jackb

I have a 2010 Novara Randonee touring bike with a Shimano Octalink bottom bracket and a Shimano FC-R453 50/39/30 triple crank. Last year in order to get some lower gears, I swapped the 30 inner ring for a 22 inner ring (or maybe it was a 23) which I got from Universal Cycles. that worked well, but I find that I am only using the four biggest cassette cogs when I am in the 39 chain ring. I never use the 50 at all and can't even imagine why it's on a touring bike. I would like to swap our the 50 and 39 from smaller rings but can't seem to find any that would fit the 130mm middle and outer bolt pattern. so my question is, can I just change the whole crankset to a mountain crankset. The Shimano deore 42/32/22 would give me the gears that I want. Would it fit my Ocatalink BB or would I have to change BBs as well? I only have basic tools and no experience changing BBs. Any advice or suggestions would be greatly appreciated. Thanks

fietsbob 

24t is smallest for 74 bcd triple, 58 bcd gets you down to 20't

outers its 34 for 110, 38 for 130
94 gets you down to 32t.

94 /58 is a MTB compact.. 110/74 is a trekking /*non compact triple
[lose the 3rd ring and 110 is a compact double , in jargon chaos]

changing over to a new MTB crank , puts you into a hollow tech,
and the BB moves to External.
so then Yes you have to adopt a whole new set..
Square taper is still on the market , then the crank set design hi/low/medium profile matters as far as How the arms interact with the BB spindle length..
for the sake of confusion reduction , get the whole set as a kit.

or farm the job out to the LBS and let them get it all straight.

loose spoke 

One challenge will be the front derailleur.. Mtn FD won't always work correctly with road shifters unless you run friction due to different pull rates. Road FD many times will not adjust low enough to shift and trim to the outer ring without hitting the center ring of a triple.. Sometimes it will work if there is enough difference in the diameter of the rings.

cyccommute 

If jackb is running the bike stock, it comes with a Deore front on bar end shifters. Going to a mountain bike crank shouldn't be an issue. The chainline might be but that can be taken care of with spacers on the external bearing BB.

I would suggest against a 42 outer. That's a really low high gear which means that you'll spend a lot of time coasting down hills. Try to find a 44 or a 48 tooth outer.

HillRider 

Even if you find an older "Octalink" MTB crank, it will use a different Octalink design (V-2) than your road crank uses (V-1) so you will require a bottom bracket change in any event.

As noted, you may have a problem with your front derailleur positioning but friction front shifting (if you have bar end shifters) will allow a lot of liberties. Road front derailleurs aren't optimally shaped for use with MTB cranks but they do work.

bud16415

I went thru the same thing on my Windsor Tourist and maybe what I found out might save you some searching. The Windsor came with 52,42,30 chainrings and 11-32 cassette 9 sp. Needing a lower granny gear for loaded climbing and not understanding much of this I found this web site that allows you to compare different gearing setup's at different cadences and outputs speeds and (gear inch) information. I knew I wanted to be below 20 gear inch for a granny and had no need for more than 100 gear inch as a tall gear. The best web site I found for comparing this is linked below.

http://home.earthlink.net/~mike.sherman/index-shift.html

After reading a lot I did the normal change out of the small chain ring to a 26t and was advised if I went smaller the drop from 42t would be pushing the limits. I also at that time added a chain minder to help over shooting the 26t. That was a great improvement and stuck with that for a year wanting a little bit lower granny still and having excessive tall gears I never used. I was debating over a mtn bike crank transplant and something no one was suggesting changing the cassette. After finding a cassette that was 12-36 and putting it in the gear calculator I liked how it dropped my low to a 19 gear inch and also lowered my top gear to something like 106 still a little high but lots better. So I did that and Totally fell in love with the ranges for me. I did have to add one link to the chain even though I would never cross chain the two big rings it could happen by mistake and I didn’t want to break something.

I kept thinking about the top gear still and a friend had a brand new 44,32,22 mtn bike crankset with the sq BB mounting and for $18 bucks I thought let's give it a try. This time I removed the link I added plus one more. Below are the before and after photos. I did drop the FD even though the photo was taken before. I ran the numbers and came up with a ridicules low gear of about 16 gear inches I think but thought who know maybe you can't go to low and I have some super steep climbs around here maybe I would use that range, and looking at the tall gear it was perfect for what I wanted I thought. So I changed it out. When I first jumped on the bike I tried the tall gear and it was great, right at my upper limit. I rode to the steepest hill I have around and spun up it so slow in the granny I was winded at the top just due to RPM needed to keep the bike going fast enough to not tip over, but the resistance was great almost zero. I started riding it around more and soon began to hate the mtn bike crank and for a totally different reason than I would have thought. What I hated is that the middle chain ring no longer covered the wide range of where I like to ride. I was constantly jumping around between the 44 and 32 in funny shift patterns as I didn’t like cross chaining off the 44 to the extent I was. What I found was for me the 42 on my original crank matched up with the 12-36 perfectly for my riding style. Once that light came on I couldn’t change back to my old crank set fast enough.




So am I done tweaking yet? Maybe not. I'm not totally happy having a chain that’s one link longer for replacement on the road, but that’s not a big enough reason to change anything. The way I use this bike I'm finding is 70% a commuter 30% touring. When I bought it I had planned to just keep it for touring and I have other road bikes and grocery getters to use for the rest. But the things that make it a comfortable touring bike also appeal to me to ride it just about any time any place. It’s a bit heavy but I don’t race and its stable and easy to adapt to whatever I'm doing. Unloaded from touring with the big ring a 48t I think I would ride a lot in the 6 smallest on the cassette 12-24. So I might just loose the 52t for a 48t.

Sorry for a longish post and I'm not trying to hijack your thread or persuade you to use the gearing I used. Rather don’t overlook the middle chain ring size where you do most of your riding and figure out where your personal sweet spot is in that regard. In my case I had to make changes both front and back to get to where I needed to be.

mvanderk

Mine works fine..... I put this MTN bike crankset on my touring bike (Nashbar frame) and it works great. Easy simple change out. I'm also running Shimano 105 front derailleur with 105 brifters which also works great.

http://www.ebay.com/itm/SHIMANO-DEOR...item43aa0d3067

fietsbob 

that's the reward I worked so damn hard coming up the other side, to enjoy...

TurbineBlade

I solved the 22-32-44 mtn crankset problem differently than this. I swapped the 32 for a 36 and grabbed one of my old road FDs (for a 42-52 double crankset) and it shifts the 22-36-44 quite well in friction mode (obviously). I just had to loosen the high gear limit a bit . Even the 22 to 36 shift is good. Good enough for me anyway. Now the gear range is great with a 11-34.

Actually 11-34 sucks, because the 11 is worthless to me. Around here I have no need for high gears like that. Flying down hills is not my thing -- that's a young man's game. The 44 X 14 is plenty, and I'd rarely use it.