Crank choices for smaller chainrings?

[Mark McM]

Originally Posted by oldpotatoe

No, just use these, mount CR on middle position. Short chainring bolts, for single rings, used in track also. Done this bunches of times for shimano and Campag triples..

Unfortunately, a typical 110 BCD 46 tooth chainring will be intended to be mounted in the outer position (middle position is typically 38 teeth or less), so the bolt holes will be countersunk on the wrong side for mounting in the middle position. For a single crank, this would be fine - the chainring bolts would just be protruding a bit. But when using the small (74 BCD), the chain may rub against the chainring bolts - particularly with such a large chainring size difference, and what will may be a skewed chainline with a short BB.

Only a few companies make 110 BCD chainring larger than 40 teeth with the pins and countersinks on the correct sides to be mounted in the "middle" position. Sugino makes them for their OX series dual BCD mico-compact cranks, and IRD makes them for their similar Lobo dual BCD micro-compact crank.

[stien]

Originally Posted by Geekonbike

For those that are running the 48t big ring. How do you like it?

For me the 50t was a weird size. I ended up liking a 52t better. Not sure why but I seemed to be able to push 52x16 ~86" gear more comfortably that a 50x14 ~94" too tall and a 50x16 ~83" too short.

Sounds like you want a 15t cog.

[RobJ]

Originally Posted by Geekonbike

For those that are running the 48t big ring. How do you like it?

For me the 50t was a weird size. I ended up liking a 52t better. Not sure why but I seemed to be able to push 52x16 ~86" gear more comfortably that a 50x14 ~94" too tall and a 50x16 ~83" too short.

I am running the 48T on a Praxis Zayante. Typically I used a 52/36 on my road bikes but thought I would try out the 48/32 for the winter and while I am getting back into shape. I really like the 48T and a lot of people seem to concur on the use of the 48T over the 50T. I find the combinations to be very good. And if you don't want the low 32t, they also have a set of 48/36 that they sell.

[fa63]

Originally Posted by Mark McM

Unfortunately, a typical 110 BCD 46 tooth chainring will be intended to be mounted in the outer position (middle position is typically 38 teeth or less), so the bolt holes will be countersunk on the wrong side for mounting in the middle position. For a single crank, this would be fine - the chainring bolts would just be protruding a bit. But when using the small (74 BCD), the chain may rub against the chainring bolts - particularly with such a large chainring size difference, and what will may be a skewed chainline with a short BB.

Only a few companies make 110 BCD chainring larger than 40 teeth with the pins and countersinks on the correct sides to be mounted in the "middle" position. Sugino makes them for their OX series dual BCD mico-compact cranks, and IRD makes them for their similar Lobo dual BCD micro-compact crank.

Thanks for this info. I inquired with Sugino about their chainrings, and they want $250 for the 46-30 combo... I also contacted IRD but haven't heard back yet.

I have been scouring the web for the past few days, and I think I have found an alternate combination that will work. TA Specialties makes a 46T middle chainring for 110 BCD. They are hard to get, but Peter White Cycles seems to have the silver version in stock. The silver color might clash with the black Dimension crank arms, but oh well. I also found some chainring tab shims that will cover the outer bolt hole to make things look a little tidier. I should have all the parts by middle of next week; I will post the results here.

[zzy]

Originally Posted by Mark McM

Unfortunately, a typical 110 BCD 46 tooth chainring will be intended to be mounted in the outer position (middle position is typically 38 teeth or less), so the bolt holes will be countersunk on the wrong side for mounting in the middle position. For a single crank, this would be fine - the chainring bolts would just be protruding a bit. But when using the small (74 BCD), the chain may rub against the chainring bolts - particularly with such a large chainring size difference, and what will may be a skewed chainline with a short BB.

Only a few companies make 110 BCD chainring larger than 40 teeth with the pins and countersinks on the correct sides to be mounted in the "middle" position. Sugino makes them for their OX series dual BCD mico-compact cranks, and IRD makes them for their similar Lobo dual BCD micro-compact crank.

This is correct. You cannot just put a outer chainring in the middle position, even with single ring bolts. The bolts need to sit flush against the ring. I;ve tried it with a number of rings - no luck.

[oldpotatoe]

Originally Posted by Mark McM

Unfortunately, a typical 110 BCD 46 tooth chainring will be intended to be mounted in the outer position (middle position is typically 38 teeth or less), so the bolt holes will be countersunk on the wrong side for mounting in the middle position. For a single crank, this would be fine - the chainring bolts would just be protruding a bit. But when using the small (74 BCD), the chain may rub against the chainring bolts - particularly with such a large chainring size difference, and what will may be a skewed chainline with a short BB.

Only a few companies make 110 BCD chainring larger than 40 teeth with the pins and countersinks on the correct sides to be mounted in the "middle" position. Sugino makes them for their OX series dual BCD mico-compact cranks, and IRD makes them for their similar Lobo dual BCD micro-compact crank.

Get a 'simple' chainring w/o pins and ramps and mount it backwards..it'll work fine.

[Clancy]

Originally Posted by Formulasaab

I've pondered this question a few times over the last several years and the answer I come up with every time is White Industries. I've now bought three VBC setups (with WI BB).

I have been thoroughly pleased with the VBC crank in every way. I dis have one chainring that had defective shift-ramp pins. I contacted WI and had a new one in my hands a couple of days later, no questions asked. I even met the guy who took care of me a few months later at the Philly Bike Expo and he remembered me and we chatted. Nice people.


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I just installed a WI VBC crankset with a 30/46. Although the workmanship is brilliant, the shifting has been pretty poor, so much so that I'd like to toss 'em I'm so frustrated.

Shifting from small to big - if I have the cage adjusted correctly, the big chainring does not pick the chain up, slips and slips and slips. To get the chainring to pick up the chain I have to adjust the derailleur cage such that it's adjusted too far out and ends up throwing the chain off.

Adjusted correctly, won't shift or takes forever ( slipping and grinding)
Adjusted so it will shift, ends up throwing the chain off.

There's no machined shift ramps on the 46T outer chainring.

I've been pretty disappointed.

Suggestions?

[bikinchris]

I haven't read this whole thread, but what about SRAM XX?

[Andy340]

Initially had front derailleur issues with a 10 speed campy compact front mech: cage was issue so used a newer 2015 chorus front mech (cage shape is different) and aligned with one of these : https://www.universalcycles.com/shop...RoCg4YQAvD_BwE

Works a lot better now - not as good as with chorus crank but more than good enough for what I need

[Formulasaab]

Originally Posted by Clancy

I just installed a WI VBC crankset with a 30/46. Although the workmanship is brilliant, the shifting has been pretty poor, so much so that I'd like to toss 'em I'm so frustrated.

Shifting from small to big - if I have the cage adjusted correctly, the big chainring does not pick the chain up, slips and slips and slips. To get the chainring to pick up the chain I have to adjust the derailleur cage such that it's adjusted too far out and ends up throwing the chain off.

Adjusted correctly, won't shift or takes forever ( slipping and grinding)
Adjusted so it will shift, ends up throwing the chain off.

There's no machined shift ramps on the 46T outer chainring.

I've been pretty disappointed.

Suggestions?

Which derailleur?

Best to use a derailleur designed specifically for compact or triple cranksets. I use Campy myself and it works a treat on a bigger jump than that.


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[Clancy]

Originally Posted by Formulasaab

Which derailleur?

Best to use a derailleur designed specifically for compact or triple cranksets. I use Campy myself and it works a treat on a bigger jump than that.


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Using SRAM Force, same set-up that I had with the SRAM Force crankset w/ 50/34.

I've readjusted the height of the derailleur of course, and proper cable tension, etc.

The shifting is no where as quick or clean.