# Mountain Biking - Losing Granny Gear going to SRAM XX, clarifications on ratios

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mx_599
01-22-10, 02:48 PM
I should know this, maybe I did and forgot and maybe I never did and pretended to.

I appreciate my easiest gear combo when very tired. granny 22t and 34t cog. Is it correct to call this 22/34 = 0.65 ratio?

Now, if I am concerned about retaining this option in the XX drive-train, do all I need to do is make sure I find a combo that comes close to this ratio and then I will have a gear that feels the same as I have become accustomed to?

for instance:

26/36 = 0.72

or

28/36 = 0.78

Is this the best it will get?? Has anyone heard if this has been a problem for people?

dminor
01-22-10, 02:55 PM
It would actually be a 1.54:1 gear ratio (your granny spins 1.54 times for every revolution of the rear cog). Think of it like a car rear differential: 4.11 gears are lower than 3.54 gears.

Edit - - on to the next question: 26/36 would be 1:38:1; 28/36 would be 1.28:1. To replicate 1.54, you would have to have about a 24t ring (36 ÷ 24 = 1.50).

mx_599
01-22-10, 02:59 PM
so I wonder if this has been a problem? I guess XX is for racers and they should be stronger and not need a super easy gear? I just need to HTFU??

dminor
01-22-10, 03:05 PM
That's something only you can answer. Personally I do better with cadence over brute force on climbs but that is just because I am not a terribly strong climber.

mx_599
01-22-10, 03:12 PM
I do pretty well with my 22/30cog as well. 1.36:1 correct?

I better verify my Granny is 22t as well.

dminor
01-22-10, 03:22 PM
1.36 is correct. If you can consistently stay to that without dropping lower, you'll handle 26/36 fine. I assume you have/are figuring on staying with 175mm crank arms?

mx_599
01-22-10, 03:24 PM
1.36 is correct. If you can consistently stay to that without dropping lower, you'll handle 26/36 fine.

sounds good, thanks for clarifying

just found out I am getting a sweet tax return. going to order my replacement Mojo sl frame very soon :)

ed
01-22-10, 07:33 PM
so I wonder if this has been a problem? I guess XX is for racers and they should be stronger and not need a super easy gear? I just need to HTFU??

Nope...XX is for ghey roadies that race the NORBA-glorified dirt "road-bike" courses that they for some reason call mountain bike courses. You should be fine with a 3:1 singlespeed.

ed
01-22-10, 07:34 PM
going to order my replacement Mojo sl frame very soon :)

You make me sick.

With my return, I hope to buy myself a new replacement cup of Joe.

sscyco
01-22-10, 09:43 PM
You make me sick.

With my return, I hope to buy myself a new replacement cup of Joe.

Hopefully a grande. (or a large for the starbucks impaired)

dminor
01-23-10, 12:21 AM
:lol: You speak santiagoese.

mx_599
01-23-10, 07:15 AM
Nope...XX is for ghey roadies that race the NORBA-glorified dirt "road-bike" courses that they for some reason call mountain bike courses. You should be fine with a 3:1 singlespeed.

:lol:

no way dude, I would kill myself if I make it to Leadville on a SS

more power to SS'ers, something I have no desire to do. I am not in good enough shape. Plus I think I would hurt my body too much on one.

:thumb:

mx_599
01-23-10, 07:20 AM
You make me sick.

With my return, I hope to buy myself a new replacement cup of Joe.

Don't feel so bad, I got lucky this year. Next year I'll be able to buy new grips for my mojo, that's about it.

I got some education tax credit I was not expecting...I think that's what did it. (thanks Obamessiah! ...if it was even his doing??) I was just flying through the TurboTax stuff, but I am confident no mistakes.

I am also going to use the money to get my Endurance Race bike for this season that I have been posting about.

I have already spent \$1000 this season in race entry fees.

Update:

I am down about 3 lbs since I started inundating the forum with my race crap! I am on my way... :innocent:

Smallguy
01-23-10, 12:34 PM
so I wonder if this has been a problem? I guess XX is for racers and they should be stronger and not need a super easy gear? I just need to HTFU??

Cadence is the way to go your cadrio vascular system will recover far before muscles that are taxed too much

Smallguy
01-23-10, 12:37 PM
Nope...XX is for ghey roadies that race the NORBA-glorified dirt "road-bike" courses that they for some reason call mountain bike courses. You should be fine with a 3:1 singlespeed.

There is certainly some truth to what are your local race course like here there are generally 2 types technical with a bit of climbing and semi technical with allot of training there is only one course with minimal climbing

Smallguy
01-23-10, 12:43 PM
just saw your thread about all your long distance races this season.. depending on the elevation profiles of those races you might want to re-think your switch to Sram XX

your going to be putting in allot of saddle time for those races and may miss your granny if you tend to use it allot

mx_599
01-23-10, 12:48 PM
yeah I know. I think you are right. I will strongly reconsider it.

Smallguy
01-23-10, 03:46 PM
yeah I know. I think you are right. I will strongly reconsider it.

certainly worth re-thinking with your desired racing length.. on the short 1h t o1.5h races you cloud probably force your body to adapt and not fail with decent base fitness. I think the XX is probably geared to the new 1 hour race xc style that there seems to be a shift to.

for a simular price you can probably get a sweet Sram X-0 DT and some carbon cranks

I know that I climb allot in my granny 34 combo on endurance races and with out it I don't think I would have finished some I'm 5'10 209 ( I'm down 6 pounds from last season) and there was one hilly endurance race I did where I almost wished I had a 36 out back

mx_599
01-23-10, 04:35 PM
certainly worth re-thinking with your desired racing length.. on the short 1h t o1.5h races you cloud probably force your body to adapt and not fail with decent base fitness. I think the XX is probably geared to the new 1 hour race xc style that there seems to be a shift to.

for a simular price you can probably get a sweet Sram X-0 DT and some carbon cranks

I know that I climb allot in my granny 34 combo on endurance races and with out it I don't think I would have finished some I'm 5'10 209 ( I'm down 6 pounds from last season) and there was one hilly endurance race I did where I almost wished I had a 36 out back

I can relate. I think on my last lap of the 24Hrs I have done I am in the granny almost the whole way !

Sweet SRAM X-O DT? what is the DT? I usually do use XO stuff with an xtr front derailleur and xtr cassette. grip shift. always.

hmmm, I just need to decide on drive train set-up now. I suppose I could do XX and switch to a triple chain-ring for Leadville if I'm that scared. Anyone know what Lance's set-up is? Because that would like be a good measure for what I need to do. :rolleyes:

seems the attraction for the XX is simplicity and it would sort of be similar to my road bike...not really, but you know what I mean.

I will probably wussy out and get a triple.

Smallguy
01-23-10, 06:06 PM
DT = drive train

I've been eyeng up the Truvative Noir 3.3 apparently stiffer than XTR with sold reviews

I have a grey/silver trek fuel ex 9 was thinking of blinging it up with Sram x0 Shifters (they make grip shift too) Sram-991 rear cassette , PC 971 chain ( bad reviews on the 991) all in the gold and a gold Chris King head set

ed
01-23-10, 06:26 PM
How much will you truly save? You can always dump the granny off a 3-ring crankset, but you will never be able to put that granny back on the new one.

mx_599
01-23-10, 06:37 PM
How much will you truly save? You can always dump the granny off a 3-ring crankset, but you will never be able to put that granny back on the new one.
you mean weight wise? for me it was so much about the weight as liking the idea of two chain rings I guess. It really will not be much lighter.

not sure what I will do yet. I will need to shop around the latest cranks. I have always liked race face but will certainly look at truvativ as well