rear axle is behind the center of the bottom bracket. Changes in bottom bracket drop have no effect on this dimension and it can be used to determine rider center of gravity & balance over a bike frame
• Actual Chainstay Length (ACL): The parallel distance (bee-line) from the BB center to the center of the rear axle. This is the dimension most people refer to when discussing chainstay length.

So, when setting up the Type 2 and older Journeyman for chainstay length, it direct reads, so for 420mm chainstays, you’d put the chainstay length pointer at 420mm. On the Super Journeyman and Type 3 Journeyman, 420mm chainstays could be within a range of dimensions considering bottom bracket drop variables so to properly set chainstay length you need to determine the ECL from your design drawing or do the math. In most cases, setting chainstay length on either fixture is not really necessary as the miter length of the chainstays will determine how the fixture is set up.

Head Tube Angle
Head tube angle on all fixtures is direct reading with 1/8th-degree resolution. The scale for the head tube angle is engraved directly into the plate at ¼-degree intervals from 60 to 80-degrees while the head tube angle pointer has three distinct witness marks acting as a vernier that allows resolution to the 1/8th-degree. Changing head tube angle does not affect head tube height.

Seat Tube Angle
The seat tube angle on all current frame fixtures offer direct reading 1/2-degree resolution with the seat tube angle witness marks engraved into the base plate the same time as the base plate is being machined. This guarantees that the angular relationship between the bottom bracket center and the seat tube angle scale is accurate to within .0005” and the fixtures are proofed using a micrometer protractor with 1-minute (1/60th-degree) resolution. The angle is read from the right hand side of the seat tube arm as you’re facing the fixture. There is a shelf on the fixtures which allows a builder to use a vernier protractor if they desire to have finer seat tube angle resolution.



*1 A blueprinted shell is one that has been measured and dimensionally documented for centerline of the shell itself and/or lug ports.
*2 Chainstay angle is the angle between a theoretical line from the center of the rear axle to the center of the bottom bracket and a line parallel to the ground.

[e-RICHIE]

The only part manipulated on the fixture is the head tube height. The rest are divorced from that setting. The bottom center of the head tube is always directly over the center of the pivot, so changing head tube angle does not affect your head tube height on the fixture itself. BB drop, fork length, head tube angle, and headset stack height are how you determine the head tube height and those dimensions come from your design. If you go back and look at the drawing I posted, you can see that the head tube height is the only dimension the fixture requires/uses.

thanks - but i use the fixture as my design(er) - it's a giant 3D blueprinter of sorts.
i would need another design (somewhere, on paper, or similar) with yours atmo?