Rear U-Brake - Specialized Rock Hopper (1987)

Hi all,

So I was lucky enough to be given a 1987 Yellow Rock Hopper, a great bike in it's day, and probably still better than most now. Problem is... It needs some work.

Now I'm not bad at mechanics I have done some basic work with cars and some fairly advance work with motorbikes, but I'll be damned if I can work out how to get this rear brake off (pics he http://imgur.com/a/MoRyd).

As you can see I have my work cut out for me as far as cosmetics go, but mechanically the rear brake is the only issue (it's completely seized up - It looks as though it has sat in the rain since 1987...). I need to take it off so that I can clean and lubricate the individual parts.

Alternatively, I could by new brakes (providing any new parts would fit), but I would still need to get these off somehow...

Has anyone ever had any experience with this type of brake or even better, bicycle? The callipers are spring based and removing the spring just reveals a hollow barrel which doesn't help to get the breaks off.

I'm starting to think that they can't be removed, and/or might be welded on....

If anyone has any info or advice, I would be incredibly grateful.
Thanks, W

On Sunday, February 22, 2015 at 5:56:53 PM UTC-5, Will wrote:
Hi all,

So I was lucky enough to be given a 1987 Yellow Rock Hopper, a great bike in it's day, and probably still better than most now. Problem is... It needs some work.

Now I'm not bad at mechanics I have done some basic work with cars and some fairly advance work with motorbikes, but I'll be damned if I can work out how to get this rear brake off (pics he http://imgur.com/a/MoRyd).

As you can see I have my work cut out for me as far as cosmetics go, but mechanically the rear brake is the only issue (it's completely seized up - It looks as though it has sat in the rain since 1987...). I need to take it off so that I can clean and lubricate the individual parts.

Alternatively, I could by new brakes (providing any new parts would fit), but I would still need to get these off somehow...

Has anyone ever had any experience with this type of brake or even better, bicycle? The callipers are spring based and removing the spring just reveals a hollow barrel which doesn't help to get the breaks off.

I'm starting to think that they can't be removed, and/or might be welded on...

If anyone has any info or advice, I would be incredibly grateful.
Thanks, W

Looks like tthe corrosion is so bad the calipers are stuck on. With the bolts removed from the mounting boss they should come right off.

I'd remove the wheel and then wigle the caliper arm whilst pulling on it to remove it.

Also, if someone really tightened the mounting bolts the boss may be deformed a bit and thus hindering removal.

Cheers

On Sun, 22 Feb 2015 14:56:51 -0800 (PST), Will
wrote:

Hi all,

So I was lucky enough to be given a 1987 Yellow Rock Hopper, a great bike in it's day, and probably still better than most now. Problem is... It needs some work.

Now I'm not bad at mechanics I have done some basic work with cars and some fairly advance work with motorbikes, but I'll be damned if I can work out how to get this rear brake off (pics he http://imgur.com/a/MoRyd).

As you can see I have my work cut out for me as far as cosmetics go, but mechanically the rear brake is the only issue (it's completely seized up - It looks as though it has sat in the rain since 1987...). I need to take it off so that I can clean and lubricate the individual parts.

Alternatively, I could by new brakes (providing any new parts would fit), but I would still need to get these off somehow...

Has anyone ever had any experience with this type of brake or even better, bicycle? The callipers are spring based and removing the spring just reveals a hollow barrel which doesn't help to get the breaks off.

I'm starting to think that they can't be removed, and/or might be welded on...

If anyone has any info or advice, I would be incredibly grateful.
Thanks, W

Take the two mounting bolts off and the brake arms will come off,
perhaps with a bit of help from a hammer. Exactly the same as
cantilever or Vee brakes.

The frame has brake mounting brackets, for want of a better word,
welded to it. You can cut or grind these off (carefully) and paint
over the results, if you want, and mount your brakes in a different
place.

See http://www.paulcomp.com/racer.htm
Note the two Allen head mounting bolts
--
Cheers,

John B.

On 2/22/2015 7:17 PM, Sir Ridesalot wrote:
On Sunday, February 22, 2015 at 5:56:53 PM UTC-5, Will wrote:
Hi all,

So I was lucky enough to be given a 1987 Yellow Rock Hopper, a great bike in it's day, and probably still better than most now. Problem is... It needs some work.

Now I'm not bad at mechanics I have done some basic work with cars and some fairly advance work with motorbikes, but I'll be damned if I can work out how to get this rear brake off (pics he http://imgur.com/a/MoRyd).

As you can see I have my work cut out for me as far as cosmetics go, but mechanically the rear brake is the only issue (it's completely seized up - It looks as though it has sat in the rain since 1987...). I need to take it off so that I can clean and lubricate the individual parts.

Alternatively, I could by new brakes (providing any new parts would fit), but I would still need to get these off somehow...

Has anyone ever had any experience with this type of brake or even better, bicycle? The callipers are spring based and removing the spring just reveals a hollow barrel which doesn't help to get the breaks off.

I'm starting to think that they can't be removed, and/or might be welded on...

If anyone has any info or advice, I would be incredibly grateful.
Thanks, W

Looks like tthe corrosion is so bad the calipers are stuck on. With the bolts removed from the mounting boss they should come right off.

I'd remove the wheel and then wigle the caliper arm whilst pulling on it to remove it.

Also, if someone really tightened the mounting bolts the boss may be deformed a bit and thus hindering removal.

Cheers

I agree with the corrosion guess. I've seen that happen with other
brakes, but not as badly. Those U-brakes mount where they get a
terrible soaking.

For cutting through corrosion like that, I like "Blaster" penetrating
oil. It seems to work better than "Liquid Wrench" IME. I'd plan on
lots of soaking time interspersed with lots of wiggling. And if worse
comes to worse, you can either cut the arms off the bosses and look for
replacements, or cut the bosses off as John suggests, then replace the
entire brake setup.

--
- Frank Krygowski

On Sunday, February 22, 2015 at 10:55:07 PM UTC-5, Frank Krygowski wrote:
On 2/22/2015 7:17 PM, Sir Ridesalot wrote:
On Sunday, February 22, 2015 at 5:56:53 PM UTC-5, Will wrote:
Hi all,

So I was lucky enough to be given a 1987 Yellow Rock Hopper, a great bike in it's day, and probably still better than most now. Problem is... It needs some work.

Now I'm not bad at mechanics I have done some basic work with cars and some fairly advance work with motorbikes, but I'll be damned if I can work out how to get this rear brake off (pics he http://imgur.com/a/MoRyd).

As you can see I have my work cut out for me as far as cosmetics go, but mechanically the rear brake is the only issue (it's completely seized up - It looks as though it has sat in the rain since 1987...). I need to take it off so that I can clean and lubricate the individual parts.

Alternatively, I could by new brakes (providing any new parts would fit), but I would still need to get these off somehow...

Has anyone ever had any experience with this type of brake or even better, bicycle? The callipers are spring based and removing the spring just reveals a hollow barrel which doesn't help to get the breaks off.

I'm starting to think that they can't be removed, and/or might be welded on...

If anyone has any info or advice, I would be incredibly grateful.
Thanks, W

Looks like tthe corrosion is so bad the calipers are stuck on. With the bolts removed from the mounting boss they should come right off.

I'd remove the wheel and then wigle the caliper arm whilst pulling on it to remove it.

Also, if someone really tightened the mounting bolts the boss may be deformed a bit and thus hindering removal.

Cheers

I agree with the corrosion guess. I've seen that happen with other
brakes, but not as badly. Those U-brakes mount where they get a
terrible soaking.

For cutting through corrosion like that, I like "Blaster" penetrating
oil. It seems to work better than "Liquid Wrench" IME. I'd plan on
lots of soaking time interspersed with lots of wiggling. And if worse
comes to worse, you can either cut the arms off the bosses and look for
replacements, or cut the bosses off as John suggests, then replace the
entire brake setup.

--
- Frank Krygowski

IIRC neither cantilevers nor V-brakes arms will fit on the U-brake studs and allow their pads to line up with the rim. If he cuts off those studs he'll have to either get new studs brazed on or use long reach brake calipers.

http://sheldonbrown.com/canti-u.html

"A U brake uses studs (bosses) attached to the front fork or frame above the rim, rather than below it, as with conventional cantilevers. U brakes use the same type and placement of studs as rolle-rcam brakes do"

"Adjusting U Brakes


First, remove the arms from the studs, and make sure the studs are free of rust. Coat the studs liberally with grease (this is VERY important!)

Install the arms with them at their maximum spread and tighten the bolts that hold them to the frame. This is how you set the springs. Only connect the transverse cable after this has been done.

A U brake uses a conventional brake lever, not the special lever with longer cable pull used with direct-pull brakes (V brakes). Set the transverse cable as short as possible for best braking, and adjust the cable and lever. (See the article about cables). There is usually a small setscrew on the side of one of the arms for fine adjustment of spring balance. Adjust the brake shoes. (See information on brake shoes in the lead article on rim brakes..)

Check the brake shoe adjustment frequently due to the decrease in mechanical advantage as the brake shoes wear, and their migrating higher and higher up on the rims. If you don't keep on top of the adjustment, they will eventually start rubbing on the tire sidewall. Many thousands of tires have been ruined by this."

Cheers

On 2/22/2015 4:56 PM, Will wrote:
Hi all,

So I was lucky enough to be given a 1987 Yellow Rock Hopper, a great bike in it's day, and probably still better than most now. Problem is... It needs some work.

Now I'm not bad at mechanics I have done some basic work with cars and some fairly advance work with motorbikes, but I'll be damned if I can work out how to get this rear brake off (pics he http://imgur.com/a/MoRyd).

As you can see I have my work cut out for me as far as cosmetics go, but mechanically the rear brake is the only issue (it's completely seized up - It looks as though it has sat in the rain since 1987...). I need to take it off so that I can clean and lubricate the individual parts.

Alternatively, I could by new brakes (providing any new parts would fit), but I would still need to get these off somehow...

Has anyone ever had any experience with this type of brake or even better, bicycle? The callipers are spring based and removing the spring just reveals a hollow barrel which doesn't help to get the breaks off.

I'm starting to think that they can't be removed, and/or might be welded on...

If anyone has any info or advice, I would be incredibly grateful.
Thanks, W


An annoyingly common problem.
Remove the bolts holding the arms to the frame. That should
relax the spring tension. If it doesn't, and if the sleeves
are completely stuck, you're in for some adventures.

The arms have a spring inside and pivot on a sleeve which
doesn't move in relation to the frame boss. The sleeve has
wrench flats and adjusts the spring tension, locked by the
main bolt. That's a point for corrosion. Slip a thin wrench
under the brake and pry the arms up, turning the sleeve with
a wrench. Penetrants such as Delco or PC Blaster can be helpful.

If it's extreme, U Brakes are a current product and not all
that expensive so destructive methods have a small downside
depending on the value of your time. If you do slit the
brake, take care not to damage the frame boss.

If you can get it apart, emery the rusted bosses and inside
bores of the sleeves, assemble with anti seize paste. Grease
the spring and inside parts. New main bolts, even in
stainless, are cheap too.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 2/23/2015 3:22 AM, Sir Ridesalot wrote:


IIRC neither cantilevers nor V-brakes arms will fit on the U-brake studs
and allow their pads to line up with the rim.

I assumed he'd have to search old bike shops, Ebay etc. to find old
U-brake arms. Not an easy task, I admit!


--
- Frank Krygowski

On 2/23/2015 1:17 PM, Frank Krygowski wrote:
On 2/23/2015 3:22 AM, Sir Ridesalot wrote:


IIRC neither cantilevers nor V-brakes arms will fit on the U-brake studs
and allow their pads to line up with the rim.

I assumed he'd have to search old bike shops, Ebay etc. to find old
U-brake arms. Not an easy task, I admit!

But I now see that Andrew says they're available as current production.


--
- Frank Krygowski

Frank Krygowski wrote:
:On 2/23/2015 1:17 PM, Frank Krygowski wrote:
: On 2/23/2015 3:22 AM, Sir Ridesalot wrote:
:
:
: IIRC neither cantilevers nor V-brakes arms will fit on the U-brake studs
: and allow their pads to line up with the rim.
:
: I assumed he'd have to search old bike shops, Ebay etc. to find old
: U-brake arms. Not an easy task, I admit!

:But I now see that Andrew says they're available as current production.

They're still used on BMX bikes.


--
sig 102

On Monday, 23 February 2015 19:01:27 UTC, David Scheidt wrote:
Frank Krygowski wrote:
:On 2/23/2015 1:17 PM, Frank Krygowski wrote:
: On 2/23/2015 3:22 AM, Sir Ridesalot wrote:
:
:
: IIRC neither cantilevers nor V-brakes arms will fit on the U-brake studs
: and allow their pads to line up with the rim.
:
: I assumed he'd have to search old bike shops, Ebay etc. to find old
: U-brake arms. Not an easy task, I admit!

:But I now see that Andrew says they're available as current production.

They're still used on BMX bikes.


--
sig 102

Thanks for the advice everyone! I have ordered some PB Blaster, and hopefully a thorough soaking with that will loosen them up and then I could possibly knock them down a bit with a rubber mallet. As you have all noticed, the corrosion is pretty bad so it may be the case that I'll have to take more extreme measures.

I did try to emery the bolt, but it's just to tight to do it properly or for it to have any effect.

Great to hear that I can get a replacement brake, I had worried that I would have to search for the same brakes.

The PB blaster should be here tomorrow so hopefully that will yield some results.

Thanks again for the advice. It's much appreciated.

W