Road Bike, Cycling Forums banner
1 - 6 of 6 Posts

·
Matnlely Dregaend
Joined
·
5,051 Posts
Discussion Starter · #1 ·
So I'm kind of considering doing a Lance Armstrong road bike build, only I am weak and need big gears...

So I'd like to go with a 52 single chainring and a mountain bike wide ratio cassette (11-34). Is this doable? Can I use a 9 speed Shimano mountain cassette with a Campy (preferred), Shimano, or Sram STI lever? Would a Jtek work somehow? Will that cassette fit on a road wheel? What kind of derailler would I need (short or medium?). Seems to me there's lots of areas where this is not doable.
 

·
Registered
Joined
·
988 Posts
Its doable with some modification to your requirements but not adviseable - biggest problem is putting the chain under stress when used in extreme (i.e. tall cog) a chainset/cassette/chain mechanism is set up so that you get a faily straight line when using big chainring with the smaller cogs on the back or the little chainring with the taller cogs - while your drive train will still work in extremes such as using big chainring with big cog or vice-versa you are creating a big deviation from the chain's straight line and therefore reducing the chain life as well as cassette life - you will also need to install a FD to keep the chain from dropping off the chainring (ala Millar).

If you are hell bent on doing it that way you can take a leaf out of touring bikes - they normally use 9 speed Tiagra shifters, chainset & FD matched to something like an XT RD & Hub for a 3x9 gear combo. For a road set up why not use a smaller chainring such as 50 or 48 matched to a road cassette such as campy's new 11 speed 12-27.
 

·
p != b
Joined
·
2,303 Posts
Definitely do-able. Look/search through any of the single-ring threads in the cyclocross forum.

My immediate thoughts:
* Chainline will be very important with this setup. Plan on reinstalling the BB several times with different spacers in order to dial it in perfectly.
* Shimano road 9 speed = shimano mtb 9 speed. A Shimano 9 speed STI will be your best option. Otherwise, look at JTek's site - they list all the possible combinations.
* If you have a shimano/sram wheel (Shimano 10s only [tall splines] excluded), a MTB cassette will fit.
* If you're going to use that wide of a cassette, I'd definitely consider a medium der. Note that your best bet shifting wise will be a shimano der.

Now, the hard question - why? 52x34 is very similar to 39x25. So, you're going to a lot of trouble to give yourself the exact same gear range as a standard double, but with less in-between options. If you really think that removing your easier gears is going to help you get stronger, then get an 11-21 cassette.

Edit: Oh, perhaps you mean big (easy) gears... Just get a front downtube shifter - you'll save almost as much weight as running a single ring, and .... (out of things to say...)
 

·
duh...
Joined
·
9,749 Posts
52?! are you a masher?

I build a 9-spd with a 42 x 14-28, Campy der, dt shifter. The low gears are enough for me and I only miss the highs bombing down hills and in really fast pacelines. Campy 9 (old) cuz that what I had. dt because I wanted it simple, wanted matching brake levers, and just because. with CR on the inner it works fine

with an 11-34 you'll have bigger jumps... too big? only you can answer that. med cage needed? prob, check the specs. are you planning on gutting the left lever or going mismatched? also, you do not need a fd... a chainguard on the outer (but will your 52 clear the stay if mounted on the inner?) and dog fang or similar for the inner and you'll be ok. sigle-ring front is def doable, but you added a couple of extra kinks in wanting to use a 52 and wide cassette
 

·
now in philadelphia
Joined
·
798 Posts
44T by 11-34T here.

It's about the same gear range of a compact double road setup. I use the outer position on the crankset which yields a 46mm chainline. I have no issues with using the extreme cogs (e.g. 11 or the 34T.) You do have to use an outer chaingaurd however as it likes to derail when in the 11T cog without it.

For the outer gaurd, I simply use a 3mm spacer over the chainring.

I am not sure you need a med cage RD or not. I use one just in case.
 

·
Matnlely Dregaend
Joined
·
5,051 Posts
Discussion Starter · #6 ·
Thanks for the info, glad to see other people have tried something similar. I think I will cobble a prototype together this fall on an old frame and see if it works acceptably. I never minded big jumps on cassettes, it just makes me spin more!
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top