Wednesday, September 7, 2011

Normalizing the Sun Spider AT

A long time ago in a galaxy far far away, I took interest in the addition of a "cheap-ish" option in the fat bike field. It finally arrived yesterday. I've got a lot to say, but I also have a lot of other stuff I gotta do right now so I'll just note the 1st-day modifications, and a gripe.

1. Swapped bars and stem -- from bmx style to Space bars.
2. Swapped saddle for slightly more better saddle.
3. Took off chain guard, which cleared the rolling tire by approximately 1 mm.
4. Added front brakes.

Super gripe: the Sturmey Archer S2C that ships on this bike is a turd, right out of the box. It skips. It slips. It's generally a major disappointment. So far, I'm not finding much love online for troubleshooting, other than some vague recommendations to let it "wear in," which is never a good sign.

Glen tacking on the canti post.
Glen thinks it may be a combination of things: he's not crazy about the chainline. The chain itself looks a bit wonky, though I've not gone through and checked for stiff links.

I'm wondering if the torque is just too much for the hub: the Sun Spider ships with a tiny tiny little chain ring (25t!) and 20t cog.

All I have to say is this: This is my third 2-speed kick-back hub. The Bendix on Liza's old bike, where nothing was optimized on a beat-up ancient bike, worked flawlessly. I also had a Sachs Torpedo. After I ripped it apart and cleaned it: no issues. So, I'm not delighted with the S-A hub at the moment, where it's giving me grief and I've not even had a chance to break it properly.

13 comments:

DAN said...

Looking good, their is one them at my local bike shop.

Fred Blasdel said...

If you complain on their facebook forum they'll send you a new hub core, but it doesn't look like it'll fix the problem 100%.

I've got a vintage Fichtel & Sachs automatic that's got a bunch of issues. I need to grind the outer bearing race on the driver, and possibly make a delrin shim to keep the journal pins that the planet gears ride on from rattling.

If I can't get it running smoothly, my current fallback plan is to spread the dropouts and rebuild the wheel around SRAM's new automatic 2-speed hub

DAN said...

Hmm crazy, I am glad I have old stuff.

John Speare said...

Fred: thanks for the pointer. I gave it a shot. Hopefully they'll take care of me.

Dan: word.

Tarik Saleh said...

Bummer about the two speed. I just picked up a 2010 Pugsley frame and pair o 135 single speed hubs. I need to figure some stuff out, but I am going to be going low freewheel on the rear and low fixie on the front. It is offset front and rear. I just need to invest in rims and tires and some wheelbuidlingfu. Anyhow. I am eager to see how things turn out with yours.

Tarik Saleh said...
This comment has been removed by the author.
Erik Spokane said...

The front canti set up with it's clearance between the cable and the tire gets me to thinking of problemsolversbike.com wide cable carrier.
Would that increase clearance? Or am I trying to solve a problem that doesn't exist?

rory said...

after drawing out the retrofit for the lugsley, i'm not surprised theres chainline problems. the chainline for a S-A kickback is between 41-44mm, and the tire itself is 100mm wide(or 50mm on one side). the frame is hopefully built offset, ala pugsly, so it can get the chain around the tire. the other part is getting the crank out to the proper line, as well.

basically, [url=http://www.flickr.com/photos/17890696@N02/6006230110/in/photostream]this
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John Speare said...

I got a reply from sunrace: +

"There was a problem with the S2C hubs that were sent to J&B for the Sun Spyder AT. We are replacing the internals of all Sun Spyder AT bikes because of this...I will send a replacement internal your way."

Cool that they're on it. Weird that they have a pull-model for replacement, instead of a push approach.

Vince Warner said...

Do you have any idea what the problem was with the old internal?

I have written a workshop review of this hub based on an internal which apparently was faulty even though it worked perfectly on the bench.

I would be very interested to know what the fault was that caused it to malfunction.

The review can be found here:
A Workshop Review of the Sturmey Archer 2 Speed Kickback Hub

John Speare said...

Vince: no idea. email me a mailing address and I"ll send you the guts. my email is john at phred . org.

Anonymous said...

How's the geometry on the spider at? I've heard sun is changing it as well. do you know if hte current geometry at j&b is the same as yours? I'm thinking about building this up as a trail bike for a greater challenge on slow group rides. 40lbs reminds me of my old bmx days, pre 2000 when a 7lb frame was too light!

KC Vale said...

I build high end motorized bikes, usually shifting bikes that use the bikes own back hub for gears.

I have a customer pushing 300 pounds that wants a bike that will hold up and looked at the Sun Spider.

Cool bike but that SA 2-speed 'kick shift' with coaster brake won't do, with a Jackshafted motorized bike the pedals freewheel at the crank so no back pedaling ability.

I figure a 3 or 5 speed Strumey and 12 gauge spokes on that doub;e wall 4" wide wheel do the trick.
It won't be cheap but it should work ;-}