Unca_Sam

I rode some gravel with the kids yesterday and noticed a rubbing sound at higher speed from the rear. I diagnosed it as the derailleur cable rubbing on the tire knobs. I have a 26x2.1 tire mounted in the frame, with plenty of space for wider, frame-wise. The bicycle sold with 2.0 tires, but has been through a wringer. I'm wondering if a different BB cable guide is the answer.

Cable is around 1 cm from chainstay centerline.

Current bottom bracket guide. Single bolt hole.

trailangel

Maybe the guide can be adjusted. Loosen the bolt and see if you can push it more to the drive side. If not, take the guide off and file a slot in the plastic so you can move it over.

Crankycrank

Easiest possible solution is to just get a different, wider cable guide. Example here. https://blueskycycling.com/products/...yABEgKbs_D_BwE

Unca_Sam

That's what I was thinking. The bike was a mishmash when I bought it, and it's possible that the original guide was lost. I'll have to see which LBS has one since I'm not interested in paying shipping for one of those.

Retro Grouch 

Probably going to be easier find a narrower tire than to find a wider cable guide that fits.

Moe Zhoost

Well if you can't find a wider one, perhaps you can modify the one you have. Enlarge the slot so that you can move it a bit further to the drive side. It doesn't look like you need much. On the other hand, if you are looking for an excuse to buy a 3D printer, this may be it.

Unca_Sam

I'm not sure it'd do much. I have the sp-17-t in my online cart, which seems like a great option. It looks like it could give me 5-10 mm to the right, which is all I need. I'd love measurements if anyone has them.



There aren't many choices for these out there. I had no idea generic BB guides were falling out of favor!

Andrew R Stewart 

Poor cable routing on that bike. Much like our second tandem had. Until I brazed on different cable stops and guides (and then had a repaint) my solution was to make a small Al plate mounted to the chainstay bridge's boss and extended to the drive side stay. The plate had a second hole located under the stay that held a small bolt that had a through hole drilled through it. The cable went through this bolt's hole and thus took a dog leg away from the tire (in my case it was in the other direction, away from the granny ring). Here's a poor shot of this arrangement. Andy

grizzly59

Check the cablestop on the chainstay near the RD. Angle of the cable doesn't look right.

Unca_Sam

As in I skipped it? It was seated properly. I took it apart this morning because I've been meaning to change the cable for the shifters to lengthen them a little.

I also wanted to measure the bolt to cable distance so if anyone chimes in with measurements of the blue one, I can estimate if it'll shift the cable far enough right. My son lost the damn thing though.

Unca_Sam

Found it! The cable paths start 20mm apart, with the bolt hole precisely centered at about 10mm from each.

Unca_Sam

Does anyone have the newer shimano style to measure, or adjustable like the campy anti-friction guide?

Campagnolo anti-friction bottom bracket cable guide.

Miele Man

Can you cut a slot in the existing cable guide so that the entire cable guide can be moved further?

Or can you drill another hole in the bottom bracket and move the existing cable guide to the new hole?

Cheers

bldegle2

https://www.ebay.com/itm/Shimano-SM-...IAAOSwTZhbt-aj new guide on the cheap with extra holes. If you can't afford the $5, then try and redo the one you have with some creative drilling of the guide, NOT the frame...

Unca_Sam

*sigh. Now there's one with "free" shipping (it's priced $3 more than other sellers that charge, still not bad).
I've already ordered the Campagnolo bracket from Modern Bike, along with other supplies. When I get it next week, I can share if it worked. FWIW, I put the old guide on and measured a full centimeter to the right, and that line would keep the cable under the chainstay.

In the meantime I'll get out the touch up paint to fix the all off the paint that wore off the bottom of the chainstay from my rear tire's sick slapp bass solo!

Amt0571

I have this blue guide on my road bike. Two of them cracked i a year. No hits or anything (it's a road bike).

Fortunately, I bought two guides at an online shop, and they sent 10 by mistake (and told me I could keep them). So at least I have spares.

Unca_Sam

Are you able to share the cable path separation at the rear of one of those guides? Shimano uses two patterns, an M5 and a plastic screw, and I'm guessing Campagnolo's oval slot version is not very dissimilar. Like I said, I'd need another 5-10mm to get the rear cable out of the tire's way, having a little assurance that the purchased guide will do the job is nice.

Amt0571

There's 2.4cm from the center of one cable to the other one.

Unca_Sam

That's a good bit more than the 1.7cm it looks like the guide I have is using. I like that I'll be able to fine tune the path a little using the campagnolo version with a slot instead of a set of holes.

chuckybb

I had a similar problem on my cheap old tandem. I didn't want to wait for a new different cable guide to arrive, so I just took a 3" piece of cable housing and some electrical tape and fastened it to the chainstay to move it slightly to the drive side. Seems to work fine.

Unca_Sam

I should follow up to say whatever I did worked. I'll have to come back later once I can look and see what I did...