Chainset: Shimano CX50 vs CX70

mattrixdesign2

Hi

Can anyone advise the difference between CX50/CX70 chipsets? Is the CX70 worth the premium over the CX50?

Also I would be removing a triple chain set, the existing triple mech and shifter will remain. Will the left hand shifter and front mech work 100% with a double, just by managing the limit screws.

One other option is to go single on the existing triple with a 38t NW chain ring, and run a 28-11t cassette at the rear. I am sure this would be fine for local flatish trails and possibly some races. The issue is I do use it as a winter road bike, and like tacking some mtb like tricky hills, and I intend to do the Southdowns 100mile off road ride. Any one tried this combination successfully? I reckon I would end up with a sub 20lb bike, so it should be fairly light for hills.

ugo.santalucia

I have the CX 50 and a friend of mine has the CX70... there is virtually no difference and I don't think it's worth premium. The CX 50 is very very good

matt@theforce

I looked into the cx50/cx70 early last year, from what I can remember from the Shimano Tech Docs, the only difference is in the chain rings (weight loss/different materials). I'm in agreement with Ugo, the CX50 is more than good enough, very robust and the chainrings last along time

mattrixdesign2

Thanks. From searching the web its seems my triple shifter will be fine, the front much may benefit from being a double design and I have a spare.

So if I go down the double chain set route I will get 36/46 with 11/28 cassette. Still thinking of 1x10 (38 with 11/28), anyone done this?

ravey1981

Only you can answer the question whether 38-28 is low enough for you. Use Sheldon Brown's gear calculator to find you're nearest current gear and try some hills with it.

mattrixdesign2

I know. Just keep mulling the options. I know I don't like the triple, I like my road compact double and my mtb 1x10.

I fancy something simple and easy to clean, and it would cope with 90% of local rides. Its if/when I decide to venture further a field and regret some lower gears.

ravey1981

I've been looking into 1-10 myself and I've seen on here somewhere that a standard short cage mech will take up to a 32t cassette so you have that option if you need a lower gear. I went out today up some big old hills (Yorkshire dales) and I was right on my limit with a 34 front 30 rear (road compact with 34-44 rings) although having said that those are the steepest hills I'm likely to go up on that bike anyway. I still out climbed my mate on his mtb though, cx bike with low weight and no power loss through suspension = win! Of course he wasted me on the descents....

mattrixdesign2

Thanks.

Its a short cage mech. 38t is the smallest I cm get in 130bcd, and I was thinking I can get away with a 28 on the rear. Hmmm.

Out riding a local club road ride on Sat, I got by in the middle ring (34t? I think) and a 11-25 cassette. Dont recall dropping it into the small ring even on the longest climb, used the big rig once to push 40mph on a nice descent.

ravey1981

Yeah I have 34-50 25-11 on the road bike and its fine, have found I need lower gears off road though, hence the 30t cassette on the cx bike. My cx bike came with a 50t big ring but it was just pointless so swapped it out for a 44, I find that set up perfect for the terrain around me.

FransJacques

The 1x10 is a good bet too.

I've raced a 1x9 and 1x10 with a 38, 39, and 42 up front and thought it was great. The 38 was a bit undergeared for all but the hilliest courses, try the 39 maybe depending where you live.

mattrixdesign2

Fitted the CX50 today, currently running 2x10. Shifts was better than the 3x10 (also 105), not sure if its down to wear as I also installed a new chain and cassette. May be doing a CX race next Sun, so will see how I get on.