Positron400

Hi,

title says it all really, but I would like to more generally know ,if it is possible to just change any (within reason) recessed bolt-type calipper to a nut mounted version.
I would presume, one has to dissassemble a brake calipper and just change the screw?

BR
P!

JohnDThompson 

The mounting bolt on the front caliper is generally long enough to work as a nutted rear caliper. You'll need to source a longer mounting to replace the former rear caliper to mount it on the front. You also want a couple shouldered washes to fit in the recesses of the fork crown and brake bridge, like these:

https://www.rivbike.com/products/nylon-brake-insert

Kontact

This summarizes other options, including how to make a nutted frame into a recessed type, and just modifying the fork and swapping front and back calipers (remember to swap pad locations if you do):

https://sheldonbrown.com/calipers.html

A modification of the questionable swap suggestion by Sheldon to use recessed nut inside the crown would be to use a threaded standoff instead inside the fork crown and then a bolt in from the back of the crown to tighten it down. You would just hand tighten the standoff onto the caliper threads by holding it with pliers and rotating the brake, then put a wrench on the standoff and tightening a bolt from the rear until there's tension between the caliper and the bolt. Reverse to disassemble.

Of course, all the parts would have to fit just so to work, so it depends on the fork crown.

HillRider

I did a variation on this, using a pair of older nutted calipers on a frame made for recessed nuts. I had obtained a new frame designed for recessed nuts and had an older pair of long reach 105 DP nutted brakes I wanted to use. The frame and fork were both steel so the fork crown was narrow enough to work. Many newer carbon forks have crown too thick to have been usable.

I made "reducer bushings" for both the fork crown and rear brake bridge out of short recessed nuts by drilling out the internal threads with a 1/4" drill bit to clear the 6mm brake mounting bolts.

sbarner 

Be careful to select standoffs that are strong enough for this kind of use. I have used some on trophies that were of a cast material that I would never trust on something as critical as a front brake.

smd4

Why would anyone want to do this?

WizardOfBoz

Ummm. To paraphrase Pascal, "The heart has its reasons that know no reason?"

If you wanted this to work I think you could use a nut with a shoulder if you had a long enough bolt. Picture below. Even better? A spacer and a regular nylock nut, to keep the nut tension constant.

Positron400

I think I might've not properly explained what I would have liked to know. Allow me to clarify: The purpose of my question was not to modify a frame to accepted nutted calipers, but modify recessed calipers with a different nutted screw to make them fit on older type frames which were not built for recessed mounting.

Kontact

Understood. The other methods offered were just because you might not be able to do what you wish or realize that there are alternatives.

My last suggestion was an alternate way to modify the calipers and leave the frame intact.

Kontact

How would these work without drilling the frame and fork? Or, how are they different than the usual recessed nut?

Mr. 66

Yes, I have done that a few times. Here I exchanged a common bolt on these RX 100 calipers.

WizardOfBoz

So the current brake lever has a recess for the head of the bolt. Probably a socket head (allen wrench) bolt. If one wants to reverse directions of the bolt and nut so that a nut goes into the recess, one can
1) Put a long bolt through the frame in the opposite direction of the original bolt. This essentially leaves a stud sticking out of the frame. Put the bolt levers, spacers, and washers on as originally constructed. One is then left with a need for a nut that fits in the recess. One could use a socket head nut, but this would require some pretty exact setup of the bolt length. Or, one could use a nut like I pictured. The shoulder goes into the recess leaving the nut hex exposed for tightening.

I would add that I don't recommend this as the original design using a socket head cap screw (SCHS, aka an allen bolt) is probably stronger than the modified setup.

Going back to a question asked earlier, why is this change being contemplated?

HillRider

I recognized your request. I just added a way to do the opposite. BTW, you could modify your frame to accept recessed mount calipers rather easily. Lots of threads here on doing this.

Positron400

Because I ride a frame that does not accept recessed mounting, and comes with side-pull Weinmanns, i would like to switch out for double-pivot style calipers. However, my choice of nutted options is severly limited (barely any). Thus my inquiry.

Mr. 66

I took the bolt off a Tektro 556, for the RX 100 rebuild.

Kontact

Assuming that you didn't mean "brake lever", I'm still not following how you would use these nuts in frame holes that are no larger than the bolt diameter.. Which "recess" are you talking about?

Kontact

If your RX100 is dual pivot, that should be pretty easy to replace. The tougher problem is a replacement bolt/pivot for a single pivot brake caliper.

masi61

Tektro makes a variety of nutted dual pivot brakes. I'm not sure of the model numbers but if you keep looking online or on eBay they pop up at decent prices. There are also replacment nutted brake bolts that can be retrofitted to dual pivot Tektro brakes.

squirtdad

unless the frame a super special unicorn, it is super easy to put recessed dual pivot on the frame. the sheldon link above show how

steps are
1) enlarge the rear brake hole in the fork (I use drill and you just little bit of shavings, I say enlarge rather than drill out so people don't freak. use could do it with a small file, but the drill is faster.
2) take the rear brake from new set and use it in front with a long enough recessed bolt (easy get these)
3) put the front brake on tha back with nut

done and start enjoying the increase braking power

icemilkcoffee 

Tektro R539 is the mid reach version with nutted mount:

I don't see why anyone needs to be drilling out forks when these bolt on calipers are readily available.

If you want to convert your existing Shimano dual pivot brakes to nutted, there is the JTEK conversion bolt:
Jtek Tektro / Shimano pattern 70mm Dual Pivot Brake Bolt

Fredo76

Clarification noted.

Just wanted to point out anyway that old-style nutted calipers can be used with a recessed-nut fork (if the bolt is long enough), by using a bushing made from tubing with a 6mm inside diameter and a 8mm outside diameter, cut long enough to be just barely shy of protruding from the fork before the nut goes on.

oldschoolbike

If you can't find a suitable nutted donor, you can get this adapter made by JTek Engineering:

https://www.sjscycles.co.uk/brakes/j...rsion/?geoc=CA

I used this product to mount a pair of Centaur 11-speed dual pivot calipers on my treasured 1987 vintage Cyclops. The braking improvement over the original Record side-pulls is very impressive, and I didn't even scratch the paint on the frame, let alone drill or ream anything.

Research at the time suggested that the adapter would fit Dia-Compe and Taiwan-made Campagnolo dual pivot brakes. I can confirm that to be true by direct experiment. I think Tektro is making just about every dual pivot side-pull out there, including Shimano and Campagnolo.

Don't forget to swap the brake shoes when you pull the front-back caliper switch.

3alarmer 

...I have done this a couple of times. Those Tektro brakes work about as well as any other of the many dual pivot sidepull rim brakes. They come in the nutted version, like you see in a post above. And it's easy to remove the lettering with a little acetone, because it's just stenciled on there. If you don't already have a set of brakes, buying those is about your easiest and cheapest option. There are a lot of upgrades that are questionable. But dual pivot sidepull brakes, as an upgrade from single pivot, is not one of them.

ign1te

Here is a classic hex nut example that I use myself. Only front version available. Buy a metric treading tool to convert the front into a rear one.

Dia Compe dual pivot front

https://www.aliexpress.com/item/1005...500818021Dt68b