Wogster

Does anyone know of a modern square taper compact crank and could you replace a standard 52/42 crank with a compact one, without needing to replace lots of other bits and pieces? I think the RD has lots of room in it, not sure about the front one, other then it's Suntour and was made in 1975.

Capecodder

This is one of many, what's your price range?.. You should not have a problem as long as the RD can wrap enough chain. The FD should be fine.

https://www.amazon.com/Shimano-2300-F...8697104&sr=1-6

Wogster

Price range is cheap as I can get The Shimano has two problems, first it looks way too modern, second Shimano NA doesn't list that part in their catalogue, so local dealers may not be able to get it. May need to shelve that project though....

Bianchigirll 

what chainwheels do you want to run? you could always go with a 110BCD triple and just leave the granny off.

Wogster

Thinkin' 53/34, we got some powerful nasty hills here.

Old Fat Guy

A compact is not a 53/34, and not many FD's can candle that jump. A compact is usually 50/34 or 50/36

Modern cranksets are mostly 10 speed, and you would have to add spacers to the chainring bolts to run 8 speeds or less. Modern cranks have the rings spaced closer than a 8 speed or lower chain will shift. Branford Bikes sells the proper spacers.

Methinks you are biting off more than you can chew. It ain't that simple. In any case, you need to provide exact components to get an intelligent answer. With the info you've provided, you will get lots of of the opposite answers.

Wogster

50/34 is what I mean't to write, about spacers, it's got downtube friction shifters so the amount the FD needs to move over between shifts isn't really an issue. It's not likely this bike will ever see, brifters, at least not on my watch, and I don't really care what happens to it after. It uses a Raleigh threaded BB so it's limited to square taper, no matter what.... I think Velo Orange has a crank that might work, and might fit the look of the bike better then the Shimano.

Bianchigirll 

what cranks do you have now? you need something smaller than a 39? I haven't seen your hills but I might be inclined to do more a triple thing maybe a 53(2)/39 and 30 or 28 granny, or you could use something slightly larger for the granny.

Road Fan

First, the issue with 10 speed is that the chainrings are close enough together that a non-10-speed chain might rub on the large chainring when on the small chainring, and when driving a smaller rear sprocket. Second, a the type of square taper you have to use is a key consideration. There are Campy chainsets on the market, ebay at least, that use a modern ISO taper. If you have an ISO BB, V-O, or what have you. Third, many easily available compacts are black anodized or partly carbon, because they were conceived for the racy racer race-like bike market. Many of these, but not all, use non-square BBs. Not bad products, but you can see where it'll be significant to answer some more questions about what your needs are.

You will benefit from repositioning your front mech to be at the correct 1 mm or so height above the large chainwheel. You should check that your braze on allows that much adjustment downward.

Beyond all this practical stuff, I've found I'd rather deal with a triple than the funny gear distribution of the compacts I've set up. I've used a Suntour Cyclone FD with Campy compacts, and they shift together beautifully - you should have no problems with the old SunTour FD.

OFG's about to tell me to HTFU, but, well, it is what it is.

Where does Ontario have hills? I think I want to see them.

Have fun, regardless!

Wogster

Right now it's a 52/42, but it's also for some odd reason 165mm crank arms, so a 50/34 with 175mm crank arms would be just about perfect.

Wogster

I don't need 10 speed, considering it's 6 speed at the back, the FD is a clamp on, so I have no qualms about moving it, where a triple becomes an issue is whether the BB spindle is long enough, it's a Raleigh threaded BB, so I don't want to monkey with it, other then occasionally rebuilding it with fresh bearing balls. Ontario has lots of hills, in fact little of it is flat, and most of the flat areas are because construction has made it that way.

Capecodder

What are you running in the rear for gears? Why not switch to a wider range freewheel say 14-34, it would make things easier?

Old Fat Guy

You will have to 'monkey' with the BB if you do any upgrades. Chances are a modern crankset, even square taper, will require a new BB. You will need to get those aforementioned spacers to run your 6-7 speed chain on the new crankset.

If this is for the Raleigh Delta, you are on a fool's errand.

bigbossman 

It seems you've mis-interpreted all the technical advice given to you.... which tells me you might not really know what you're getting yourself into.

Wogster

Well I now know not to bother, Capecodder had an interesting idea, with a megarange freewheel, it's actually about the same difference as to gear inches, I can probably go 7 speed and the parts are cheaper.....