Hi , can anyone identify this particular model of crankset?
all 3 charings seems to be oval , and looks like they are 28-38-48 ( counted from another photo , so i don't know if they are correct).

The double version of this crankset was the Solida 5271. I'm not sure of the model designation for the triple version.

Solida was originally a French manufacturer of steel cottered cranks for the lower priced market.

At some point, probably in the mid 70's Solida was taken over by Stronglight.

From the late 70's until the end of the 80's??? Solida made cast aluminum 2nd tier cotterless cranks with swagged on chainring webs to compete against the deluge of Japanese "melt forged" cast aluminum cranks used on entry level to mid range models like this Tourney model.



It's hard to tell what model crank you have because Solida produced a wide variety of alloy cotterless cranks. By the late 80's Solida was also making models with integral webs for the MTB market. Your triple cranks were probably made for that market.

Your question about the chainrings, Stronglight brought out their own version of the Shimano BioPace oval chainrings called BioStrong. Your cranks probably have chainrings made with that design.



My objection to swagged together alloy cranks is that making crankarms with cast in spiders had just about the same manufacturing costs and provided a more rigid part.

The early Japanese swagged cranks had a lot of failures and those memories stuck in my craw: 40+ years as a manufacturing engineer - do it right!!!



Stronglight and Nervar made some inexpensive cast cranks with integral spiders for that same market.

Stronglight TS crank arms.



Nervar Cast Cranks



Making pressure cast "melt forged" parts is fast and easy. Adding an integral web adds very little to the cost of the part.

verktyg (retro grouch)

I like the triple spider cranks

Me too.

That's a lot of information. Do you think the chainrings will be removible and also the protective guard?
I'll get this chainring as a gift for a multi ithem shop , do you think shuold i ask for a better model? i'll using it for a gravel bike with full vintage parts.
have a good day

The bash guard is removable, the two smaller rings are removable, the largest ring is not removable. Unless this is very cheap, I think you can find a better vintage crankset on ebay for a fair price.

edit: As an example: Crankset

It's in pretty nice shape. No idea if the cranks work with your bottom bracket or chain line, but this would be a fine crankset. Especially since it comes with a 39t ring, which, in my opinion, is good for gravel grinding assuming that you're planning on using a single front chainring.

As verktyg points out, these type of cranks were somewhat prone to failure so no, especially for any kind of rough stuff.

There are many, many great examples of one piece forged cranks for very little $$$ like Piff shows.

No reason to be looking at these substandard cranks imo.

Do you think this can be a better option? This seems in bad condition (take a closer look to the bottom bracket pin) Also the material seems to be plastic (as usually ofmega crank are). I was thinking that Solida was better since i can polish it.
Do you think a little bit of soldering can help reduce the possibility to break?

https://ibb.co/pj43jnZ
https://ibb.co/fnLt62Y
https://ibb.co/bbLZ54z

Solidas were cranksets used on many lower end model French bikes in the 80's. Many of their cranks were of the swaged spider type. Nothing wrong with them, just a cost effective alternative to Stronglights and other more expensive brands.

hehe sorry...i know my english is not very clear. Which part you do not understand?

Its ok, the ofmega's are not plastic just painted and look that way, the solida is still a poor choice no matter what and no, soldering will not help, might actually weaken it a bit.

Before i give it away i had an old mtb branded legnano , nothing special just a cheap bike with old shimano sis and thumby shifters. That bike had an ofmega and it break near the bolt. The damage show the plastic of the crank and inside it a bit of metal where the botom braket's pin will be secured. That's why i was talking about the material.

Tnx for the help guys. I'm going to tell to the seller to swap the crankset...hoping that he will do whitout any price difference.
Ps. is the ofmega from 90' ?

+1

Hi guys , today the crank is arrived. there is a little problem , i can't remove the chainrings.... in the crank there is a piece very similar to those crankset bolts (5mm hexagonal) but from a close view they are more similar as rivets...
Can i replace with normal 5mm hexagonal? but first ... how i can remove them? tnx!

img there https://imgur.com/aRbQcDG

Uhmmm....... Those look like modern, standard flush Allen head crakset chainring bolts to me. You do not want to replace those with regular hex head bolts. if you look in the back you will see the back end of the tubular nuts that retain them. You can use a big coin to engage the slots on them and use an Allen head wrench to remove the bolts at the face of the crank. There should be videos in the net that shows how you remove these bolts. Just do a Google search.

Yea they really looks like them, but they are not. The piece is flat in the two faces and there is not any place for the Allen key or similar. First time I have seen this strange way to lock chainrings...

I have a modern SR Junior triple crank with the exact same 'rivets' They take a hex key on the front but they're press fit into the rear. This was mentioned by [MENTION=360647]Piff[/MENTION] in post #7 of this thread.
I would find another crank or live with it if it's not too worn.

Nothing wrong with them? I'm feeling ill...

Almost all cranks that style look CHEAP to me... Like looking for an integral derailleur hanger on a frame, I instantly look to see if the large chain ring or spider is swagged onto the arm.

When I first moved to the Bay Area in 1980, there were a lot of foundries, pressure cast and injection molding businesses in the area that that made parts from aluminum, brass and Zamak zinc alloy also known as pot metal. I dealt with a lot of them.

I saw first hand what a cheap manufacturing technique the "melt forge" pressure casting process was. The most expensive part was making the molds or dies. One place in Oakland made promotional belt buckles for Snap-on in both brass and Zamak.

Early memories of my experiences with the first Sugino Maxy crank failures, spinng several out plus seeing the same kinds of failures in the first Takagi and SR Sakae Ringyo cranks persist to this day.

One exception that I found are the SR Apex cranks. They're really beefy and have a well designed web and swage. They feel just like a good forged crank.




I'm sure there are others made like these but...
No offense intended Chombi but... WOW! I COULD HAVE HAD A V8! (forged crank)

verktyg

If so, you will have to drill them out.


Which will be a problem, because they will probably spin, the bit won't bite, and it'll ruin the crank-arm hole.


However, if you have (a friend with) a drillpress and a table vice with a vertical v-grove (not uncommon) it can be done [1].


You mount one drill bit vertically, point up, just proud enough that when the crank is placed on the table the bit bites one end of the rivet. It has to be enough proud that when you bring the upper bit, mounted in the press chuck, down on the other end of the rivet, the pressure of the upper bit pushes the rivet down on the the lower bit. This means the crank is held off the table about 1/16", you have to steady it as you start the top bit.


If the rivet spins (as it may do), stop, loosen and tap the lower bit upwards, and have another go.


[1] no v-groove? Drill a hole with the bit you're using in a parallel-sided block of something, cross-drill and tap a hole for a set screw, grind a flat on the bit. Or do anything to grab the drill - Mole grips under the table and a pair of clamps, whatever.


If you are doing a single-ring you may have to grind the tip of the bottom bit flat for top-bit-clearance.

oh well..... i think im going to keep in this way... for now
tnx for answer