Mtn Bike Crankset in a Road Frame?
 

Hi,

This is my first post. I am a retiree who has become addicted to cycling. My wife calls me obsessive; she's right.

I have a 2006 Specialized Sequoia Elite. My age is 68 and I do 50-100 mile club rides in a hilly area with hopes of doing a trip like Mountains-to-Sea in NC or the Blue Ridge Parkway before I have to use a walker.

I have had difficulty with long, over 10% climbs so I replaced the 11-25 (9 speed) that came with the bike with a 11-32 Mtn bike cassette (Deore) to go with the 52-42-30 Sugino triple crankset.

This has made climbing significantly easier and I am very happy with the extreme 30/32 ratio. However, what I gained in climbing, I have lost in ability to keep up with the better riders in my club because the gap between (cassette) gears has gone way up. I realize that I need the close ratios of a 12-23 cassette.

So, I thought: why not install a 44-32-22 mtn bike crankset (Deore XT) with a 12-23 cassette. That way I would have both the hill climbing capabilty (22/23 extreme overall ratio) and the close ratios for level paceline riding. What I would give up is the higher speeds from the 52 wheel, which I am happy to do because I seldom, if ever, achieve (level, wind-free) speeds of over 22-24 mph. And, going downhill for me is more about applying brakes than cranking.

First, technically and mechanically, can one use a mtn bike crank (Deore XT) on a Sequoia frame (9 speed)? Any issues with bottom brackets, etc.?

Second, will it work? Will I meet my twin objectives of: climbing capability and close ratios? Has anyone done this?

Any help will be greatly appreciated. Thanks. Ted

Technically... some things to think about, but no problems at all:

• You may need to change the bottom bracket to match the new crankset, but practically all modern frames (road or MTB) use the same BB threading, so there's no issue there.
• You'll certainly need to adjust the front derailer height to match the new crankset. You may have to actually replace the FD as well... many people will tell you this is a must but I have found you can make practically any triple FD work with practically any triple cranks in practice :)
• You'll probably have to remove a few links from your chain to get rid of the slack from the smaller chainrings. Easy.

As to whether it will achieve the desired effect... hard to say. You're proposing to switch from a 30/32 low gear to a 22/23 low gear. That means your LOW GEAR will actually get slightly higher!!! (Compare the ratios.) So this change certainly won't improve your low-end gear for those steep hills.

As for close-spaced gearing on the flats: between the 11-25 cassette and the 11-32 cassettes, you lost the 15T and 17T cogs. It's likely that you used one of those a lot and that "perfect" gear combination (for you) is what you're missing with the wider cassette. You might consider getting a custom cassette with those cogs included... say Sheldon Brown's Century Special: 13 14 15 17 19 21 24 27 30. That seems like it might be a decent compromise, and would be a simpler and less expensive solution that replacing your cranks, BB, and possibly front derailer. What do you think?

Are you talking about the newer, external bb, Hollowtech XT's? If so, I can't foresee any problems, just follow Shimano's instructions as per how many spacers to put on each side (for a 68mm shell, I beleive it is 2 on the driveside, and one on the nondrive).

Yes it will work. But rather than a 44/32/22, I'd suggest a Shimano Trekking 48/36/26 like this one. You will probably have to get a new, narrower bottom bracket but at $40 this is a killer deal on a great crank. If you need lower gears, the inner ring is replaceable with down to that 22. Derailers for the crank shouldn't be a problem either. I run an Ultegra triple with mine and I run a Tiagra with another crank that has a similar range (46/34/22) and have no shifting issues.

The 48 will give you an advantage over the 44 in a higher high.

Good luck

I agree that crankset is a steal, but not sure if a tight cassette and smaller chainrings are really what the OP needs. It seems like the main thing he's missing are a couple crucial cogs in the cassette...

What Sugino crankset do you have? There are lots of Sugino triples out there with 110/74 Bolt Circle Diameter (BCD), if yours is 110/74 you could come very close to the chainring sizes you're wanting by simply replacing chainrings instead of buying a whole new crankset. You can go as small as 24t with a 74mm BCD, and as small as 33t with a 110mm BCD. Here's a link to Sheldon's site that shows how to determine BCD, and it also has a long list of the available chainrings in the various sizes-

http://sheldonbrown.com/harris/chainrings.html

Many thanks for all the ideas.

I'll review the suggestions with my local bike store.

I've spent the better part of the evening studying Sheldon Brown's website. There's a wealth of info.

Ted

Once you discover Sheldon Brown's site, you soon wonder, "How did I ever ride my bike without this?" :)