Converting to Index Shifting

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  #1  
Old 02-03-11, 11:55 AM
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Converting to Index Shifting

My wife's bike does not have index shifting and, although she's a decent (or better) rider, her comprehension of what that derailleur does back there is -- ahem -- imperfect. The bike is late-60's French, I built it up from a foundling long ago, and outfitted it with a Campagnolo Record steel/brass rear derailler from the early 1960's, a great little unit that takes a lot of punishment.

I'm wondering if anyone has ever converted a specific non-index derailleur to index shifting; I'd like to keep the bike kitted out with all-classic componentry if possible. Alas, when I got out of college and gave up being a bike mechanic, the first index systems were just coming out -- horrid little things based on the equally-horrid Shimano Lark. So, I'd need a wee bit of guidance.
 
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  #2  
Old 02-03-11, 03:25 PM
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Hi Tiger, I managed a shop in NJ just a few years behind you so the old steel Shimano is what I'm used to seeing. Back then they used a front freewheeling system with a friction drive cluster to keep the chain in motion. This allowed changing gears while coasting, a total no brainer. However, for recreational biking, it was impressive to new inexperienced riders and I sold a bunch of them.

To retrofit to the derailleur you have would mean finding a shifter that detented with the same spacing and that might be trial and error. Obviously I have never done this, but if I were to, I think I would go for a complete set, shifter, derailleur, cluster, and chain. The cluster and chain could come later after you judge the performance of the other.

Best I can do,
Bud
 
  #3  
Old 02-04-11, 07:15 AM
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Thanks Bud, and it was purest optimism to have posed the question in the first place. If the old-bike community was like the old-car community, someone would be making retro-fit kits by now.

All of my still-riding friends hound me to ditch all of our antediluvian bikes -- that is not going to happen.

So, we'll struggle along. I doubt she can kill this derailleur, it's that tough (bested only by the Campy Gran Tourismo which can be used to drive tent pegs). I can simply ride wearing ear plugs so I won't have to listen to all the grinding...
 
  #4  
Old 02-04-11, 11:54 AM
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You could try a new chain and cluster if you haven't replaced them recently. A worn chain will bend and hesitate to make the change, forcing the rider to fine tune every shift.

I was thinking a bit more about the cable travel and I think all 5 speed clusters should match 5 position shifters and likewise for 6 and 7. And there are detent shifters out there, at least there were . It just falls back to the chain/derailleur/cluster to be able to follow the lead of the shifter. If you remember, Shimano used a special bowed link chain and matching cluster in their system.

Bud
 
  #5  
Old 02-07-11, 12:48 PM
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Originally Posted by Bud9051 View Post
If you remember, Shimano used a special bowed link chain
Not until you mentioned it, I had forgotten.

I was getting caught up in mm of cable travel per gear -- getting headache from it.

I'll check for chain stretch, just for fun. Thanks.
 
  #6  
Old 02-07-11, 04:12 PM
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Do you have a reference for chain stretch? I developed my own standard to be able to recommend chain or chain and cluster, or the entire package. If a chain has gained a quarter of an inch in 12", just about everything is toast. 1/8" I would recommend chain and cluster. 1/16" of an inch or less and they might get away with a chain or cluster alone, but it depended upon their riding habits. Once a chain passes 1/8", it may perform well, but it will be wearing your front sprockets to match, which can get expensive.

Been a long time, but that is the general guide I used.

Bud
 
  #7  
Old 04-18-11, 01:13 PM
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Problem solved but not in the way you'd expect. We got burgled and they took almost nothing from the house but they got her bike! She is heartbroken.

Interestingly, she's leaning towards another classic bike as a replacement, once I figure out where to shop for one (eBay/ Craigslist/ someplace bike-centric?)

They have no idea what they got -- wait until they try to pump up the tires!
 
  #8  
Old 04-18-11, 02:24 PM
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LOL, sounds like kids. However, the real loss is the peace of mind that goes away now that you know someone can and will enter your home. I got hit when I lived in NJ and I don't think I ever recovered. I now live in the country where many don't bother to lock their doors, but I still do.

Good luck with your search. With the communications network we have available today, you should have little trouble finding another special machine.

Bud
 
  #9  
Old 04-19-11, 05:10 AM
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Thanks, Bud. Are you in the trade and, if so, have you seen any major bike-centric forums like this one where I can ask around for places to shop?

She does not even want to test-ride a modern carbon-fiber bike.

Yeah, kids, I guess. All thaey got for there efort (and extensive damage to the house to get in) was the bike, and the snow tires (odds sizes) for my Honda S2000. Basically unmarketable.
 
  #10  
Old 04-19-11, 05:32 AM
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No, retired now, or at least trying to. Sold my bike business back in the mid 80's so rather out of touch. I just try filling in here when I can.
When I was selling I picked up a mid line of Panasonic bikes which had made the switch to positron shifting with a front freewheeling system.. All steel and nothing to brag about, but because of the ease of shifting I was able to sell a ton of them. For the recreational rider, the system simply eliminated all of the gear changing problems. Feedback from the ones I sold was five stars every time and always resulted in a friend or neighbor as a referral.

For you, it sounds like it would be a challenge downgrading to this simplicity and to be honest I have no idea as to what is being manufactured today. However, if that Shimano system worked that well back then, seems like there should be something better available now.

Try to get her to a shop to do some test riding, or maybe a rental, to better judge what would be best for her.

Good luck
Bud
 
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Old 04-19-11, 05:05 PM
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Not nearly as knowledgeable as bud but my wife has and old Schwinn World Sport she might be willing to part with!
Interesting posts guys. Sorry to hear the bike got taken though.
 
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Old 04-20-11, 06:58 AM
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Panasonic? Worked for a dealer in my college days, mid-70's, even raced on a bike I built up from a DX1000 or DX2000 frameset. Been buying Panasonic consumer products ever since. Barely remember positron.

A friend I've ridden with off/on since 1971 offered his wife's unused road bike on long-term loan. Cool! Plus she got a big cash gift from her employer yesterday.

Craigslist here in the Baltimore/Washington area came up with a few interesting hits already. Strangely, one was purported to be a late-70's Peugeot, nice in the pictures but the crankset was Stronglight 49-D, I'd think that was much older (and a bit flexy IMHO).

Originally Posted by Bud9051 View Post
No, retired now, or at least trying to. Sold my bike business back in the mid 80's so rather out of touch. I just try filling in here when I can.
When I was selling I picked up a mid line of Panasonic bikes which had made the switch to positron shifting with a front freewheeling system.. All steel and nothing to brag about, but because of the ease of shifting I was able to sell a ton of them. For the recreational rider, the system simply eliminated all of the gear changing problems. Feedback from the ones I sold was five stars every time and always resulted in a friend or neighbor as a referral.

For you, it sounds like it would be a challenge downgrading to this simplicity and to be honest I have no idea as to what is being manufactured today. However, if that Shimano system worked that well back then, seems like there should be something better available now.

Try to get her to a shop to do some test riding, or maybe a rental, to better judge what would be best for her.

Good luck
Bud
And thanks for the offer, Tolyn, right now I'll keep checking, I don't need to act quickly now.
 
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Old 04-25-11, 10:28 AM
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I found a forum for bikes, much like this one, joined and getting a little info, but have not seriously started shopping yet.

We have the 'loaner bike' now, sans pedals - I think the first time she rides it, her sense of urgency for a better bike will increase. A lot.
 
  #14  
Old 08-24-11, 12:28 PM
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Well, we got her a "Windsor Professional" from the 1970's and in great shape. Campy NR derailleurs, I have not yet ridden with her to see how the NR's do for her vs. the old steel & brass unit; maybe she's shifting better. Even if the technology existed I'm not sure I have the nerve to hack up the deraialleurs to convert to index shifting.

Funny thing, I think I feel a wee bit of chain stretch on this bike so I'll measure for "If a chain has gained a quarter of an inch in 12", just about everything is toast. 1/8" I would recommend chain and cluster. 1/16" of an inch or less and they might get away with a chain or cluster alone".
 
  #15  
Old 08-24-11, 02:00 PM
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Glad you found something. I have faith that she will do just fine.

As for the chain stretch, it is a paradox. As the chain stretches it moves into a higher orbit. As the cluster or chain rings wear they support a lower orbit. The result is the chain rides up on the pushing surface of the teeth and creates a wider valley which quickly becomes destructive to new chains. A spinning cadence in a variety of gears instead of a few tall gears and power will extend the life of the system, but being able to measure the actual stretch and learn what numbers work for you is a real benefit.

If you wrap a worn chain around a worn chain ring and lift up in an area where they should be tight you will see how they have lost their compatibility.

Except for the hurricane and earthquake, should be a great time for some riding.

Bud
 
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