Forgive my newness to biking with this question, but I've been patiently on the lookout for a Stronglight crankset as I am building up an old Peugeot into a fixed gear. As best I can tell, this combo would work. Am I right? Thanks.

Stronglight Crank Arms: Alloy, 167.5mm Arms, 122mm BCD, Dust Caps, 381g - Bike Recyclery

Depends on which Stronglight cranks you are using. Got a picture?

If the BCDs match you're good to go! Both 122BCD in this case so enjoy.

1. You'll need the right BB. These probably used Stronglight's 118.5mm spindle length. Of course that will give you a slightly off chainline on either the inner or outer landing, so if this matters to you you might have to do a little experimenting.

2. Since you're building a fixed gear, what chainring size are you interested in? The 122BCD will limit the readily available sizes out there.

3. I have a Peugeot branded Stronglight 104 crankset you might be interested in, assuming #1 & #2 above don't sway your thinking.


EDIT: I didn't catch on my first reading that you had located a 45t ring - I think I have one of those, too, but I'll need to check condition. PM me if interested.

That crank, in my opinion, is no great prize. It's pretty much the bottom of the line Stronglight crank from the early 80's. It has the advantage that it probably takes a standard 22 mm puller, which is good, but it has none of the elegance of the classic Stronglight cranks of the 70's.

+1. A swaged crank wouldn't be my choice for a fixed gear.

I appreciate the responses. This is a 1983 PFN 10 with an English-threaded BB that I am rebuilding for the bike.

I wasn't aware of the swaged crank issue on a fixed gear. Thanks for pointing it out. Once again Sheldon has good info on it:

https://www.sheldonbrown.com/gloss_st-z.html

Yeah, I'm afraid that crank is a little too cheesy for that frame! Your frame probably came with a Stronglight 104 originally, but when looking for the perfect crank I'd prioritize the quality level above the word "stronglight." You could use anything with a bcd 144, 130, 110. Something like a Sugino Mighty should be pretty easy to find and look great.

Just for future reference - I had very good success running a stock Stronglight mod. 93 crank with its stock 118 mm offset Stronglight BB on a bike with 120 mm OLD dropouts. I used single stack chainring bolts and the inner position running a Maillard track hub and got perfect chainline.

Okay I am looking at picking up a used IRD Defiant crankset. I assume this will work with the Stronglight BB? It is English-threaded and square tapered. I haven't measured the axle length but it say "S" on one side and "18" on the other. Thanks.

Square Taper Bottom Bracket Interchangeability

I think your spindle is ISO and crankset is JIS. Might be OK but proceed with caution. You don't want the crank to bottom out in the spindle.

Thanks. I read this and came to the same conclusion. That means either get compatible cranks (eg. Stronglight) or change to cartridge bottom bracket that is JIS, right?

Yes. Is the BB French? I think VO sells a French threaded JIS BB.

English

The more I read about this ISO and JIS thing, the more I got confused. I think mine is ISO. Here's a pic of my bottom bracket spindle:



Here is what Sheldon has; https://sheldonbrown.com/bbtaper.html

That means I either need to buy compatible cranks or swap it out with a JIS-compatible bottom bracket like a Shimano UN55, right? I notice too [that some Stronglight and some Sugino cranks are ISO while others are JIS.

Thanks for the help.

Check out my Flickr Album. Read the comments under the pictures - if it fits, it works:

https://www.flickr.com/photos/282672...7627678462359/

Back in the 70's Phil Wood only made 1 style of taper on their BB cartridges. They worked without any problems.

verktyg

Chas.

Even if the tapers are compatible, there's no guarantee that your Stronglight BB is the right length for the Defiant crank. For fixed-gear, having the right BB length is pretty important. Just buy the right BB for your new crank while you're at it.

Very helpful, thanks!

I would follow up Ex Pres' offer on the Stronglight 104. Get a crank + chainring together.

Editorial Rant - Swagged Aluminum Cranks:

The majority of 3 piece cottered steel cranks ever made have the chainrings or spiders (chainring carriers) swagged onto the drive side arm. See pictures.

Contrary to what some folks want to believe there was never much of a light weight sporting bike tradition in Japan. Keirin track racing is a sport in the sense that horse racing is a sport. The attraction is the parimutuel betting!

During the C&V era most Japanese bikes were 50 lb. single speed rod brake behemoths - a European design dating back to the early 1900's.

Those bikes were used for basic urban transportation (they're still popular in a large part of the world).

Where is this going?

In the 1960's Japanese bicycle component manufactures (primarily Suntour and Shimano) where keen to break into the world market. The US bike boom of the early 70's gave them that opportunity because the European suppliers where hard put to meet the market demands.

Suntour's rear derailleurs set the standard and helped to improve the image of Japanese made components. But... most of those products were made for export not domestic consumption.

Poor quality cottered cranks were major problem/complaint with lower priced bikes during the bike boom fad. The cheap cotters were soft and frequently came loose, especially with strong riders.

There was a call for inexpensive cotterless cranks - both for marketing an performance reasons.

When Sugino, SR Sakae Ringyo and Takagi first started producing low cost aluminum cotterless cranks they didn't have a clue about what they were doing!

They used the same swagging process used on steel cranks. Steel is 2-3 times stronger that cast aluminum plus it's much more malleable; it can be deformed much more than aluminum without braking or cracking.

Japanese in general are smaller in stature than westerners. Most Japanese rode 19"-21" rod brakes.

When larger, heavier westerners started riding those first cranks there was a high failure rate.

I assembled a 1973 Gitane Interclub with a Sugino Maxy crank. When I took it out for a test ride and stomped on it, the pedals spun about a quarter turn. I thought that it was the freewheel tightening up. NO! I spun the chainring on the crankarm!.

We had that problem with all of those Interclubs and it took about 6 months before we got improved replacement cranks.

Pictures show a 1st generation Maxy crank and the problem with the size of the swage on the back side. Compare that with with a larger swagged area on a later model Maxy crank.

As I mentioned in a post above all of these swagged cranks are "melt forged" which is a euphemism fro pressure casting. Because the aluminum casting alloys were weaker than forged alloys the crank arms were made up to 25% larger.

I've ALWAYS considered "melt forged" swaged cranks cheap! By the the 1980's a number of crank manufactures started producing better quality pressure cast cranks with integral spiders.

I still prefer forged cranks!

verktyg

Chas.