Road Fan

NIIICE! Thank you!

Road Fan

But Bob, you can use a cassette with a smaller little end, and then shrink the big chainring proportionately. 52/13 is very similar to 44/11. If you then went to 44/30, you could still have an 11/30 cassette with a 26" granny gear, just like with a triple. Or you could do a compact triple, 44/34/24 and actually have gearing a little smaller than that.

Dfrost 

PM sent about available 13 and 14 1st position cogs.

bark_eater 

Even on a good day I'm not Bob.
There are a couple barriers for flowing in the small chain ring direction. Vintage bikes have cranksets designed to work with a 14t first position freewheel cog. For the want of a $5 14t first position cog your into changing out a crankset and or bottom bracket, and if your going to a triple with smaller rings, maybe a new front derailleur.

For me I'm working with 110 BCD cranks set up as doubles, so my "grannie" is 34T.

Then there's the extra wear from running small cassette cogs. I don't the document miles I put on my bikes, but if the 2 that have about the same use on fresh chains the one with the 11-28t cassette is showing chain stretch before the one with a 14-28 freewheel.

SJX426 

The Bike Friday I had for a short time had a Capreo hub and cassette with a 9 tooth sprocket. I can see the use of low tooth count cassettes for folding bikes with the small wheels. Negates the need for large chain rings.

AJI125 

Here's a 13t 9s first position Ultegra. You might just try it, or see if you can slip a 0.4-0.5mm or so extra spacer in there to get to 8s spacing. Only bought 1 used cassette so far but worked fine (albeit with custom spacers to get 5.0mm for Campagnolo), an old 12-28 Shimano 8s loose cog.

https://www.universalcycles.com/shop...52&category=40

https://www.amazon.com/dp/B001GSKRMG...v_ov_lig_dp_it

pastorbobnlnh 

At the moment, I'm staying on the GA coast and riding my fold-up, fit in a big suitcase, check as luggage on Southwest, Dahon 20" (406mm) wheeled bike.

It's set up as close as I could make it to a road bike for flat riding. Early to mid-1990s Shimano 105 double, RD, FD, and barend shifters (in friction mode). The chainrings are 53-42 and the 9-speed cassette is 11-24. Only occasionally do I use the 42T for climbing over a couple of bridges crossing the Inter-Coastal waterway. Even when I have a significant tail wind, can I stay in the 11-53 combo very long. Yesterday, when it was slightly breezy, I mostly used the 13-15-17 sprockets.

Hahaha! We all do well to just be ourselves!

bark_eater 

I saw those and there are some Miche sprockets available listed as 8-9 speed, so I'm kind of curious about what their fixed spacer dimension is.

The Miche catolog is here: https://www.miche.it/pub/media/productattach/m/i/miche-catalogo-2021_EN-FR-DE.pdf

Check pages 110+112

AJI125 

Yeah they must use something in between? Or maybe just 9s spacing and "close enough"? Here's a catalog shot of the 8s/9s page, the first position sprockets are the same for 8 and 9 (SPPR90PS), while the rest of the sprockets and spacers differ. Before I pulled up that link I just pulled up 2020, but should be the same I'd think.

shoota 

LOL that gave me a good chuckle, thanks!

bark_eater 

I got a new scheme... If I take a 10 speed cog an add a 1 mm spacer and factor in the extra thickness of the 7 speed second position cog I get a center to center of 5.025. That's debating hair color close.

AJI125 

I'm running a SRAM 8 11-28 (still sorting stuff out, intended for a 46/30 crank but currently a 53/42 old Croce D'Aune since it fit the BB until I get a replacement for a pedal thread issue) with some hodgepodge spacers to get 5.0 spacing for 8s Ergos. The reduced spacing of the first two cogs with built-in spacers seems to throw off the shifting to 1st position just a tad on the stand (down to the first position), but when I was out riding I didn't have any trouble other than finding a downhill where I could pedal 53x11 at any justifiable cadence. When I first had the 12-28 on there, with only 1 built in spacer, shifting was crisper down to the small cogs, and I might just go back to that cassette. I would guess your scheme will work just fine.

Dfrost 

OP and I are both curious about the 13T and 14T 1st position cogs I’ve offered him. They both came from 7-speed cassettes (13 is stamped G-H-K-M, 14 is stamped F). For confirmation, here’s Sheldon’s charts of Shimano cassettes by Group letter:

https://www.sheldonbrown.com/k7-7.shtml

Here are the cogs themselves:



BUT, both of these measure only 3.9mm (+/- a few hundredths) thick, unlike most 1st position cogs that are a full 5.0mm thick with an integral spacer.

Please help us both remember what goes under them to achieve correct cog spacing. OP thinks that black 1.13mm thick spacer in the photo above is supposed to go between position 2 and 3, and he’s probably correct.

BradH

That black spacer goes between one and two.

pcb 

Not sure I understand the concept of vintage cranks being designed for 14t smallest cogs? How does switching from a 14t to 13/12/11t smallest cog require changing cranksets?

bark_eater 

Not necessarily. If you can make use of 52-11, pushing 127 gear inches at 35 mph, more power to ya. You can tell me all about it when you lap me.

bark_eater 

Sorta Naw... but Naw... but Yea....

https://manualzz.com/doc/53868345/sh...-exploded-view

The spacers go up against a riveted cog body.

So it looks like 7 speed 13 and 14t first position cogs use a spacer with a 6 cog bolted body. 11t first position cogs match with a 12t 2nd position cog that uses a spacer with a 5 cog bolted body? I'm not absolutely sure about 7 speed 12t first position cogs, but I've seen 13t 2nd position spacers. I think.... and I haven't confirmed with cogs in the hand yet, but it looks like 10 speed 13t first position cogs have just about the same spacing as Dfrost's cogs, which was my "What the?" moment for yesterday.

pcb 

Right, this is exactly where my not understanding comes in.

You (paraphrased): vintage cranks were designed for 14t smallest cogs...not being able to get a 14t cog means you're changing crankset/bb
Me: What part of the crankset prevents you from using a smaller outer chainring to maintain the same high gear with a smaller cog? Why is the outer ring fixed at 52t?

bark_eater 

Well, 52-14 is 100 gear inches. 41-11 is 100 gear inches. Might need a new front derailleur. Smallest ring your crank takes is 39? Hrmmm Luckily I've got a 110 bcd crankset, and I can run a 34 small ring. Or if I had a 13t cog I could be at 100 gear inches with a 50t chainring and use the original derailleur and crankset. Crazy talk?

PS had to edit for math glitch. For my purposes, a 48-34t chainrings with a 13-30t 7 speed cassette gives me a 96 to 29 gear inch range.