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curved seat and chain stays with dropout

So im trying to figure out how to add my curved seat and chainstays with my dropout into my bike design. I have columbus zona  butted cyclecross S bend chainstays oval/round 24 od 8/.6 wall and columbus zona 29er S bend seat stays 19 od  .6 wall . The dropouts are allotec rear through axel for flat mount disc with eylets [ M12x1.0] any help would be appreciated



Curved seat stays and chain stays with dropout

Below is an auxiliary view of a pair of chain stays. Note that you can display all these dimensions in the Dimensions dialog box by going to the Stays (auxiliary view) >> Chain stays tab. It may take some massaging, but by tweaking the A, B, C and D dimensions in the chain stays dialog box, you can hopefully match the dimensions for your particular stays.

Chain stay bends

The wall thickness is only required when generating miter templates and you'll be able to enter that in the dialog box that appears when you save miter templates.

If you can share a drawing of your dropouts, I could include them in the next update of BikeCAD as described at: bikecad.ca/dropouts_from_static_drawings. Failing that, you can define them yourself parametrically. The most important dimensions for insuring that your dropouts will fit with your frame are the Sx, Sy, Sz, Cx, Cy and Cz dimensions that locate the ends of the stays with respect to the rear axle.

seat and chain stays

Thanks for the help Brent i think im making

progress wwith the stays.the dropouts are not going as well.

ive included the picture of my dropouts .By changing the SX and SY Ive gotten closer but I cant seam to get the curve in the dropout that goes to the seat stay. Would it be posibile to explain where the sy and sx mesurments are on my drive side dropout. Thanks again.

Dropout dimensions

The Sx dimension is the horizontal distance from the center of the thru axle to the end of the seatstay. Cx is the same, but to the end of the chainstay. Sy and Cy are the vertical distances to the ends of the stays.

Considering how Cx is measured, note that your 120mm dimension along the bottom of the non-drive side dropout starts behind the thru axle, so you'll probably want to shorten that measurement a bit so that it can be taken from the center of the thru axle. Your 88mm dimension is a good one to check with a user dimension in your BikeCAD model, but it is not one that can be used as a driving dimension in BikeCAD. When measuring your dropouts, you'll want to make sure that each dropout is positioned at the same angle. In your photo, your drive side dropout is rotated in a counter clockwise direction relative to how you are showing your non-drive side dropout. Don't feel like you need to measure them at the exact same angle they will be used in the frame. You could measure Cx, Cy, Sx and Sy as though the chainstays are going to be horizontal and then you could rotate them in the model using the theta (θ) dimension.


OK thanks again ,that is making sense. I really appreciate your time

non drive dropout data

Hi Brent  sorry to be such a pain,  but I can not figure out how to enter the data into the non drive side for the dropouts . The windows are there but im only able to enter the drive side data.

Non-drive side dropout data

To enable those fields, select asymmetric chainstays and seatstays. This is done at the top of the chainstay and seatstay dialog boxes.


Thanks so much Brent 

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