SRAM Dual Drive hub
May 11th, 2008
Recently, I won an ebay auction for a wheelset that came off a Cannondale hybrid bike. I was mainly interested in the SRAM Dual Drive hub, since I’d like to use it with my Tikit. When I got home today, I finally got a chance to play with it. At first, when I tried spinning the cassette, the movement wasn’t smooth, and something didn’t seem right. After taking the hub apart, I found a metal piece on the edge of the hub’s shell.
SRAM’s website and parts list shows this as “Assy Planet Gear Carrier Dual Drive” and part number 65 0372 111 100 . I’m not sure how much this part costs, but I’m not really in a hurry to install it. Maybe tomorrow I’ll give the bike shop in College Park a call to see if they can find out how much it’ll cost.
Oh I see what’s wrong. Your broken part is half of a pawl. There are 4 dual-tooth pawls on the driver held by a spring (I don’t see the spring in the photo but maybe it’s there). A non-broken pawl has two teeth to engage a circular rack, the center is grooved to accept the spring. Call SRAM for an exploded view (maintenance diagram) of the Dual Drive, and for a replacement pawl. I had my Dual Drive apart when it started to squeal after I dunked it (google YouTube for Ov3rTheHill). Oh, the pawls can be flipped backwards very easily, be sure when reassembling that they are flipped the right way.
And I would add…
* The grease looks a bit cakey, is it dried out? Suggest get the lubrication and reassembly instructions from SRAM and do the whole clean and lube job. It requires both oil (SRAM recommends Tri-Flow bicycle oil) and a proprietary SRAM-spec grease (but I used Phil Wood and so far so good, 500 miles later).
* All you need is a replacement for the broken pawl. It should cost a buck or three. The full blown planet carrier assembly might go for a hunderd and all it needs is the pawl and a lube.
* Lift the ring spring holding the other 3 pawls in place on the carrier and you’ll see how the pawls are supposed to work. They are the moving parts of rotating ratchets, together becoming a freewheel. You can lift out any of the other pawls to see what a non-broken one should look like. If they don’t snap back up when pressed down then your grease has gummed them up and that’s why one broke… and the whole thing (all parts) need to be cleaned of the old grease, re-oiled and re-greased per SRAM’s instructions… I suppose.
* You can take the planetary gear assembly fully apart (and you should if you’re cleaning and lubing it). I found scale on the pinions holding the planet gears on mine, which had suffered from rust, unlike yours.
* It may not look like it at the moment, but it is possible to put this thing back together and actually have it work.
* Get the installation and user guide [a different PDF from the one showing disassembly, lubrication and reassembly] for the Dual Drive off SRAM’s website. It indicates where the centerline and chainline go, and I believe there needs to be a bit of “dish” when you spoke up the Dual Drive. I’ve never spoked up a wheel, but the rear wheel on my Dahon with the Dual Drive in it has straight radial spokes on one side and crossed spokes on the other. That’s dish, right?
* If you have given up and just want to sell the parts parts as-is, contact me!
Thanks for the suggestions. Maybe I’ll give SRAM a call sometime next week. Previously I looked at a pdf file off SRAM’s website that listed the parts for the dual drive, but I didn’t notice a pawl as a separate part. I’ll take a look again. Thanks!
http://www.twowheelsgood.co.uk/index.php/product/hubsandhubspares/internalhubparts/index.html
It’s H232 SRAM DualDrive Assembley Planet Gear Carrier and it lists for £16.47
I just ordered the Gear Carrier from Bike Friday for $25. That’s much cheaper than ordering it from the UK, the only place I’ve seen to order it. Surprisingly, no place I’ve called or emailed could order the part.