ddeand 

I've been running an old Dura-Ace groupset on my bike for a while, and as happens with many of us as we get older or expand our riding range, I'm finding that I'd like to have smaller chainrings on my vintage rider. I have a 2005 CX bike that I use for gravel, and it has 46/34t rings on the front, and that seems to work pretty well for me. The smallest I've been able to go on the D-A cranks is 48/38t because of the 130 bcd crank (the 48t is OK, but the 39t is a little big for some of the hills I've added to my rides). So, I'm thinking that maybe I might want to find a crankset that has a smaller bcd so I can use smaller chainrings. I just don't know what's out there that might be of similar quality with the D-A crank other than Campy stuff (and even then, I'm not sure of the ramifications of mixing and matching Campy and Shimano stuff). Can any of you recommend a quality, vintage, square-taper crankset that has a smaller bcd and will allow for smaller chainrings? I guess my other option would be to try to get a different cassette (I'm presently running 12-28, 8-speed), but I'm not sure how large the D-A rear derailleur can handle. Any advice/opinions are appreciated.

52telecaster

TA? Cyclotourist cranks work for me or the shimano deore version. You can go as low as 26. Also and this doesnt help much, but you can go to 38 on a 130bcd.

ddeand 

My mistake on the 39t - I have a 38t ring on it now. Thanks for the help.

52telecaster

being a person who wants the most out of everything i have a 38 in 130 and a 33 in 110.

nlerner

You can go to a 36t ring on a 110 bcd crank, I believe. Otherwise, in addition to 50.4bcd cranks (TA, Stronglight, Nervar, the rare Shimano PX, plus new ones from V-O), you could opt for an 86 bcd crank and go as small as 28t, I believe. Those were made by Stronglight, SR, and probably others.

Another option is to attach BikinGreen 46/30t rings to a 110 bcd crank:

canklecat

If you don't mind switching rear derailleurs, and have friction shifters (downtube or bar end), the old Shimano Exage 500 CX and Deore LX long cage RDs will cover 11-32, possibly larger big cogs. That's what I have on one bike now, an 8-speed 11-32. These are 7-speed RDs, but will work with friction shifters. In index mode it won't hold the big cog securely and tends to ghost shift down to the 28T cog. That's due to a physical limitation inside the RDs that hinder cage swing. I could grind it down but haven't done so.

And there are later RDs that will handle index shifting across the 8-speed cogs.

BTW, check MicroShift cassettes. They work as well as Shimano for me.

Salamandrine 

How vintage are we talking about? TA and Sugino Mighty tour were among the most common 'compact' set ups in the late 70s.

Sugino Mighty Tour like ^^^. They will take a 34T IIRC, as standard. Sugino Mighty is quality stuff and I'd rate them higher than the first few generations of Dura Ace. I have the modern version and it's great.

TA was possibly more common. At one time they were a good value, and they can be set up pretty much however you want. Single, double, triple, with whatever gearing. There's also a Stronglight equivalent, the 49D. Modern copies of both are available, and for that matter the original TA 'cyclotouriste' is still available.

bikemig 

The easiest is to find a shimano MTB triple (or a sugino) and run them as a double. A lot of them were made and the prices are good. Those are 110/74 bcd which means you can run as small as a 34 on the inside or you can buy the nifty rings nlerner has in post 5 and go 46/30. The sugino mighty tour (hard to find) is 110 bcd.

There are "modern" 110 bcd cranks that will look good on a vintage bike.
https://www.planetx.co.uk/i/q/CSHOCN...retro-crankset

If you want to stay vintage, you can also find an 86 bcd crank like a Stronglight 99 or an SR apex. That will let you go as low as 28. You can run them as a double or as a triple. Rings are available for them via Spa cycles in the UK. Plus the prices on those rings used don't tend to be bad because a lot of those cranks were made.

Or you could go with a TA cyclotourist (or the modern version of it sold by Velo Orange). These are pricey but you can run a 46/30.

IRD also makes a "wide" compact in 46/30.

ddeand 

The bikes that would be applicable for the swap are a 1987 Centurion Ironman, a 1974 Raleigh International, and eventually, an early 80s Serotta. The Ironman is my immediate candidate, since it will be my main road bike this season. I hope to replace it with the Serotta next season. The Raleigh is mostly a cool project (and really pretty).

The major issue is that I'm getting pretty old, and I'm finding more difficult hills as I stretch out my rides and try new routes. Here in the Twin Cities, we have a tremendous path system that generally can handle both bikes and pedestrians nicely. But because of the present pandemic situation, the paths are being swarmed by pedestrians (that's not a complaint - I'm glad people are being more active). Consequently, I'm on some nice country roads that seem to go up and down more - the down part is great, the up . . . not so much. For gravel riding, I take my 2005 Blue CX 6.5, but for the road stuff, I really like my old bikes.

wrk101

Being on the thrifty side, I take an old Sugino double crankset with 110 spacing, then swap in a set of the two larger rings from a MTB triple. Instant vintage compact crank. I end up with something like 45/34.

Salamandrine 

OK, for the Ironman, one idea would be to go with something like a Sugino XD600T triple (or XD701D double). It's not going to hurt anyone to have a bailout gear. It will look basically correct on an Ironman, because they haven't really changed the design in like 30 years, other than making the chainrings 10s compatible. This allows you to convert to a stealth modern drivetrain if you want. There's also the slightly more traditional Alpina crank. If you look for them on sale they can be fairly cheap.

The vintage 70s / early 80s style Mighty Tour crank would look at home on the Raleigh and the Serotta, IMO. TA would also be good on the Raleigh. They are a bit floppy for my taste, but depending on your pedaling style, can be very versatile, and they certainly look cool.

FWIW there are similar but different pedestrian issues here in LA, due to the pandemic situation.

Here's an XD600T on my Clem. 30/40/50 chainrings. Says late 80s all over it...

reissue59

I run 7700 and 7800 Dura Ace on a few bikes.
switched the 53 ring to:
for the 7700, 50 shimano ring, 30 cassette.
7800, found matching nos 7800 46 ring, 30 cassette
7800, also matching 7800 nos 50 ring, 30 cassette
works awesome and the 7800 matching ring looks great with the crank

non-fixie 

The 50.4 BCD with TA Cyclotouriste rings is definitely the most versatile. Made this for mrs non-fixie recently. Classic French touring setup:



Also nice, the Stronglight 99. Here in 49/32 guise:



SR made something similar in the Apex series. 50/30, I think:



Speaking of Apex, they made an 118 BCD Campy clone as well. I used it with a 36T inner ring and an NR transmission for L'Eroica in 2017.



For L'Eroica 2019 I rebuilt it with Simplex and a Stronglight crankset with a 37T inner ring, supplied by jonwvara:

Lascauxcaveman 

@non-fixie, your input is much appreciated. And pretty much always drool worthy.

Piff 

It's the wrong era, but these are NOS 130/74

https://www.ebay.com/itm/NOS-SUGINO-...oAAOSw0Xhenmva

AJI125 

If you decide to go the triple 130/74 modified route, I just posted on modifying to a sub-compact on a 9s triple. Wrong era but there may be older triple setups like this: https://www.bikeforums.net/classic-v...e-gearing.html

And for TA, BikeRecylery has one (remembered seeing this). So far I've just bought a couple cheap finishing items, but they've been great with quick shipping, good descriptions, etc.: Specialties TA Pro 5 Vis Cyclotouriste Crankset: Capped Pedal Holes Early Version - 170mm x 54/44T Double - English (Near Mint+ Low Miles) - Bike Recyclery

I remember looking at some vintage Stronglight 110 BCDs as others have mentioned. And I think the smallest you can get in that route is 34t chainrings.

The Dura Ace FC-7703 triple crank (9s era) had a 90 BCD inner I believe, 130 outer. But it doesn't really match that era, and used octalink (not sure if that's a dealbreaker) https://www.ebay.com/itm/Shimano-Dur...YAAOSwGylebcLE

Rene Herse are very nice looking but pricey. Pretty classic looks. https://www.renehersecycles.com/shop...-double-crank/

VO has a couple options that may interest you: https://velo-orange.com/collections/...rankset-34x48t , https://velo-orange.com/collections/...-crankset-mkii

IRD Defiant looks nice I think: https://www.interlocracing.com/shop/...ct-double-2801

natterberry 

It’s 92, but also tripleized off the middle ring.

AJI125 

I'll try to log that in the memory banks, thanks! That comment brings up another idea that should've been obvious, tripleizer. And here's a thread on this exact idea: https://www.bikeforums.net/classic-v...iplelizer.html. Interesting idea on that thread to try the tripleizer ring in the outer and see if the inner fits with the bolts/spacers... not sure but at least the inner bolt holes are offset in the two tripleizers linked below, so they wouldn't contact the spider arms. Just have to find the right BB length if you mount inner, and deal with the wide Q, I think chainrings are nominally spaced around 5mm (so +10mm on spindle), but I'd measure what you have first to check. You'd add no more than double the chainring spacing to the BB spindle to move chainline to where you currently are, I think. Also have to see if your spindle is symmetrical or not, I don't know on the old DAs.

Willow 46t 130 BCD tripleizer: https://www.ebay.com/itm/Willow-Trip...t/183805425281. Could try a 46-32?

TA makes a tripleizer for 130 BCD, up to 42t. https://www.peterwhitecycles.com/ta-chainrings.php (Alize K Tripleizer Middle Chainring (accepts a 74mm inner chainring)) So you could run something like a 42-30 or 42-28.

Probably some more out there, but at least some decent potentials for a conversion if you want to keep those current crank arms. Best of luck!

mgopack42 

I put new TA chain rings on my 7400 DA crank, 48/38/28. had to use a pretty long spindle, so the chain line isnt the the best, but it shifts with a 14-30 freewheel. and now I am ready for Eroica 2020, even if it is next year!.

natterberry 

No problem! Totally doable. Here’s a Stronglight option:

https://www.spacycles.co.uk/m2b0s149...D-Adaptor-ring

52telecaster

Wow they have a 38! My 39 works but i would have bought the 38 if i could have found it.

Bamicus

Any one ever try a compact crank on an 8 speed campy group?

Spaghetti Legs 

Im using IRD 46-30 with 8 speed Ergos, Racing Triple RD (I’d bet a regular short cage would work though) and on another Sugino XD 50-34 with a regular Chorus RD

Bamicus

Where did get the Sugino? Does it work with campagnolo ergo shifter? What BB does it take? What is an IRD?

ctak

ddeand great idea, let us know what direction you take

+1 for SR Apex
Here's my preferred 47/34 compact for long rides, converted from the stock triple chainset on my 1980 Centurion Pro Tour



Used mostly in a 2x9/10 speed setup w/ Simplex Retrofriction downtube shifters, long cage Ultegra RD, "pinched" Cyclone FD, KMC chain, 12-27t cassette (or 13-29t with campy hubbed wheels)..