A friend of mine just came across a couple brand new cranksets and I am thinking about putting them on my beater. The have a real cool ring pattern, and I've never seen a bike with cottered cranks (maybe that's a sign). He said if I took a set he'd throw in a Bicycle Maintenance book from 1978 that would show me how to install them. What do you think?

-Links

Does he have the book from 1968?


There is a reason cottered cranks are no longer used.

I don't know what year the book was put out, he just said that it covers installation and removal of cottered cranks.

-Links

There is still the fact " There is a good reason cottered cranks are no longer used and fading into history."

Cottered cranks are very heavy. If you can get past that, then you will like them for a beater. I suspect cottered aluminum cranks wouldn't work because I don't see the aluminum alloy of the time containing a cotter pin. You would have an aluminum crank, and a steel pin.

You can take a cottered crank off with a 10mm wrench and a hammer (In reality people outside the bike shop tap them off with a hammer instead of getting a cotter pin press. I have a nice VAR pin press). You don't need a crank puller to get your crankarms off. If your an old school mechanic, you have at one time encounter a cheap square taper crankset and pulled the threads out of the crank, even though that tool was bottomed out. Then you have to break out the car engine pulley puller and rig something.

A contemporary example are those Black Widow Lite, BMX cranks that they put about 3 threads for your tool to grip and thread into, that I've pulled the threads out of 2 sets of these because of the ham-fisted people that installed them at 1,000,000 psi. . . . Black Widow cranks are small kids probably between the age of 4 and 8 years old . . .

In other words I hated pulling cranks off square taper, and I still do. Plus I have seen old cranks that the hole expanded and became loose on the spindle.

I liked ISIS, but the bearing are too small to get the job done. I like the external bearing bottom brackets and 2 piece cranks (Props to Bullseye, but for some reason the idea didn't catch on). The problem I have seen are those companys that make the left arm detchable. It's the left arm that comings loose because of . . . . ? . . . I forget the word, but it's the same reason they put left and right threads on pedals. Even with the pinch bolts they still come loose. Every bike we send out we put blue loctite on the threads on the pinch bolts, and the crank bolts. No design is perfect, but I think the Race Face, Deus is a good design.

If it's possible to over complicate something, then people are going to do it. You have to know what the cotterpin diameter is. 8.0, 8.5, 9.0, 9.5 are the most common I think, and it always seems I'm out of the size I need.

If they are free, and they are going on a beater, then use them. For me it's hard to find the chainring size I need. I also find a lot that are for 1/8" and not 3/32", and you have to find the right length. I have a set that are going on a fixie project I have. They are cool for pub crawl bicycles.

A friend of mine just came across a couple brand new cranksets and I am thinking about putting them on my beater. The have a real cool ring pattern, and I've never seen a bike with cottered cranks (maybe that's a sign). He said if I took a set he'd throw in a Bicycle Maintenance book from 1978 that would show me how to install them. What do you think?

-Links

You need the correct diameter and taper of cotter. An old trick is to put some magic marker on the taper and tap it in(not too hard or it might get stuck) then pull it out and see how much of the marker was rubbed off. If the taper is wrong, there will still be a lot of marker left. Some people would file the taper until it was perfect.

When you remove the cotter, you can often reuse it if you use a block of wood between the hammer and the threaded end when you pound it out. If you just pound on the bare end, you might mushroom it. Of course, some rich people had pullers. I never saw one, even in the shop I worked in where we serviced a fair number of these.

As mentioned, other than some nebulous cool factor, cottered cranks are boat anchors. I remember drooling over a Sugino cotterless crank when I had my first good bike, which had cottered cranks.

If you want real cool, try to find a steel cotterless crank! They do exist.

Here's a Campy cottered crank on a 1955 Bianchi. Not all that heavy, at least for that time. Coppi won many races on cottered cranks.

My most recent project (http://forums.roadbikereview.com/showthread.php?t=129617) has them, I plan on overhauling the headset and bottom bracket after I finish my next project (probably this weekend), I'll let you know how it goes.

IME cottered cranks are indeed heavy, with a capital H. They're not too bad to install or remove. Just remember when you're tapping the cotter out, it's vitally important to support the bb axle with a piece of wood or something. If you don't, you'll brinnel the BB cups.

IME cottered cranks are indeed heavy, with a capital H. They're not too bad to install or remove. Just remember when you're tapping the cotter out, it's vitally important to support the bb axle with a piece of wood or something. If you don't, you'll brinnel the BB cups.

Cottered cranks were a royal pain in the ass to maintain, IME. If they'd been on for a long time, it could take a hellacious amount of pounding to get the pins out. The pin was generally destroyed by this process. Then you often had to do a lot of grinding on the new cotter to make it fit right.

Hey hokinunit, I have a steel cottered crank on my fixed-gear commuter. I'm not sure which old bike it came off of. Possibly a low-level Kabuki (Bridgestone) that my wife rode in the 70's. It's not light, but it's rugged. One nice thing about a steel crank on a square-taper BB: there are none of those issues about how tight to torque, whether to grease the tapers, and all that. Since the hard steel crank is essentially damage-proof, I basically grease the tapers and bolts and just crank the heck out of it.