Crank for a Atlantis
 

I need some advice on crank gearing for a my new Atlantis frame. Rivendell recommends 46/36/24, however Peter White recommend a 46/34/22. Peter says better clearance between the chainrings and the chainstay can be obtained with this setup. I am pretty clueless when it comes to things like this, but I am concerned with chain suck. After looking at hundreds of pictures of the Atlantis on the internet I have noticed quite a few with paint damage on the gear side chainstay. I am paying extra to have my frame custom painted, so I would like to do whatever is necessary to prevent unnecessary paint damage.

First off, there's little, if any differance between a the gearing you're looking in real life riding. I'd stick to a 46-36-26 myself, because that's Sugino makes that combo of chainrings ramped and pinned. The greater the number of teeth between chainrings, the more trouble you're going to have.

Here's the crankset

http://www.jensonusa.com/store/produ...s.aspx?sc=FRGL

This stock crankset will work fine.

Also get one of these to stop chain suck.

http://www.benscycle.net/index.php?m...0&currency=USD

My advice is to not make this any harder than it needs to be.

Also if you plan on using a 110/74 bcd crank your inner chainring is limited to a 24t as they don't make 'em any smaller. If you want to go smaller you'll have to look into mountain cranks or much more expensive options(TA Zephyr -now discontinued, TA Carmina, NOS stuff, etc). You didn't say if you already have a crank or not(I'm assuming you don't) but the obvious bang for your buck(and availability) winner is the Sugino XD which I've seen offered in: 46/36/26, 46/36/24, and 48/36/24. The 22t small ring would be nice to have but is not all that much better than having the 24, IMO. If it's only chainstay to chainring clearance you're worried about why not get a 2-4mm longer BB(or just offset a Phil until the clearance is acceptable to you)?

I had the chain fall off my Atlantis a few times after I felt sure that the derailer was properly adjusted. It never occured to me that the paint would be damaged but I sincerely did not want to have the damn chain fall any more. My best guess was that the chain came off when it was at a lot of angle and that the solution was to up-shift the rear sprockets before moving the chain onto the big chainring. The chain has never come off in the year since.

I's stick with the Sugino in 46/36/24. I like to use TA rings so I buy the crank without the rings. If you want to stop dings on the chainstay use a chainstay protector.

I use a 46/36/24 and 12/34 combo and I've never had the chain come off. You can limit that possibility by good FD adjustment and keeping cross chaining to a minimum.

Most of the chainsuck damage you see is from sloppy shifting. Get whatever you feel comfortable with and make sure you have your front deraillure set up correctly.

http://http://farm4.static.flickr.co...ffe6ca4d_m.jpg

http://http://farm4.static.flickr.co...e9800074_b.jpgMost of the chainsuck damage you see is from sloppy shifting. Get whatever you feel comfortable with and make sure you have your front deraillure set up correctly.

You can also install a chain deflector or "dog fang."

http://smartbikeparts.com/search.php...b1602beed14cc6

All, thanks for the advice.

one other point to consider:

depending on your FD, the 46/36/26 combo can be problematic. Some mtb-style FD's want a 12t jump between the big and mid ring for awesome shifting. the answer, of course, is to get the XD cranks, try em out, and if the shifting is consistently from the butt no matter how hard you tune, replace the 46t with a 48t. it worked for me, and look at me now: I'm a total hero.

of course, if you're using a road triple FD, and with the atlantis, you probably would be, you won't have these embarassing problems. however, months later, someone with a mtn FD might be in a similar situation, and find this thread in a search. I want that someone to be covered!

over n out.
-rob