Stainless Steel Braze-ons

[9494arnold]

How about getting your tame framebuilder to run the cables inside the top tube?

Or do away with stops altogether and run a continuous cable held down by plastic cable clips?
(I ran a front changer from a bar end like this on a frame that only had one gear lever boss for years)

Or do that but just have the rings to run the cable through (I've seen secondhand chain rollers used for this)

[robc02]

How about getting your tame framebuilder to run the cables inside the top tube?

I'm not quite sure how this is done. Is there a tube running inside the top tube to act as a cable outer casing? If so, what happens when it gets clogged/worn/corroded (if metal) etc? However its done, I think I'd prefer the cables outside where I can easily get at them for maintenance.

Or do away with stops altogether and run a continuous cable held down by plastic cable clips?

That's my 4th option, but with stainless steel clips, and the way it was originally done on this frame. It's probably due to my carelessness, but I find this tends to result in a lot of scuffing of the the top tube and accumulation of sweat around the clips and under the cable encouraging corrosion.

Or do that but just have the rings to run the cable through

This one of my preferred options but with stainless guides as I've had plain steel ones rust away.

[Brucey]

with clips, you can protect the paintwork beneath by using clear self-adhesive film; a length under the cable and a turn around the tube beneath each clip. When it starts to look tatty, you can replace it.

cheers

[robc02]

with clips, you can protect the paintwork beneath by using clear self-adhesive film; a length under the cable and a turn around the tube beneath each clip. When it starts to look tatty, you can replace it.

cheers

...or I could just be more careful!

The clips method does have the benefit of being completely removable if necessary for proper cleaning, and doesn't have the sharp edges and crevices for corrosion to take hold. For these reasons I wouldn't rule it out, however, I was hoping that stainless braze-ons would give me a tidy, efficient and near corrosion free alternative.

[robc02]

For a bare wire installation, I'd suggest that you can use Jagwire cable ferrules; they are difficult to find but they have a fat alloy body (with a liner tube for smooth operation) and enough meat in them that you can turn a ~5mm long spigot into them any diameter from ~4mm to ~6.5mm.

Are these the type you have in mind?

I've obtained some 8mm OD grade 303 stainless rod that is machining nicely, so I will make my own fittings. I just have to decide whether to make the brake cables fit directly or via ferrules.

I'll also make a gear cable guide for the chainstay but will probably use a ferrule on that. I didn't explain earlier but I'm preparing an old Woodrup frame for refinishing. It currently has rear derailleur cable guides on top of BB and chainstay, and a front cable stop on the downtube next to the BB. I've decided to route both cables under the BB so need to relocate the chainstay stop. I'm also adding bottle cage bosses, mudguard bosses on rear bridges and maybe under the fork crown, and down tube gear lever bosses. I'll be using Ergo shifters but the bosses give more flexibility for the future.

[Brucey]

yup, they look like the same ferrules as I have used.

cheers

[531colin]

I finally got some daylight, but it was getting dark fast, so apologies for the dirty bikes and filthy cable stops, these are literally as they were torched off the frame.
Photos are the cable stops I ground from the head and plain shaft of M10 A2 bolts; brazed to the top tube and re-sprayed by Bob Jackson, and silver soldered and hand-painted by me. I didn't bother to paint the whole stops, I just wanted to ensure the joint was covered......you can see the paint chipping off the sharp edges on the Jackson respray. I couldn't see any rust on the frames, I think the gap between cable and frame lessens paint damage.
The loose stops are made from M5 hex. bolt heads as the "base" with the head of M5 cap head screws brazed on; drilled and slotted for cable stops, tapped for barrel adjuster, brass tube added for BB and chainstay cable guide. (this with 3 temperatures going on.....brazing for the bolt head to bolt head joint, high temperature silver for the tube, low temperature silver to attach to the frame)

[pwa]

I gave up on steel frames (which I otherwise like) because of repeated rusting problems around the forward cable stop beneath the top tube. The bloke at Argos Racing Cycles blamed my especially corrosive sweat, and that area is certainly where sweat from my face tends to land. Parts of the frame closer to the ground do not rust in the same way, so it cannot be to do with road salt.

I believe Thorn use stainless bits and pieces on some of their frames, so I expect it helps.

[robc02]

Colin, thanks for the photos - I think we can assume you don't have a corrosion problem! I notice you chose to seat your cables directly in the stop, rather than use ferrules. Was there any particular reason for that?

I have now made some stops, and test fitted one of them to an old frame tube - as much to make sure my flux worked with the stainless steel as anything. At the moment they aren't slotted, but that might change. I'm waiting for some sealed gear cable ferrules to arrive before I finalise everything.

[robc02]

I gave up on steel frames (which I otherwise like) because of repeated rusting problems around the forward cable stop beneath the top tube.

That's similar to the problem I've had and the reason for this thread.

At one point I decided to go with aluminium frames instead, but still suffered corrosion around every attachment point - cable stops, bottle mounts, forkends etc. I realised I'd just swapped one problem for another, very similar, one. I got that frame stripped and anodised and it seems to have solved the problem, though the anodising shows every blemish in the metalwork, some of which appeared to have been there since the frame was made and the manufacturer was happy to hide under the paintwork!

One of the things I like about steel frames is that I can readily carry out these kind of repairs and modifications myself.

[531colin]

No corrosion that I can see in around 15 years with stainless cable stops. The original (mild?) stops were toast in much less time than that.......as you may have noticed, I'm not an assiduous cleaner of bicycles!
Re. ferrules, I don't think I have ever bothered using them on regular spiral brake outer (except on an alloy frame where the stops were drilled for big ferrules)
Index gear outer is different, of course.
Flux....I use Tenacity 5, apparently "designed" for stainless, but its the only flux I have ever used for silver/braze.

[robc02]

Flux....I use Tenacity 5, apparently "designed" for stainless, but its the only flux I have ever used for silver/braze.

The Flux I used was a pot of SIF flux labelled "Silver Solder" (just about visible) that I bought in the 1980s as I recall! I read that a special flux may be needed for stainless (SIF do one) and wouldn't have been surprised if mine it hadn't worked. As it turned out it worked perfectly.

[Brucey]

there are several reasons for using the ferrules I suggested;

1) those ferrules have a liner in them so run smoothly even if the cable makes a slight angle to the ferrule
2) the housing is better supported inside the ferrule because they have a square-bottomed hole in them
3) the housing is better held in alignment as it enters the fitting
4) the fitting itself can be clearance drilled at ~ 5.0mm dia so can accept either housing (for a full housing run) or used with shouldered ferrules (for a bare cable run).

So they are certainly a more flexible approach if you can't make your mind up which kind of cable run you want, and if you use a bare cable run, there is little or none of that slight groinching sensation you get when the cable enters a slightly angled housing end.

The flux might go off if it gets damp enough for long enough... but if you try a testpiece you can soon tell if you are in trouble that way or not before you do the job on the frameset.

cheers

[531colin]

Look what I found, while looking for something else.......http://www.llewellynbikes.com/HTML/framebuildersuppliescontent/FramePart%20Data%20Sheets/Limpet%20top%20tube%20brake%20stop%20data%20sheet.pdf

[FarOeuf]

I believe Thorn use stainless bits and pieces on some of their frames, so I expect it helps.

One of the reasons I sent my Thorn back was the paint flaked off most of the braze-ons (on day one). They said the braze-ons are stainless steel, and that's why the paint doesn't adhere properly. And once the paint is flaking off you end up with exposed steel which does rust.