pccp

I am at my wits end trying to research this stuff and I feel like even more of a noob than before. I rode this bike 20 years ago in college and I tried it again recently and fell in love with it but I'd love to make it more functional. The first problem is that it has 52/42 front and 13/28 back, 12 speeds total and the gearing isn't enough for where I live. I'd like to add a triple front at the very least before I think about changing the wheel and adding a higher count rear set. Also can I change out the brake pads for a modern one? I found koolstop holders for 25 dollars a pair but I'm not sure I can put them on (the brakes are shimano 600) or if it's even worth when I can probably upgrade to a more modern dual pivot for not much more?

The biggest thing I wanna change though again is the gearing, if I add a triple front crankset 52/42/30 which I found on ebay for $67 with shipping, Sugino crown triple 130 74 bcd, would that work with the bb axle that's on there currently or would it need to be longer? Also would the front derailleur and rear derailleur need to be changed? The front derailleur that's on there now has a much wider range with the friction shifter than the double chainring needs and I know similar models of this bike back in the day had a triple front chainring.
I have more questions about front and rear derailleur compatibility for future upgrades but for now I mostly wanna know how to get a triple on the front for the least amount of money and I'm eyeballing that ebay sugino hard. If the derailleurs need to be changed though, I don't know what is compatible...

Hondo6

Without knowing specifics (e.g., make and model numbers of existing components and intended replacements), what follows is speculative. But here goes anyway.

1. My guess is you'd indeed need a different bottom bracket spindle. For square taper, the crankset almost always determines the spindle length required for proper chainline. You might get lucky, but I wouldn't count on it. And since we're talking a Peugeot, there's a fair chance the bottom bracket is French threaded. That introduces another potential complication if you can't find a replacement spindle of correct length and need to replace the bottom bracket.

2. I'd also guess there's a good chance you'll need a new RD (and maybe a new FD as well). FDs designed for double cranksets sometimes don't "play well" with triple cranksets. The late Sheldon Brown's website has a page regarding FDs that explains why. Regarding the RD, there are two factors of importance: min/max sprocket size supported and total capacity. Total capacity required can be calculated: (max rear - min rear) + (max front - min front). Going to a triple, you're going to raise the total capacity required substantially - in the case you posit, from 25 to 37. My guess is that's almost certainly going to require a long-cage RD - and even that may be iffy with period-correct RDs.

3. I've heard great things about Koolstop pads and how they improve braking performance. I've not yet tried them, however, so I can't say anything about them from personal experience.

Posting photos would be a big help, and might get you more accurate answers.

Best of luck.

DiabloScott

I get this - it's a fun project with some nostalgia thrown in... but.
Getting lower gears on old bikes is one of the most common questions we get in here... and the Mechanics subforum.
The answer is it is almost always too expensive for what the owner wants to do... likely cost more than the new purchase price of the bike back in the Reagan administration.
Crank, axle and BB, shifters, front and rear derailleurs, freewheel... on top of the normal tune-up stuff like chains and cables and brake pads.
A 1984 Peugeot might have 27" wheels; there's another big expense.

If you're an experienced wrench with lots of resources you could probably do it anyway.
If this is your first restoration, you'll likely find it frustrating and unfulfilling.

I know you like it. There's another bike out there that'll make you happy.

pccp

I just looked up the Simplex SX610 RD that's on the bike and there's two versions. The GT has a total capacity of 38T (link1 link2) and the T version doesn't say. If it's the GT I think this will work. The bottom bracket spindle may need to be changed and I don't know which length I need, but velo orange sells a french threaded sealed cartridge bb in variable lengths for $50, if it is indeed french threaded. If all I need to change is that and the crankset I wouldn't mind doing this. Do you think it's worth the risk to just buy the crankset now? The ebay seller just offered $5 off lol.

As for the wheels, they have 700c tires on them so I assume they are 700c wheels... Shifters are friction, and I don't mind keeping them as is. I'm leaning toward just buying the triple crankset and playing around with it.

Pictures - ignore the cheap saddle, pedals and my mess




replaced the jockey wheel on here a while back as it had a broken tooth that's why it's a different color.

markk900

I think you are just looking for someone to give you encouragement/permission to buy the crankset - go for it 😀

You can always resell if you don’t end up using it….

3alarmer 

.

• ...it's pretty easy to figure out if it's the GT version of the rear derailleur. Look at the cage length. 52/42 and 24-28 were considered "alpine" gearing back then. I suspect your bicycle was put together originally around this gearing, and while you can change it out with enough investment, I personally would not do this project.

nlerner

Rather than convert to a triple, why not convert to a compact double, and you likely won’t need to find a longer BB spindle. Lots of options out there in 50/34t or 46/30t configurations. Remove old crank, install new, lower your FD a bit, shorten your chain by a link or two, and you’re good to go.

3alarmer 

.
....that's a short cage rear, I think, from your pictures. That limits yoiur total overall gearing range (high to low). But as stated above, you can drop the gearing overall by reducing the size of the rings on the front.

Mr. 66

That could be Swiss threaded bb

pccp

Ya I think you're right, it looks like the T version from this picture. 28t Total capacity so I would need to change the rear derailleur. Because it's friction shifting couldn't I just get cheap medium cage modern RD with the right total capacity? I found some on ebay, 8,9,10 speeds for $30. I can just set the limit screws in and I would be fine? Or would I be limited to 6,7, 8 speed crankset if I wanted to hold off on new wheels? If so would a 8 speed compact crankset with medium cage 8 speed rd work with my current rear gears?

Changing to a compact double crankset is also still outside of my rear derailler total capacity at 31t but that is an attractive option. Especially if I get a new rear derailleur with 9 or 10 speed and upgrade wheels and cassette later on.

If the bb is swiss threaded I think I'm out of luck with a triple for sure.

52telecaster

That's what I would do!

Hondo6

Based on the photo of the Simplex SX610 GT/SP at this page on Mike Sweatman's Disraeli Gears website, I'm fairly sure you're correct. The cage on the OPs RD certainly looks shorter than the one in the photo at Disraeli.


Edited to add: sorry, posted the above before I saw that the OP had already come to the same conclusion. Oh well, probably not my first mistake of the day . . . or the last.

Hondo6

You might run into another problem: a Simplex RD hanger that's integral to the frame. The Simplex Mounts section of this article (I believe it's by regular BF commenter @jonwvara ) explains the potential issues.

Most modern RDs expect to find a Campagnolo-style dropout (or the newer "direct attach" type). If you have a Simplex-only hanger, that will be an issue.

I also have read somewhere that at some point Simplex started making rear dropouts with integral hangers that included the Campagnolo-style "tang". If that is correct and your frame has one of those (or has a Campagnolo-style dropout), then the hanger issue shouldn't crop up.

sincos

Looks like a braze-on FD, so there might be an issue with using smaller chainrings. Though maybe if you go super-aggressive you can fit a clamp-on under the FD boss.

pccp

Well that really chaps my hide. I was wondering about that... If it's not compatible they do say I can chop it down and put a campagnolo mounting claw (not sure if thats even the right one though for a modern rd) on it. I'm not entirely opposed to it. A little worried I'll mess it up. Maybe I'll buy the rd and just check it before anything else. I can always sell it.
Just to check again since no one replied to that part of my earlier message.. I can use an 8 speed rd on my current 6 speed right?

dukeofearl 

I've been looking into doing something similar with an earlier peugeot and there's a lot involved. I bought a longer spindle for the bottom bracket, a triple crankset, a long cage simplex rear derailleur and am still looking for a triple front derailleur. The cost is adding up and will be lot of work but I enjoy doing this stuff and have other bikes I can ride in the meantime.

A much easier way to go would be for the compact crank as others have suggested. You wouldn't have to change anything else, just lower the fd and shorten the chain a bit. And you'd get those lower gears you desire.

I think Peugeot derailleur hangers by this point would accomodate other brands but I'm surprised to see that sx610 on there. I have an 81 that works with a suntour derailleur and hasn't been modified.

nlerner

Yeah, I see that now, but there’s a good 1cm of lowering possible, plenty to go from a 52t big ring to a 50t.

pccp

So what do I do for the crankset? Chainrings or a whole new crankset? The chainrings seem to have to conform to a 122mm bcd and I don't see anything smaller than 38 according to sheldon brown.. For cranksets, they have a specific spindle length. I found a cheapo amazon no name for $40 50/34 that requires a 113mm spindle. Do I have to take off my cranks and measure the spindle length to be sure?

:edit: i'm buying a claris 8 speed rd medium cage and a lockring wrench and going to town. Rear dropout has threading, so that's promising that it's not a simplex only. If bb is french threaded and not the right spindle length I'll buy a velo orange bb and find a suitable crankset that's better than the amazon cheapo. Also found an 8 speed rear wheel on ebay that I made an offer on and can pair with an 11-34. This rd better work or I'm gonna have to get the hacksaw out or try to cancel my wheel offer and give up. Stay tuned.

Soody

Consider that derailer capacity may not matter.
You need the chain to be long enough so that the big+big combination does not explode your drivetrain. With a short derailer cage, ie, low capacity, that means the small+small combo will drag on itself. Does that matter? It's not a critical failure, just make a racket to remind you you dun goofed shifting. It's not a useful gear either.
Same thing with the front derailer low end. It needs to move in and out enough, but if the cage isn't low enough, the small+small will rub on it. Again, who cares? The granny can only work with the top 2-3 cogs and serve it's purpose.

I think everything you currently have would work with a triple crankset and the only issue is the bb which also might work.

Soody

Also, specified spindle length is not specific and nor are taper standards. The amount a crank presses on will change due to wear. The stated chainline may be conservative, it may be better to flirt with it rubbing or binding on the inside. It's something you have to make guesses on and experiment with, not an exact set of standards to rigidly follow. The thing worth trying to work out without just experimenting is asymmetry.

Soody

And if you're doing this, it's worth removing your bb to service it and seeing if it's worn or not, before you try to find a crank which might work with it and before you think about changing it. Don't make plans around a pitted spindle. And likewise, if it's good, best to keep it.

pccp

I'm committed to the 2x8 now. The new rear derailleur might just work, I just screwed in an old acera and it screwed in at least but it's also all bent up so I don't know what the alignment looks like. The ebay wheel seems like a good deal too if they accept. Just need to take apart the bb and see what I'm working with. Then decide on a crankset.

pastorbobnlnh 

C&V's own jonwvara owns Red Clover Components and makes a 122BCD triplizer. He also sells a 37T 122BCD chainring. Not inexpensive, but another alternative.

An 8-speed will require 130mm rear spacing and you probably have 126mm (or less) and will need to spread your rear dropouts.

I can't see your freewheel all that well but I'm guessing it is a Maillard Corse or a Helicomatic. Can you confirm or take the wheel off and post a picture. If you have 126mm you should be able to fit a 7-speed freewheel on your existing hub.

pccp

Yes it's a helicomatic and I anticipate having to cold set to 130. Trying to find an inexpensive wheel or wheelset. Looking at this wheel atm but not sure it's a good deal. Thinking maybe trying to find a set is better. The helicomatics have 36 spokes though, seems pretty good no?
I'm getting a little tired now though, think I'll continue this tomorrow or 2 days from now when I receive the rd and bb tool. Lot's of ideas to consider. Thanks for all the help so far everyone! The journey continues.

dukeofearl 

bottom bracket could have any kind of threading. i have a 78 peugeot with english threading (those are usually french) and an 81 with swiss. i made the mistake of buying a french sealed bb before checking.

stronglight 99 cranks are 86bcd so lots of options for chainring sizes