Metieval

I have a bike that is 2x9 Sora. the current crankset is compact FSA vero 50/34

The bike is heavy and I also run 40c tires. Thus I want to go to a 46/36 cyclocross crankset. compared to my lighter road bike on 25c 50/34 my knees are begging for different gearing. Plus as a commuter bike I have rear rack and/or backpack on!

So I can't seem to find 9 speed cyclocross cranksets. Do I buy a 10speed and then run 10s chain?

If I actually upgrade this bike then I'll go to 3x10 tour/commuter/gravel grinder bike. not ready for that, because at that point/cost this might not be the bike I want. For now a change of gearing makes sense

hueyhoolihan

i would look into purchasing two new chainrings only. see what you think.

like this.

and this.

if something like this is suitable, they can probably be had for less with a little googling time and effort.

cale

Have you considered going to a mtb crankset? I'm awaiting a Nashbar Mtn triple that I plan to use as a 32/44 double w/9-speed 11-32 cassette. With a 20% off on this Memorial Day, the crank, before BB and install tool runs $40. Shameless promotion, apologies in advance. Haha

Bezalel

Why the need for a CX specific crankset? Just get a compact double.

dsbrantjr

This would be my solution as well.

trailangel

I Cracksets!

alcjphil

I don't understand. A 46/36 crank will give you a lower highest gear, but also a higher lowest gear. If you find the bike heavy and hard to pedal, a harder low gear is the exact opposite of what you seem to want

1983

alcjphil nailed it, op. If you go with a 46/36, your top speed will decrease and your granny gear will be more difficult relative to the same cogs with a 50/34. You already have a compact double so ignore that comment above.

Changing your cassette would be potentially less expensive and will give you the range you're looking for. May very well need a longer chain if you snag a cassette with a big low end, and I'm assuming your rear derailleur can handle a 30t+ big cog.

A 50/34 with a 11-28 cassette will give you very similar gearing to a standard road triple, so your not going to gain much by switching; an mtb triple will limit your top speed by quite a bit. Look into changing cassettes, maybe to a Shimano HG400-9 in 12-36. $30/free shipping on amazon.

dr_lha

This is a total non sequitur. What are you actually hoping to achieve?

fietsbob

Another person is confused by what "Speeds" actually means .. its a Parts Count.

Cranksets only have 3 "speeds" Max.

the bigger number only applies to the back end, count how many cogs stacked in there , and that is the 'speeds' ..

buy a chain with that number on the packet.

Metieval

Fiestbob, I heard a 10speed chain won't work on a 9 speed crank. Yet, a 10speed chain will work on a 9 speed cassette. Thus I am asking the compatibility question. As it seems 9 speed 46/36 cranksets are non existent! Including 9 speed chain rings.




You do understand, you just don't see it from my view. All day 100 miles in a 50 whatever sucks, unless a guy wants to cross chain. Cross chaining is a bad idea btw. 100 miles in a 34t chainring also sucks equally badly and is also cross chaining on the opposite end of the spectrum.


a 46t chain ring allows me to not cross chain and gives me a lower gear per the weight of bike/gear for efficient travel speed. The 34 or 36 smaller chainring up hill is irrelevant with a 11-32 9 speed spread.

46t vs 50t, huge difference. I already have a compact double 50/34..... I want a 46/36
You asking why, doesn't help me get there, or get the job done.



^ this is the most expensive, yet most logical solution. However I have 2x9 Sora shifters. So to go triple, I need to buy shifters and front derailleur. If I am buying shifters then I will go to 10 speed cassette, add on a cassette and rear derailer to the cost of a triple crankset be it road or mtb doesn't matter. For all of that I'd choose the triple 48/36/24.

Or I can re gear my current compact double 50/34 to a 46/36 and be better for the least amount of money. The issue is finding 9 speed 46/36 chainrings.
So If I put on 10 speed 46/36 chainrings.... what compatibility issues will I have with a 9 speed cassette?

Metieval

No he didn't nail it.

I am not looking for range. I am looking for that all day 46t spin vs an all day 50t spin. I already have a 11-32 casstte.

the granny gear 34 or 36 on this bike is irrelevant. I spin a 32t 1x on my 29er. I absolutely loathe the 34 on the road. on the topic bike loaded/unloaded. Matter of fact I loathe the 34 chainring on my road bike. My road bike would be much better being a 50/38.

As for the 46t vs 50t, at one time I ran the same 700x40c tires on a 29er that had a 44t large crank. The 44t was better than the 50t for my stature/tire size combo, but I lost too much top end. Thus 46t chainring is the answer for now, Unless I change every thing and then I will go to a triple 48/36/24 for this bike.


Instead of telling me my choice in gears is wrong, how about just a little help on answering the original question**********????

which is...... Can I run a 10 speed 46/36 chainring combo with a 9 speed cassette. If yes, which chain do I run 9 or 10?

fietsbob

Its only a thickness difference in the teeth the chainrings there are still only 2 of them..

"Speeds" confuses people so Easily. You are in a big group on that ..

Buy a 46t chainring , you can leave the 34 until you wear it out then choose whether you want a 36t.

Metieval

thank you!

I would have already done that before, but on a compatibility question on the 46t chainring someone said a 9 speed chain wouldn't work. hence I posted the question.


as for the rest of the post here they can be summed up with,

"How do I slice an apple, wtf you want to slice an apple for just buy an orange and peel it." LOL

The bike is a Trek Crossrip, and in my opinion (because I already own it) is worthy of a chainring swap, but NOT worthy of a groupset swap... the frame sucks energy and then expels it everywhere but to the rear wheel.

1983

Oooooookay then. If you already know what you want, then why are you asking and lambasting answerers?

You already have a good range to work with, just learn to use what you have. A 50t big ring is not hard to utilize, start riding more. You said you want 46t spin....46t by what? How can you not find the gear inches you're looking for in a 50/34x11-32 setup? If you want a 46t big ring, then find one that matches your crank's bcd instead of waxing flippant academic about what you think you want.

fietsbob

Dont even believe every thing you think , let alone what someone else tells you.

Metieval

Only one person gave an answer on how to make a 46t chainring work, that answer didn't get lamblasted. Stupidity got lamblasted, and I am glad you feel lamblasted. you're welcome now go ride your butthurt off a cliff.

headasunder

which is...... Can I run a 10 speed 46/36 chainring combo with a 9 speed cassette. If yes, which chain do I run 9 or 10?[/QUOTE]

Answer...Yes... as to the chain 9speed will be fine but if you are replacing the chain due to wear go for a 10speed they are usually cheaper

Metieval

Awesome Thank you!!!!!!

1983

Interesting. On the way there I'll use my 52t big ring instead of being weak and crying about it on bf.

Tim_Iowa

+1, replace your 50T big ring with a 46T big ring, it will work fine.

I disagree. @Metieval, you are still using a 9 speed cassette, correct?
The cassette has ramps and sculpting on the teeth to pick the chain up to the next cog. These ramps and sculpting are designed around the specific width of a 9-speed chain, in order to engage the outer chain plates.
A narrower 10-speed chain will engage the cassette's ramps and sculpting less effectively, and deliver worse shifting. It will work, but a 9-speed chain will work better.

The same is true regarding the ramps and pins on the 10-speed chainring, but it affects you less. Front shifting is more forgiving (a double is binary, after all) and it sounds like you don't plan on shifting the front as often anyway.

Theoretically, the narrower 10 speed chain will be lighter, but less durable (thinner plates).
@headasunder, where are you finding 10-speed chains cheaper? I'm curious.

Drew Eckhardt 

A 36 is harder than a 34. On the big ring you have the same effort running one cog bigger with the 50 ring.

You can space them out to 9 cog dimensions. LeTour and Wheels Manufacturing have 0.6mm spacers, Origin8 has 0.5mm spacers.

I did that with my FSA "9 and 10 speed compatible" Carbon Pro Compact crank which had no usable overlapping gears due to rub on the big ring when paired with a 9 speed Campagnolo chain.

New shifters, derailleurs, and crank imported from the UK are far less expensive than a new bike.

You could even come out ahead buying used ones off ebay and selling your left overs.

reddog3

I've put out many bikes swapping out the 50 for a 46t, and keeping the 34 tooth inner. I use the Shimano CX70 which gives the better shift of
o
t
h
e
r
s

reddog3

Sorry for not completing my thoughts- The 9sp chain is just fine on the 10sp front ring.

Drew Eckhardt 

You can run down to a 24 inner on a road triple. With the same cassette the biggest usable gear on the 39 ring is effectively three teeth harder than you'd have with a 34 ring on a compact double maintaining the same chainline, two if you eschew small/small. For the same range you can run something like

53-39-26 x 13-14-15-16-17-18-19-21-23-25 vs 50-34 x 12-13-15-17-19-21-23-25-28-32

The two are not remotely similar.