I have a chainless bike, ask me anything

[NJmaverick]

Dynamics makes it

[happyslug]

1. Dynamics Website

http://www.dynamicbicycles.com/


http://www.dynamicbicycles.com/buy/Bikes.php?prodid=60


http://www.dynamicbicycles.com/buy/Bikes.php?prodid=66

[NJmaverick]

2. I got the Crosss Roads 8

[wtmusic]

3. You got the shaft!

Pros (besides not having to clean the damn chain)?

Cons?

[happyslug]

4. The big Con is the transmission (i.e. the Chain or Shaft) must be custom made for the bike.

Chains have the ability to be adjusted based on the difference between the front peddles and the rear wheel. A shaft MUST be bike specific. No differences no matter how small. This can vary based on how tall is the bike and maybe even how thick a tire you use (i.e. you may NOT be able to switch from 2 inch tires to 1 inch tires even if you wanted to, for that switch may move the rear tire to close to the Peddles to use the same shaft). If you go to the Web site you will see these are NOT sold after-market, and do to the inability to adjust the Shaft for different lengths between the rear wheel and the front Peddle is is probably why. This technology is NOT new, it has been used on Motorcycles and Automobiles for decades (and in after market "upgrades" of Jeeps one of the things that get changed is the transaxials, which is what the Shaft is called in a Car). Such shafts work on Motorcycles and Cars for no one makes to radical a change in the length of the Shaft. There is no need to for power is provided by the engine NOT the person peddling. In a bicycle the power is provided by the person riding the bike and thus how well in that person sitting on the seat. The better fit for a bike the better peddling you will do. The problem is that as the bike grows in height to better fit the rider, the difference in the Shaft lengths changes. In most bikes this difference is to great, so chains have stayed the main form of transmission.

As I said above, the shaft makers are making them only for their own bikes using a Modified 7 or 8 speed Shimano internal hub. I own a 7 speed internal hub by Shimano and I like it. The seven speed does a good job, not as good as the XT system i have on my Cannondale, but good enough for most flat trail). I make the last comment for I like in the Mountains of Appalachian, and going up the local hills you notice the difference, but on the relatively flat trails in this area the difference disappears.

[wtmusic]

5. DIdn't even think of that.

Thanks for info. :thumbsup:

What about weight? It seems the system would be significantly heavier overall.

[happyslug]

6. Hollow tubes tend to be stronger then solid metal, so weight of the shaft might be lighter.

All depends on how the Shaft is designed. Hollow Aluminum is stronger then a solid piece of Aluminum thus I suspect the Shaft is hollow making the overall tube lighter. Chains tend to be solid Steel or Aluminum thus "weaker" on a piece to piece comparison, but nothing in real life (In regards to chains, huge difference when it comes to tubes of the bike itself AND racks for bicycles).

I suspect the Shaft is LIGHTER then a Chain but that gets us into two other parts, the Front Peddles and the Rear axle unit. Derailleurs are lighter then internal hubs, much lighter, thus the overall system of using a shaft will be heavier, even through the Shaft is lighter then a Chain. I can NOT see how you could use a derailleur system with a Shaft, since the chain in the direct mechanism used in a derailleur system that is shifted when you change gears.

On the other hand an Internal hub uses a chain or a shaft as a fixed gear ratio from the front to the rear. Thus the Shaft is usable on an Internal Hub, for the gears are shifted inside the hub NOT by shifting the chain Thus the Shaft is usable on an internal hub (Or on a single gear bike) BUT not on a Derailleur system. Given Derailleurs overall lightness compared to internal hub systems, the overall system Chain AND rear Derailleur Hub is much lighter then the Shaft and a rear internal type hub.

Another problem is the lack of a front derailleur system. Can't be hooked up do to lack of a Chain to be shifted, thus the front gear is always fixed (as is the case in almost all internal hub system unless they also have a derailleur front system, which can NOT be used with a Shaft system in any case). Thus while the Shaft may be lighter then a Chain, the overall system will be heavier. Remember we have to look at the overall system not just the "transmission" i.e Chain vs Shaft.

Lets look at the inherent advantages of an Internal hub, like the Shimano hub used with these shafts. In the days when Bicycles were how people in Europe got around, the French used derailleur systems do to their light weight (and the tendency of racers to use derailleur on the Tour de France again do to they light weight), while the English used internal hubs for they stayed cleaner do to the mechanism being protected by being inside the Hub. An internal hub has the additional advantage of being able to be shifted even when stopped (Unlike derailleur which only shift gears as you peddle). In bad weather I prefer the Internal Hub (long with a front hub generator for lights) but in good weather the derailleur advantages come into they own.

Thus while the shaft system may be heavier and has a narrower gear ratio system (i.e. its lowest and highest gears are NOT as low or high as in a derailleur chain system) AND has smaller difference between gears (i.e. the internal hubs 8 gears are greater in difference then a derailleur 24 gear system, more a factor in the mountains when racing then anywhere else) it is competitive if you accept its disadvantages and work with them NOT against them.

[NJmaverick]

7. There are two other advantages

1) Shifting can be done anytime, due to it's internal hub gearing

2) Less gears since 8 speeds are equal to the usual 20

Although admittedly you can get this internal hub gearing with a chain drive as well.

For me not having to clean the chain, not having to worry about getting socks and pants greasy and being able to throw the bike in the back of my Murano with out having to worry about damaging anything delicate or getting dirt/grease on anything is a big plus.