9volt 

Just some pics of an early SR crankset I picked up recently. The crest on these is really neat. I want to build a frame around this stuff.





First time I've run into these chainring bolts - SR Silver Cotterless

juls

I have the 3 arm version. They are purty. Mine has a chainguard 52/47

juvela

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The three arm model with this crest was offered in a boxed luxury presentation format, similar to original Shimano DuraAce components.



Before putting it to service check carefully to see if it is made for two degree or for three degree taper. Many of the early Sakae Ringyo sets were done for three degree.

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9volt 

3 arm is very cool. I need to locate a pair of those dust caps.

9volt 

Thanks for mentioning this. I wasn't aware and it didn't come with a BB.

juvela

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The odds are pretty strong it is two degree. In general, the ones with the three degree are variations of Silstar. Some of these were private labelled, IIRC. Do not know if anyone else made three degree cotterless chainsets...

One potential stumbling block to making use of the three degree sets is locating the correct spindles.

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Bikerider007

That is cool looking. Have seen the three arm but not that one. SR is seen lower range but did have some neat stuff and their quality increased with part of that being BMX in the 80s. Sheldon Brown does an explanation of countries beginning with a cheap offering for a decade or so, moving to quality for decade.... etc in stages that ends up being too expensive to continue or something to that effect. Just insert one of the old company names. It's interesting. Anywho, that's a nice looking set. And the chainring bolts as well.

rhm

The best thing about the SR Custom 3 (on your photo) is that the three pin 86mm bcd chain rings have recently become available from fsa, in sizes as small as 27t. You can make yourself a very nifty compact crank. Downside is that there is very little space between the large chaining and the crank arm so though the Q factor is small, most "modern" front derailleurs won't work.

But I digress. Sorry for the off topic bump.

juvela

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Thanks rhm for this good point about interference/clearance.

Only encountered it once as a spanner twister. Ironically it was on a 1959 Cinelli fitted with Cinelli-Magistroni cranks and T.A. adaptor for Criterium chainwheels. Not a whole lotta residential space in thar...

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Came upon this fitting of a three-arm Custom the other day on a private-labelled Flandria frame from the '60's. Cycle domiciled in Poland.







As I remember it, launch was ~1974.

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juls

https://www.bikeforums.net/images/attach/jpg.gif

rhm

Here's the 'compact double' version! As shown here, the 47t ring is placed so the teeth are on the outside. This allows the chain ring bolts to sit in the recess designed for them. But I've found it works better when the ring is reversed, with the teeth on the inside, so the heads of the chain ring bolts stand proud of the surface.

juvela

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Thanks so much!

Looks like they were still copying Verot and Specta at this juncture in only cutting teeth from one side.

Later, top models joined the balance of the known universe and had their teeth cut from both sides of the stock.

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rhm

Yeah. These were a pretty cheap crankset and it was presumably cheaper to cut the teeth on only one side.

Whatever. I'm just happy we can get teeny tiny little chainrings that fit it!

juvela

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Always much appreciate any and all notices regarding modern available spares which fit annuated componentry. An excellent resource to keep our vintage equipment in operation!


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9volt 

Great pics! Feel free to hijack with modern chainring discussion

When were these cranks new? Early/Mid/Late 70s? Did the 3 arm come before or after the 5?

juvela

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These are good questions!

From what I have seen and worked with the earliest SR chainsets were three-arm Silstar variants whose outer chainwheels are swaged to the right crank arm. These included alloy cottered models. Would think launch mid-to-late sixties but do not know a hard date. Other readers are sure to know more precisely.

Five-arm models seemed to appear later, beginning 1970-ish.

The many iterations of SR chainsets through time can be seen pretty well at VB.

https://velobase.com/ListComponents.aspx?Category=115

There is a relatively late Sakae Ringyo catalogue from 1980 housed here:

https://cyclespeugeot.web.fc2.com/rem...ce/sakae80.htm

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Chombi1 

What is the difference between "Melt" and "Regular", as we know, aluminum forging?

rhm

There was a thread on that once, many years ago:
https://www.bikeforums.net/classic-v...st-forged.html

What we learned, from the 1992 Bridgestone Catalog (https://sheldonbrown.com/bridgestone/1992/1992.pdf):

"MELT-FORGING is high-pressure casting, in which molten Ac4c-T6 aluminum (tensile strength
approx. 32,714 psi) is forced into a mold under roughly 11,378 .4 lbs. of pressure. This eliminates ,
bubbles much faster and more economically than in gravity-casting. The "forged" piece is then
cooled quickly with water. To compensate for the lower strength Of Ac4c-T6 (only 50 percent of
typical. crank cold-forging alloys and 75 percent of crank gravity-casting alloys), the parts tend to be
chunkier . Since Ac4c-T6 cannot be anodized, melt-forged parts never display the fine finishes
possible withhot-forgings, cold-forgings, or gravity-castings . Still, melt-forging has made relatively
lightweight, attractive, reliable components affordable to people who would otherwise ride steel."

bark_eater 

I've got a set of these on the way and I have a few questions. I found the FSA 27t chainrings. The come in steel and alloy. I was wondering if I should go with the steel chainring for durability?

The other technical issue is the chainring bolts which are not original and too long. Is there anything specific to the original bolts, or can I just file the replacements to leangth?

Third question is gearing. This is starting as a 52-40t and I'll be going down to a 40-27t. Any recommendations for 6-7 speed gearing. I'm generally riding in the flat lands, but hopefully will riding hilly areas next summer. Thanks

branko_76 

This is something I've wondered as well. My thinking is that steel chain-rings will last longer but would be harder on your chain and if not replaced regularly, a worn chain would wear the rear cogs faster. I have bikes with steel chain-rings, but I don't ride them hard.

oneclick 

The material that chainrings are made of makes a difference, but not in the direction you think. All else being equal, steel teeth will wear more slowly than aluminium ones; and it is the point-stress created on single rollers (when a sprocket is worn) that wears chains - so steel chainring teeth are better for your chain that aluminium ones.

And the fewer teeth the more this matters.

juvela

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When this set came packaged for retail sale it appeared in a presentation carton the interior of which was coated with a velvet look layer.

Can recall seeing one in the display case o' me local ~1973-74.


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steve sumner

just a polite or higher tech sounding way of saying "cast" not as strong as cold forged

Dougieh65

hi the crest is right , but it’s not the right one , the chain guard is thicker , I wish I could post pics on here as I have a few of what I need

bark_eater 

Here's another one: Ebay listing