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Hooded dropout values

I'm working on a couple bikes. One has the standard Paragon vertical hooded dropout and the other has the Paragon Slider. Is the generic hooded based off the paragon dropout?


Also I tried customizing the slider dropout but seem to be running into measurement issues. When I imput the,whats thought to be, proper values for the slider, it pulls the hood away from the stays and leaves a gap. Do you have the values for a Paragon slider?

When changing values in dropouts, is "R" the diameter of the hood? i.e. the diameter of the hood from paragon is roughly 38mm.



Hooded dropouts

The generic hooded dropout is not based off any particular dropout.

If you adjust the Z value to shift the sliding part of the dropout in or out, you might be surprised that the sliding part seems to stay in place while the rest of the dropout moves.  It is possible to leave the dropout where it is and have the sliding part move.  To make it work that way, you need to lock the frame.  The reason for this behaviour is explained at: bikecad.ca/track_and_sliding_dropouts.  (Quick summary:  Chain stay length is not an actual measure of the physical chain stays, it is a measure of the distance from the rear axle to the center of the BB.  An exact value for chain stay length has been specified in the Primary dimensions dialog box.  By default, BikeCAD has to retain that value even if you are sliding the movable part of the dropout in and out.  The only way to retain the same chain stay length when adjusting the Z value in the dropout is to move the dropout itself.  When you lock the frame, BikeCAD locks all the tubes of the frame at the current length, but allows the chain stay length to change as the Z value of the dropout is adjusted.)

R is not the diameter of the hood.  As you can see in the exaggerated example below, R is the radius of the hood.  Because not all hooded dropouts have a simple cylindrical shape, BikeCAD includes dimension E, F, and G allowing for a wide variety of hooded dropout shapes.  If you are looking for a very simple cylindrical shaped dropout with the base of the slot at the center of the cylinder, simply set E, G and R to the same value and set F to twice that value.

In the above screen capture, I intentionally set the display mode to hidden line view in order to expose the ends of the seat stays and chain stays.  The ends of the stays are located with the Cx, Cy, Sx and Sy dimensions.  At this time, BikeCAD does not cut the stays to conform perfectly with the contour of the dropouts.  Therefore, it is recommended that you adjust Cx, Cy, Sx and Sy to achieve an approximate fit and then use a user dimension to measure how much to file off one side of the end of the stay if required.

Having similar problems

Trying to model the Nova hooded sliding MTB dropout. Can't seem to get the ends of the stays to line up/attach to the hoods of a hooded dropout. I have imputed Sx Sy and Cx Cy values via measurements from a drawing. If I switch to a plate dropout the tabs line up with the tubes. Two screen shots. Same values. Just hooded or plate. 

Any help?

Modeling hooded dropouts

When modeling plate and socket dropouts, the shape of the dropout itself is governed by among other things the Sx, Sy, Cx and Cy values which control the end locations of the seat stays and chain stays. When modeling hooded dropouts, the shape of the dropout is controled by dimensions A, T, Y, S, D, , E, F, G, R and t. However, the dimensions Sx, Sy, Cx and Cy only control the locations of the ends of the seat stays and chain stays, they do not affect the shape of the dropout itself. You can resolve your issue by either lengthening dmension G (to stretch the length of the dropout so that it may reach the stays) or reducing the dimensions for Cx and Sx (shifting the stays backward toward the dropout).

The option to model hooded dropouts was intended to model dropouts resembling the one below.

It will be difficult to capture all the nuances of the shape of your particular dropout using the parametric controls available. In an effort to more accurately represent some of the more popular dropouts, the option to define dropouts by static drawing has been included as an alternative to defining dropouts by parameters. By switching the menu from Define by parameters to Define by static drawing, you can select the Paragon DS0001 sliding dropout along with the DR4006/DR4009 inserts to get a better approximation for the similar dropout by Nova.

hooded dropout values

Thanks for the response. Helpful. I was able to get things looking better by changing dimensions ATYSDEFGR and t. Not sure I have things axactly correct. I had put in the paragon dropout using the static drawing, but I was not sure how close the dimensions are between the Paragon and the Nova dropouts. Anyone know how close they are? I looked at Paragon's drawings but could not find the measurements I was looking for. 

Measuring standard dropouts

If you display the Paragon dropout in a BikeCAD model, you can take any measurement you like off the dropout with a user dimension which is described at: bikecad.ca/user_dimensions.

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