Lugged Cyclocross Geometry

Hello,

I've been trying to work out building a lugged cyclocross bike but conventional lug geometries do not seem like they would be compatable with a 71.5-72deg head angle with a 73ish seat angle.

My general question is how much can you vary the angle of a lugged joint without compromising the strength. Is this achieved by filing down on side of the lug socket to accommodate the angle shift, brute bending the angled joint down or maybe a different method?

Any insight would be appreciated.

Thanks!!

Matt

I'm betting e-RICHIE will chime in with the "show it who's boss" wisdom. I have no experience myself.

There are many ,many more than one thread on lug manipulation in the archives.

Depending on the skill of the builder and his motivation a few degrees of change can be had (from the lug's intended angle). Depending on how this change is done brass might be the filler better suited to deal with the internal gaps created. Andy.

Quote:

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Originally Posted by Dasistmeinmoped

Hello,

I've been trying to work out building a lugged cyclocross bike but conventional lug geometries do not seem like they would be compatable with a 71.5-72deg head angle with a 73ish seat angle.

My general question is how much can you vary the angle of a lugged joint without compromising the strength. Is this achieved by filing down on side of the lug socket to accommodate the angle shift, brute bending the angled joint down or maybe a different method?

Any insight would be appreciated.

Thanks!!

Matt

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One degree of HTA is barely a change, no sweat.



"Show it who is boss"

"You'll get more tail than Sinatra"

"the lug angle isn't the bike, the bike is the bike"

Testing positive for ATMO.....

:bigsmile:

Quote:

---

Originally Posted by Dasistmeinmoped

Hello,

I've been trying to work out building a lugged cyclocross bike but conventional lug geometries do not seem like they would be compatable with a 71.5-72deg head angle with a 73ish seat angle.

My general question is how much can you vary the angle of a lugged joint without compromising the strength. Is this achieved by filing down on side of the lug socket to accommodate the angle shift, brute bending the angled joint down or maybe a different method?

Any insight would be appreciated.

Thanks!!

Matt

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Here's some insight atmo. The lugs are only there as envelopes that surround pipes while you are sweating in filler material. The miters, the quality of your torch work, and the alloy rod you use will determine the strength of the joint. I know of no lugs or framebuilding parts that cannot accept angles at least 2-3 degrees on either side of the one they are fabbed in. It's the fixture(s) that holds the angle rather than the part. The short answer includes opening up the pockets for a sloppier fit, fixture everything, and make a determination regarding where some creative manipulation situations are needed. And then systematically attack these spots.