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Old Motobecane STI conversion HELP

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Old Motobecane STI conversion HELP

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Old 11-07-07, 01:44 PM
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Old Motobecane STI conversion HELP

Hello, I am totally new to this forum (and to bikes, for that matter). I received a Motobecane "Jubilee Sport" from a friend and I've devoted my time recently to fixing it up and daydreaming about adding sweet components to it. It's a standard 2/5 10 speed with the classic shifters on the downtube, and I was wondering how difficult it would be to switch to an STI system. A few things come to mind:

1) I would definitely need a new freewheel, seeing as there are no STI options for a 5 speed freewheel.
2) I would need a new rear derailleur. What kind of derailleurs can I retrofit my bike with?
3) I'm hoping I can leave the crank as is (double crank), and therefore leave the front derailleur alone.
4) I may have to bend the frame out in the back for the new freewheel. Would a 7 or 8 speed freewheel fit without bending of the frame?
5) Can I keep my brake calipers (is "calipers" the right term?) despite having new STI levers?

I'm thinking of doing this relatively cheaply. I'm totally okay with getting used parts from ebay, but I'd still prefer to get reliable components. I was looking at the RSX systems and the Ultegra systems, and from what I've read, the Ultegra setup is more reliable (and more expensive). Also, I'm not worried about going light weight or anything.

Can anyone help point me in the right direction? My bike is totally rad and I'm looking to make it even radder!
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Old 11-07-07, 02:04 PM
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1 & 2) To go above 7-speed, you'd need to lose the freewheel system altogether and get a new hub with a freehub that takes cassettes. Your frame is probably spaced 120 mm, it is likely steel so can be stretched to accommodate 6- or 7-speed (126 mm, freewheel) or 7- (w/4.5 mm spacer) 8-, 9- or 10-speed (130 mm, freehub/cassette). If you go to 130 mm, might be good to have a shop permanently set it.

2) The current RD would probably work actually, but I'd get a new one.

3 & 5) Crank and calipers should be fine. The front derailleur should be okay, but a 7/8-speed or higher chain might be too narrow and affect shifting--but it would probably be okay. Front derailleurs are cheap though.

What you'll need is:
New rear hub & cassette
New chain
New shifters
Maybe new rear derailleur and front derailleur

Look for older 7- or 8-speed STIs, or go for a new Sora 8-speed.
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Old 11-07-07, 02:33 PM
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You might want to (or need to ) swap out the wheels for more tire options. You then might need long reach brake calipers.

btw, I did the same thing with an old Motobecane - the more modest Mirage.
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Old 11-07-07, 02:45 PM
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I wouldn't rush into it. Ride it as is for a while, and decide if maybe you don't mind the downtube shifters. Or, another (easier) upgrade you might consider is bar-end shifters. I still ride downtube shifters only, but lots of folks like the barcons; they let you keep your hands on the handlebars. I'm no expert on them, but I'm pretty confident that you could get a friction set to use with your existing setup, or you might consider replacing the freewheel for a 6-speed, which would likely fit on your wheel with no frame stretch necessary.

My other, albeit unsolicited, advice is to tear down the bottom bracket and headset and do a thorough cleaning and re-pack with new bearings and good grease, eg. Phil Wood. If your bike is vintage it almost certainly has French or possibly Swiss threading. This will make finding replacement parts more difficult, though not impossible. Take care of the ones you have. If you're unsure of your skills, spend some time at Sheldon Brown's website and read the Park Tools pages on bearing service. It's not rocket science, and it's time well-spent with inexpensive tools.
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Old 11-07-07, 07:06 PM
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Originally Posted by Dufflespank
I'm thinking of doing this relatively cheaply.
Not gonna happen.
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Old 11-07-07, 09:51 PM
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Originally Posted by Retro Grouch
Not gonna happen.
Aw come on, don't be so discouraging!

Thanks for all of the advice! I'm still not sure what STI system I should go for. It appears that the RSX shifters are relatively hard to find (I found only two auctions on ebay for a set), however I think that the RSX shifters are the only option if I decide to go with the 7 speed freewheel. I read somehwere that the RSX shifters were kind of a drag (weak brakes, impossible to service, gunked up easily). Anyone else have any reliable, cost-effective suggestions? Thanks for the help!

Also, I'm not worried about getting in over my head. I'm new to bikes, but I work on cars and like to think of myself as a relatively savvy mechanic.
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Old 11-08-07, 12:35 AM
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How about going with Campy 8 speed shifters? Are Campy components and Shimano components relatively compatible?
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Old 11-08-07, 12:44 AM
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Originally Posted by Dufflespank
Aw come on, don't be so discouraging!

Thanks for all of the advice! I'm still not sure what STI system I should go for. It appears that the RSX shifters are relatively hard to find (I found only two auctions on ebay for a set), however I think that the RSX shifters are the only option if I decide to go with the 7 speed freewheel. I read somehwere that the RSX shifters were kind of a drag (weak brakes, impossible to service, gunked up easily). Anyone else have any reliable, cost-effective suggestions? Thanks for the help!
.
Shimano makes a SORA brifter for 7 speed.

https://harriscyclery.net/itemdetails.cfm?ID=1015

I met a guy on a weeklong ride last year who, in the middle of the ride, had to replace his RSX shifter. He said the SORA worked much better than RSX. Just saying.....

If you wish to pursue this, I suggest you be content upgrading to 7 speeds in the rear. If 7 speed freewheel will fit your wheel and within the dropouts, that's as good as its going to get IMHO.
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Old 11-08-07, 05:05 AM
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Originally Posted by Dufflespank
Aw come on, don't be so discouraging!

Thanks for all of the advice! I'm still not sure what STI system I should go for. It appears that the RSX shifters are relatively hard to find (I found only two auctions on ebay for a set), however I think that the RSX shifters are the only option if I decide to go with the 7 speed freewheel. I read somehwere that the RSX shifters were kind of a drag (weak brakes, impossible to service, gunked up easily). Anyone else have any reliable, cost-effective suggestions?
At minimum you are going to need new STI 'brifters', an indexing rear derailleur, an indexing front derailleur, new chain and freewheel, new cables, housings and handlebar tape. That's quite a few parts to acquire which is why I said it isn't going to happen cheaply.

How do your shifters attach to the downtube? If they're clamp-on, the cable stops that you need may be hard to find. If they're braze on, probably any LBS will have a drawer full of the stops that you need.

I'd be leary of used STI's. That's pretty much a non-user-serviceable part and they do eventually wear out. I'd wonder how much life is left in an old, used set.

You'll probably have to rework your rear hub, and reset the rear of your frame a bit, to fit a 7-speed freewheel. If you have quick release it might require a slightly longer rear axle.
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Old 11-08-07, 10:44 AM
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Were I you, I'd look at buying a cheap newer roadie with all that stuff on it. You are in for a big headache and a large sum of $$. It will absolutely be cheaper to just buy a modern used bike on Craigslist. And you're talking to a cheap ******* who loves to tinker. It just won't be worth it.
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Old 11-08-07, 12:31 PM
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I just upgraded an old freewheel bike to STI, and it cost me about what it would cost me for a new entry level bike.

However, in my case, I started with a like new lugged Columbus steel frame, so for my particular requirements, it works out quite well. (The mechanic didn't think the frame had even been built up before, but I knew otherwise).

What I needed (I went to 10 speed compact):

Custom built 27" wheels on modern hubs (still much cheaper than what many people around here spend for wheels).
STI levers.
Bottom bracket.
Crank and chainrings.
Front derailleur.
Rear derailleur.
Chain.
Cassette.
Rewrap bars.

If you can use 700c (the brakes might reach) you can get off the shelf wheels.

If you go 7 or 8 speed, you can probably skip the BB/crank/chainrings.

Unless your bike is a nice chromoly frame, I would save the money for a new bike in the future.

If you really don't like friction shifting (I don't), then you may want to look at a 6 speed freewheel, a new RD capable of indexing (they are avalable cheaply) and upgrading to indexed downtube or stem shifting as another option to get you some of the advantages without the extra cost of a complete upgrade.
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Old 11-09-07, 07:33 PM
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I've got no advice on your STI questions, but I recently got an 82 moto mirage sport with downtube shifters and I love it. I like how they are out of the way and it is not a big deal for me to reach down a bit to change gear. The only thing I did to mine was flip the bars and chop them. So it is a reverse bullhorn, like a touring bar, with the points pointed towards me and down. I really hate and cannot ride drops. It is murder on my back - weird lanky posture I have.

I am guessing it would cost quite a bit of $ to update it like you want. So my advice is do the required to get your baby tip-top ($50 for new cables, brake shoes, tires, lube, etc) and save up for another frame or full bike. It's your bike though, have fun & good luck!
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Old 11-11-07, 10:33 AM
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I'm in the process of making some of these same decisions with an old Univega Sportour. I paid $75 and knew the the wheels would need replacing when I bought it. Yesterday I discovered the BB to be shot and the cranks to be cheap SR's. Nashbar sells a double crankset combo with a BB for a hundred bucks. My question now is what to do with the rear hub and wheel. The bike has very dirty good working Shimano 600 derailleurs and I donot mine the down tube friction shifters. Ideally, I'd like to have a 9 or 10 speed cassette on 27" wheels. Any ideas would be greatly appreciated.

This is a 25" CrMO frame that I can get powder coated for free. For me the expense of some decent components is well worth the money.
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Old 11-11-07, 12:01 PM
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I converted an old Gitane to 10sp 105. I picked up parts over a period of a couple years, taking advantage of great deals that came my way. Anyway, I love the results. The bike fits like a glove and rides like a dream. Heres a pic:

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