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-   -   Plastic guides for BB shell? (https://www.bikeforums.net/classic-vintage/1114208-plastic-guides-bb-shell.html)

1987 07-10-17 04:17 AM

Plastic guides for BB shell?
 
What are these plastic thingies called?
And where can I get them or similar items to reduce ware and friction on BB shell?
Is there some sturdy teflon tube available for making your own?

http://i.imgur.com/G3Mb3WQl.jpg?3

Chombi1 07-10-17 04:43 AM

Those small plastic (and sometimes rubber) donuts are used to protect a bike's frame from getting scratched by bare cables slapping or rubbing against them. They are not really for reducing friction between the cable and the frame. They might protect the paint at the openings of the cable guides, but they do not really help that much to reduce friction or protect the paint from cable abrasion on the rest of the cable guides length. If you want to reduce friction between the cables and the bottom bracket cable guides, you should use a section of plastic tubing that you can pull out from brake cable casings that have them. Cut the plastic tubing just a little longer than the length of the cable guide so it it sticks out a couple of millimeters from the ends of the guides that will keep the cables from contacting the surface of the guide and slide against the much more slippery surface of the plastic tubing.
I recently did that on my last Italian steel bike build and it works pretty good. I was able to get the tubing from cable casing scraps that I had from cutting my brake cable casings to length for my brake system installation.

juvela 07-10-17 05:46 AM

1 Attachment(s)
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Juy offered them as well:

qcpmsame 07-10-17 05:56 AM

If you just want the little doughnuts, they can be purchased either in the cable sets, or individually. Jagwire, Shimano, etc., have them available. I try to stockpile them when they are included in the prepackaged cable kits, they harden and crumble over time so a few extras are welcome. One use for them is as a form of seal where cables run into the frame tubing, also. Not the best, but it is nice to have if you are ride in the rain or gritty, dusty roads a lot.

The inner cable from a housing that [MENTION=426321]Chombi1[/MENTION] recommended:thumb:, is the best idea I have received in a while, when I asked here about finding some small diameter tubing for my Tommasini this was recommended to me. No cost, works great and does the job with no fuss or muss.

Bill

due ruote 07-10-17 09:07 AM

Re: the brake housing idea - I have heard the criticism that the tube provides a place for moisture and grit to collect and potentially corrode the cable. Decide for yourself; I suppose it's worth considering. Obviously to a great extent it will depend on how/where/under what conditions you ride your bike.

texaspandj 07-10-17 09:13 AM


Originally Posted by Chombi1 (Post 19707681)
Those small plastic (and sometimes rubber) donuts are used to protect a bike's frame from getting scratched by bare cables slapping or rubbing against them. They are not really for reducing friction between the cable and the frame. They might protect the paint at the openings of the cable guides, but they do not really help that much to reduce friction or protect the paint from cable abrasion on the rest of the cable guides length. If you want to reduce friction between the cables and the bottom bracket cable guides, you should use a section of plastic tubing that you can pull out from brake cable casings that have them. Cut the plastic tubing just a little longer than the length of the cable guide so it it sticks out a couple of millimeters from the ends of the guides that will keep the cables from contacting the surface of the guide and slide against the much more slippery surface of the plastic tubing.
I recently did that on my last Italian steel bike build and it works pretty good. I was able to get the tubing from cable casing scraps that I had from cutting my brake cable casings to length for my brake system installation.

Good idea, definitely doing that next build. Thanks.

SJX426 07-10-17 09:20 AM


Originally Posted by due ruote (Post 19708148)
Re: the brake housing idea - I have heard the criticism that the tube provides a place for moisture and grit to collect and potentially corrode the cable. Decide for yourself; I suppose it's worth considering. Obviously to a great extent it will depend on how/where/under what conditions you ride your bike.

if you are using SS cables, it is not a problem. Alternatively, you can always shoot it with WD-40 periodically.
[IMG]https://farm6.staticflickr.com/5518/...882eec6b_k.jpgP1000536, on Flickr[/IMG]

gugie 07-10-17 09:28 AM

I think you're looking for one of these?

https://cdn.shopify.com/s/files/1/03...G?v=1470513973

Can be had here and other places.

Drill and tap an M5 hole in your bottom bracket, easy peasy. I use them all the time.

1987 07-10-17 09:31 AM


Originally Posted by Chombi1 (Post 19707681)
Those small plastic (and sometimes rubber) donuts are used to protect a bike's frame from getting scratched by bare cables slapping or rubbing against them. They are not really for reducing friction between the cable and the frame. They might protect the paint at the openings of the cable guides, but they do not really help that much to reduce friction or protect the paint from cable abrasion on the rest of the cable guides length. If you want to reduce friction between the cables and the bottom bracket cable guides, you should use a section of plastic tubing that you can pull out from brake cable casings that have them. Cut the plastic tubing just a little longer than the length of the cable guide so it it sticks out a couple of millimeters from the ends of the guides that will keep the cables from contacting the surface of the guide and slide against the much more slippery surface of the plastic tubing.
I recently did that on my last Italian steel bike build and it works pretty good. I was able to get the tubing from cable casing scraps that I had from cutting my brake cable casings to length for my brake system installation.

Thanks

I have actually never bought new brake cables as a kit. Just by the foot.

But I can't find the "doughnuts" sold separately.
SJS cycles carries a big inventory of parts, but I can't find any:
https://www.sjscycles.co.uk/gear-spares-other/

These doughnuts must have some more technically correct term.

Yes, I am aware of the brake cable housing sleeve trick.

1987 07-10-17 09:35 AM


Originally Posted by gugie (Post 19708208)
I think you're looking for one of these?

...

Can be had here and other places.

Drill and tap an M5 hole in your bottom bracket, easy peasy. I use them all the time.

Great idea. But not for my Cinelli SC :innocent:

The Golden Boy 07-10-17 10:33 AM


Originally Posted by Chombi1 (Post 19707681)
Those small plastic (and sometimes rubber) donuts are used to protect a bike's frame from getting scratched by bare cables slapping or rubbing against them. They are not really for reducing friction between the cable and the frame. They might protect the paint at the openings of the cable guides, but they do not really help that much to reduce friction or protect the paint from cable abrasion on the rest of the cable guides length. If you want to reduce friction between the cables and the bottom bracket cable guides, you should use a section of plastic tubing that you can pull out from brake cable casings that have them.

I think you guys are talking about two different things. The things he's referring to look like plastic ferrules that would partially fit into the metal guide. If you were to look at it from the side it would look like a T.

SJX426 07-10-17 10:37 AM


Originally Posted by The Golden Boy (Post 19708407)
I think you guys are talking about two different things. The things he's referring to look like plastic ferrules that would partially fit into the metal guide. If you were to look at it from the side it would look like a T.

Actually, I noticed that but.... didn't think it was a great solution because the cable still rides on the BB shell. If a more complete solution exists, it would be to use the liner.

The Golden Boy 07-10-17 10:44 AM


Originally Posted by SJX426 (Post 19708421)
Actually, I noticed that but.... didn't think it was a great solution because the cable still rides on the BB shell. If a more complete solution exists, it would be to use the liner.

Yeah. The liner protects it all along.

qcpmsame 07-10-17 11:34 AM

Here is a link for Hudz rubber donuts at Amazon, cable liner is also available. https://www.amazon.com/Hudz-HiTech-C...07865&sr=1-248

Many contemporary bikes with exposed rear brake cables have them in place. For what you are wanting the inner liner will work better, if you don't have any cable pieces, check with an LBS or Co-op for drops or old cables you can pull the liners out from. If you are in bad need of some liner, shoot me a PM and I'll strip out a decent length from some drops I have in the spares and send it to you. Looks like you have a pretty nice bike there.

I have stainless steel cables on all three bikes, and things get cleaned out regularly, including the liner sections beneath the BB shell of my Tommasini. Its better than letting the Derailleur cables saw on the BB shell.

Bill

1987 07-10-17 01:12 PM


Originally Posted by qcpmsame (Post 19708612)
Here is a link for Hudz rubber donuts at Amazon, cable liner is also available. https://www.amazon.com/Hudz-HiTech-C...07865&sr=1-248

Many contemporary bikes with exposed rear brake cables have them in place. For what you are wanting the inner liner will work better, if you don't have any cable pieces, check with an LBS or Co-op for drops or old cables you can pull the liners out from. If you are in bad need of some liner, shoot me a PM and I'll strip out a decent length from some drops I have in the spares and send it to you. Looks like you have a pretty nice bike there.

I have stainless steel cables on all three bikes, and things get cleaned out regularly, including the liner sections beneath the BB shell of my Tommasini. Its better than letting the Derailleur cables saw on the BB shell.

Bill

Thanks. Most kind of you! But I live on the other side of the pond.
Some short cable drops should not be a problem to find around here.

qcpmsame 07-10-17 03:03 PM

If you do need some just let me know, but it wouldn't be my first mailing across the puddle. I think you'll find the liner works very nicely. I got the idea from another C&V regular, last spring. That looks like a nice BB shell, I don't blame you for wanting to protect it from having the cables cut into it.

One other item that could keep the cables off the metal of the guides is the plastic insert seal, that slides into the cable ferrules, with the long tube off the end. Slip the tail in the guide then insert the cable through them. But this won't be a freebee like the liner will.:innocent:

jiangshi 07-10-17 03:55 PM

What the OP is looking for is no longer available. I have never seen them on anything other than a mid 80's Cinelli SC.

I would just use teflon cable liner if I didn't have the originals.

1987 07-11-17 05:39 AM


Originally Posted by jiangshi (Post 19709328)
What the OP is looking for is no longer available. I have never seen them on anything other than a mid 80's Cinelli SC.

I would just use teflon cable liner if I didn't have the originals.

Looks like I will have to buy a 3D printer.


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