New drivetrain for Rivendell #2

[Patrick Moore]

Well, most of it is new, tho' there's very little to swap out since it's a fixed gear. 

Before: TA Pro 5 Vis 46 with 15 and 17 t cogs on the Phil fixed/fixed rear for 76 gi and 67 gi.

After: Dura Ace GS 200 or 300 (Can anyone say which? How are the 2 models different?) 52 with single rear Dingle 17/19 for 76 gi and 68 gi.

Chain remains the same (2 links added) and so does Phil ti 113 mm bb assembly.

Curious: It felt easier to pedal on the just-under-20 lightly rolling terrain ride, both uphill and on the flats, and with and against the wind. I'm not going to draw a conclusion from 1 experience, of course, but it does raise the question: is the reduced friction from larger ring and cogs really so noticeable?

Also: I may eventually cut off the "shelves" for the inner ring. Has anyone done this? What's the best way to get clean cuts and a smooth final result? Will a Dremel work?

BTW, the crank isn't as dirty as the photos make it seem.

Thanks.

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Patrick Moore

Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum

[lconley]

Shelf removal: 

Grind it down 80-90% with a bench grinder if you have access to one (faster), Dremel if you don't. Another alternate if you are careful is a hacksaw across 2 shelves at a time - used a spacer (file folder cardboard or?) against the backside of the arm (chainring bolt surface) so that you have some finishing room left. - and alternate around during the cutting so you are not left with  a single shelf with nothing started at the end. 

Then take it down the rest of the way with a flat file across 2 arm shelves at a time (alternating). 

Optional finishing touch: finish with fine to ultrafine wet sandpaper on a flat surface (flat car glass is excellent for this - i.e. old VW beetle side windows) - all 5 arms at the same time. 400 - 800 - 1200 ... up to 2000 if you want.

Laing

[Garth]

I suppose I could question you Patrick 'till the cows come home and I'll never understand why you'd want to permanently alter a perfectly good crank.

[lconley]

I cannot answer for Patrick, but for myself, if it were mine - better frame clearance for the lowest possible Q factor. Getting rid of a few unused grams as a bonus.

The crank will flex -> I have removed the paint (and a little metal) from the chain stay with the crank and chainrings on my Paramount using the narrowest BB that will fit (triple crank on double BB with spacers on the crank side cup). It clears the chain stay when static, but obviously hits when pedaling.

Laing

Who misspent his youth modifying Campagnolo and Stronglight chainrings.

[Ryan]

That is a very clean looking bike...in both senses...as in the drivetrain looks clean enough to eat off and the minimalism of the bike overall. Lovely color....doesn't need the cream. Less really is more

[Patrick Moore]

Thanks for the tips. I'll lean my tendency to procrastinate against my perfectionist compulsion to remove unused metal, and probably wind up just leaving things as they are. But I think I'd try a Dremel cutting wheel first.

Garth, when I look down between my legs and see those inner ring shelves rotating uselessly around, it irritates my aesthetic sense.

But my main question: Will 52/17 materially reduce chain friction over 46/15? In your plural experience?