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Tubes straight with plugs


For my first bike frame I am planning to use the rear dropouts pictured below.

As can be seen, these dropouts have plugs that are meant to fit snugly inside the chainstay and seatstay tubes. What I would prefer though is that the tubes extend directly from the plugs without any change in angle. I am wondering if bikecad has a means of telling that the stays are perfectly parallel with the direction that they are extending too, which are indicated in the above drawing with lines KK and MM.

In my current bikeCAD model, it seems that the chainstays in particular do not point in the same direction as the original dropouts, which I worry may be a problem. Is their a way to ensure the angle the dropouts and stays point perfectly match?

Sorry, it looks like the

Sorry, it looks like the first image in my above post did not take.

Angles of dropout plugs

The best way to confirm the plugs in the dropouts line up correctly with the angle of the stays is to view it in 3D. This can be done using the export to FreeCAD feature.

Direct angle Measurement

Hi Brent

I used a protractor and the allotec blueprints I got to measure the angle of the rear dropout plugs relative to horizontal. I then compared these dimensions against the "chain stay angle (actual)" and the "chain stay - seat stay angle", with my understanding that "chain stay - seat stay angle" minus the "chain stay angle (actual)" gets the angle of the top plug relative to horizontal. Would you say these this understanding is accurate? I am hoping this method yields the correct angles such that the tubes and plugs are parallel.

Dropout plug angles

You described how you began by measuring the dropout plug angles. Therefore, when you went on to describe the next step in your process, I think you meant to say it was to obtain the seat stay angle, not the dropout plug angle which you've already measured. Your process would work, but be aware that you can also just show the angle of the seat stay directly as shown below:

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