Silver shifter surgery and corrosive metal welding

[Eric Marth]

Before we begin I must admit that I should have documented the process below in greater detail. I realize it would have made for video content that at least a few people here would have found worthwhile. This mechanical occurred as I was trying to sneak in a 90 minute ride before it got dark and I was determined to get it resolved as quickly as I could without stopping for pictures or documentation. 

I have a few questions about the problems I encountered. Rather than searching the Web for answers I've included my questions below, hopeful that forum members can share their knowledge. In addition to expertise on bicycles I'm aware that some members are scientists and engineers who might have fun pockets of information to share with the group. 

I run Silver bar end shifters on my Sam Hillborne. Recently I left for a ride and once I got a few blocks from my house I realized the front derailer was rubbing the chain. When I went to trim the gear the shift lever slipped into the relaxed position and dropped the chain to the small ring up front. I tightened the wingnut to restore tension but there was no tension to be found. I had an idea of what was going on: the ratchet was clogged with corrosion, preventing the spring from engaging the pawl. I rode home in a very easy gear. 

Back in the shop I loosened the clamp bolt on the front derailer to free the cable. When I went to pull the cable out of the shifter lever it wouldn't budge. The head of the shifter cable had chemically bonded to the lever itself. I removed the nuts and bolts that hold the lever to the bar-end shifter pod. I should note that I had previously replaced the external plastic nut cover with a brass counter-sink washer. I think the presence of the brass encouraged corrosion. I then struggled to get the cable out even with the lever freed from the pod. 

I then noticed that the brass ferrule I'd used at the end of the shift cable housing had bonded to the bar-end pod. I now had two instances of dissimilar metals bonding together. 

I snipped the shift cable, pinched the loose end with pliers and tried to wiggle and finesse it free. No luck! I tried to drill out the head of the cable, that also didn't work. I decided to abandon the shifter and salvage the innards for parts. 

   

Terrible pictures showing drilled head of shifter cable and snipped off cable stuck in lever.

I store my bikes in my shed, an unconditioned and uninsulated space in Virginia. It is very humid here. The spot where I hang my Hillborne seems to attract a lot of moisture and I really need to find another place to store that bike. Sometimes when it rains the handlebars feel damp and corrosion forms around the seatpost collar, on the chaingring bolts and the rear dropouts. The roof of my shed does not leak. I think the rust accumulation has to do with ventilation issues and related to the bicycle hanging between a door and a window, there must be some kind of draft situation going on and that spot is a real moisture magnet. I don't have the same problem with other bikes I hang in adjacent spots. 

What causes the shifter cable head to bond to the lever? What materials are the shifter cable head and Silver shifter levers made from? Do the dissimilar metals encourage bonding when moisture is present? What causes the brass to bond to the bar-end shifter pod?

In my video about repairing Pam's Silver shifters I mentioned corrosion as a potential problem with a Silver shifter that doesn't hold tension. Here was an opportunity to show the world! I was frustrated and eager to get it fixed quickly. Setting up to make a video really bogs things down. 

I took the lever with the cold-welded shifter cable stuck inside and pried it open. Indeed, the spring was clogged with corrosion. The corrosion was chalky and white, resembling the type of build up sometimes seen on car battery terminals. With the spring clogged it won't push against the pawl which won't hold position on the ratchet wheel which won't allow the lever to hold tension to counteract the spring action of the derailer. 

Thanks to board member Mike Godwin, who sent me some old Suntour levers to help repair Pam's shifters, I had some extra parts around. Shifter bodies (one good, one broken), spare cover plates and some ratchet wheels. I also had replacement springs I'd ordered from McMaster-Carr. I mated one of the Suntour levers from Mike with parts from my damaged lever and got them put back together. Pinching the parts together I could tell the ratchet was working. I set it aside to work on the shifter pod. 

The brass ferrule had welded to the pod. I tried to pull it out with pliers. No luck. I'd encountered a welded brass ferrule before so I was relatively sure before I started that I wouldn't get it freed. I've heard that squelching is one method that sometimes works to free welded parts but I didn't have the means or patience to heat the parts. So instead I decided to saw off the ferrule and file it flush with the pod. I could run the shifter cable into the remnant of the ferrule. 

With the ferrule flushed up I reinstalled the pod in conjunction with seating the shifter cable. I installed a new shift cable and re-installed the newly rebuilt shifter lever. 

I got the shifter wired up and everything worked as intended. 

I have a newfound reluctance to use brass parts going forward. While my love of brass is well documented in my builds it has caused me several problems over a short few years. Twice my bar-end shifters have stopped working, I believe due to corrosion encouraged by the presence of brass and the contact between dissimilar metals. I have also twice had brass ferrules get welded to other parts. Here on the Hillborne it was the ferrule and the shifter pod. On my MB-2 it was a ferrule that welded to a Suntour brake lever. 

Perhaps you can use brass parts if you live in drier climes or have better luck than I do. But I'm going to be phasing brass out of my bikes and builds from here out. Or until I move to the desert. 

Thanks for reading along and happy trails :0) 

[JohnS]

Thanks for sharing Eric, that would be galvanic corrosion...

[Patrick Moore]

Eric: Thanks for the clear and comprehensive description and the warning about brass-on-aluminum.

Remark: I am so very glad that high humidity where I live is 50% and that's seasonal and rare.

Question (to all): are there not marine greases or applications made precisely to prevent such corrosion?

Patrick Moore, who had a very nice late "monsoon" mid-afternoon ride just now at an about-normal 90*F and 23% humidity in a very comfortable ss wool jersey.

--
You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/6d491863-15d7-42c9-8611-b9110b904c53n%40googlegroups.com.

--

Patrick Moore

Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum

-------------------------------------------------------------------------------------------------------

Executive resumes, LinkedIn profiles, bios, letters, and other writing services

-------------------------------------------------------------------------------------------------------

When thou didst not, savage, know thine own meaning,

But wouldst gabble like a thing most brutish,

I endowed thy purposes with words that made them known.

[Mackenzy Albright]

hmmmm. This got me thinking about my beloved Blue Lug brass crank caps on my riv silver cranks - especially living in the pacific northwest. 

Curious of ample grease and yearly teardown will prevent the galvanic corrosion. 

[P W]

A friend swore off the brass self extractors (White Industries, Blue Lug, Etc.) for exactly these same reasons. 

He’s been encouraging me to do the same for over a year now.

I really should replace the two sets I have, even here in arid Southern California.

P. W.

~

(917) 514-2207

~

On Sep 4, 2024, at 1:29 PM, Patrick Moore <bert...@gmail.com> wrote:



Eric: Thanks for the clear and comprehensive description and the warning about brass-on-aluminum.

Remark: I am so very glad that high humidity where I live is 50% and that's seasonal and rare.

Question (to all): are there not marine greases or applications made precisely to prevent such corrosion?

Patrick Moore, who had a very nice late "monsoon" mid-afternoon ride just now at an about-normal 90*F and 23% humidity in a very comfortable ss wool jersey.

On Wed, Sep 4, 2024 at 9:58 AM Eric Marth <eric...@gmail.com> wrote:

Before we begin I must admit that I should have documented the process below in greater detail. I realize it would have made for video content that at least a few people here would have found worthwhile. This mechanical occurred as I was trying to sneak in a 90 minute ride before it got dark and I was determined to get it resolved as quickly as I could without stopping for pictures or documentation. 

I have a few questions about the problems I encountered. Rather than searching the Web for answers I've included my questions below, hopeful that forum members can share their knowledge. In addition to expertise on bicycles I'm aware that some members are scientists and engineers who might have fun pockets of information to share with the group. 

I run Silver bar end shifters on my Sam Hillborne. Recently I left for a ride and once I got a few blocks from my house I realized the front derailer was rubbing the chain. When I went to trim the gear the shift lever slipped into the relaxed position and dropped the chain to the small ring up front. I tightened the wingnut to restore tension but there was no tension to be found. I had an idea of what was going on: the ratchet was clogged with corrosion, preventing the spring from engaging the pawl. I rode home in a very easy gear. 

Back in the shop I loosened the clamp bolt on the front derailer to free the cable. When I went to pull the cable out of the shifter lever it wouldn't budge. The head of the shifter cable had chemically bonded to the lever itself. I removed the nuts and bolts that hold the lever to the bar-end shifter pod. I should note that I had previously replaced the external plastic nut cover with a brass counter-sink washer. I think the presence of the brass encouraged corrosion. I then struggled to get the cable out even with the lever freed from the pod. 

I then noticed that the brass ferrule I'd used at the end of the shift cable housing had bonded to the bar-end pod. I now had two instances of dissimilar metals bonding together. 

I snipped the shift cable, pinched the loose end with pliers and tried to wiggle and finesse it free. No luck! I tried to drill out the head of the cable, that also didn't work. I decided to abandon the shifter and salvage the innards for parts. 

<IMG_2311.JPG>

   

<IMG_2309.JPG>

Terrible pictures showing drilled head of shifter cable and snipped off cable stuck in lever.

I store my bikes in my shed, an unconditioned and uninsulated space in Virginia. It is very humid here. The spot where I hang my Hillborne seems to attract a lot of moisture and I really need to find another place to store that bike. Sometimes when it rains the handlebars feel damp and corrosion forms around the seatpost collar, on the chaingring bolts and the rear dropouts. The roof of my shed does not leak. I think the rust accumulation has to do with ventilation issues and related to the bicycle hanging between a door and a window, there must be some kind of draft situation going on and that spot is a real moisture magnet. I don't have the same problem with other bikes I hang in adjacent spots. 

What causes the shifter cable head to bond to the lever? What materials are the shifter cable head and Silver shifter levers made from? Do the dissimilar metals encourage bonding when moisture is present? What causes the brass to bond to the bar-end shifter pod?

In my video about repairing Pam's Silver shifters I mentioned corrosion as a potential problem with a Silver shifter that doesn't hold tension. Here was an opportunity to show the world! I was frustrated and eager to get it fixed quickly. Setting up to make a video really bogs things down. 

I took the lever with the cold-welded shifter cable stuck inside and pried it open. Indeed, the spring was clogged with corrosion. The corrosion was chalky and white, resembling the type of build up sometimes seen on car battery terminals. With the spring clogged it won't push against the pawl which won't hold position on the ratchet wheel which won't allow the lever to hold tension to counteract the spring action of the derailer. 

Thanks to board member Mike Godwin, who sent me some old Suntour levers to help repair Pam's shifters, I had some extra parts around. Shifter bodies (one good, one broken), spare cover plates and some ratchet wheels. I also had replacement springs I'd ordered from McMaster-Carr. I mated one of the Suntour levers from Mike with parts from my damaged lever and got them put back together. Pinching the parts together I could tell the ratchet was working. I set it aside to work on the shifter pod. 

<IMG_2312.JPG>

The brass ferrule had welded to the pod. I tried to pull it out with pliers. No luck. I'd encountered a welded brass ferrule before so I was relatively sure before I started that I wouldn't get it freed. I've heard that squelching is one method that sometimes works to free welded parts but I didn't have the means or patience to heat the parts. So instead I decided to saw off the ferrule and file it flush with the pod. I could run the shifter cable into the remnant of the ferrule. 

<IMG_2308.JPG>

With the ferrule flushed up I reinstalled the pod in conjunction with seating the shifter cable. I installed a new shift cable and re-installed the newly rebuilt shifter lever. 

<IMG_2313.JPG>

I got the shifter wired up and everything worked as intended. 

I have a newfound reluctance to use brass parts going forward. While my love of brass is well documented in my builds it has caused me several problems over a short few years. Twice my bar-end shifters have stopped working, I believe due to corrosion encouraged by the presence of brass and the contact between dissimilar metals. I have also twice had brass ferrules get welded to other parts. Here on the Hillborne it was the ferrule and the shifter pod. On my MB-2 it was a ferrule that welded to a Suntour brake lever. 

Perhaps you can use brass parts if you live in drier climes or have better luck than I do. But I'm going to be phasing brass out of my bikes and builds from here out. Or until I move to the desert. 

Thanks for reading along and happy trails :0) 

--
You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/6d491863-15d7-42c9-8611-b9110b904c53n%40googlegroups.com.

--

Patrick Moore

Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum

-------------------------------------------------------------------------------------------------------

Executive resumes, LinkedIn profiles, bios, letters, and other writing services

-------------------------------------------------------------------------------------------------------

When thou didst not, savage, know thine own meaning,

But wouldst gabble like a thing most brutish,

I endowed thy purposes with words that made them known.

--
You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/CALuTfguVmg7f0eAEr-oM2bo2aMVwx_LiTCYFdc7jfqBoPHBcYQ%40mail.gmail.com.

[AppaLanta]

@Patrick, perhaps these kind of products...

https://www.cytech.training/uploaded_files/study_documents/7.%20Lubricants%20and%20Greases.pdf

...suggesting a copper-based grease to be used between dissimilar metals.  This seems like a prevention of the symptom (corrosion) rather than the cause (using dissimilar metals when similar could be used in the first place)?

@Eric, thanks for this post.  I forgot to say - I really appreciate your videos!

[Danny]

Thanks for the write-up Eric. I'll give my brass parts a once over a couple times a year after reading this. Did you grease your ferrule exteriors before installing?

I typically give any brass part a liberal greasing before installing, which in theory should help prevent, or at least slow galvanic corrosion. But maybe areas that see more moisture like crank caps/extractors need more frequent attention.

-Danny

To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/c0299797-bf11-47c2-8934-94a26f45d15an%40googlegroups.com.

[Stephen]

Hey eric, 

Yeah ive had similar issues. Had a mildly stuck cable end in a silver 2, think i was able to get it out with a needle and small hammer, basically punched it out. Noticed the brass ferrule corrosion too. I’m still working through a stash of them, but ive also been getting over my brass preference in favor of lightweight aluminum where reasonable, like headset spacers. I’ll have to check my brass crank extractor caps as mentioned by others…

[Michael Baquerizo]

citing another instance of brass ferrule stuck in a deore RD, this time in NYC (where summers and winters can both be humid)

[Eric Marth]

Thanks to everyone for your replies and notes on galvanic corrosion and otherwise! 

I haven't greased any of my brass ferrules. I did liberally grease my brass Blue Lug crank caps, tho. I have considered greasing them or coating them with some Renaissance Wax which certainly couldn't hurt but I worry about the longevity of the wax. In some instances, depending on how the ferrules interface with parts, it could be very difficult to re-wax or re-grease the spot where brass and aluminum meet. 

[Jim in Mpls]

I also grease the cable heads(which I believe are zinc?) to help prevent seizing in the shifter bodies.

Jim in Mpls

[J]

Good coverage here. I stopped using brass bits on bikes a few years ago after a single brass ferrule issue, and I always wondered if anyone else had issues as the rise of brass bling took hold in recent years.

[Mackenzy Albright]

I've been looking into this more for fun - because why not? 

It seems like using a non metallic barrier (aka) grease may be preferable to metallic such as copper or aluminum. Wax may also work well too. At the end of the day most answers were referred to regular maintenance especially in wet climates is a necessity. places where they are not maintained and sit indefinitely are a big nono as galvanization is almost a given. 

I'll probably keep using my crank caps but will make sure to remove and regrease bi-yearly.

[raw_meet]

This is fascinating, I built my wife's Platypus with brass ferrules on all the cables. I'll have to pay attention to them and probably hit the contact points with aluminum with grease soon. We live in Rhode Island so the weather isn't on our side when it comes to slowing corrosion.