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-   -   Rear frame rebuild- cycletruck (https://www.bikeforums.net/showthread.php?t=1192381)

jawnn 01-21-20 01:43 PM

Rear frame rebuild- cycletruck
 
I am rebuilding the rear of my cycletruck. Does anyone have a template for dropouts with disc brake mounts? I looked all over the internet for heavy duty dropouts and no one has them.



I have 1/4 inch stainless steel flat bar I could have them cut out with a laser cutter. And I have 1 x 2 inch rectangular tubing.



I found some photos of a trike someone built, but there seems to be a curve in the design that I do not understand.

https://bronkalla.com/blog/2017/08/2...akes-and-seat/
https://cimg1.ibsrv.net/gimg/bikefor...f8828caf43.jpg
https://cimg7.ibsrv.net/gimg/bikefor...31b4fa1ffc.jpg
https://cimg0.ibsrv.net/gimg/bikefor...59d3b4a9f0.jpg


If someone has photos I would love to see them...

unterhausen 01-21-20 02:54 PM

paaragon has their designs on their site. Looks like the ones they used to make that might fit your needs are no longer there though

jawnn 01-21-20 03:21 PM


Originally Posted by unterhausen (Post 21294050)
paaragon has their designs on their site. Looks like the ones they used to make that might fit your needs are no longer there though

ya that's why I need a template....or a jig that costs too much for a single bike....

CliffordK 01-21-20 03:41 PM

It looks like you are already pretty close to what you want.

Not necessarily a dropout, but looking up "Flat Mount Brake Specs" on the web turns up quite a bit.

Flat Mount MTB | Peter Verdone Designs
Shimano Framebuilder Info - Pvdwiki

I presume there would be quite a bit of info about post mount too.

Canaboo 01-21-20 03:58 PM

What sort of template are you looking for?

Kuromori 01-21-20 04:41 PM


Originally Posted by unterhausen (Post 21294050)
paaragon has their designs on their site. Looks like the ones they used to make that might fit your needs are no longer there though

The PDF drawings for their low mount disc drawings should be good enough to get the relevant dimensions relative to the dropout right, even if the part itself isn't the right shape. Of course the ISO disc mount specifications from the Shimano frame builder materials are available if you don't want to copy from Paragon.

Shimano gives these dimensions as 78.1mm from axle to the forward ISO mount hole, 51mm from between ISO mount holes, and 39.9mm from the rear ISO mount hole to the axle. Axle slot is 10mm, ISO holes are 6mm, holes/slot should be slightly oversized and if it wasn't stainless, it would not be too difficult to make with a drill press and hand tools. The dropout needs to be shaped to clear the disc brake, especially between the ISO disc mount holes to make room for the pot.

ISO disc drop outs should essentially be a single flat plate though, so I have no idea what's going on in the example pictures. Care should be taken not to orient the disc brake such that the axle wants to pull out of the opening of the dropout when braking.

jawnn 01-27-20 02:49 PM


Originally Posted by Canaboo (Post 21294157)
What sort of template are you looking for?

I finally found a measured template for the left side but I still need one for the right side preferably for a 42t sprocket cassette.....? I just need to know the distance from the axle to the derailleur hanger hole center........hoh I missed that link above
http://www.peterverdone.com/wiki/ind..._Configuration


https://cimg7.ibsrv.net/gimg/bikefor...4fadf03850.jpg



https://cimg9.ibsrv.net/gimg/bikefor...280685cdc0.png

jawnn 01-27-20 02:54 PM

Is this reading 28 to 30 mm axle to hanger hole? what is the right measurement for a 42t cassette?


https://cimg0.ibsrv.net/gimg/bikefor...63429dd5ec.jpg

unterhausen 01-27-20 03:46 PM

The rear derailleur takes care of the 42 tooth cassette. Shimano has a direct mount hanger spec, but you probably should avoid that. Unless your question is how do you incorporate something like a Road Link to use a derailleur that isn't made for a 42 tooth cassette, and I can't answer that.

dsaul 01-28-20 05:34 AM

The Shimano MTB standard for the drawing in your post has an L dimension of 28-30mm from axle center to mounting hole center and an X dimension of 6-10mm offset from axle center. As Unterhausen said, there is no special length for a 42t cassette. That capability will be built into the rear derailleur.

Andrew R Stewart 01-28-20 10:56 AM

Anyone catch the drop out thickness detail view? Note the measurement points. The inside one is the chainstay end (or the drop out face, whichever protrudes more).

Also note the lack of drop in the main drawing. The axle and BB are on the same plane, parallel to the drawing's bottom edge. Andy

unterhausen 01-28-20 01:15 PM

the drawing showing a dimension to the stay is a mistake, it says thickness of dropout. No reference to the stay. It would be nice if they gave a better view and more dimensions

The lack of drop is because they rotated the frame. They give a dimension referenced to the centerline between the bb and axle.

Kuromori 01-28-20 02:27 PM

It's supposed to be a weird diagram of the dropout and hanger. The critical dimensions are the inner face of the dropout, and the outer face of the hanger. Lack of drop is because the drivetrain only cares about the relative position of the drivetrain parts, which follows the chainstay, and some kind of frames like minivelos actually have BB rise.

Andrew R Stewart 01-28-20 07:15 PM

I was not questioning the lack of drop. Just pointing that the base line the other dimensions were referenced to wasn't related to a horizontal but instead to the stay. I can just see (someone like me) making a drop out and after finding that the angles and off sets were wron from the assumption of the top of the page not being "true north".

The side view of the dropout thickness makes sense as a mistake. Never thought that the big S would do a boo boo, especially in their published stuff. Andy

Kuromori 01-28-20 07:48 PM

It's not really a mistake though, it's just not a very illustrative diagram since dropouts aren't usually shaped like that. It's a bad approximation of something like a stamped dropout with welded on axle faces, or something similar like FE-PR20. It's saying the points of reference of are at the axle for the inside, and the hanger for the outside.

unterhausen 01-29-20 10:01 AM

I have found mistakes on drawings produced by bigger companies than Shimano and I imagine those companies have stricter engineering review processes than Shimano would apply to a manual.

If nothing else, the dropout drawing fails to properly convey what they are talking about.

Kuromori 01-29-20 05:46 PM

The problem is that what Shimano is trying to convey can't be conveyed with a diagram of a "normal" looking steel dropout where the axle/hanger faces are in plane. It has to look unusual to illustrate the point. It kind of looks like a stay, but it makes no sense for the axle to attach to the stay. The diagram is for MTBs and all materials too, and there are probably a number of dropouts that do look like that from the rear. The inner face of many replaceable hangers isn't quite flush with the inner face of the dropout. There are some heavy duty dropouts with built up axle faces where the hanger must be relieved to meet the dimensional requirements. The Allotech breezer dropout with replaceable hanger is kind of like this. I've also seen it on mass produced aluminum frames like CAADs.

It could use a sentence of explanation, but I don't think there's anything technically wrong with the diagram itself. It's meant to cover dropouts that aren't just flat plates, as well as materials that aren't steel.

jawnn 01-30-20 03:36 PM

ok I want to use this cassette: https://www.amazon.com/gp/product/B0...E180VKRW&psc=1
what derailleur will work with it?? I forgot to look at the one I have for a 34t cassette..
I think I should just weld these dropouts to the end of the 1/4 inch flat bar I have.
https://www.paragonmachineworks.com/...r-dropout.html
The center of the axle to the center of the derailleur bolt is 1.180"
https://cimg8.ibsrv.net/gimg/bikefor...06fc666a06.jpg

unterhausen 01-30-20 10:20 PM


Originally Posted by jawnn (Post 21306641)
ok I want to use this cassette: https://www.amazon.com/gp/product/B0...E180VKRW&psc=1
what derailleur will work with it?? I forgot to look at the one I have for a 34t cassette..

not sure, I don't think there were that many derailleurs in the 8 speed era that were 42 tooth capable. I thought sunrace had a 1x drivetrain that worked with big cassets, but I'm not seeing it




Originally Posted by Kuromori (Post 21305238)
It could use a sentence of explanation, but I don't think there's anything technically wrong with the diagram itself. It's meant to cover dropouts that aren't just flat plates, as well as materials that aren't steel.

If someone can tell me what I'm supposed to learn from that diagram, I'm interested. Seems to me that a typical rear dropout is about 7mm thick. Then add half of whatever stay they have drawn and what they have drawn there is about 10mm on any bike I have ever seen. Plus there needs to be a radius out from the axle to tie all this info together. I guess it doesn't matter too much, because I just cut back the stay until it clears a 13 tooth cog and I'm done.

Kuromori 01-30-20 11:27 PM

It has nothing to do with the stay. It just happens to kind of look like a stay. Completely ignore stays. Stays are a red herring.

As the label indicates, it's entirely about dropout thickness. There is only the dropout. It's the rear view of a dropout with axle faces thicker than the hanger. The seat of the RD bolt must be 7-8mm away from the rear wheel axle locknut, that's the only thing it is conveying. The narrow part represents the hanger of the dropout, the wide part is the axle part of the dropout. This looks very strange to a builder using high quality forged steel dropouts because they tend to basically be flat. It's less strange when you consider the various shapes of replaceable hangers on other frame materials, which sometimes do result in the hanger being thinner than the axle faces.

Also non-paragon dropouts can be purchased for $10-20 from the various supply houses.

dsaul 01-31-20 06:44 AM


Originally Posted by jawnn (Post 21306641)
ok I want to use this cassette: https://www.amazon.com/gp/product/B0...E180VKRW&psc=1
what derailleur will work with it?? I forgot to look at the one I have for a 34t cassette..
I think I should just weld these dropouts to the end of the 1/4 inch flat bar I have.
https://www.paragonmachineworks.com/...r-dropout.html
The center of the axle to the center of the derailleur bolt is 1.180"
https://cimg8.ibsrv.net/gimg/bikefor...06fc666a06.jpg

There is no rear derailleur that will work with that cassette on its own. All of the 8/9 speed compatible rear derailleurs max out at 36t, so you will need a hanger extender to make it work with a 42t cassette.

jawnn 03-02-20 01:43 PM

https://cimg9.ibsrv.net/gimg/bikefor...45f6a759e4.jpg
As you can see in the photo there was no problem with the 42t cassette. My cheap derailleur works fine. I am having a little problem with cable adjustment, possibly from using cheap cable. I better get a new slicked and stretched cable.


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