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I'm trying to free up some cash from selling my road bike. The bike came with compact cranks but I changed them to 53-38 (ish) for a bit more top end but I still have the compact cranks.
I've put cx tyres on my FS 29r but would like taller gearing to match. Since I have a spare set of cranks anyway I was wondering if I could replace the mtb cranks with the 50-34's? General googling generally says no but they're usually using triples or square taper BB when i'm on HT2.
Am i just wasting my time? Will I need to buy a touring 48t crank/chainring for taller gearing?
Obvious answer, it depends.
Is your BB 68mm or 73mm, 73mm they wont fit.
Will the front mech work due to the narrower chainline and bigger rings, probably not, but it might, depends which one it is.
Will the 50t ring fit a FS frame, very unlikely (even with an MTB crank).
You should probably tell us what bike it is your trying to bodge, and post a pic so we can have a good laugh 😆
Not mine but basically the same.
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Just looking at that i can see its going to be to tight. Its currently on a triple with a 44T. Looks like the [s]best[/s] only option will be a cassette with a 10T
Yep I got some FSA road square taper cranks on an old single speed Spesh P1, works ok but it did take a little experimentation to get a good chainline.
EDIT also tried some campy cranks on Shimano square taper, I know it's not supposed to be done but works for me. Handy when you need a big ring on the front.
It might (I've done it), but it would be down to a mix of luck and bodging.
Might just need a smaller front ring than a 50T. Otherwise, I can't see a problem.
Think the axle spindle is shorter on road cranks, as you don't get spacers that were be used to accommodate BB fitted chain devices. If I'm right, that means the chainrings will be closer to the frame, exacerbating the problem with clearance at the stay for a larger chainring.
You'll just have to try it.
44-11 on 700c wheels and 35mm tyres. That's 30mph at a modest cadence of 90rpm. If you can spin your legs upto 140rpm for the few occasions you would need it, you hit 45mph! do you really need a 50t?
Edit: that came out snarkier than intended. apologies, I'm just meaning you may get a better result by improving your cadence rather spending money.
Back in 2007? Nicolas Vouilloz rode a 150 mm travel bike with a Dura Ace chainset. If it worked for him...
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k'in big ring.
Works on my hardtail. Though I only run a 36 (1X9) tooth mounted as an outer which gives it more room.
I think cranks are Sora compact 170mm's. i can't imagine there been much room with that rear triangle of yours.
Also on my cross bike commuter with 37c tyres, ended up running a 13-25 cassette and a 34/48 compact. Amazing how going from 25 to 37 tyres messes with the gearing.
Flippin eck bottom bracket on that is about a foot long!
que?Flippin eck bottom bracket on that is about a foot long!
Vouilloz, bottom bracket.
IIRC it was a D-A chainset (compact) with an XTR bottom bracket spindle pressed in. Stock D-A wouldn't fit. Axle too short, clashes with rear triangle, all the usual.
Back in 2007? Nicolas Vouilloz rode a 150 mm travel bike with a Dura Ace chainset. If it worked for him...
By the way the ring just clears the chainring bolts, If that's a compact I'd gather the ring will be around a 34tooth. If it's not a compact it'll be around a 39. Both MUCH smaller than the 50tooth proposed, and much smaller even than the current 44tooth fitted to the OP's bike.
not a fair comparison.
It's actually a triple now i look closer, so 130/90 something bcd.