itsneddy

I have a 97 Jamis Aurora with an RSX 3 x 7 drive train. I want to gradually rebuild the entire drive train. I want to start with the crank set which is now 46/36/26. I want to go to a 50/39/30. Problem is, I can't get the crank bolts off to see if the spindle is square or another type. The BB seems fine. I have the correct size allen key, but I don't think it is torquey enough. Any help will be apprciated.

Bianchigirll 

Hello itsneddy Welcome to the forums. You might be able to see from the back side of the crank if it is square taper or the isis or whatever shipmano had for awhile. Is there a reason you can't simply upgrade the chainrings?

What kind and size of allen wrench? A multi tool doesn't have enough leverage, for cranks your better off using a bit type witha 3/8 drive ratchet. Any chance you have a single key release system? Pics or more information on the crank will help.

HillRider

The RSX used a standard Shimano square taper bottom bracket. The bolts should take an 8 mm allen key but be sure to use one in good shape with sharp corners so you don't round out the recesses. The bolts are both conventional right-hand threaded.

itsneddy

Thanks. I was using a multi tool, so I'll try the ratchet.

I don't want to replace the chainrings because the existing crank is getting pitted and dull. I am thinking an fsa vero if it will work with a 118 mm spindle. Any thoughts?

itsneddy

Thanks. So I could go with the fsa vero?

cny-bikeman

If the existing BB is 15 years old just go with a complete crankset with BB. All you have to do is make sure the chainline is proper for your rear setup. Also, on a mountain bike I don't see much value in raising all of your gears. The highest gears are of little utility and wear faster; the lower ones may be missed as you add a few more years to your body.

itsneddy

My bike is actually a touring bike. More of a road set up than MTB. This is the bikepedia link https://www.bikepedia.com/quickbike/B...e#.UR-0tx2ceHM . Mine is a 50cm. The 46/36/26 crank really limits the top end. Based on this, any recommendations for a complete crankset?

itsneddy

My bike is actually a touring bike. More of a road set up than MTB. This is the bikepedia link https://www.bikepedia.com/quickbike/B...e#.UR-0tx2ceHM . Mine is a 50cm. The 46/36/26 crank really limits the top end. Based on this, any recommendations for a complete crankset?

fietsbob

Contrarian,

you dont have to replace the cranks entirely, if you just want new chainrings.
buy the 3 chainrings, actually just get the bigger 2..

i use a 50,40, 24 triple, have for 20 years..
i wouldnt want to raise the low gear.

BB might be worn , , seek bike shop help , for direct replacement..
I'd bring the bike to the Shop and let them have a look.
since I cannot see what your wear and tear condition of stuff is over a website.

dsbrantjr

"I was using a multi tool"
Multi tools are only good for emergency on the road repairs, if that, and for damaging fasteners. Trying to use them for tightening or loosening crank bolts is asking for trouble.

itsneddy

I'll remember that. Got it with my 8 mm allen key and a big crescent wrench

itsneddy

Thanks. I'll take a look at the chainring fix since you are the second person to recommend it. Now I need to figure out the BCD on the existing crank.

The bottom bracket on the bike seems fine. I know it's old, but when I got this bike last May everything was original spec right down to the tires which were still serviceable. I have replaced them, but overall condition of this bike is very good at worst. I really just want to get a little more top end speed.

gilaasepeda

if you like to change the crankset take a look shimano FC-2303 52-42-30T maybe included with bb i'm not sure, please check at your LBS.

fietsbob

Got a crank arm extractor? You need one of those..

itsneddy

It's been ordered. Thannks

cny-bikeman

Whoops, mixed up yours with a bike from another thread. to each his own.

As for "limits the top end, a 46-12 gives a speed of 31 mph at only 100 rpm. If you are talking about touring in the sense of fun, long distance day rides or even moreso for loaded touring there is nothing to be gained by moving that up to 34 mph. You will not achieve either speed except very briefly or on downhills, where it's wiser to coast. On top of that, because gear ratios are a percentage you are going up 9% for your highest gear range but losing almost 16% for your lowest.

To each his own, but for me I'd rather make sure I can get up hills without strain than worry about being able to pedal downhill.

itsneddy

Nevermind!

HillRider

Your 7-speed RSX triple crank has BCDs of 110 and 74 mm.