How Internally Geared Hubs Work

Ever wonder just what was going on inside your internally geared hub?

Here are some photos of some the hubs we have recently had the pleasure to tear apart, clean up, overhaul and reassemble.

For starters, here is very quick summary of the function of planetary gearing (that's the magic inside your internally geared hub). For the sake of simplicity, there are three main components to gearing of 3 speed hubs: the driver, which is attached to the sprocket, the planet cage, which houses the planet gears, they use the stationary sun gear fixed to the axle the increase their rotational rate and interact with the third main part, the gear ring. This all just means that the sun gear is held stationary in relation to the bike and as the planet gears revolve around they rotate faster individually than the planet cage does as a whole which in turn causes the gear ring to rotate faster than the planet cage. Both the planet cage and the gear ring have pawls which can drive the hub body and allow for coasting.

So, if you want your hub to spin slower than the sprocket (low gear) you have the sprocket drive the gear ring while the planet cage drives the hub. If you want your hub to spin at the same rate as the sprocket (middle gear, or direct drive) you have the sprocket drive the gear ring which then also drives the hub. If you want your hub to spin faster than the sprocket (high gear) you have the sprocket drive the planet cage while the gear ring drives the hub. Simple! Want more speeds? Add more sun gears and/or planet gears in a similar manner and you get more than 3 gears. These changes inside the hub occur when you use your shifter to position the clutch which sets up whether the driver interacts with the planet cage or the gear ring and you never even need to think about it. On to the photos...

We begin with the classic. The Sturmey Archer AW for use with rim brakes. This one happens to be from 1959 and it still runs smooth.
These hubs are fairly easy to disassemble completely for servicing. replacement parts are available.

Now for one of Sturmey's current offerings. The new X-RD5(W). Its a 5 speed hub with a drum brake.



You may notice how many fewer parts there are in the X-RD5(w) than in the AW. This is representative of the new standard for internally geared hubs; modular design where many of the main components are meant to be broken down only so far (that, and we didn't photograph the drum brake, sprocket, axle nuts, etc.). This makes servicing simpler and eliminates the possibility of installing parts in incorrect positions. On the flip side, you also need to replace entire components groups, and often the entire internal assembly, if one small part wears out or gets damaged.


Shimano has been making internally geared hubs for decades and this is one of their newer models. The SG-3D55. It's a 3 speed hub with a disc brake.As in the newer Sturmey Archer hubs, Shimano has simplified things with modular design. If you look closely you can see that some of these parts are rusted out from a harsh Minnesota winter. Though these hubs are relatively low maintenance, if ridden in extreme conditions, moisture can work its way into the hub where it will wreak havoc on the assembly. A new internal assembly and now it's ready for many more miles of happy riding.

Another of Shimano's internally geared hub offerings is the very popular Nexus 7 speed. This one is the SG-7R40, set up for use with a roller brake (not pictured).



As with most internally geared hubs, very little is recommended in the way of maintenance. Get your hub cones adjusted well and properly set up your cassette joint and shift cable, then ride. That being said, don't ignore your hub. You can have the internal assembly removed, cleaned and re-lubed to keep things running smoothly and to avoid unnecessary wear to the expensive parts inside.

Last, but not least, we've got another new hub, this one from Sram. It's the S7, this one has a coaster brake, and it is by far the most complicated hub out of this bunch...


The operation of this hub is just as smooth and simple as the Shimano offerings. Sram uses a modular design as well, but many of the sub assemblies can be broken down to their smallest parts. In practice there is no need to ever take one of these apart to such a degree.

If you are interested in learning more about internally geared hubs, and the bikes they are available on, then stop into our Minnehaha shop. You can test ride bikes with different types of hubs or talk to our service staff about one that you are already riding.

Look for The Hub at this years North-side Bike Fests

The Hub will again be providing mechanical support for the 2011 North side bike festival events. The events will be packed with bicycle-fun for both kids and adults. Below are the times and dates. Hope to see you there!

Saturday May 21 is the big kick-off to the summer; this event will take place at the Special Operations Center on 41st and Dupont in North Minneapolis. We will be staged across the street at the Salem Lutheran Church Parking Lot from 10am - 2pm.

Other event dates include:

Thursday, May 26 Harrison Park 503 Irving Ave. N 4 - 7pm
Thursday, June 2 Creekview Park 5001 Humboldt Ave. N 4 - 7pm
Thursday, June 16 North Commons Park 1801 James Ave. N 4 - 7pm
Thursday, June 23 Farview Park 621 29th Ave. N 4 - 7pm
Thursday, June 30 Glen Gale 2448 Ilion Ave. N 4 - 7pm

The Hub at Last years Festival

Earthday 2011

The Hub Bike Co-op joined the School of Environmental Studies (SES) for Earth Day 2011. The day was packed with activities including an opening speech by Governor Mark Dayton. The Hub staff rode to the event pulling a loaded “Bikes to Work” trailer with a bike fitted with a Bionx electric assist. It was inspiring to meet with SES students who are committed to environmental causes. While riding back from the Apple Valley school we passed a group of SES students working to rid the Minnesota River area of invasion buck thorn. Way to go SES! Thanks for a great day!

Spring EXPO!

That right folks its that time of year again! The birds are chirping, the sun is screaming and the cyclists are happy! This weekend The Hub will again be collaborating with Midwest Mountaineering in their Spring EXPO. We will have tons of killer deals just for you!

• Select 2011 bikes on sale
• Get a $50-100 gift certificate with any new bike purchase over $650
• All remaining 2010 bikes on closeout
• 10-15% off select apparel

Sale prices are only active during the EXPO so hurry down! If your not in the market for new goodies, fear not, The Hub always provides! We will also be offering 3 free seminars for your enjoyment.

• Top-10 places to mountain bike in the metro area.
  
• What to look for in buying a new bike.
  
• How to be more efficient in your next bike tour.
  

2011 Spring EXPO - April 15-17. Our Cedar location will have extended hours, see our website for more details.

Starting Tuesday, January the 11th, the Hub Bike Coop’s winter spin training will resume at the Hub's 3020 Minnehaha Ave. South location. We are offering spin training two nights a week.

Tuesday nights, we will be suffering to performance training videos. On the 11th , we will be watching “Cyclops Race Day”. In this video, we will be riding with coach Robbie Ventura in an Elite level National criterium, via a POV camera. Experience the strategy, the failure, and the effort required to climb back to the top. This video is thrilling to watch and uber motivating.

On Thursday nights, we will be Zombie Interval Training version 2, or Z.I.T. v2. Z.I.T. v2 involves watching movies from the extensive zombie genre and cranking up the RPMs when ever the still living on the screen are running from or fighting with zombies. Based on feedback from the last season of Z.I.T., version 2 will include a bit more coaching to guarantee a good workout and to ensuring participant’s RPMs are matching the intensity of the film’s brain hungry undead. We will begin, January 13th , training to outrun undead Nazis, by watching an Official Selection from the 2009 Sundance film festival, “Dead Snow”.

Dead Snow trailer.

http://www.youtube.com/watch?v=3-KQh87_V2Q

We will have 12 trainers available for attendees to use with your own bike, and 8 storage spots for spinning bikes. Call the Hub to reserve your space 612-729-0437. If you are not at the Hub at 7pm the night of your class your reserved spot will be forfeited to Spinees who are waiting. Please bring your own trainer, if you own one, so more people can participate.

Giant Anthem X 29er 2

The other day I was fortunate enough to spend some quality time with the hottest new bike in Giant's 2011 line-up. Before I get too much into it I would like to describe this bike as what you get when you mate a howitzer with a razor blade. The 2011 Anthem X 29er has all the design features that previous 29ers simply didn't provide. The combination of it's tapered head tube and QR15mm front thru-axle give you razor sharp stearing and a BB92 bottom bracket to ensure stiffness clearly shows that Giant went the extra mile in producing their first ever full suspension 29er. Giant also uses their Maestro suspension system which gives you a single floating pivot point to increase your pedaling efficiency. The frame was designed using Giants very own ALUXX Aluminum, a light weight grade of aluminum created to withstand the highest tolerances, not to mention it is molded at Giants in-house foundry.

If you're looking for a bike to pound the competition into a fine powder, look no further. This bike has already been proven a race winner as Carl Decker of Giant's pro race team won the 2010 Sea Otter Super-D in California. I feel confident in saying the Anthem X 29er will far exceed all expectations, don't believe me? Come on down to our 3020 location for a test ride,we've got a medium in for limited time as a demo, so come in and ride it!

The best season for cycling begins now. Nothing is automatic. Step out the front door,
throw your leg over the bike for your commute and the sleepy winter mind comes alive.
A quick trip for groceries becomes a complex adventure. The ride to often becomes the
event of the day, and some of the best conversations are the ones a winter cyclist has with
them selves and the environment. Should I ride the off camber ice transition next to the
parking lane, or the sidewalk? How are the cars doing with these conditions? Wow! I
made it down that whole block of tire ruts without putting a foot down. Now that was a
little bit of hell. So hard core. I’ve never seen snow do that. I’m sick of the wind.
My god that’s beautiful. Cars are so filthy. I didn’t know it was possible. I’m going to be
so strong come spring and my skills are growing like mad. The list goes on and on.
Sun., Nov. 21, 2pm David Meyer and Chris Huff (me) will be presenting a talk
on Winter Biking at the Midwest Mountaineering, Expedition Stage. I started winter
commuting 17 miles at midnight to my job sorting at U.P.S. in Eagan the winter of 1987.
My first winter bike was a Schwinn Varsity, and my gear was well suited to deer hunting
at that point, but also worked for cycling. I’ve had many winter bikes since. I rode a
Centurion Ironman down Franklin Ave. the morning after the Halloween blizzard in 30
inches of snow. I’ve run various MTBs geared and single speed. I’ve had everything go
horribly wrong and gotten some good lessons from that that I can help you not repeat.
I’ve seen a lot of what works and what doesn’t and I’m still learning every year. David
has run fixed and this year is running a kick back brake and has an impressive resume
himself. So come to Midwest Mountaineering on Sunday if you want some of this frost earned wisdom. It's free.