My all-around commuting road bike is a Salsa Casseroll, geared right now at 39/53 and 12-25 in the back, both of which are too high for my purposes. I'm working on replacing the drivetrain and am hung up on the crankset. I'd like to keep it a double, but it's very hard to find doubles with low gearing. I was looking at some mountain doubles but I'm wary of the width that they would place the pedals. Yes, the 'q-factor', I can in fact feel it.

So then I looked at the Velo Orange Polyvalent 30/46 crankset, which is close, but I'd want to go even a little lower. With a 11-28 cassette and 26/40 chainrings I can get 25 to 98 gear inches, which sounds about right to me. My first thought was to replace the Polyvalent's chainrings because it's hard to find cranks with 110/74 BCD, but I did find some:

https://harriscyclery.net/product/dim...r2330-qc49.htm

They're both square taper, take the same length BB, and are 110/74 triples. But I trust more the Polyvalent because they're sold as a set. If I throw some chainrings on the middle and inner spots on the Dimension cranks, will it shift well? I'd use nice TA chainrings because I can get them in the exact size I want.

As far as the chainrings themselves go, I'd use https://harriscyclery.net/itemdetails.cfm?ID=1427 for the larger of the two. Says it fits the middle position of a triple so no problem right? And for the inner ring, I'd use a sugino ring: https://harriscyclery.net/product/sug...r1151-qc49.htm Logic tells me that this setup would be fine, but I've done some questionable things with bike parts with not the best results. And of course we see parts marketed as sets that are 'supposed' to go only with each other. In short, it's hard to separate the cases where you can be flexible with bike mechanics from the cases where you can't.

I trust that the unmodified Polyvalent works fine, can I do the same with my Dimension/TA/Sugino setup?

And the last issue is chainline. Shouldn't I move the cranks outward a bit in order to make a perfect chainline? I'd rather not do that, so how much does this matter? Obviously the Polyvalent and the Dimension cranks aren't the same, but can I extrapolate that using a 113mm BB will result in a viable setup because the Polyvalent, a similar 110/74 bcd triple also uses a 113mm BB?

Or lastly, what are other options for a very compact double? I suppose if I spent 100 bucks more I could get a White Industries VBC road cranks. That would probably have a better chainline than a inner/mid triple-to-double conversion.

Whew, thanks for reading. I hope was clear, and thanks in advance.

Check out TA cranksets. They used to offer road doubles that accepted very small inners. I'm not sure if they still do. Another possible source to check is Peter White Cycles. They stock a nice assortment of this kind of niche product.

What's wrong with a triple? It would solve all of your gearing issues without fooling around with mismatched or obscure parts and wouldn't leave big gaps in the commonly used range of gears. A Shimano 105 triple is geared 50/39/30 and the 30T granny ring can be easily and cheaply changed for a 26.

I use Campagnolo's 'Race' triples on my sport bikes, a 50/40/24,

any one want a new, take off 74bcd /30t?

And if thats not enough and think you need more - suggest you check out the double and triple cranksets commonly used on cyclocross machines.

Chainrings are typically 34/50; 36/46; or 50/39/30 and its fairly easy to go smaller.

Ok, I'm probably being too particular on the issue of a double. Cyclocross doubles are out the window because you can't get very low on 110 BCD. Touring triples, close. Basically, what I want is a mountain triple with narrower tread. I have no need for wide tread because I'm on a road bike with relatively narrow tires. So in that case, I could turn the Dimension cranks above into a triple. The only reason I'm fixated on those cranks is because they're the only ones I can find as just cranks with no chainrings. It seems silly, not to mention more expensive, to buy a whole crankset only to replace all the chainrings when I can buy a bare set of cranks. They're sort of generic, but that doesn't mean they won't work. Or that they will work. Can anyone comment on possible mechanical problems with that setup for a 9-speed drivetrain?

Perhaps get a Triple, and substitute a guard flange for the outer chainring.
Cyclo-crossers use them on both sides of a single chainring,
so there are some nicely made ones available in aluminum and carbon fiber.
110, 130,135 bcd.

I'd say be aware that with big drops between 2 chainrings,: read the terrain.
once you are in the small ring, wait until you are at the crest of the hill
so the pressure you are exerting on the chain can be slacked off,
and the chain will shift up to the larger ring much better.

NB
Bottom of this list :
https://www.peterwhitecycles.com/chainrings.asp
there are Triplizer chainrings, to substitute for the inner chainring
on double road cranks [you will need a wider BB axle]
then you bolt the small 3rd ring to the 2nd one.

130bcd, or Campag 135, and a 42t for 70's 144 cranks.

there is a Sugino external bearing type crank made so a 2nd chainring
can go on either of 2 bolt circles
Where to buy them other than Japan , I don't know..
see this page:
https://www.suginoltd.co.jp/english/o...in_english.htm

Others?

If you are talking chain line, a road triple sits about 5mm closer to centerline than a MTB triple. Not much of a difference.

Yeah, I was a little concerned with what Peter White says about Shimano and Sugino chainring spacing. I have no idea what kind of standards those Dimension cranks are made with.

Those Sugino OX801D cranks are gorgeous though!!!! Too bad they are over 500 bucks!

However.... I just did my taxes, so maybe some White Industries VBC road cranks are in order. That seems like a sure solution. Not a huge fan of the retro look, but I can't complain at this point. Plus they're made in the US! I'm just tryin to do my part to stimulate the economy