Bicycle Mechanics - Carnk set replacement for LeTour?

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View Full Version : Carnk set replacement for LeTour?


wardie
04-02-12, 09:58 PM
I have a 94' Letour, friction shifting Shimano RSX/300ex components. I'd like to get better climbing gearing than 39/53. I'd like a lower double if possible. Here are my crank specifications;
116mm spindle, 68mm English BB, 7 speed 1/2 x 3/32" chain
I've swapped the cassette/freewheel but need better gearing. Can anyone suggest an inexpensive solution that provides ease of installation and inexpensive but decent quality. I don't need the latest greatest but something that's dependable and works. Wardie


stowellt
04-02-12, 10:35 PM
What cassette do you have on there now? Looks like the original was a 13-26. They go up to a 14-32 http://www.universalcycles.com/shopping/product_details.php?id=24130&category=42

As far a doubles go I don't see many that are compatible with a 116mm spindle...


On second thought why don't you just replace the chainring rather than the Whole crank?

FastJake
04-02-12, 10:59 PM
Looks like you want a "compact" double, which would normally be 34/50 lowering your gearing a decent amount. Triple is another option, but that might require a new FD. Not sure how much you were looking to spend but here's a nice one for $60: http://www.ebay.com/itm/SHIMANO-SORA-50-34-9-SPEED-COMPACT-CRANK-SET-175MM-ARMS-FC-3450-NEW-IN-BOX-/230771372337?pt=Cycling_Parts_Accessories&hash=item35bb0bb131

Pretty surprised that now even Sora has gone to the external bearing setup. It's a 9 speed crank but should work ok with your current setup.


What cassette do you have on there now? Looks like the original was a 13-26. They go up to a 14-32 http://www.universalcycles.com/shopping/product_details.php?id=24130&category=42

On second thought why don't you just replace the chainring rather than the Whole crank?

Would need a new RD and chain to go to the 14-32 cassette, and would have a much wider ranger cassette making the gaps between gears bigger.

Replace the chainring? 53/39 = 130 BCD. Smallest ring that will fit is a 38T which will offer virtually no change in gearing.


wardie
04-03-12, 05:49 AM
Looks like you want a "compact" double, which would normally be 34/50 lowering your gearing a decent amount. Triple is another option, but that might require a new FD. Not sure how much you were looking to spend but here's a nice one for $60: http://www.ebay.com/itm/SHIMANO-SORA-50-34-9-SPEED-COMPACT-CRANK-SET-175MM-ARMS-FC-3450-NEW-IN-BOX-/230771372337?pt=Cycling_Parts_Accessories&hash=item35bb0bb131 I have a JIS 116 mm spindle this wouldn't work

Pretty surprised that now even Sora has gone to the external bearing setup. It's a 9 speed crank but should work ok with your current setup.



Would need a new RD and chain to go to the 14-32 cassette, and would have a much wider ranger cassette making the gaps between gears bigger.

Replace the chainring? 53/39 = 130 BCD. Smallest ring that will fit is a 38T which will offer virtually no change in gearing. You are correct I can't find a smaller chainring than 38T thus replacing the cranks.

Biggest concern is 116mm spindle Square Taper.

FastJake
04-03-12, 08:49 AM
You are correct I can't find a smaller chainring than 38T thus replacing the cranks.

Biggest concern is 116mm spindle Square Taper.

Ok, my bad. That crank I posted did not come with a BB and you'd have to buy a new one, so that's another $20.

If you're dead set on keeping the original BB I'd suggest looking for a used crank from the 80s/90s with a 110 BCD so you can run your compact ring setup. Not going to find much new stuff that will work in the square taper variety.