awhitebear

Hi everyone,

First of all its not drilling a new hole entirely... its basically widening a threaded hole so a long drop brake caliper can fit. I bought a used bike frame the other day and it was originally stocked with disc brakes. I want to turn this into a pretty long distance tourer and I already have wheels which aren't disk compatible I intended to use. Also I'm not overly keen on reinstalling discs, mostly because I want something low maintenance on long tours and also because I have a budget/I already have parts.

So basically I'm thinking of widening the hole where you would usually mount a rear brake on that little cross section (not sure of the name) but I thought it could also be a terrible idea. The frame is Reynolds 725 steel, and I was also wondering as the hubs on my wheels are a little narrower would there be any shifting problems? if there were would I be best just forgetting the idea and saving up for some new wheels?

Thanks

Jamminatrix

It depends on the frame, but generally speaking, the bridge between the seat stays serves little/no structural purposes except to offer a place for the rear brake to mount. Many disc brake frames do not even have bracing between the stays.

I would be more concerned about how much material is left surrounding the brake bolt after drilling it out - assuming you remove a lot of material.

Johnny Mullet

I drilled a hole in the rear brake/reflector mount and also made the front fork hole bigger to mount caliper style brakes on my Huffy commuter when I did a 700c wheel conversion and had no issues at all...........

Cross Creek

Are you drilling both sides of the brake bridge or just opening the back (actually front—the side facing the seat tube) side for the recessed nut? I've done that before with no problems, but I used progressively larger bits in small increments, turned the chuck by hand, and the brake bridge was large enough diameter to support the bigger opening.

Bezalel

What exactly do you have. Most threaded brake (or fender) bridges are made by adding a rivnut to an old style bridge. Removing the rivnut will allow you to mount a nutted brake.

CliffordK

It should be ok. Be careful that the hole is centered.

Make sure your brake callipers have half round washers that match the curvature of the brake bridge.

awhitebear

Hi,

Thanks for the replies its actually the side facing away from the seat tube, it probably needs a millimeter take away roughly, the hole at the back is actually wide enough to take the bolt but probably not the recessed nut, I'm going to get a set of brakes with just a hex bolt so hopefully it should be wide enough. it also has a lip kind of around it giving it a bit of extra strength.

I think I'll probably give it a go progressively after I order the brakes.

Thanks everyone.


R

rawly old

By all means, get out there a put that bike thru some close-order drill. It develops
discipline. Soon your bike will be more obedient than ever.

FastJake

I was initially concerned but after seeing the picture, go ahead and drill it. Just make sure you buy brakes with the correct reach.

Cross Creek

That brake bridge looks like it's already set up for the M6 bolt on caliper brakes. Are you sure it's not just paint making the hole too tight? Possibly running a small rat tail file through it (carefully) a few times will take care of the problem.