RTUOTB $15 MTB plate yoke design (ready to use out of the box)

Daniel_Y · June 30, 2023, 1:10pm

RTUOTB Yoke:

I always wanted to try a laser cut and bent sheet metal yoke from Send Cut Send that was ready to use out of the box (RTUOTB). I knew it was possible, but never had the opportunity to try it. Luckily, Whit @Meriwether had a frame that was a great candidate for a plate yoke:

super short 395 CS
clearance for 2.6
52mm chainline
38t capacity

The tire and drivetrain constraints required a really long, thin, yoke, which I didn’t feel comfortable 3D printing.

This plate yoke was designed as a sheet metal part in Fusion360, mitered to the BB shell, then flattened. It is made from .25thk 4130 steel.

Send cut send has a CNC “bender”, which allows for really tight radii and good bend tolerances. The end result is that you get a ready-to-use-out-of-the-box yoke for $15.

It does require a tiny bit of filing to make the BB miter flush with the BB. It also helps to file down the excess material after welding on the CS. So… ALMOST ready to use out of the box .

Results:

The result was much better than I expected! Check out Whit’s photos and build:

I enlisted the help of Daniel Yang to help me with the engineering and 3D CAD. We were able to drop the CS length to 395mm all the way forward while fitting up to a 38t chainring. To achieve this we used a lasercut plate yoke on the driveside and a 3D printed yoke on the non-driveside. With these yokes the frame fits a 29×2.6 in the longest setting (415mm) and it’s up to Abe what he wants to squeeze in there in the shorter settings. Utilizing this technology is all new to me. I’ve always bent the plates by hand and i could never get as tight a bend as this one. 3D CAD allowed for compound 3D bends, and the 3D CAD just helped all the weirdness come together and make my time in the shop much more efficient.

.We were actually planning to use 3D printed yokes for both sides, but the customer would not budge on the 38t chainring, which forced us to switch to the plate yoke last min.

Files:

DXF:
plate yoke 38t A.dxf (5.2 KB)
Fusion Link: Fusion
Bends:

30deg up and down

image1507×547 52.1 KB

Bending information

.25thk 4130 bending rules: 4130 Chromoly Laser Cutting | SendCutSend
bending limitations: Sheet Metal Fabrication Bending and Forming Guidelines

terraformbicycles · June 30, 2023, 1:17pm

Really, really cool! I’ve wanted to use SCS for a while.

Meriweather gave me great advice when I inquired about making my own yoke plates. Cool to see something like this!

Daniel_Y · June 30, 2023, 1:25pm

Predecesors:

@ben.land101 $10 Yoke:

Ben’s yoke was the inspiration for my $15 yoke design. The only difference is that my CAD projects the BB shell onto the yoke, so it is “premitered”

Konga Yoke:

I am impressed die used to create the yoke’s shape:

Mikesbikester · June 30, 2023, 2:43pm

This is awesome!

Meriwether · June 30, 2023, 2:48pm

It was super nice to have this made, them bending it was key! I loaded both CS into the mitering fixture and just took that edge off the BB end and it was ready to weld. I did run the dynafile over the edges to chamfer those a bit, they are a little sharp. The taper from the T47 shell to the 3/4” rounded end is great and easy fitup as long as you can do a straight ~45 degree cut on the tubing.
Wish I had known about this option earlier!

Matt · June 30, 2023, 3:08pm

Very nice!

Matt · June 30, 2023, 3:10pm

Thank you for the die picture, it’s giving me good ideas!

gschwell · June 30, 2023, 3:50pm

Nice execution, I like the 1/2&1/2 combo of plate and tube.

The pre-miter is a good move, I’m going to do that on my next project. As a grinder and file guy, it’s a lot of material to remove at the BB.

I’ve been using .190" for my plates with success. I also do some rounding of edges to make it look a little more finished.

jcurr16 · January 14, 2026, 5:16am

This thread has motivated me to make my own send cut send yoke. I’m curious if anyone has any real strong opinions on the chainstay end connection being slotted or just a straight cut?

I sketched this slotted connection up for a gravel bike that’s in the works

And then was scheming a fat bike and went with the straight angle cut

I don’t know if there’s benefit to one or the other. I haven’t used slotted drop outs yet, and have been hesitant to do so out of fear of mucking my tubes up with an ugly slot. That’s my fear with the yoke as well, but maybe it’s time for me to get over it. Would love to hear from folks that have more experience than I

stevenshand · January 14, 2026, 12:36pm

I’d personally use the flat cut tube onto the plate rather than the slot but only because it’s a little less work.

Are you set on doing both sides rather than just the drive side?

We used almost exactly this system on one of our production models a few years ago. I’ll see if I can find some pics.

gschwell · January 14, 2026, 2:22pm

Straight would definitely be easier to weld. I’ve done the angled version on all my frames (including a fat bike), and it’s somewhat tricky welding at my skill level. I might try your straight design next time, seems like a nice option. The actual mitering of the angled stay is really easy with a disc sander.

jcurr16 · January 14, 2026, 8:43pm

I’m not married to doing it on both sides but I was thinking it would make my life a little bit easier and maximize tire clearance. I don’t have a chainstay jig, nor a tube bender. So the simpler the CS/BB connection is the better for me

jcurr16 · February 9, 2026, 4:17pm

Opted to go with the slotted symmetric style. I included a cutout and tab for the gusset to mate with the side plates and make alignment mostly dummy proof. Haven’t had a chance to get out for a ride yet, so hopefully it holds up

gschwell · February 9, 2026, 7:23pm

Looks great. Will you post a photo of the drive side?

jcurr16 · February 9, 2026, 10:59pm

This is on a fat bike with 27.5x4.5 tires (measure close to 4.35” at their widest) and a 32T chainring

gschwell · February 10, 2026, 2:55am

Looks great.