need a lil advice for caliper brakes when theres no mount

[heartlandcruisers]

Ok I am reaching out to my fellow rrbers for some advice I know you guys are geniuses and if anyone will know it will be you guys n gals but here is my dilemma I am currently building a sears spyder 20 inch for the rrbbo and I am considering doing a 5 speed conversion to it the issue I have is there is no mount on the fender bracket that goes across the rear downtubes to place a caliper brake. I considered drilling one but needed to know if there is any ideas to do something like this without compromising the bikes frame structure.
I do not know exactly what will be needed but the other issue is will a 5 speed wheel fit in a caster brake frame without chopping or bending the frame up? the bikes rather cheap so I am ok with some mods but I do not want to compromise the frames structural integrity
any ideas or advice?

 

[deorman]

I'm running an old Shimano 5-spd freewheel on a Huffy Good Vibrations coaster bike, by just spreading the dropouts by hand while installing the wheel, no permanent re-setting it just springs back when I take out the wheel. You may have to change the spacer and/or re-dish slightly, depending on original application of the wheel. as for the brake mount I have had some success by attaching a piece of right angle steel to fender mount holes.

 

[Wildcat]

I made this bracket from a couple pieces of scrap metal. The bike had holes, but the brakes needed to be at a different spot to reach the wheel. But it will work for what you need without drilling any holes in the frame:

Just cut out 2 pieces to size, check where the brake spindle should be, bolt up the plates and attach the brake. You can use a spacer on the spindle between the plates.

 

[heartlandcruisers]

I made this bracket from a couple pieces of scrap metal. The bike had holes, but the brakes needed to be at a different spot to reach the wheel. But it will work for what you need without drilling any holes in the frame:

View attachment 50785


View attachment 50786

Just cut out 2 pieces to size, check where the brake spindle should be, bolt up the plates and attach the brake. You can use a spacer on the spindle between the plates.

i like that idea I may use that one it looks nice n clean and no welding necessary thanks wildcat I am gonna try that

 

[Indyjps]

I welded in chainstay mounted v brakes to get around this issue. Theres always a way, still not sure why I chose the most difficult one.

Wildcats bracket looks good.

 

[Wildcat]

V brakes are much better at braking, especially if you are in the 100kg and above class!

 

[Bicycle808]

I agree that v-brakes are typically stronger than calipers, generally speaking. But, I wouldn't hesitate to drill the seatstay bridge; that's not really a load-bearing piece. It's more to just keep the rear triangle stiff. Drilling the hole won't cause any problems; if the bridge is totally rotted, drilling it would be a disaster but the frame would probably be toast in a scenario like that, anyway. Just remember, measure carefully, drill carefully, and use the intended brake as a guide in terms of the bit you use and if you need to drill the one side out wider if you're using a brake with a recessed nut (which seems highly unlikely, but i try and be thorough...)