Scatterjoy

Hi

I've got a modified 70's Raleigh Sport that seems to have a later era crank and a somewhat modern cassette/ hub. It's really a smooth setup and works great. It's a rider, not trying for restoration.

the problem is gearing. I'll never make it up a hill with the current setup.
the choice is to either add a larger sprocket to the cassette or replace the crank with a smaller diameter.

I would prefer to search for a single front crankset but it's probably smarter to identify the cassette and count the sprockets and search for some options. I for-see lots of Google time to figure it out.

Any guidelines to get started? Like "look for Brighton cassettes" (totally made that up...) Or "all Raleigh cranks fit..." or "here's a great source of cassette parts..."

hoping to benefit from some of your advanced knowledge before taking this apart again. It's such a pleasure to work on rather than googling.

abdon 

I'm sorry, my crystal ball is broken. You are going to have to actually say what size front rings and rear sprockets you are using now. I can't even tell from here how many sprockets are in the rear nor the brand and model of the crank, so please do volunteer that info.

repechage

With a single ring up front if I read this correctly, the question becomes, what is the low you need and the smallest high gear you can tolerate?
using inches of development.
as it is a Sports, confirm the tire outside diameter too.

nlerner

So it’s a Sports without an internal gear rear hub? If so, I’m guessing it’s a threaded freewheel/gear cluster on that rear hub, not a cassette, and probably five cogs total unless someone really stretched out the rear end of that bike—or is it a Sprite, which would have come with a gear cluster originally?

Trakhak

Edit: see next post for photo of bike. Lady's '70's-era Raleigh with front and rear derailleurs.

CO_Hoya 

Pic found in OP's gallery.

As I see a rear derailleur and it has a vaguely Raleigh Sports shape I will assume this is the specimen of interest. More, better pics will be needed for posters here to be able to assist.

Trakhak

Forgot to say that Scatterjoy should upload pictures of the bike, including closeups of the parts in question, to his/her Bike Forums gallery so that one of us can post them in this thread and end the speculation about what parts are needed.

Scatterjoy

Thanks for your inputs. I’ll grab some pictures (but still can’t post)

guess my question was TOL specific. If I want to increase a cassette gear or shrink a crank gear,

the cassette will have any number of shapes and sizes? It’s not a Raleigh 3 speed.

Where to look for rings with the same center fitting?

the crank must fit specifically to Raleigh, right? It too does not appear to be original. But if I look for a crank gear, how do I find a hub match? There are hundreds? Thousands? Of choices maybe?

bark_eater 

The most direct path I can suggest I finding a bike coop, or worst case financially a commercial bike shop, and have them install a new cassette with the lowest gearing that your rear derailleur will handle. You will likely need a new chain also.

Changing out the crankset might be feasible at a Coop that has used parts, the tools and old bike experience. If you went to a commercial bike shop for this the cost might give you a nosebleed.

Third option, the relies on your ability to find a hens tooth, is to chase down a 36 tooth chainring that will fit your crank arms. You would be looking for "116 BCD" and "36t". Best chance would be to find a bolted together set of 52t and 36t. They come up on eBay occasionally. Good luck.

P.S Its kind of hard to tell from your pictures, but a 116, bcd 40t inner chainring might be enough of improvement, and they are a lot more common.

John E

The single chainring limits your options considerably.
I would consider replacing the current short cage derailleur with a SunTour VGT. If you have an old-school 5-speed screw-on freewheel, as opposed to modern freehub/cassette, 14-34 should work nicely with the SunTour, because this was a very popular combination on early 1970s Japanese bicycles.