Changing Crank set, need some advice.

cjpowl6818

I have a chance to buy a shimano deore 9 speed FC-M590 crank and it has 26/36/48 chain rings and my bike has 22/32/44 chain rings. will I have to change my chain out to run this crank and will it work with the cassette that is on my bike. I have a 2005 Jeckyll with a truvative isoflow 9 speed crank.

cooldad

Yes and yes. But you may have to do something with your front mech. Those would be considered trekking ratios and that's a big ring.

nicklouse

You might also need a new BB.

Lack of info reduces any further comment.

cjpowl6818

I am a complete newbie at this and it has been 30 + years since riding, I got electrocuted a at my shop welding last year and it put me down for 6 months and I got way out of shape from not being able to do anything, I am down 15 pounds from riding so far and want to lose more. I have really gotten back into riding and I want to upgrade the components, so far I have upgraded the brakes and shifters and want to do the crank next. below is what came on the bike when it was built. I am thinking it would just be easier to just replace the crank with the same size chain rings 22/32/44 I have heard that most BB's for the Jekyll are the same size which is 68 and 113, the 590 crank comes with the bottom bracket and it says BB51 shell width 68 will I have any problems using this BB with the Shimano deore M.590
2005 Cannondale Jekyll
Fork Manitou Splice Super 100/130 w/ RTWD
Rear Shock Fox Float RL Pro Pedal
Rims Sun Black Eye Disc, 32 hole
Hubs Cannondale Fire Disc
Spokes DT Champion
Tires IRC Serac XC, 26 x 2.1"
Pedals Wellgo alloy cage w/clip and strap
Crank TruVatiV IsoFlow, 22/32/44
Chain Shimano 9-speed
Rear Cogs SRAM PG-950, 11-34
Bottom Bracket Shimano 4-taper
Front Derailleur Shimano Deore
Rear Derailleur SRAM X-7
Shifters SRAM X-7 Trigger
Handlebars Cannondale Earth, 15 mm rise
Stem Cannondale 3-D Forged
Headset FSA Converter
Brakeset Avid BB5 Disc

The Rookie

That's the right BB for the cranks, you'll need 3 spacers to fit into your frame (2 drive side, one non drive side).

Best to get the frame faced before it is fitted as well.

Personally I wouldn't use those chainwheels unless you only ride on the road, too tall gearing, you could swap on the rings off your current crankset.

cjpowl6818

cooldad wrote:

Yes and yes. But you may have to do something with your front mech. Those would be considered trekking ratios and that's a big ring.

I went a head and got the new crank set FC-M590 26/36.48 and also bought the BB51 Bottom Bracket, All Jekylls require a standard "bottom-pull" type front derailleur with a
31.8mm clamp diameter.
Because the front derailleur mounts to the swingarm, and has a limited
range of vertical adjustment, some derailleur designs (like Shimano
"Top Swing") are not compatible.

My ? is , I should just be able to raise the front Derailleur a little bit to make it fit the new crank right.
I live in the country and nothing but flat country roads around me, so no trails just road riding.
I take it trekking is on roads and long distance ?. forgive me for being a newbie.