Yet Another Cycling Forum
General Category => Freewheeling => Velo Fixe => Topic started by: rogerzilla on 25 June, 2018, 08:24:34 pm
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Any experience? In 17T for occasional track use with a 52T ring.
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I reckon you'll eat them in fairly short order.
No personal experience whatsoever.
ETA - It isn't a material I'd consider as suitable
for producing robust sprockets.
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Indeed. Remember a test in the comic of a custom alloy Campag(fit) cassette in which the tester mentioned stripping almost all the teeth off one cog when he stood up on the pedals.
Not a ballsout sprint either, just the equivalent of a quick take off from the lights.
I wouldn't.
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Why are aluminium chainrings fine but aluminium sprockets a non-starter?
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Torque and the multiplication thereof.
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I've been using them, mostly 16T with a 42 but sometimes a 17T. With a geared cassette I'll try and change the chain before it's too worn to protect the cassette but the chain wears so rapidly on my fixed that I just leave it on and change both, the trouble is when the chain gets so worn that I feel I have to change it then I get the grumble noise from the cog so I tend to change both. From my not very vast experience I'd say they were okay and none of the failures that are alluded to above, sure they wear but no more than I'd expect and I've done a few hilly rides this year (Chapman, Brevet Cymru) so there's a fair bit of torque going through. If not these then what?
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I should point out that these are 1/8" and the chain tension from a 52T is not especially high.
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Aluminium sprockets on a fixed gear? Why?
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I've got them, both bolt on for the audax bike (so no real alternative with their modified hub, apart from their steel version) and threaded for the commuter. Come in pretty colours and save about 10g in weight! Guestimate I've got at least 5000km out of them - swapped the original one out before the Transatlantic Way last year for prudence really, wasn't showing that much wear, that's still going, and I run a 16T pretty tight with 44/45/46T depending on terrain.
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Aluminium sprockets on a fixed gear? Why?
EAI are very hard to get hold of now that Will is no longer running Hubjub. And it's a stupidly light wheelset.
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It is for use on a velodrome? So your bike never gets ridden in the rain and does comparatively few miles. Go ahead, no reason not to use an Al cog.
52 x 17 seems a little low-geared though. A 16t might be a better option unless the velodrome has a slow surface.
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Calshot: they recommend going a little lower (48 x 16, not 15) as it's only 1/7km and very steep.
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Makes sense then. I mostly used 47-49 x 14t but on bigger velodromes.