Cead_tinne

Is there a smaller chain ring available for the crank set listed below? I didn't find any options on google. I put my bike together 4 years ago and never imaged I would want any lower gearing, but now i have two kids and they are getting really heavy towing up the hill we live on.


SRAM Rival Crankset 2013 Black, 180mm, 34X50T
Shimano Ultegra 6700 Cassette 11-28T

fietsbob

Nope, 34t is the compact double 110 bolt circle minimum, but you can close up the difference with a smaller Outer chainring..


Consider putting a long cage RD on so you can put a 12-36t (or 34t) cassette on, and a new chain.
[and/or a triple crank]

Marcus_Ti

The smallest standard rings for a 110BCD crankset is 34T. That is it. To get a lower crankset granny gear requires different crankarms.


Note 1) PraxisWorks has a 48/32 crankset based on 110BCD...that they make work by doing some fancy engineering of bolt placement inside the the ring.

Note 2) There are several 46/30 (or lower) cranksets to pick from-however almost all are square taper BB. And will cost $250USD-$400USD new retail. In no particular order...IRD Defiant 46/30 ($250), White Industries VBC cranks and rings ($200 for crank arms plus $200 for rings), Sugino OX901D 46/30 ($399).

Racing Dan

An option I have considered for myself, is getting a lower end (Sora) groupset with a triple 30/39/50 crank and a suitable cassette. An other option is just getting a new (mtb) rear DR with a long cage and and a ~11-34 cassette. I believe SRAM is cross compatible between road and mtb without too much fuss.

jimc101

33t if you look around SPECIALITES T.A. 110 BCD inner 33-36t :: £28.00 :: Parts & Accessories :: Components - Gears - Chainrings - TA :: Spa Cycles, Harrogate - The touring cyclists specialist.

woudl look at the RD gearing as the cheapest option as suggested for a larger/lower ratio, going 3x at the front will either be expensive if you have Shimano STI's, or impossible (as in it not made) if you have SRAM shifters

Cead_tinne

I thought 30t was the max even with a long cage ?

fietsbob

You're in Eugene, Consult with some bike shops there, they will show you options..

2 parts: Capacity, and wrap up.

MTB Rear Derailleurs have bigger numbers in both..

XT is as fancy as ultegra .

oldbobcat

The problem with smaller-than-standard chainrings, i.e. the 33t on a 110mm BCD, is that as the rings and chain wear, the chain might start riding on the crank spider flange instead of mating properly with the cog. This will cause the chain to skip. We had a talk about this some years ago with guys using 38t cogs on their 130mm BCD cranks. You only get a less than 3 percent reduction anyway.

Conversion to Shimano STI, using a medium-cage road rear derailleur and/or triple chainrings, and possibly a MTB (9-speed) rear derailleur is certainly doable but levers, a crankset, and a front derailleur will add to the expense. I guess to save money you could run double-tap up front and STI in the rear, but, really?

My suggestion is a SRAM WiFli 10-speed rear derailleur, available in Red, Force, Rival, and Apex (choose your price point), and an 11-32 cassette. That derailleur might even work with an 11-34 cassette, but you'd be on your own with that. You might need a longer chain. You can keep everything else as it is.

Cead_tinne

I'm actually using Shimano STI shifters. The front crank set is the only thing SRAM. I can't remember why i did that, i think it was for the crank arm length. I like the idea of the mountain bike 9 speed rear derailleur. I did a little googling after reading your post. i think i would just need a 9 speed derailleur, cassette, and new chain, right?

Racing Dan

The new Shimano R3000 GS rear DR takes a 34t, but is technically a 9 speed. I do how ever think it would work just fine with 10sp as well.

Take note. The new Tiagra 4700 RD does not work with older shifters, even if its a 10sp part. Cable pull is different.

Cead_tinne

Ok sohow about a Shimano XT 9 Speed Rear derailleur (medium cage?), 11-34 mountain 10 speed cassette, and a
new ultergra chain with 116 links?

Jeff Wills

Get the long cage derailleur. It will shift the same and it will make future modifications easier.

Other than that, go for it.