Comments on: Internal Hub Meets Shaft Drive

By: shaft , jr.

shaft , jr. — Mon, 02 Apr 2012 03:32:39 +0000

I am using a Sonoma cruiser shaftdrive for around town errands, lunches, bank runs and hot dates and it is great. Not sure what Dynamic is complaining about other than lost business, but the ride is a glide, shifting is smooth, and no grease or noises to worry about. Unless you are competitive (point taken about the Dynamic roadbike with a chain) the point of biking is exercise and transportation and these bikes are great. Sonomas are half the price point or less than Dynamics, and roll just fine. Just like BMW and Suzuki cruisers!

By: John W.

John W. — Sun, 19 Feb 2012 00:09:05 +0000

What happened to the review? Been much longer than a month. “We’ll publish Jamie’s review in about a month.”

By: John Macossay

John Macossay — Wed, 21 Sep 2011 15:01:02 +0000

I have a 7 speed Dynamic bike with a shaft drive and I like it fine. Sheldon Brown claims that the advantages of the shaft drive can be duplicated with a fully enclosed chain case, but such bikes are not available in the North American market. Those for sale in Europe are limited to single speed, and are both heavier and more expensive than equivalent shaft drive bikes.

My shaft drive bike is particularly great in the city, where I have to stop every block or even half block. It’s nice to be able to shift gears even while the bike is stationary. Racers will not like a shaft drive because you have to ease up the pressure on the pedals when you shift, and racers don’t like to break cadence. That’s why they have so many speeds. However, this is a characteristic of the internal hub and not the shaft per se.

By: Ted Johnson

Ted Johnson — Wed, 29 Jun 2011 22:58:42 +0000

Good question.

Sonoma also makes shaft-drive bikes, but with the drive shaft in the chainstay.

Here is what Dynamic Bicycles says about it referring to “our competitor”–presumably Sonoma:

Our competitor’s shaft drive bike frames eliminate the critical horizontal frame stay on the drive side of their frame. This puts force and strain on the shaft drive that it was never designed to handle. Our competitor fails to understand that the shaft drive is a drivetrain, not a structural component. By eliminating this frame component, our competitor’s frames cause unnecessary loads on the gear and bearing components causing inefficiency, excessive wear, and potentially premature failure of the shaft drive and/or the frame.

By: Paul S.

Paul S. — Wed, 29 Jun 2011 21:06:57 +0000

I’ve been interested in these things for years from a “boy would that simplify the black grease spots everywhere and exposed delicate gearing” perspective. But one thing I’ve never been able to understand is why they don’t integrate the shaft into the chainstay? It seams an obvious weight saver. Am I missing something here that makes this impossible or is this just an obvious trick that no one has gotten around to yet.

By: Ted Johnson

Ted Johnson — Thu, 16 Jun 2011 15:31:11 +0000

I think you’re right. Even road bikes made by Dynamic Bicycles have chain drives.

However, from what little research I’ve done, it seems as though a clean shaft drive is as efficient as a dirty chain drive. For people (like me) who don’t pamper their drive train, it could be that a shaft drive plus internal hub is ideal.

Jamie is not one to suffer inefficiency. He pampers his bikes. But he also knows you don’t evaluate a commuter bike by the same criteria you would evaluate an aggressive mountain bike. I’m as curious as anyone to see what he will conclude.

By: John Romeo Alpha

John Romeo Alpha — Thu, 16 Jun 2011 14:08:06 +0000

The shaft drive approach for bicycles is usually panned for its higher inefficiency compared to a chain drive: a shaft and gears sufficiently small so that it doesn’t weigh too much or cost a crazy amount tends to distort under the greater forces due to a smaller moment arm than the comparable chain drive. Heavier, less efficient, and more expensive tend to work against adoption of alternates to the chain drive even when they have other advantages to recommend them.

By: Paul in Minneapolis

Paul in Minneapolis — Thu, 16 Jun 2011 13:48:45 +0000

I’m really looking for this review..

One of my questions. Those who live on flat land and those who live in mountains will need very different gearing.

> Will there be some way to raise or lower that overall gearing?

With my Euro city bike with front and rear panniers and loads can be 100 lbs with real world hills, a 20″ or lower gear is needed ( I like ~16″). But someone who live on flat land and caries little will want the gearing much higher.

> Will a owner be able to change the overall gearing or will it be based on when the bike was built?

If they push this as a one size fits all (the American way) it will be doomed.