BB Cable guides

[Dogtrousers]

From another thread

Over BB cables so that's my era

I was thinking about this when cleaning my filthy bike. My first drop-bar bike (a 60s era racing machine that was pretty worn out when I got it in the 70s) had over BB cable guides. I think every bike I've had since then has had under-BB guides. Not sure, but I think so.

Under the BB is guaranteed to be the muckiest possible place on the bike. Over BB brazed on guides look elegant but (I can't remember) I imagine are a bugger to clean and probably gather much crud. And I guess if they broke you would be stuck.

When did they change and why? Is this another thing that we should be demanding to be brought back because they were clearly much better (like wheel nuts, friction shifters and Capstan full strength)

 

[nonowt]

@midlife is your man for this kind of info, but I seem to remember a similar conversation over on Retrobike a while back and the general conclusion was that over BB guides disappeared pretty much completely by around 1981-82.

I guess one reason would be that it would be cheaper and quicker to drill a hole and bolt on a plastic under BB guide than cut, shape and braze-on steel over BB guides. Also frames and parts are becoming more minimalistic during this period and things are moving towards the aero trend. Imagine the air drag from an over the BB guide - it doesn't bare thinking about!

I have over BB guides on one of my bikes and I can confirm that it's much more of a pain to clean. The dirt gathers in the many little nooks that even a toothbrush won't reach.

 

[Cycleops]

My two year old Specialized has full length outers running under the B.B. so no probs with dirt.

 

[NickNick]

My two year old Specialized has full length outers running under the B.B. so no probs with dirt.

IS there any reason as to why gear & brake cables don't have outers over the full length of the bike? Is it a weight/cost issue or is there a mechanical performance reason?

 

[Cycleops]

I don’t have a answer for that but does mean if using full length outers they need to be supported along their length with clips so maybe roadies and others find this visually unacceptable. On my tourer/adventurer bike I don’t have a problem.

 

[MichaelW2]

Full outers are less precise than exposed cables but more resistant to wear and tear. Can you run a modern 12 speed using covered cables the whole length?
My Bob Jackson tourer has two braised on cable holes under the BB and the change in direction means that cables always wear and break at the same point. A longer, smoother transition in direction from a curved guide would be better.

 

[mjr]

Under the BB is guaranteed to be the muckiest possible place on the bike. Over BB brazed on guides look elegant but (I can't remember) I imagine are a bugger to clean and probably gather much crud. And I guess if they broke you would be stuck.

If you've mudguards and flaps, the inside of the chainstays just behind the mudguard seems to be muckier than under the BB... but as the rear cables go past there too, that's still not exactly a win.

If over BB guides broke, you might be able to do something with SA-style bolt-on pulley wheels or even clamping lengths of outer to the tubes between fulcrum clips.

 

[midlife]

I was around at the time of the change and there was never a convincing explanation apart from fashion trying to hide things away. Maybe aero might have been one reason but the aero Cinelli BB made me smile as planes use flaps to slow down lol

When we converted 5 to ten speed we slung the cable for the new front mech under the BB as it saved faffing about with a frame cable guide

 

[BalkanExpress]

My old Peugeot has one guide over the BB and one under ...very Cartesian

 

[BalkanExpress]

@midlife is your man for this kind of info, but I seem to remember a similar conversation over on Retrobike a while back and the general conclusion was that over BB guides disappeared pretty much completely by around 1981-82.

Was that the thread about dating frames? Very interesting it was too until it descended into a petty slanging match..which seems to be a regular occurance over there at the moment.

 

[midlife]

Was that the thread about dating frames? Very interesting it was too until it descended into a petty slanging match..which seems to be a regular occurance over there at the moment.

I'm on Retrobike too. Like most forums (including this one) it can get a bit catty, at which time I bow out. However it all pales into insignificance compared to LFGSS lol

 

[Illaveago]

If it was done to aid aerodynamics they seemed to have forgotten all about it by the time they got to the rear brake bridge and fitted a huge piece of angle iron as an air brake.

 

[midlife]

Here's the advert for the Elan in 1981, the description says it has under BB guides like very expensive frames.... In 1982 the cheaper Nuovo Record had under BB guides. The times they are a changin'

 

[biggs682]

I'm on Retrobike too. Like most forums (including this one) it can get a bit catty, at which time I bow out. However it all pales into insignificance compared to LFGSS lol

Now that is a harsh forum best left to the brave

 

[rogerzilla]

My circa 1982 Bob Griffin had over-BB cable guides. I had them removed as it's now a singlespeed. I thought them rather ugly.

MTBs often have all the cables routed along the top tube to keep them out of the mud. Sturmey-Archer used to be the same, with a "fulcrum clip" on the top tube (a fancy name for a clamp-on cable stop, and a brazed-on cable stop works perfectly well instead) and a pulley under the seat cluster. Nearly all the cable run was bare.