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-   -   Adding granny gear (https://www.bikeforums.net/bicycle-mechanics/1254923-adding-granny-gear.html)

arsprod 07-10-22 06:13 PM

Adding granny gear
 
Is there some clever gadget out there that allows adding a granny gear to a 2 sprocket crank, or am I looking at replacing the crank with a triple? Thanks!

Rogerogeroge 07-10-22 07:20 PM

And a shifter and most likely a front derailleur.

rccardr 07-10-22 08:02 PM

What you need is a tripleizer. Replaces inner chainring with one that is drilled to accept a granny.
Available in many common BCD’s.
Yes, likely requires a triple FD and a 5mm wider bottom bracket.

arsprod 07-11-22 07:21 AM


Originally Posted by rccardr (Post 22570423)
What you need is a tripleizer. Replaces inner chainring with one that is drilled to accept a granny.
Available in many common BCD’s.
Yes, likely requires a triple FD and a 5mm wider bottom bracket.

Brilliant! I knew there was a gadget to make this work! Thanks

alcjphil 07-11-22 11:38 AM

Is your front shifter designed to shift a triple crank?

arsprod 07-11-22 04:58 PM


Originally Posted by alcjphil (Post 22571073)
Is your front shifter designed to shift a triple crank?

Don't know, but looks to have enough travel and I'm using friction shifters. I guess I'll find out!

Leisesturm 07-11-22 05:17 PM


Originally Posted by arsprod (Post 22571450)
Don't know, but looks to have enough travel and I'm using friction shifters. I guess I'll find out!

If your bike is a presently a double, then it was designed for that purpose only. The front derailleur cage of a double is shaped quite differently from that of a triple, the 'middle ring' won't have ramps or pins, but it will all likely at least work. These innovations did not always exist. Cheap thumbie type friction shifters won't have too much difficulty adapting to a triple, but fancier stuff might. If only because there won't be any labeling for the new gear. OCD is a *itch. So, as you say, you will find out.

Iride01 07-11-22 05:54 PM

Seems like buying a 3x crank would be cheaper than a tripleizer. Chain line will probably be more correct too assuming the bikes not out of whack already in that department.

arsprod 07-11-22 06:28 PM


Originally Posted by Leisesturm (Post 22571460)
These innovations did not always exist. Cheap thumbie type friction shifters won't have too much difficulty adapting to a triple, but fancier stuff might. If only because there won't be any labeling for the new gear. OCD is a *itch. So, as you say, you will find out.

Well besides the shifters being rather pricey bar enders (:)), I actually prefer old school tech for this touring bike. I just can't get up the hills all loaded like I used to!

rccardr 07-11-22 07:36 PM

Bar ends will shift a triple just fine.
A tripleizer is less expensive than a triple crankset these days.
Either way you’ll need a wider bottom bracket and a FD capable of shifting a triple.
Some additional information on your present crankset would help

Andrew R Stewart 07-11-22 08:51 PM

The issue with a middle ring made to mount a granny to is when that ring is worn out the replacement costs more (if it is still made years later). A proper triple crank will end up costing less over the years IMO and have far easier to find replacements.

As to what type of crankset a ft der is made for- thousands of riders have done fine with their "double specific" ft ders from when that spec wasn't a reference. I think what is driving the assumption of specific double or triple ft ders is 1- the marketing of "better/faster" **** that we have gobbled up for decades, and 2- the lack of most current riders not learning how to make their bikes shift best. But this boarders on other rants:) Andy

Iride01 07-12-22 08:12 AM

A new Shimano 3x crankset can be had for 32 - 38 bucks.

https://www.universalcycles.com/shop...s.php?id=46763

Fredo76 07-12-22 08:32 AM

I didn't need a new front derailleur with my Red Clover triplizer - my old Suntour Cyclone FD works well. Nor did I need a new bottom bracket - I had enough clearance with my old Phil Wood. Others will say that your chain will rub, but mine didn't. If you like your present crankset, a triplizer might be a good solution.

arsprod 07-16-22 12:10 PM

Well, after going down the rabbit hole of possible options I'm back to square one. The tripleizers are unobtainium, at least in 110 bcd. I went to order a Sora triple fc-r3030-3 in 165mm and they're all sold out. I need some help with options.

I currently have an older Sora 2X 165mm, 110bcd, currently with a 34 on the inside. I don't want to replace the Hollowtech bottom bracket (fairly new BB-RS500 BC1.37x24 road) with a square taper. I'd be happy with a 2x mountain bike crankset that let's me put a 30 or smaller cog on the inside. I'd rather not spend a ton of money but... So, what MB crankset would fit? Are Hollowtech BB's all the same inside diameter? Thanks!

Aaron

Iride01 07-16-22 12:45 PM

Your big issue with just swapping the small ring for a smaller ring is that you'll probably be well out of your rear DR specs with any significantly smaller ring.

You'll have to sacrifice your top end by also going to a smaller big ring. But smaller on the top isn't really as bad as it may seem. How often are you truly putting out max power in the big ring and small rear? Might mean someone beats you to the bottom of the hill, but over the entire ride it probably won't make your times much different.

Knowing what kind of riding you do, your experience and fitness along with what your desires are might let someone help you figure out where to compromise.

arsprod 07-17-22 06:54 AM


Originally Posted by Iride01 (Post 22576621)
Your big issue with just swapping the small ring for a smaller ring is that you'll probably be well out of your rear DR specs with any significantly smaller ring.

You'll have to sacrifice your top end by also going to a smaller big ring. But smaller on the top isn't really as bad as it may seem. How often are you truly putting out max power in the big ring and small rear? Might mean someone beats you to the bottom of the hill, but over the entire ride it probably won't make your times much different.

Knowing what kind of riding you do, your experience and fitness along with what your desires are might let someone help you figure out where to compromise.

Good questions, and put simply I don't care about top end. This bike is my daily commuter and loaded touring bike. I'm an old guy but fairly fit, and on a recent trip with long steep hills it was clear to me that I need lower gears. The two guys I was with had triples and while they were spinning away at 3 mph, I was cranking way too hard at double their speed!

I have an 11-36 10-speed cassette, and small ring up front is a 34. By my calculations, dropping the front ring to a 26 is a 6" gear inch drop. A 24 would be even better.


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