corwin1968

I am going to remove a crankset (but NOT the bottom bracket) from a bike and then install a new bottom bracket and that crankset on another bike. I've watched numerous videos and read a couple of manuals so I'm very comfortable with the process. I removed the dustcaps, took a 14mm socket and what came out was a nut rather than a bolt. A quick look back at the manual shows that I simply have the 2nd type of spindle, the one where the bolt section is actually integral to the spindle. Do I simply use the same Park tool and let it press on the end of that bolt/spindle or is there a separate tool that I need? My plan is to measure the spindle once the crankset is off so do I simply measure from the point where the square taper section becomes a bolt?

Also, since I'm going to buy a new cartridge BB, I don't have bolts from the old one so do I need specialized bolts or or are they something I can simply buy at a hardware store?

My final question is chainline. The crankset is coming off of a 1983-85 MTB with what was probably 126mm rear spacing. Can I simply use the same spindle length as is on the BB in that bike or does the fact that the bike the crankset is going on has 135mm spacing change the length of spindle I need? Also, the old bike has a 68mm shell and the "new" bike has a 73mm shell. I'm going to build a single-speed with a spacer kit for the rear wheel so I probably have room to fudge but I want to get the BB length right in case I decide to have a dedicated SS/fixie wheel built in the future or to go back to a full cassette.

Have I forgotten anything here? All of the processes seem pretty straightforward and these are the details that aren't quite clear to me at this point. My inclination is that the normal Park crank removal tool will work and that the same length spindle will work but I won't proceed until I know for sure.

Thanks!

bikeman715

Yes the same Parktool will work for you . Most of the tine the BB will come with new bolts but not always . Check the box before you leave the shop and if there none then ask for some . If you order online ,you can always add some to the order . it very with the crankset you have and the frame .

hueyhoolihan

it will probably change the spindle length.

a few years ago i had to replace an old square tapered BB on a '97 Gary Fisher MTB. i just took the bike to the LBS, pretended i didn't know much, (not difficult) and asked them to sell me something that would work. i was in and out in about 15 minutes with a 35 dollar BB that i could only have saved about 10 dollars on if i knew what i wanted, waited a week for delivery and bought it on the web. sometimes an LBS is the right choice.

not to mention that if it didn't work out, i could go back, do the disappointed customer routine and probably get what i wanted right then and there, maybe even a begrudging apology.

corwin1968

I also just discovered that there are different types of square taper spindles. My crankset is a Takagi from Japan so likely JIS. Is this the norm for cartridge BB from Shimano or Tange or are those ISO? I see on Sheldon's website that I can use a combo as long as I factor in the change in chainline.

ETA: Just found a site that specifies that Shimano's Cartridge BB's are JIS so that question is answered.

Homebrew01

Make sure you thread the remover in as far as possible so all the threads are engaged.

Jeff Wills

You will probably have to match the spindle length with the crank. Bikes of that era typically had 122mm to 127mm length spindles. Bikes from the early '90's started featuring "low profile" cranks, which tended to have 110mm to 113mm length spindles.

However, since you're doing a single-speed, you have a lot more leeway with spindle length. The essential elements are that the crank and chainring not hit the chainstay and the chainring should line up with the cog. Since you don't say what kind of frame your installing the crank on, it's tough to say. If it's a "road" frame, I bet you could get away with a 116mm spindle. If it's a "mountain" frame, I wouldn't go shorter than 120mm.

Back when I was a shop mechanic (1979-1984), it wasn't uncommon to try several length spindles to come up with the desired result. Guess-and-try was how we did things. You kids nowadays are spoiled.

corwin1968

I'm going to swing by an LBS on my lunch break today and buy a crank puller so I can get the cranks off and actually measure the spindle my crankset was mounted on. I'll be installing this on a 1992 Rockhopper which I believe has 135mm dropouts (I won't have the frame in-hand until this weekend). I'll spend the next couple of days doing some research on chainline in the hopes that I can figure out a way to get the best BB length without having to purchase several cartridges.

corwin1968

UPDATE:

1) I bought a crank puller and the crank is now off the bicycle. The original bottom bracket spindle is 126mm long in a 68mm BB shell. My understanding is that the frame I'll soon be getting has a 73mm BB shell. The guy at the LBS thought I could just use the same length spindle on the newer frame and the 126mm vs 135mm rear spacing wouldn't make a difference. Is this correct?

2) I took the chain rings off and put the middle 38T ring on the outside of the spider where the 48T ring had been. To my surprise, the original bolts were the right length to secure the chain ring. I have ordered specific bolts to make this change. Is putting the ring on the outside of the spider a bad idea? Would the original bolts still be the right length if I put the middle chainring back where it was originally, on the inside of the spider?

Jeff Wills

1: As I said, the only way to find out is to try it out. You've got a lot of different ways to finagle the setup.

2: Putting a "middle" ring on the outside is no problem. If it bolts together without parts flopping around, you should be OK.

corwin1968

The frame and parts should start arriving tomorrow and hopefully I'll get this thing put together over the weekend. I'm looking forward to the process itself.

corwin1968

I got the bottom bracket installed from the driver side and it's completely flush up against the shell. However, the non-drive side sleeve is tightened down but there is still four threads worth of the sleeve sticking out of the BB shell. Is this normal or did I do something wrong? The shell is definately 73mm as measured with digital calipers and the BB is also 73mm.

Jeff Wills

This is normal for cartridge bottom brackets. Carry on.

hueyhoolihan

you may be able to put a lock ring on there to cover the threads. my white industries BB comes with one and does just that.