pastorbobnlnh 

About 6 years ago, as a way to reintroduce myself to cycling, I bought a 2003 Cannondale Comfort 600. Standard equipment included SRAM's Dual Drive which has a 9 speed cassette and a 3 speed internal geared hub. It has a Headshok for front suspension and a sheatpost shock.

During the past few summers I've swapped the original straight MTB bars for Northroads, lost the gel saddle for the Brooks B-15, added the rear rack and bags.

This summer the BB was ready for replacement and the front single chainring was worn, so I decided it was a time to do a little surgery. When I replaced the chainring, I lost the guard, and added a larger outside ring. Of course I then needed an FD and shifter. I used a Shimano FD mounted to a BB held arm, and a $4 friction thumb shifter from Nashbar.

Last week I mounted the fenders, new Michelin Country Rock tires, and the seatpost bottle cage for the headlight battery pack.

I thought you might like to see the latest results.

jayfromqns

Great Bike. How do you like the Sram Dual Drive?

pastorbobnlnh 

It's a great system. I can't say it has been trouble free. Two years ago the axle broke. SRAM did replace the entire hub guts for free, except the LBS labor costs which was $25.

mcgreivey

Why didn't you put a triple on the front?

pastorbobnlnh 

Good question!

I considered doing so, but my original crank was in fine shape. By losing the chain guard I could add the 42 outside ring. Originally the chainring was a 33 tooth, but I could only find a 32 in it's BCD. The FD can handle a triple so at some point in the distant future, this might be in the works for this bike. Just think, an 81 speed hybrid! An interesting set up might be 26-36-46.

Here's how it looked last winter with the original chain guard in place.

Wanderer

Wow! Neat choices....... Just think, with a triple, and 26,36,46, you could peddal all day, and never move........ It would make a driveway ride a long excursion. A ride around the block would be an unsupported tour.......... a ride to church would take the other six days, etc, etc, etc.

Truly, that is unique, and I'll bet, FUN!

Now, to gt rid of that suspended seatpost............. LOL

pastorbobnlnh 

Wanderer,

Thanks for the nice compliments.

I actually like the shock absorber seatpost! Our roads here in the NH mountains are rather rough. We have this affect called "frost heaves" which plague us over the winter and leave many cracks, dips, rises, etc., in the road. The worse time of year is Feb-Apr. But year round, unless the road has recently been repaved, there are unexpected bumps. Also, the C-Dale frame is very stiff, with hardly a trace of flex. Suspension is much appreciated!

Sirrus Rider

The question is how many of those gear ratios are needless duplication and how many are effective? Interesting engineering exercise though!

pastorbobnlnh 

Great question! Since I'm a pastor and not an engineer, I'll let the slide rules determine the redundancy percentage!

Ultimately, I wanted a higher gear for descents, and something more suited for Rails to Trails riding. The 42 tooth big helps out very well in both these respects.

tatfiend 

I have considered doing a touring frame build with the SRAM DualDrive and triple front chain rings. I have always thought that the DualDrive was a unique piece of engineering that has the possibility of extending the range of gears available for those who want an extremely broad range of gearing on a bike. 81 speeds has to have a ridiculous number of duplicates and overlapping ratios but makes a gear freak's heaven.

pastorbobnlnh 

I had contemplated using a triple. But since I didn't want to spend the money on a new crankset, and didn't have an appropriate spare on hand, I decide to just convert the original to a double.

I did this back in July and probably have about 500 miles of varied terrain riding in it's saddle since. My observations: A triple would be overkill. The big chainring makes for a perfect overdrive to descend faster without topping out as quickly. Also, when on rail trails (i.e. flat rides), I only use the big chainring. I like it better for "cruising."

When I'm riding from my house, I'm still thankful for the smaller chainring, especially on the really steep climbs, rough dirt & logging roads, and off road paths. Also, since I load this bike up, for a trip from the grocery, or errands, and since I'm rather heavy, it's nice to be able to switch into the gearing needed for the particular ride at the time.

I'd like to see the DualDrive laced into a 700c or 27" rim and used with a double or triple on a touring frame. It would make a great deal of sense.

A challenge might be shifting all the gears. The DD shifter is really meant for upright and not drop bars. But a little clever tinkering could make this work (sorry for the out of focus picture, but the pebbles are pretty).



For instance, a 9 speed Shimano brifter should work the RD and cassette. The left hand brifter could work the FD on the double or triple crankset. Possibly a triple FD barend shifter (I'm thinking aero bars) could be utilized for the DualDrive hub?

Ciufalon

I have a Koga Miyata Road Gentlemen bike with an older model of the dual hub utilizing a 7 speed freewheel and a triple crank. If I define redundant gears as being less than one gear inch difference I have 7 redundant gears out of 63 total. My spread is 18.4 gear inches to 140.8. I actually love this setup and I do use bar end shifters in addition to a third shift lever that is currently mounted on the seatpost tube where the generator lever is designed to go, but I am planning to move that lever to the down tube using a clamp on shifter boss. The bike was set p this way when I bought it. Your bike and setup looks just great the way it is. I do have aero bars on my bike and like it that way. If you like aero bars, then you would probably enjoy the change, but the way your bike is now, it looks like a super sweet way to get around! You did a great job of choosing your setup! That is a really nice bike and I hope you are thoroughly enjoying it. I have enjoyed the dual drive set up so much that I bought another dual drive hub to set up another of my bikes with it but have not yet gotten around to it.

pastorbobnlnh 

Out of curiosity, what are the tooth counts on your chainrings and the range of your cassette?

I've never used aero bars. Originally this had slight swept up MTB bars, which I found completely uncomfortable. The current bars came off a dump find bike.

I do enjoy this bike. It is the bike I always take on vacation and has been to Bar Harbor, ME, Cape Cod, Nantucket, and is the only bike in my fleet ridden across an international border into Quebec! On the days I have errands and can ride to do them, this is my bike of choice. The road bikes are more for exercise and speed. This one is mostly about fun and practicality.

Ciufalon

My rings are 48, 36, and 26 - my freewheel is 12, 14, 16, 18, 21, 24, 28. I used Sheldon Brown's gear calculator here https://sheldonbrown.com/gears/ to figure out what I was dealing with. The SRAM dual drive is one of the options in the dropdown boxes. Hope this helps. I can't figure out how to put a table into this message or I would show you my gear table, but you can do one for your bike and see exactly what you have.

pastorbobnlnh 

Thanks for the tip. I guess I hadn't realized the gear calculator could handle an IGH and a double or triple crankset. I need to verify the tooth count on my cassette.