Hello, I would like to build an S40 using SRAM eTap Rival group-set. SRAM tech says a maximum cassette is 10/36T. Anyone have a suggestion on a cassette/2X configuration (i.e. how many teeth on the front 2 rings ). What is the smallest chain ring the Cruz derailleur stalk will allow? Thanks
Running SRAM Rival eTap on S40
- Thread starter Danno61
- Start date
Frito Bandito
Zen MBB Master
I know that at least a 50/34 works. I have a 52/36 on the front, and for the flats I was running an 11/23 on the back. That worked for anything between 10-68kph under the right conditions. However, I Frankensteined the rear to an 11/29 to work for all but the very steep climbs where I can pedal at a comfortable cadence and maintain 8-9kph in the lowest gear without looking like a newborn giraffe wonkering around. Below that speed I spend more time going left and right than I do forward. If I focused on improving my low speed balance I would probably benefit with up to a 32t rear for the steep climbs, or maybe changing the front 36t to a 34t. That would allow me to climb at about 6kph which would be my limit because I would rather get off and push the bike uphill. On an S40 with up to a 36t on the rear and a 50t on the front you should be able to keep it upright at 3-4kph if your balance is good. I believe some can ride at 3kph or maybe even slower, but that is not in my bag of tricks, especially on a V20. Does SRAM make anything smaller than a 50t?
FBandito, thanks for your input. I’m currently riding a Schlitter Encore (triple 10sp). Up front I have a 50/39/30 and in the rear an 11/36. I actually use the triple, but almost never the granny 36 gear because I can drop to the 30t up front if I need it. Not owning a Cruz yet, I’m thinking things just don’t transfer over correct? Meaning due to the Cruz design, gearing is not necessarily apples to apples? So my thought is do I go with a 1X or a 2X? Cruze S40 I believe comes outfitted with the 42 up front and an 11/42 rear? They must have put a lot of thought into that configuration. I was thinking a 46t up front and 10/36 cassette? My terrain here in Florida is mostly flat with some bridges and overpasses. Thoughts?
Frito Bandito
Zen MBB Master
A triple 10s is pretty nice. My v20 came with the triple Tiagra 4700 groupset but I gave the important bits to my friend whose wife now rides with him. I almost have enough to equip my commuter bike with a 2X 10s Tiagra, which I will do in the near future.
I could be quite wrong by missing something in my hard head, but I am not sure there is much difference in the gearing. Even though the BB is moving a bit, I don't think it is affecting power transfer much or at all, so going with similar gearing that you have on your Schlitter should be fine. Maybe tweak it a little up or down depending on where you will be physically in the near future. It would be interesting to know the pros and cons when comparing a 1X and 2X. The only thing I can think of that might concern me is if the gaps between the gears on the 12 speed put me too far out of my comfort zone. Now, rpms in the mid 80s are where I am at and occasionally get to 120 when the conditions are right. I don't do as much sprinting as before so my legs might complain more with those gaps. Keep in mind I am just speculating because I have not tried a 1X12 yet. If my legs could handle those gaps though, SIGN ME UP! I am all for losing the derailleur weight, shifter weight, the improved aerodynamics, and less stuff that could go wrong or need fixing at the most inopportune time.
I'm mostly on the flats too and kick around the idea of a 53 or even a 55 on the front with my 11/29. With a 10/36 I could probably live with a 50 on the front but doing so would probably be then end of my 70kph dreams hahaha. Depending on your top speed wishes a 46 might work though. A gear calculator will set you straight, or wait until someone here who knows more of what they are doing chimes in.
By the way, Schlitter looks like a nice bike. Are both of your wheels 700c?
rx7mark
Guru
Be careful in that SRAM E-tap AXS has specific gear tooth limits for the front derailleur. The limit is 13 tooth. So the options from SRAM are 50/37, 48/35, 46/33, or 43/30. I talked to SRAM tech and anything more than 13 teeth range on the crank will void the warranty on the FD. For the 10-36 rear cassette make sure you get the larger rear derailleur cage that says it is for a 36T maximum. Most are limited to 33 t. Those RD's will not work with the 10-36t, though some have done a hack to make it work. But if you are buying new, just get the one designed for the 10-36t cassette. If you really need more than 13t up front, then you might be able to use the SRAM AXS 12x1 system on the rear with a friction front derailleur to shift a bigger range up front. Sort of a hybrid 1x12+ system. This is what I am planning for my next build, because I really need a granny gear for the hills in my area around Seattle.
Note also that the KMC 12spd chain will work with the SRAM system.
Good luck. I think the 46/33 or 50/37 or 48/35 should all work for you. You may need an adapter on the FD hanger to run less than 50t.
Mark
Thanks Frito and Mark for your comments. You both are right on with your statements. I checked with Robert at Cruz and he co firmed that the SRAM 48/35 and 46/33 would both work on the S40 also using the 10/36 cassette. A hearing calculator should provide confirmation. Thanks again guys. I will post when I undertake the build.
Merczak73
Active Member
I have a similar thread (S40 upgrading - tech advice) but have used the SRAM Force AXS. I am using a 46/33 front and 10/33 rear. This gives me the gearing to get up some steep hills, but also gives me the oomph to really crank it out on the flats or down hills. I have also been pleased that I am searching for the right gears less and less. It is wonderful. Yes, you will need a longer rear derailleur to handle the 10/36 cassette. However, I question, in FL, where it is mostly flat with some overpasses, will you need the 36 cassette? I find that I can crank it out with the 33front and 33 rear on a 10-12% grade quite easily (for a short distance). I used this site to calculate what I wanted when I went from a 1x11 to a 2x12. Very helpful and insightful. https://sheldonbrown.com/gear-calc.html . Hope this sheds more light on the subject!
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Merczak73, thanks for the input. I'll also check out your other thread you mentioned. Question, so you feel the 46 up front is sufficient on the flats for speed? I'm currently running a 50 and 11-36 rear. I don't usually hit speeds above 27 when pushing and the 50/11 is sufficient. Thoughts?
Merczak73
Active Member
Danno61 - I guess it all depends on your cycling style. I am a spinner, and like to keep my ppm 90-100. The 46-33 and 10-33 gearing is perfect for me. I use the upper gearing for blasting down hills. On the flats, I dont reach over 30mph, and use the 46-13 or 14 to spin it out.
If you are pushing 27 on the 50-11, then I am guessing you have a slower ppm? If that is the case, then you might consider the larger AXS chainrings.
Go to the website I linked and put in your current configuration. It will spit out the gear ratios. save those by scream shot. Then put in the sram specs and find out which gearing is close to what you are currently riding. That’s what I did and I am quite happy with the results.
If you are pushing 27 on the 50-11, then I am guessing you have a slower ppm? If that is the case, then you might consider the larger AXS chainrings.
Go to the website I linked and put in your current configuration. It will spit out the gear ratios. save those by scream shot. Then put in the sram specs and find out which gearing is close to what you are currently riding. That’s what I did and I am quite happy with the results.
rx7mark
Guru
Merczack73,
I wish they had the 46/33t available on a shorter crank, as I agree that would make a nice combo with either the 10-33t or 10-36t cassette, depending on conditioning and local hills. The only short crank combo that is AXS approved is from Rotor, and they only offer 50/37 or 48/35 at the moment for Axs. I have asked them to add the 46/33t option but nothing yet.
Mark
I wish they had the 46/33t available on a shorter crank, as I agree that would make a nice combo with either the 10-33t or 10-36t cassette, depending on conditioning and local hills. The only short crank combo that is AXS approved is from Rotor, and they only offer 50/37 or 48/35 at the moment for Axs. I have asked them to add the 46/33t option but nothing yet.
Mark
rx7mark
Guru
I like 150-155mm. I checked and no the Rival AXS compatible cranks are not confirmed to be able to be shortened. I would have to buy a crank and send it out to see if it could be done. A definite risk. The shortest SRAM AXS compatible crank at 165mm is just too long for me.
Mark
Mark
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