I replaced my shifter cables with new Jagwire Stainless Steel cables and was planning on changing my brake cables as well. A buddy told me they are different cables. True? if so, what cable is recommended. When shopping on Amazon and Ebay I saw no real differences???

The direct answer to your question is, "yes, there is a difference between Shimano brake cables and shift cables." There's a difference between brake and shift cables regardless of brand -- brake cables are typically thicker (1.2mm rings a bell to me) and have different cable ends than shift cables, which are usually thinner (1.0mm?).

Many people use the multi-packs you can get on Amazon and eBay, many people use only high-end stainless cables, and many people prefer to trust the quality of whatever the local bike shop carries (which is usuallly Jagwire). Most bike shops carry both standard and stainless varieties, so you usually have a few choices there.

Not sure I understand your question. Are you asking if shift and brake cables are different? If so I don't understand how anyone could not see that they are in fact very different.

Well, I haven't had the brake cables out to inspect them and have not done this before. The shift cable replacements were easy enough. I just didn't know the brake cables were different. Thanks for the confirmation and now I need to order the correct configuration to replace my brake cables.

Don, also be aware that Shimano compatible road bike brake cables and mountain bike/hybrid brake cables use different ends.
Based on your profile, you own both kinds.

Thanks! Yeah this is for my road bike! So thanks for that clarification

I think that on the very old bikes of the 70's that the cables were about the same diameter if not the same. But the terminus or whatever the proper word is for the thing on the end of the cable was different depending on whether it was to fit in a shifter or a brake lever.

When indexed shifting came along and particularly with STI's and their cousins, the shift cables got even narrower in diameter.

I might be speaking nonsense, someone else should double check what I'm spouting from just off the top of my head. <grin>

I would also recommend using the Jagwire Brake Housing from their top tier group as they are much less prone to compression sponginess. You'll notice a difference when switching from Shimano and others that the brakes will feel firmer and easier to modulate. Also, Shimano uses a 1.2mm shift cable and Jagwire plus some others use a 1.1mm. I've used both cables in JW or Shim housing and no issues so basically interchangeable.

Yes they are very different.

If I were buying new stuff I would go with Jagwire Elite Link kits for both brakes and shifters or at least the Pro Level and I would make sure I am getting the right stuff. Luckily your local shop can help you out both with getting the parts (if they don't already have them) and also with install. Buy local Billionaire Jeff Bezos does not need any more of your money, he is plenty rich without it plus he is useless when it comes to bike queries or fixing anything.

Always buy the best slick stainless (and ideally polished) cables and the highest quality housing for your bike as it will improve things quite a bit without costing a whole lot.

The inner cables are different and, crucially, the housings are of very different construction, shift housing being substantially weaker. Never use shift cable or housing for brake systems, ever.

Just to add an illustration to the above info, here are end differences in the cables (note, don't pay too much attention to the cable lengths shown in the bottom right. Most likely the cable you buy will be sufficiently long and you just cut to fit). You can get road or mountain specific brake cables, or you can buy universal brake cable that has the road (mushroom) and the mountain (barrel) configuration on each end and you cut off what you don't need.

The main change is that back then we used the same steel wound housing for brake cables and shifter cables. With indexed shifting came the new shifter housing with longitudinal wires. I don’t recall any change in cable widths.

Otto

When I first replaced the the shifter cable on my '78 Raleigh Competition GS, what I took off was quite a bit larger diameter. I don't think it was quite as big as the brake cable, but certainly not as small a diameter as what I replaced it with.

At the time I did this back circa 2010, there was a site talking about how the diameters changed over the progression from down tube friction shifters and just 5 speeds on the rear to more modern indexed shifting with more speeds on the rear.

Of course now that I need some backup I can't find the site or article I thought I'd read. So it's not a big worry one way or the other for me.

If it's of any help, I wrote in some detail about the shifter, brake cable, and housing standards - with pics and all.

It's clear that I was off with my thickness recollection above. I appreciate the resources listed giving the correct info!

Well, I switched to the linked housing from the cheap TRLREQ brand and it is the same for brake and shift cables and superior, mostly vastly, in other ways. Actuation is more precise, tight turns are possible, no housing ends are needed, the links are reusable and color combinations can be used to mark individual cable runs.

BTW unless you have a problem with yuor cables rusting, stainless cables are not better than galvanized cables. Galvanized cables are self lubricating and less brittle.

Simple. Buy a Shimano shift cable and a brake cable, Compare, The difference will be obvious

You could buy a 'universal' cable that had a brake terminus on one end and a shift terminus on the other end. Handy to carry as a spare on a long tour.

Well that's interesting. I wasn't aware of that or if I was then old age and dementia have addled my mind. <grin>

Since the bike was just acquired by me in 2010 it's probably very likely the cables weren't original to the bike made in 1978. Perhaps this better explains why they seemed the same size.

Please provide a link to this as I've never heard of it. The cable diameter is different, 1.6mm for brake and 1.1-1.2mm for shift. Explain how this would work. There are 'universal' brake cables that are mountain on one end and road on the other, and shift cables that are Campy on one end and Shimano/SRAM on the other...but a cable that doubles as both shift and brake? I doubt it.

This, and the size (1.2mm shfit vs 1.5mm for brakes) and the cable ends are different.

You want an internet link to something that was available 40+ years ago...

In the 10-speed, friction shift, single pivot brake, pre-mountain bike era, things were more forgiving. As were people.

You might also have to explain that 40 years ago, 10 speed was 5 on the rear times the 2 on the front.

Yeah, I can’t recall yea or nay, but it could totally work. Shifters (at least the thumb and DT shifters I have) can handle brake cable width and since all housings back then could handle it, too, why not have a combo brake/shift cable? Back then, the only shifter housing would usually be the 12” section (of brake cable housing) from chain stay stop to RD.