Modern V brakes on a vintage frame

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I came up with a way to run a modern rear V-brake (rim brake) on a vintage frame. My goal was to make it a modular bolt on set up without welding posts on the vintage frame. Anyhow, I tested them out last night and they work great. Pretty simple set up. I bought a 14mm split shaft collar (.551") and TIG welded a 10mm X 1.25 nut to it. On the side of the 10mm nut I TIG welded a .125" X .375" dia roll pin to be used as a clocking feature for the V-brake return spring. The 14mm split shaft collar matched the diameter of my 63 Schwinn frame tubing. However, any split shaft collar size could be substituted, standard or metric, to fit just about any frame. Check it out.
BTB-rear-brake-view-1.jpg

BTB-rear-brake-view-2.jpg

BTB-rear-brake-view-3.jpg
 
Where were you when I was trying to adapt a six speed, 24" MTB rim running a 24 x 3 tire,to my 26" Huffy frame!!
HAHAHAHAHAHAAA!!!! Awesome engineering, will probably have to steal your idea in the future.. :wink:

Cheers!
Dr. T
 
Ha Ha. Everyone kept telling me to just weld posts on my frame like modern bikes. I just had to do it differently. I haven't seen this set up before, but I wouldn't be surprised if someone else has done it in the past. The split shaft collars have a cool industrial look to them. I used the same technique for making my motor mounts attach to the frame.

Dr. Tankenstein said:
Where were you when I was trying to adapt a six speed, 24" MTB rim running a 24 x 3 tire,to my 26" Huffy frame!!
HAHAHAHAHAHAAA!!!! Awesome engineering, will probably have to steal your idea in the future.. :wink:

Cheers!
Dr. T
 
cman said:
Great idea. This looks like a very marketable product.

Thanks. Very cheap and pretty easy to make as well. I think the mounts cost me less than $10.00 to make for the pair. The split shaft collars were the bulk of the cost. Most of my time spent was dreaming up a clean way to do it.
 
Nice job, I went the hard way and welded the hoop off of a cheap front shock to the seat stay.
 
Thats just perfect! I have been wanting to use some Split collars for a light mount on truss rods now I have even more reason tho get some. Awesome!
 
very cool !!! and like cman said, looks like you could market something like that, maybe to the fixed gear crowd running brakeless.
 
XC204 said:
Thats just perfect! I have been wanting to use some Split collars for a light mount on truss rods now I have even more reason tho get some. Awesome!

Those split shaft collars have a high tortional and axial load rating as well. For a 1/2" - 9/16" I.D. split shaft collar the clamp rating is 1,400 lbs to either rotate the clamp or move it along it's axis by .010". So one clamp per brake lever is an estimated 2,800 lbs of compression force they can withstand before twisting. In other words, I'm thinking this is more than enough for the force that these brakes see at the pivot junction.
 
Awesome idea! I've never seen a set up like this, that I can remember. It looks as though you can even slide the brakes up and down to accomodate just about any size wheel that you choose!
Very Cool
THANKS!
 
Chainsaw said:
Awesome idea! I've never seen a set up like this, that I can remember. It looks as though you can even slide the brakes up and down to accomodate just about any size wheel that you choose!
Very Cool
THANKS!

Exactly. You can adjust them up or down, or rotate then as well to change your pad preload, contact plane, or loaded arm vector. You can also run them on the rear bottom of your frame vs. rear top. I was going to run this V brake down by my crank, but my vintage Schwinn crank was a little too narrow and would contact the brake arms. If you were running a wider crank you could hide the brake down low by the chain and make it less visible.
 
this is awesome. when/if I build a clunker, I'm going to do this. thanks.
 
Schwinn made a clamp on cantilever brakes back in the day.
The go pretty steep on the bay.
nice work......
 
Dowie Soetenga said:
Those split shaft collars have a high tortional and axial load rating as well. For a 1/2" - 9/16" I.D. split shaft collar the clamp rating is 1,400 lbs to either rotate the clamp or move it along it's axis by .010". So one clamp per brake lever is an estimated 2,800 lbs of compression force they can withstand before twisting. In other words, I'm thinking this is more than enough for the force that these brakes see at the pivot junction.
Do you have any concerns about high stresses in the seat stay tubing at the section where the collars are attached? You might experience some local buckling effects in the area where the clamping forces are concentrated. Probably won't be an issue on a heavy cruiser bike with thick ductile steel tubing but it might cause problems with something lighter.
Ask me how I know :roll:
 
2manybikes said:
Do you have any concerns about high stresses in the seat stay tubing at the section where the collars are attached? You might experience some local buckling effects in the area where the clamping forces are concentrated. Probably won't be an issue on a heavy cruiser bike with thick ductile steel tubing but it might cause problems with something lighter.
Ask me how I know :roll:
I thought about the same thing...but since I like the design, I would think that if you were to add a second clamp tig welded to the other side of the bolt, it would then isolate the torquing motion by dissipating the stress evenly to 2 clamps...thats if the second clamp doesn't get in the way of the brake movement. Thats my 32 cents... :mrgreen:
 
I think that properly sized the clamps should distribute the forces 360 deg. around the tube. The braise on or weld ons hit about 1/4 of the tube or less thus same force on smaller area and more stress/area . The clamps if too small would tend to crush the tube that could lead to failure. I think........
 
XC204 said:
I think that properly sized the clamps should distribute the forces 360 deg. around the tube. The braise on or weld ons hit about 1/4 of the tube or less thus same force on smaller area and more stress/area . The clamps if too small would tend to crush the tube that could lead to failure. I think........
I agree with you as far as the force being distributed 360 deg. , but you have to take in consideration that the post would have to be on top of the clamp not 1/2 -3/4 inch to the side. The torque stress then would be on the weld ( a twisting motion outwards when the brake is applied) ...with 2 clamps on both sides, the post is now centered. my 4 cents :mrgreen:
 
Cool idea, That'd be a great product to market, I know the V-brakes stop A LOT faster than the oldschool single bolt side pulls.
 

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