Wait. Did I do this wrong?
 

Is this cable guide supposed to go under the heart? The second photo highlights the routing with the red line under the cable. Shifting has been fine as is, but it looks like the cable could be closer to the chainstay. Am I imagining that?


https://cimg9.ibsrv.net/gimg/bikefor...8f210d440.jpeg
https://cimg0.ibsrv.net/gimg/bikefor...281bddc87.jpeg

Vote for under.

Figure which way the cable tension is pulling the clamp, and what is supposed to be stopping the clamp from sliding.

The clamp should go under the heart to keep it from pulling up.

Agreed, I think it should be under to stop the clamp from sliding.

Thanks, all... Just needed the confirmation of what I was already thinking. Whoops!

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my recollection of these heart shaped no-slide pibbs is that manufacturers usually mount them so that the "lobes" of the heart perform the no-slide function

this pibb looks upside-down mounted to me which may have contributed to any confusion


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I've done way dumber.

Another vote for under or as close to the bb lug as possible. I’ve actually never seen a braze-on stop in the location. Bike manufacturer?

It’s the Campania I’ve been messing with for the past year or so, which is either a rebadged Fuji or made by Kawamura, not 100% sure either way. Gratuitous glamour shot:


https://cimg5.ibsrv.net/gimg/bikefor...e7eed317d.jpeg

I would leave it. If the band slips (it probably won't) then move it.

Remove the red line. It will snag on the big ring and throw your chain.

Before you decide on over/under, look at the FD cable. Would moving the band down make the housing bend on the FD cable too tight? I rarely (never?) see a pibb in that location. I doubt the cable tension is enough to move the band clamp.

None of my bikes have them and I shift quite frequently. No band movement.

I’ve never seen a cable stop that low on frame. I’ve seen lots of them that locate where the downtube shifter clamp is placed. Yours has one as well

https://cimg1.ibsrv.net/gimg/bikefor...21ae2abad.jpeg

I don’t think of them as some kind of anti-slip device but a locator. I suspect that the manufacturer of your bike intended them for the same thing.

Even if the stop is intended to act as an anti-slip device, using the point of the heart to keep the clamp from slipping makes no sense. You’d want the most contact available which means the top of the heart which provides to points of contact vs one. Bottom line: mount on top.

They are anti-slip devices. In this case, mounting the stop above the braze-on would do nothing. The force on that stop is upward. The force on a stop (or shifter band) at the top is downward.

So, I'll be contrary here.

That band on stop doesn't actually need the brazed on heart to keep it in place. On most bikes they stay on without one just fine.

I think the heart is there to show you where to put the stop, and you're supposed to mount it above it, just like you have it now.

It's a bit confusing because it's not the norm to put a braze on like that there at all, so I get the confusion here. But I think you have it right as-is.

Cable sits too high above the chainstay to be mounted above the heart. IMO, should be below. I like the story above about the heart being an anti-slip point. Actually, I'd like to believe that, it would be a sure-fire way to accomplish multiple goals: 1) Not negatively impacting the frame steel or paint because it's over-torqued to prevent slippage, 2) avoiding slip damage to the paint/tubes if it were to rattle loose, 3) additional design aesthetic, 4) Remove questions about where to install the lower cable guide to get correct cable height/tension over parallel to the chainstay. There may be even more advantages, these are just the blatantly obvious ones (to me, at least)

Well, given that I haven't had any negative effect on shifting performance, I'll just leave it as is and keep an eye on it. Thanks, everyone, for weighing in.

I recently saw someone's photo of a similar cable guide mounted under a similar pibb, so it got me thinking. Either way, it doesn't seem broke, so I won't fix it.

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btw -

T-Mar has posted as to which specific Japanese manufacturers have employed these heart-shaped no-slide bits

their presence can be a helpful clue in determining the identity of the actual maker on some Japanese produced frames/cycles

it is moot in this case since noobinsf already knows the two possible makers for the subject frame


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They would only be “anti-slip” if the clamp were very, very loose. Most of the time, the clamp is tight enough that the clamp won’t slip. Even if they were meant to keep the clamp from slipping, a clamp would rotate if it hit the point of the heart. That’s not going to have a good result.

Without a braze-on, a band like that will slip even if it's slightly loose, not "very, very". Even with the band pretty tight, when the derailleur seizes up, and you pull the lever, guess what happens.

Not in my experience. I have personally owned many bikes with that kind of band and worked on, literally, hundreds more. The clamp on the shifter doesn’t shift even when you are pulling on the lever to shift gears. The action of moving the levers cause more of a twisting action than the lower clamp will ever experience.

There is another Campania for sale that has the same heart shaped stop but the heart is oriented 180° to noobinsf’s bike. I still doubt that the function of the stop is to keep the clamp from sliding and is only meant for positioning.

I've seen a lot fewer, but I have seen them slip (including direct experience). In any event, by no known laws of physics could that braze-on stop that clamp from slipping in its current position, as implied in post 12.

Perhaps it was the first day on the job for the person that did the brazing of the lower "pibb"! The one for the shifter band was oriented with the "lobes" up so they did the same for the lower one :foo:. I'm wondering if the "heart" shape of the pibb was design specific for a proprietary set clamps that had corresponding cutouts :foo:? I'm going to say that it's my opinion that the SunTour clamp being used is designed to be mounted closer to the bottom bracket. I would mount the clamp so that the rim of the cable guide on the drive side was just barely above the bottom bracket. The upper edge of the clamp band might not even touch the pointy part of the pibb.

Usually the "heart shaped stop" was in fact meant to be paired with a clamp that had a sort of "diamond" or lozenge shape to the clamp, like your classic Campy NR, and the copies. In that case one of the clamp "points" fits right into the cleft of the Heart, sort of like a song lyric....I also never saw a stop for a BB cable guide like this Campania has, but I think this clamp is too "high and forward" on the down tube so your RD cable is riding high, just move the guide down nearer to the BB/DT joint: all will be fine

I can't say if this is what the pibb was designed for, but on my 1973 Nishiki it pairs perfectly with a Shimano 333 clamp (with the heart brazed on the other way around).

https://live.staticflickr.com/65535/...bf1fd476_c.jpg

The clamp has seen better days. It was original equipment on this bike.

You're right, THAT clamp is a Hot Mess!