soyabean

Whenever I encounter vintage Trek/Specialized bikes, I notice they always have 5mm wound housing for both brake and shift.

At first I thought the last guy that worked on the bike lazily used brake housing for shift because it easy, or bought it from Walmart, but I am seeing it on vetted virgin barn finds that have never been repaired and all original.

Was this standard for manufacturers to use universal housing for their bikes then? Or done only on mid/low-end bikes to save on costs, inventory?

Unless someone can say otherwise, I can't see 5mm housing correct for shifter use because that just creates imprecise shifting. Brake housing expects a 1.5mm cable. There's simply just too much room in there for a 1.1mm shift cable to flay around, which is why 4mm compressionless housing is correct.

smd4

If you mean was coiled cable used for derailleurs, that's how I remember it. You can still find some images using it (below). It wasn't until later that the "SIS" compressionless cable with linear wires came along (which, in a twist, some of us now use for brakes). Back then, we didn't have long lengths of shift cable exiting our brake levers. The 10 or 12 inches of coiled cable at the derailleur didn't compress enough to cause any great loss in shifting accuracy.



You can still find some NOS with coiled cable housing:

MNBikeCommuter

Coiled housing worked just fine for friction derailleurs. One moved the shift lever until the shift was completed and the chatter died down.

roadcrankr

The Gore-Tex one came out in the 90's. Man, that worked great.
I kick myself for not buying loads of it. Not cheap. Wonder if anybody has a source.

smd4

Worked pretty damn good for indexed shifters, too.

streetsurfer

...your cable isn't seated in the ferrule properly. Your shifting will go away when it releases

Aubergine 

I'd say rather that the coiled housing was adequate at the time, but that even friction shifting is improved with compressionless housing.

slow rollin

I like running old coiled housing for my friction shift bikes. Can use the same stuff and I don't have to figure out which freaking ferrule I need......... Cuts easier too.

smd4

Not my bike, but thanks for noticing. The shifting will improve if he ever gets it seated properly.

smd4

Not all of us have these issues.

Rick

Rohloff shift cable housing is coiled with a high quality nylon liner. Rohloff states not to use any grease or lubricant also.

soyabean

Yes, I already called that out, how it can be the lazier choice.

As I don't do half-arsed repais, I just couldn't figure out why manufacturers made bikes chose to keep the same housing for both.

smd4

Because back in the day, that's all there was.

bboy314

It works fine for friction shifting, and also for 5/6 speed indexing. Once bikes starting using more gears (narrower cog spacing), the compressionless housing helped to make shifting more precise. It’s not so much the diameter, but the stiffness of compressionless housing that helps.

soyabean

I understand how frictionless levers are forgiving to even the worst housing setup, and similar could be said for vintage derailleurs where the indexing was on the derailleur.

I was just surprised to see the stock 5mm coil wound housing on vintage 8s groupsets. Yes I can't believe that actually used to work.

I'm one of those "keep it as original as possible" types, but I'm game for tossing out all new condition 5mm housing just to get proper 4mm in there.

smd4

And yet it did, your belief to the contrary notwithstanding. Either way, I never cared if something as mundane as a cable housing wasn't "period correct," especially if it looks nearly identical, but functions better.

soyabean

I've discovered that with proper 4mm housing, RD alignment can be eyeballed and would work fine.

With the larger 5mm housing, I have to use my DAG-3 on it. I rarely pull out this tool for dumpster finds.

Dumpster finds also only deserve used housing, brake and shift.

KCT1986

You may be seeing 5mm wound housing, but Shimano and Suntour had a different type of wound that were designated for index shifting. Wound is still used by Shimano on the lower speed groups even now, called OT-SIS40.

And the new special housing for the Shadow type RD is also wound, OT-RS900. This is used at the RD run only, so usually quite short & straight and should not have much of an effect.

Additionally, the early SP (linear) was 5mm, commonly used for SIS groups through 8 speed, called OT-SP50/51.

Here is Shimano current line-up.

Dan Burkhart 

A Rohloff is indexed in the hub rather than the shifter so a bit of compression in the housing doesn’t matter.

soyabean

I don't doubt there is shift-specific housing that is 5mm coil wound, but all the ones I've replaced look identical to cable housing, which I've verified by cross-section cutting them with a grinder to compare what's in them and ID and OD.

KCT1986

Shimano & Suntour included wound housing with their RD in the early index days, marked SIS or Accushift.

Bike OEMs and shops may have neglected to use the 'approved' housing (wrong color?). This is what you may be seeing.

Suntour, whos system was very sensitive to poor setup issued a tech doc to help. They didn't like linear housing, probably because of the poor cutting method being used.

Excerpt about housing.

soyabean

I heard about all of the above before but didn't suspect as much until I saw more and more virgin vintage bikes lacking 4mm housing.

I try to spend the least amount of time necessary to fully repair a bike for resale, that often means adjusting derailleurs/brakes just once by experience, any problems after that are reported by the buyer when they require aftersales support.

That was when I started to make sure all shift housing were modern compressionless and the RD complaints all stopped after that.

I'm rather generous with the housing at that large bend at the RD, I believe modern compressionlesses are better today than the time of the docs above.

Kontact 

My recollection is that MTBs in the early '90s had coaxial housing that was 5mm. Shimano currently calls it SP51. I think this preceded 4mm by several years.

I don't think bikes with relatively smooth cable runs have any trouble indexing with brake housing. And downtube index shifters don't require anything special for that short length at the RD.

JohnDThompson 

Compressionless derailleur cable housing only became necessary with the advent of indexed derailleur shifting, in the mid 80s. Prior to that, friction shifting worked fine with the same type of housing used on brake cables.

smd4

As I pointed out, early index derailleurs didn’t use compressionless housing.