Kustom Kruiser Roadster and disc brakes.

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good day all, thank you for taking the time to read my post. have a few questions about a new build and super new to this. I picked up a Kustom Kruiser Roadster recently and am planning on electrifying it :) going to be using a Bafang midmotor i have laying around for it. Now currently it has coaster brakes in the rear with a 3 speed shimano IGH. The midmotor will negate the coaster brake in the rear. I picked up a S/A front hub that has a dyno and drum brake built in but am not sold on just front brakes. I have tested the frame and it appears to be steel (magnet sticks to it). my question is this in fact true and if so does anyone know if the rear seat stays can withstand the torque of disc brakes? Kicking around the idea of having a mount welded to the frame in the rear. Thank you in advance!
 
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IMG_0305.JPEG
if this is not good i will try to take better/closer pictures of the seat stays when i get home
 

Captain Awesome

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Post a picture of the frame. I have seen people weld an extra brace by the dropouts to stiffen things up for disc brakes.
This^

You can definitely add disc to just about anything. Some just require more creativity. Adding a brace is pretty common practice to keep the stays from flexing and or bending under the load

 

twojs.bike

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You can also buy bolt on disc brake adapters. There are a few models, so it might be trial and error to see which works best on your frame. They are pretty inexpensive. You can find them on eBay. I bought the one below for less than $10. I have not tried it yet, but I think I saw the same one on a bike @OddJob built.

63EFCAB0-99E0-4BB4-AE05-D40F41AB5285.png
 

OddJob

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Yes, twojs, I have used that mount on a couple different builds, both klunkers. They may need some tweaking and use of spacers (washers) to get a good line with the rotor, but they are very inexpensive and work for those of us who don't have a welder.

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On this build in the photo below, Desert Sky, there is actually only a functioning disc brake in the rear. I just used a disc compatible front wheel from a cheap Goodwill bike buy to complete the look. :wink1: A perfectly good front disc wheel for only $15.99.

It was a silver alloy color, painted it to match. Looks like it was meant to be there.


Desert Sky Klunker.jpg
 

us56456712

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Im not a fan of disc brakes except for technical mountain biking. It’s like riding with a meat cleaver. People are getting sliced up with them, especially on road bikes. A knee cap was recently sliced complete off by a disc brake in a road bIke accident. Road racing has had its share of disc brake slices. No thanks.
 

MattiThundrrr

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People are getting sliced up with them, especially on road bikes. A knee cap was recently sliced complete off by a disc brake in a road bIke accident. Road racing has had its share of disc brake slices.
Wow I had not heard that! A little research reveals that serious burns are happening too. I'm not convinced that it has a place in BMX racing either.
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Here are my 5 cents.
Do not use those "adapters" posted up there, they will bend like tin foil under the torque generated by a heavy ebike.
I suggest you to use roller brakes. I run such a setup on my Project Firebolt build. They sufficiently withstand the load and are very easy and comfortable to use. Also they won't require a frame modifications of any kind.
Good luck with the build!
 
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Here are my 5 cents.
Do not use those "adapters" posted up there, they will bend like tin foil under the torque generated by a heavy ebike.
I suggest you to use roller brakes. I run such a setup on my Project Firebolt build. They sufficiently withstand the load and are very easy and comfortable to use. Also they won't require a frame modifications of any kind.
Good luck with the build!
thank you very much and yes I was looking at them and honestly just looking at them thought better of it for the exact reasons you said. I have since installed a front hub w/dynamo and roller brakes and I also have installed a motor cutoff switch on the brake handle which kills power to the mid-drive and so far "knocks on wood" has worked out pretty well. It is definitely a different ride style than my super73 scout with dual piston hydraulic brakes. Those will look the wheels up and can stop almost on a dime. Just takes some adjusments in riding style is all.
 

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