Classic & Vintage - Sachs 8 Speed Freewheel Spacing

This is a bit of an odd one. I'm building a CX bike for which I have two wheelsets; a freehub/tubular set and a freewheel/clincher set. I will use a Shimano HG-50 8 speed cassette on the tubular set. I have an 12-24 8 speed Sachs freewheel, which I assumed would index perfectly with my planned setup, but having just seen this (http://sheldonbrown.com/cribsheet-spacing.shtml)I'm unsure.

It seems the Sachs 8 speed freewheels used Campagnognolo 8 speed spacing until 1998 when they began to use Shimano/SRAM 8 speed spacing. I'm not sure if I could tell the difference by looking or even measuring with a caliper. Maybe I can, but if there's an easy way to date these freewheels then that can only help. The freewheel I have does not have Shimano/SRAM ramped (Hyperglide) cogs, but rather the notched teeth.

Anyone know?

Justin,

Good question and I don't know the answer on how to ID the difference between 8 speed Sachs freewheels (Campy vs. Shimano).

Did you try placing the Shimano cassette on a flat surface (largest cog down and loose cogs stacked on top) and the Sachs FW next to it with the small cog down and see how closely the cogs line up?

My '83 Paramount (which you saw last summer) uses a 7 Speed Sachs FW and Shimano 105 downtube indexed shifters and they play perfectly together.

Sorry for the OT, but it looks like Mr Allen updated the cribsheet today! (The goofed-up code toward the bottom of the chart had bothered me for a while.)

Is that one you got from me? If it helps I was using it on a CampI C-Rec hub with a DuraAce Integrated 8 RD and DT shifter. IIRC it worked OK on my bike and on a customers who had the early CampI 8spd Ergo. I actually set my wheel up to be interchangable on his bike, as when riding togather it was more important for him to get to work than me, so I played Domestique. Now I have an unknown CampI 8spd cassette hub and it still runs OK with the DA.

I'll dig the wheel out and check the hub spacing but I used a WheelsManufacturing 141 or 144mm axle and lots of spacers.

Did you try placing the Shimano cassette on a flat surface (largest cog down and loose cogs stacked on top) and the Sachs FW next to it with the small cog down and see how closely the cogs line up?

I think I did when I first received it, yeah. They looked pretty close, but who knows.


Is that one you got from me? If it helps I was using it on a CampI C-Rec hub with a DuraAce Integrated 8 RD and DT shifter. IIRC it worked OK on my bike and on a customers who had the early CampI 8spd Ergo. I actually set my wheel up to be interchangable on his bike, as when riding togather it was more important for him to get to work than me, so I played Domestique. Now I have an unknown CampI 8spd cassette hub and it still runs OK with the DA.

I'll dig the wheel out and check the hub spacing but I used a WheelsManufacturing 141 or 144mm axle and lots of spacers.

Yeah, that's the one. You're adding even more cooks in the kitchen with that Dura Ace 7402 talk!

Google brought me to an eBay auction for a Sachs Aris 8 speed freewheel with some interesting information that wouldn't seem to jibe with the different spacings as indicated on Sheldon's crib sheet. If this is to be believed, Sachs designed them to work "good enough" with any 8 speed indexing system.

From the seller:


The Sachs, French made, Aris (Advanced Rider Index System) freewheel has taken off in popularity, because it is well thought out and crafted, but most of all the thickness of the cog and the spacing make it trouble free with index systems other than ARIS including, Campagnolo Synchro, Mavic, Shimano SIS & HG systems, and Suntour Accushift. And if that weren't enough, (and golly gosh, it ought to be), it will of course work with every friction shift system ever made! The cogs measured by micrometer to a 1.9mm thickness, while the spacers are 3.0mm thick, well within the machine tolerances of bicycle parts to be compatible with all the previously described index systems.

The tooth profile, Sachs calls "RGS" for "Rapid Grip and Shift". Each of the teeth on the cogs are the same, and they are the same on all cogs in the set. The front of the tooth is machine beveled, to make it thin at the top, and thicker at the bottom. The top of each tooth has a V-shaped groove in it running lengthwise, then the back half of each tooth top is crimped, pushing the V on the back closed, and raising the tooth height slightly at the rear. A single, simple system.
The cogs are made of steel, that is hardened prior to being nickel plated, giving them a bright Silver color. The 4 largest cogs have plastic spacers between them, the set of three weighs 8 grams. The 2nd, 3rd, or on an 8 speed freewheel, the 4th position cog thread onto the freewheel body. The 1st, or on an 8 speed F/W, 1st and 2nd position cog thread internally into the cog ahead of them in line. This threading of the first, or first and second cog, into the next is why the Sachs Aris freewheel can make an eight cog freewheel still fit, and work, on just a 130mm over lock nut dimensioned rear hub.
The outer cone race is forged of steel, that has four dimples pressed into the outside face to remove it, by turning it clockwise, with some difficulty. The cone race itself is ground and polished before it's given its Black color. The inner and outer body pieces are forged as a single piece of steel, with all races ground and polished, before they are given their Black color. Beneath the outer cone race are thirty-one 3.0mm diameter steel ball bearings revolving in a polished cup race built as a part of the inner body piece.
There are thirty-eight 3.0mm steel ball bearings that make the inner bearing assembly, again revolving on two polished surfaces. The Aris freewheel uses two steel pawls held in place and operated by a circular wire spring. There are no lubrication ports on the freewheel body to permit external lubrication of the bearing cavity, you will have to take it apart, or use a Phil Wood grease injector to re-lubricate it. Sachs chose to use the Shimano freewheel notch pattern for their freewheel, so a Shimano TL-FW30 or a Park FR-1 freewheel removal tool will be the proper removal tool.

This quest for info is really just an exercise in clearing up the info as I went ahead and bought an 8 speed 13-28 DNP freewheel with HG cogs today.

Google brought me to an eBay auction for a Sachs Aris 8 speed freewheel with some interesting information that wouldn't seem to jibe with the different spacings as indicated on Sheldon's crib sheet. If this is to be believed, Sachs designed them to work "good enough" with any 8 speed indexing system.

From the seller:



This quest for info is really just an exercise in clearing up the info as I went ahead and bought an 8 speed 13-28 DNP freewheel with HG cogs today.

Copy and paste ;http://www.bikepro.com/products/freewheels/sachs.html

Copy and paste

I had no illusions the eBay seller actually wrote that, did you? Anyhow the content is what's relevant here.

All Sachs 8 speed freewheels are 5mm on center. The later Sachs 8 speed spacing was for Shimano compatible Sachs made cassettes & cassette hubs. In other words, Sachs 8 speed freewheels have 5mm spacing, Sachs 8 speed cassettes have 4.8mm spacing.

I had no illusions the eBay seller actually wrote that, did you? Anyhow the content is what's relevant here.

Of course I did not as I immediately recognized the original source as I am running seven and eight speed Sachs on both Campy eight speed and a odd mix of Shimano 9 speed Ultegra shifters coupled with 7400 DA RD.

Of course I did not as I immediately recognized the original source as I am running seven and eight speed Sachs on both Campy eight speed and a odd mix of Shimano 9 speed Ultegra shifters coupled with 7400 DA RD.

Can you elaborate on the latter mix? How well does it work?

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Can you elaborate on the latter mix? How well does it work?
Works fine, Ultegra 9 pulls the same cable as DA eight. Not as crisp as Campy eight but would you expect it to be? As that Bikepro write up says, The Sachs Aris is pretty versatile, but not quite as quick as a Shimano Cassette so if you went that route I am sure you would be real happy. Unfortunately I have three nice sets of Freewheel wheels so I am married to the Sachs for a while.