Does your current BB guide look worn? Have you replaced your shifter cables with good quality stainless steel (not galvanized) cables recently?

 

I haven't started anything yet. The bike probably came with stainless steel cables, 15 years ago, it wasn't a cheap bike. I just need to know if those plastic guides are usually replaced.

 

I have one bike with 160K miles on the same plastic cable guide, and my current ride has over 100K miles on the original plastic cable guide. No obvious wear issues and the shifting is fine. No need to replace unless the guide is somehow damaged.

 

I can't say those things are replaced for general maintenance if that's what you're asking.

Hesitation shifting to smaller cogs tells me there is friction somewhere. If cables haven't been changed in 15 years, I would change both cables and housings as well.

 

On a road bike, there shouldn't be a need to replace the BB cable guide. Friction is likely in the housing or shifters. Replace all the cables and housing with good quality SS cables, and clean the BB guide and avoid any sharp bends. I stick with Campy (what I use on all my road bikes) and Shimano cables on the mtn bikes. No harm in applying a light smear of grease through the guide.

 

I have had to replace one due to an impact, Campy groupsets come (or did come) with a guide that should fit most frames. I generally don't grease them because dirt gets in that area every ride, so I use dry lube instead.

 

My utility/touring bike needs some new parts after 15 years of use, so I'm planning a refit. I was looking for a new bottom bracket cable guide to add to my list of replacement parts, but these little doohickeys seem to be rare items nowadays. Have they been replaced by something better?

I have no trouble shifting the rear derailleur to a larger cog, but there's a moment of hesitation when I go the reverse direction. I keep the channel on the bb cable guide clean and lubricated, per the suggestion of a local bike mechanic, but it doesn't help.

This is the thing I refer to:

View attachment 506300

I have never worn one of these out. If you haven't replaced your cables in 15 years I'd say that is your problem. If you did need a cable guide they are certainly still around and any shop should have some

 

My utility/touring bike needs some new parts after 15 years of use, so I'm planning a refit. I was looking for a new bottom bracket cable guide to add to my list of replacement parts, but these little doohickeys seem to be rare items nowadays. Have they been replaced by something better?

I have no trouble shifting the rear derailleur to a larger cog, but there's a moment of hesitation when I go the reverse direction. I keep the channel on the bb cable guide clean and lubricated, per the suggestion of a local bike mechanic, but it doesn't help.

This is the thing I refer to:

View attachment 506300

rare, now?

I haven't replaced one or looked for one in years, but a quick google search shows them in stock

when I did replace it, it was just because I was replacing all the cables and housing. Not sure it really needed it, but it was such a low cost item, figured why not at the time. I'm pretty sure I kept the old one in my parts bin just in case.

Universal Cycles -- Shimano Bottom Bracket Cable Guide [Y66Y98600, Y66Y98610]

Shimano SM-SP18-T Bottom Bracket Cable Guide - Performance Bicycle

 

We have a bike coop nearby with many dozens of old frames and bikes hanging and many dozens of bins and piles of old parts to sort through which can be had for whatever one can afford to pay. Maybe there is something similar near you. Good luck in your search for your part. But as long as the part on your bike is intact, I would not think the material it is made of would have a change in it's friction qualities over time, if anything plastic would tend to harden and produce less friction? If the cables have cut into the part so they are being grabbed tightly by it, maybe re-shaping the grooves the cables ride in with a jeweler's file of a larger diameter than the cables would restore it's functionality, as long as there is enough material left in the part so it is not worn through and letting the cables rub the bottom-bracket itself. Again, good luck.

 

Update: the bike has completed its overhaul with new cables, casings, cassette, chain, and the worn middle chainring replaced and is now shifting as it should.

Unfortunately the only 130mm BC chainring I could locate is not intended for shifting, so the mechanic told me. So now I have a single 36t ring to go with the 11-34 cassette, and no front derailleur. Oh well, I barely used the granny ring and outer ring anyway and this gives me a low gear close enough to 1:1 to get up any hills here.

 

Nice that you are back on the road.