Subcompact gearing - 42-28 possible with T47 BB?

[EnginCycle]

The Sugino rings are of incredible quality. The thing to realize is there are two versions and some are specific to certain inner rings. They need to be the ones that work with the 30 and 32 inner rings versus the ones for the 34 or 36 inner rings. The rings are flat on both sides so they can be mounted on the inner tab and the outer tab. My spider uses the inner location and the 74 ring lives on a mount that does not require spacers. The system uses single bolts on the inner and male/female bolts to mount the outer. Even though it is a single outer ring it uses the bolts for a double.

They will be available in black only at the moment and hopefully will be $150 each. If interest is big and the numbers allow there can be colors but they would be more and limited to only a few colors.

Again if anyone has questions feel free to ask here or send me a PM or email through the message system.

Thanks,
Drew

[Mark McM]

Originally Posted by NHAero

Mark, how special are these Sugino chainrings? Peter White's site shows TA Zephyr rings that are 110 BCD for the middle position of a triple, from 34T to 46T, in one tooth increments at that.

Apart from being made in larger sizes, the main difference between 110 BCD middle chainring and the OX outer chainrings is the addition of an anti-chain-jam pin. Another possible difference is that chain lift pins on OX chainrings are optimized for larger chainring differentials, although I've found that typically the chain lift pins can tolerate a wider range of chainring differentials than they are labeled for.

It's great that TA Specialites make 46 tooth middle chainrings, but there's still a need for a 48 tooth chainring for the popular 48/32 combination.

[NHAero]

Of all the modifications I can contemplate, drilling, tapping, and making an anti-chain-jam pin seems modest!

Originally Posted by Mark McM

Apart from being made in larger sizes, the main difference between 110 BCD middle chainring and the OX outer chainrings is the addition of an anti-chain-jam pin. Another possible difference is that chain lift pins on OX chainrings are optimized for larger chainring differentials, although I've found that typically the chain lift pins can tolerate a wider range of chainring differentials than they are labeled for.

It's great that TA Specialites make 46 tooth middle chainrings, but there's still a need for a 48 tooth chainring for the popular 48/32 combination.

[owly]

Finally got around to putting together the 2x after being off the bike for a few weeks with an ITband issue.

I'm a clueless beginner bike mechanic, so the switch took me all day, reading and figuring things out.

What didn't quite work is the Red derailleur very slightly contacts the chainstay when resting in the small ring. I do know of a couple of carbon clamps with cutouts in them (to fit the lower bottle mount in between the clamp gap) but thats an option for later on. That would raise the derailleur quite a bit though.

Not quite sure what it is about my chainstay design that positions the derailleur like this, as there's a few online pics of other similar builds (with a 40t large ring) with the end of the cage clearing the chainstay easily.

Took me some head scratching to figure out the positioning of the Carbon Ti X-Pull for best derailleur swing-out/leverage to the large ring.

Anyway, the shifting works really well, now I've fine tuned things.

12-27 in the back, with 40/26 out front. Will also get an 11-26 and a 11-28. Can go up to a 43t large 2x ring with this bcd, but 40t is fine for my riding.


https://imgur.com/a/jViC6fh