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Discussion Starter #1
Anyone tried this? Is it even feasible?

Lots of new dropper options seem to be showing up as internal-only, including my new favorite the Bike Yoke Revive. So I'd love to retrofit my SB95 for one, but would obviously feel better if someone else had tried it with success.

Generally speaking, lots of folks have drilled holes in their alloy seat tube to route a dropper cable. But the SB95 is pretty busy w/ Switch linkage bits, severely limiting the hole location and/or the housing path to any hole, so the approach (if any) is not as obvious as some other brands/models.

Any insights welcome.
 

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Discussion Starter #3
I think I figured out a way to do this that will both avoid any interference w/ the linkage assembly and not weaken the frame in any meaningful way.

I'm thinking of drilling holes where I marked black dots with a Sharpie in the attached photo. The view is from the non drive side, with the camera sort of resting on the downtube and pointing at the seattube, and I've got all the linkage and rear triangle removed while I'm replacing bearings. The second hole location, the one that actually enters into the seat tube, is a bit hidden in the shadow.

IMG_0150.jpg

Since the cable/housing would pass through the cast/machined BB assembly, rather than directly into the seattube, it shouldn't create any meaningful weakness (that cast/machined bit is MUCH thicker than the seat tube). And since the cable/housing comes into the very base of the seat tube, it doesn't need to make any sharp radius bends inside the tube. Also, the housing can be routed on the existing downtube braze-ons, which orients the housing quite nicely for the entry into the "first" hole.

Thoughts? Am I missing something?

I'm not one to care much about cosmetics, so normally wouldn't bother with this, but I'm seriously so enamored by the Bike Yoke Revive (which is internal only) that I really want to find a way to do this.
 

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I'm glad you posted this. I've been considering drilling a hole in the same location as I don't think it would negatively affect the integrity of the frame. I'm also looking at the bike yoke to replace my gravity dropper. I say go for it. If you do please post pics on how it turned out.


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Well I finally got courageous with some drill bits and went ahead with my plan. Long story short: it worked out beautifully. Very smooth routing and virtually no impact to the integrity of the frame.

The final outcome:
SB95_Stealth_after.jpg
 

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Some "before" photos . . .
IMG_0151.jpg
IMG_0153.jpg

I initiated the holes with a step-drill since the vertical "flutes" on them tend to stray less, and permit you to effectively apply side pressure to "move" a hole laterally once its drilled. Then I used conventional bits to get the right hole size.

Its a pretty tight area, and drills are big, so you need to come in at an angle. It turned out better than I thought it would when I began. The "first" hole (the one that gets you into the casting, but not into the seattube) was easier. The hole into the seattube was harder.

I was able to get a deburring tool into the first hole. But cleaning up and smoothing the second hole required a small piece of emery cloth, rolled up tight, and inserted into the hole, then moved back and forth w/ a needle nose pliers.

I'm happy with the outcome and would not hesitate to recommend it to others. The routing down the downtube, and into the casting, is very smooth and a modest radius, and enters the seattube very low. It is completely out of the way of any of the linkages and the holes are in a very strong part of the frame, so I have zero concerns about weakening the frame.

The best time to do this is when you're changing bearings. You really need to have full access to the eccentric casting to get it done.
 

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yes, the hole is right above the eccentric facing the rear wheel. it routes externally down and under the bb up to the handle bars. im using a fox transfer internal routing dropper
 

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yes, the hole is right above the eccentric facing the rear wheel. it routes externally down and under the bb up to the handle bars. im using a fox transfer internal routing dropper
Hi there, wondering about the long term affect of this if any..?

I'm about to figure this out and drill a hole for internal routing on my SB95C...
 
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