sd5782 

I am finally showing a little love to my well used and slightly abused 73 Schwinn Super Sport that I bought in 1975 as an 18 year old. I started by doing a lot of cleaning and a bit of bearing work. Being a bit older I thought some easier gearing would be nice, but the Ashtabula crank is kinda iconic so... Searching eBay turned up a 110bcd spider that looked as though it would fit on the 1 piece crank. It was an inexpensive item so it matches my well used slightly resto mod update. It was probably meant for a single speed, and the prettier finished side faces inward. In this position, the inner chainring is in plane with the spider just as the stocker.


dropped front DR down a bit

46-36 for now

As the stock Schwinn outer ring's mounting is a bit different shape, I needed some spacers to have the chainrings a proper distance apart. I did move my washers to a different position for a better chainline. 3/8" hardware store washers that are 2mm thick seemed just the ticket. This item was a simple cheap stamping so required a bit of tweaking to get it to run fairly true. Runout maybe 1mm now after a bit of persuasion. .






Anyhow, it will be interesting to see how it works. More than half the weight of the stock setup is the chainrings. This saved over a pound and I may get to play around with some different chainrings while also rehabbing an old friend and warhorse.

BFisher

Looks promising. Interested to hear how it performs.

machinist42

Clever.

Is that the Chromed Steel version of the spider? If I found what you're using, it appears there's an aluminum option as well?

Do report back on how it works on the road?

canopus 

No reason you can't do it as long as the chainring bolts still fit through both chainrings, the washer and the spider to keep them aligned concentrically to the spider. But if you do have issues you can always get an adapter and put on a three piece you might have laying around.

sd5782 

Yes, it is chrome steel. Probably made for a bmx or fixie. The side with better polish and chrome faces inward with how I have it mounted. One I bought on eBay was $3 with $5 shipping, I must not have seen one you have found with an aluminum option.

branko_76 

Nice mod to the crankset.

Salamandrine 

Try it. You may want to put some loctite on the bolts. IME the slightest amount of potential play can cause issues. Probably depends on lots of factors.

I remember having trouble trying to use a single chainring on a double crankset when setting my bike up as a fixed gear. The chainring bolts kept loosening up. Finally gave up and ran 2 chainrings.

I still want a bike with a solid titanium ashtabula crankset. That would be the epitome of cool.

Bianchigirll 

You do realize there will be huge run on those causing a price spike.


great idea

BFisher

I think I have one of those spiders in aluminum. If I recall correctly, Sugino made it. They came on some of the mid 80s Schwinn Predator bmx bikes.

sd5782 

I believe they were a NOS item of maybe a dozen or so. Gone now I think, but pricier higher quality similar items remain. A 3 pice crank conversion would be cheaper and probably smarter in that case. EDIT Actually some left. “Vintage NOS old school bmx chrome spider” may be the listing. I can’t guarantee it is durable or even doable, but the price was right.
I also got a NOS upper bearing headset race for the Super Sport there as mine was in poor shape. I believe that was his last one of those

madpogue 

Not going to happen. There's a city ordinance in Ashtabula, OH, banning the possession of titanium.




Okay, I made that up.

Velo Mule

Keep us posted sd5782 Good pic's too. Up until recently, I would have said to go with a three piece crank conversion, however, you are right, that would change the iconic look of the bike. With this new spider you can have the original crank and the gears that you prefer. Good idea. I may have to remember this.

Those spiders were really handy for BMX because you did not have to remove the crank to change the chainring.

halb 

If you haven't looked, check Porkchop BMX, they have their own line of chainrings, power discs, and spiders. All alloy.

sd5782 

Reporting back finally. It worked out wonderfully but other stuff delayed me. Steering upper cone was pitted, as were both BB cones. Actually, I found that spider while searching online for the proper upper headset cone. BB cones from co-op. New cables and housings since it was all apart and neglected for 30 years.

Anyhow, I swapped out the 36T sprocket for a 34 that I had after I looked at the gearing calculators. With the 46T outer and Suntour perfect 14,16,18,20,23,28, it was very nice gearing. Using the 34 required different spacers/washers of smaller diameter which took a bit of thinking. Being high tech, I drilled out some 1/4” washers that were 2mm thick. Job done. Stock gearing was 33-100 gear inches. Now I have 33-89 roughly which is nice for this old guy. I like the closer gear spacing in the 10-18mph range.

On the stand, I was less than satisfied with my 40 year old Suntour V-gt. Perhaps it is worn, but previously and currently it required a bit of over shifting and then trimming back. It could also be the long cage which was no longer needed. I just happened to have recently purchased a VXs medium cage RD. It works wonderfully too. I thought about swapping out the Schwinn command shift stem shifters for some nice ratcheting Suntour stem mounted ones I have, but that would ruin the character of the bike.

I just got back from a 9 mile ride and was pleased with the feel before I got rained on. I weighed a few things while apart but din’t write it down. IIRC, the crank and spider was a bit less than a pound heavier than a Sugino AT that is in the parts bin. The Schwinn sprockets without the pie plate is about 600 grams and 800 with the plate, while the two110 bcd sprockets are perhaps 120 grams. That means at least a pound less rotating weight.

Notice, I said rotating weight. I have another nearly stock Super Sport in my possession, so I will have to do some back to back riding to compare and confirm. I remember the heavy crank and sprockets to have quite a flywheel affect compared to my more “modern” and upscale 80s bikes. It took a bit to get that mass rotating, but if you were a spinner, it kept spinning. Taking a pound off the rotating flywheel affect gave a nice feel. It wouldn’t be confused with my 83 Trek 700, but it also won’t be confused with a Varsity either. All in all the crank feel is more appropriate for the nicer Super Sport frame. It still has the vintage Ashtabula mojo and easy serviceability. I will have to get a few pics posted.

sd5782 

Some pics added. The inner chainring is steel. I ordered what was listed as an aluminum and got this one which I know nothing about. Tooth profile? I questioned seller who refunded me and said to just keep it. Seems to be no problem.



34-46,, shifts fine

2mm thick washer/spacer




Chainline seemed very good like this even though one would think that the inner ring was meant to be on the same plane as the spider as was the stock one while I have it spaced 2mm inwards.. Compact 6 speed 14,16,18,20,23,28.




Small ring and cog 3

Big ring and cog 4

Smooth and quiet.

Medium cage VXs


Just thought others might be interested.

dddd

It sounds to me like you've improved your chainline as well as the gearing!

There was a Tioga 110mm spider adapter made from thick aluminum casting with bosses for a granny ring. Really nice, hard to find part, I've had people beg a couple of them off me.

Tange offered much higher quality caged #64 bearings that had a greater number of balls, I've put these in my best bike's bottom brackets.

For best shifting with the long cage Suntour rear derailers, I usually end up pulling out the B-tension screw and even grinding some of the boss to further reduce the pulley-to-cog chain gap.

machinist42

This one?



That would be nice, but the price is twice what paid for my '64 SS, and thrice for the '74.
<sigh emoji>

(By the way, I've read your ruminations on keeping an SS's original (Ashtabula) flavour, and they've factored in on my decisions with my SS's futures. For now, I'm going to run them stock, for the Clunker Challenge, and then see how to proceed. So thanks for expressing your opinion in other threads and in other Forums even.)

sd5782 

That is quite nice. I think I saw a Sugino one too. The Sugino I believe sells for over $50. Might as well go with the 3 piece adapter then. Now if one had an old stash, that’s a different story.

machinist42

And you were right.
I'm interested.
I guess I'm an "other"?

Thanks for sharing your work on your SS!

(Here is a link to the steel spider I think you purchased, on the off chance other "others" are lurking or come across this thread? Seller says he has many more and is willing to ship two for only a dollar more in shipping costs. So I may get a second or third and see if it can be drilled out for a granny, like the Tioga.)

sd5782 

Yep, that is the one. Since mine worked out so nice, I got 2 more. My old SS along with being dirty and a bit beat up was neglected by me maintenance wise as I rode little and raised a family. The triple you speak of sounds interesting. Perhaps you live in a hilly area and use a bigger ring. Here in the flatlands the top several gears are never used by me, so a compact double works. Nice thing about those spiders is the cheap price so you can play with them.

Once mounted up, a bit of bending persuasion was needed to get mine true enough. As far as strength, I think they are fine for me but perhaps may distort for a young racy guy, or maybe not. The surprising thing to me was those tiny little bolts holding the stock big ring on with just a few threads only into the inner ring. I had 2 stripped bolts on my 2 sports and retapped them. Glad others may be able to take advantage of stuff.

dddd

They actually made another forging besides this one. I recall a more angular-looking spider "face" with protruding facets. Your Ebay example looks like a newer, more modern version.
I've found two over the years and never paid over $40 for one, but that was like 10-12 years back.

chas79

Thanks for posting - I have a '71 and '72 SS that need front shfiter adjustments to smooth out the transition for lower to higher. They are both stock, so any measurements or guidance would be appreciated. It takes too long for the chain to grab the larger front sprocket - I have to slow and baby the shift up which is annoying when on a ride, especially in the hills when I am trying to keep up with other riders.

Your tooth profile is radically different. Any issue with the flatter tooth sprocket accepting your chain? Is there a tendency to jump out on an ride?

Great post and pictures

sd5782 

As far as front shifters, mine is the stocker. I am sure I lowered it down a bit for the 46T big ring I am running on it now vs the stock 52. What chain are you running on yours now? Reason I ask is because I just put together a very nice 73 with nearly all stock parts except for a few parts from a 72. The stock chain was in great shape as were the chainrings yet I had problems with the front shift also. I put on a Sram 850 and all is well. No expert here at all, but from what I have read, the shape of the side plates is beneficial to shifting. This style chain also helped rear shifting too.

As for that 34T front sprocket, I was surprised at the tooth shape too. I ordered an aluminum one and was sent this steel one. It seems aluminum ones are hard to come by, and I think even the silver one in 34T is too. I am a weak old guy, so don’t mash the pedals hard and haven’t had any problems. I was quite curious as to the tooth profile too, but for now, all seems just fine and the steel ring should last as long as I do. Of course you know pics are required when other bikes are discussed.

P.S. As an aside, I did try to bend the lip on the front inner cage plate on one of mine. I think it was a 72 that I sold. It was a stocker and it may have helped just a wee bit but I was just grasping at straws. That very nice stocker shifted the front poorly also. I pointed it out to the purchaser.