Campagnolo EPS/Chain catchers with SRM magnet hacks (on page 2)

Discuss light weight issues concerning road bikes & parts.
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Calnago
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by Calnago

Thanks Miller... more importantly... and unrelated to the chaincatcher... what’s going on with your waterbottle cage bosses? What’s inside them?
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

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Miller
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by Miller

You don't miss much! The Genesis frame I got recently had these weird little blanking screws in the bosses, God knows why, was that really cheaper than just supplying proper bolts. Anyway, rather than throwing them away, I transferred them into the empty bottle bosses in my TT frame. I don't do any TTs that would require two drinks bottles.

by Weenie


Bridgeman
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by Bridgeman

Miller wrote:
Fri Jun 22, 2018 2:16 pm
Image
Thanks Miller! I've been looking into this topic as I've dropped my chain a few times with my EPS setup.

The K-Edge hack is interesting but I am also concerned about the amount of force exerted by the FD and the small nut used to affix it to the frame. Looks like there's some good history with a pro team and it appears to be working for Alex.

You know, the FD shifts fine when I remember to rotate about a half turn slowly and with zero load while making the shift, but those times when it gets chaotic are when it gets dropped. Really a drag, and I can't help but to think the frame manufacturers should be providing a solution by now. Utilizing the FD bolt is not ideal.

Thanks for your post Alex!

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Calnago
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by Calnago

I kind of like the full contact of the mounting bolt with the stud coming out of the EPS derailleur on the Campy Catcher. And the slot that the catcher portion slides along is looks like it provides good support, so that's good. I suspect maybe the reason Loto is using the K-edge version is for the magnet compatibility with the SRM. But the magnet attachment on the SRM unit is simply screwed on with two small screws. I'd bet it'd be easy to tap a couple holes in the Campy version to mount the little SRM magnet attachment arm, but of course you'd need the magment and arm in the first place. But since Alex is scrapping his sacrificial protype he already has that piece, giving him the option to go either way if he wants. Anyway, good bit of info in this thread.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

Bridgeman
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by Bridgeman

Calnago wrote:
Fri Jun 22, 2018 5:00 pm
I kind of like the full contact of the mounting bolt with the stud coming out of the EPS derailleur on the Campy Catcher. And the slot that the catcher portion slides along is looks like it provides good support, so that's good. I suspect maybe the reason Loto is using the K-edge version is for the magnet compatibility with the SRM. But the magnet attachment on the SRM unit is simply screwed on with two small screws. I'd bet it'd be easy to tap a couple holes in the Campy version to mount the little SRM magnet attachment arm, but of course you'd need the magment and arm in the first place. But since Alex is scrapping his sacrificial protype he already has that piece, giving him the option to go either way if he wants. Anyway, good bit of info in this thread.
I agree Cal. The Campy Catcher, with the independant adjustment is the proper way to go, thought not particularly ww. I like the Campy version as well, and will go with it.

Also, like you mentioned, tapping a couple of holes would be quite easy.

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Calnago
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by Calnago

The K-Edge also has independent adjustment, and I think it’s generally a prettier solution than the Campy one. The only downside is the minimal number of threads that end up being in use as a result of the mod you have to do and what looks like a very minimal recess in the hex portion of the bolt that you need to use in order to tighten it down without rounding off the edges.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

AlexC
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Joined: Thu Oct 11, 2007 8:24 pm

by AlexC

I originally went with the K-Edge for the SRM magnet, since I’m tired of glueing magnets to frames.

I was only going to consider the Campagnolo option if I couldn’t get the K-Edge to work.

But I think it’s worth trying because it’s such a sleek and elegant solution and team Lotto-Soudal haven’t yet had any problems I’m aware of. I watch almost every race and can’t remember seeing any of their riders sidelined by a detached or jettisoned front derailleur.

I saved my original K-Edge prototype and will order a Campagnolo chain catcher so I can mount the SRM magnet from the K-Edge on the Campy one. As Calnago states, the magnet is only attached by two small screws, so it should be easy to swap.

As you can all see from my previous photos, I’m still a ways away from completing my C60 build, but when I’m done I’ll post pics, weights, and total costs of both chain catcher/SRM magnet solutions as well as step by step instructions.

AlexC
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Joined: Thu Oct 11, 2007 8:24 pm

by AlexC

The new K-Edge pro chain catcher with SRM mount arrived today, so here’s the EPS/SRM/Chain Catcher with magnet solution #1
Apologies for the iPhone photos. Click on the photos to enlarge.

Total weight:
7BB75343-9FD3-4354-8BB7-2EC4BEC4C0D8.jpeg
Total cost:
60 USD (MSRP of chain catcher)

What you’ll need:
1 K-Edge Pro Braze-on Chain Catcher with SRM magnet
1 round nut for 5mm Allen key from EPS battery or internal battery mount kit (can’t remember which one, but 2 are supplied and I didn’t use either)
Some emery cloth
A file
Good calipers (optional, you can easily do this by feel)

Step 1:
File down mounting stud that sticks out of the front derailleur by 2 threads
From this:
93F865ED-818F-4301-A24D-A64CB6B9E5E4.jpeg
To this:
FCEC4270-CC88-4252-AB20-039E0A0FD44E.jpeg
Step 2:
Insert 5mm Allen key into nut, roll emery cloth around nut, pinch firmly, and twist the Allen key and nut back and forth to ensure even wear
From this:
ED27BCE4-7827-487C-A93A-ECF4D5D295A2.jpeg
To this:
DD9FAD0E-D653-44A3-AB21-F198AD772EFE.jpeg
Note: Internal diameter of the top hole in this chain catcher was 8.01mm on my calipers
6A0FABE6-0B3A-439D-9694-71CB2EDAB414.jpeg
Diameter of supplied K-Edge M5 mounting bolt was about 7.9mm, about .1mm less than hole diameter
748BB2EC-8C9C-4C72-AB5A-B20B253DD3F1.jpeg
I got the nut to within .01mm of the hole diameter. I just went by feel, sanding a little, then testing the fit, then sanding, then testing. The fit is extremely secure. There is absolutely no play in the chain catcher hole - nut interface whatsoever. The emery cloth did wear off the black finish on the nut, so you might want to grease outer circumference of the nut prior to installation to prevent oxidation and corrosion.

Step 3:
Install the chain catcher and front derailleur. Tighten the nut down to 7 newton-meters as specified in Campagnolo’s FD manual
59AA19EA-88AC-4FB2-9C0B-2DE958581B5F.jpeg
Note: Although the hex inset in the nut is only 2mm or so deep, it is an extremely tight fit with both Bondhus and Silca 5mm Allen keys. There was zero play with either, so I had no problems at all tightening the nut to 7 newton-meters. No play, no slippage, no worries.

Whole process took about 10 minutes.

I haven’t been able to test this yet, but it seems to be working well for Lotto-Soudal:
Greipel:
03F9D558-8AAD-4A84-A26D-10CB4961F1F3.png
Roelandts:
21D60B17-EFE3-429D-9248-3272C8051FEB.png
Last edited by AlexC on Sun Jun 24, 2018 12:11 am, edited 2 times in total.

AlexC
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Joined: Thu Oct 11, 2007 8:24 pm

by AlexC

And De Gendt:
684D5E9D-CEAA-4BE3-A134-E88E5C545D16.png
When the Campagnolo chain catcher arrives in a few days I’ll post solution #2

AlexC
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Joined: Thu Oct 11, 2007 8:24 pm

by AlexC

The Campagnolo chain catcher (as pictured above on Miller’s bike) arrived today but it appears that this isn’t a simple case of attaching the K-Edge SRM magnet to the campagnolo chain catcher.

The inside face (closest to the bike) of the Campagnolo chain catcher isn’t flat. There’s a spine that protrudes and runs down the posterior edge of the chain catcher, not leaving a large enough flat surface to mount the K-Edge magnet and arm.

The outer face (closest to the chainring) of the Campagnolo chain catcher is flat and has enough surface area to mount the K-Edge arm, however mounting the arm and magnet on that side prevents the chain catcher from being positioned close enough to the chainring, due to the protruding screw heads and magnet arm.

It’s still possible to make this work, but you‘d have to first grind down spine on the inner face of the Campagnolo chain catcher until it’s completely flat, then drill two holes, and then tap them. For me, at this point, it’s more trouble than it’s worth. But if someone does manage to make the Campagnolo option work, I’d be interested to see it.

I’ve been running the K-Edge setup for a few days now without any problems. The front derailleur hasn’t budged and the chain catcher and magnet remain perfectly aligned. But if I do have any issues in the future i’ll be sure to report them here.

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Calnago
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by Calnago

Good info @AlexC: now that you have worked with both, assuming there’s no powermeter involved, which catcher would you rather use? I think in the case of just eps with no PM maybe I’d lean towards the Campy catcher. And for mechanical drive trains, I’m pretty happy with K-Edges product. It’s just that funky eps attachment bolt that makes using the K-Edge more of a hassle.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

AlexC
Posts: 16
Joined: Thu Oct 11, 2007 8:24 pm

by AlexC

@Calnago, Thanks.

Both the K-Edge and Campagnolo chain catchers are well designed and beautifully machined from Aluminum. I wouldn’t hesitate to use either one.

Both designs, while effective, are slightly different. The K-Edge pivots around the top bolt so the arm arcs towards and away from the inner chainring, whereas the Campagnolo catcher slides laterally towards and away from the inner chainring, staying parallel to the chainrings at all times. That’s really the only functional difference I can discern between the two.

Although my K-Edge setup continues to work flawlessly, I think in the case of EPS without an SRM I’d opt for the Campagnolo chain catcher since it requires no modification to the front derailleur whatsoever. The modifications required to make the K-Edge work, while minimal, probably void the front derailleur warranty. Plus, the simplest working solution is usually the best one, and in the case of EPS without an SRM, the Campagnolo chain catcher is the simplest solution.

Except for not running a chain catcher at all, which is an entirely feasible alternative assuming the front derailleur is setup properly.

But like you and many others, I prefer having the extra insurance anyway.

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