Author Topic: Why internal hubs?  (Read 7233 times)

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Offline RussSeaton

Re: Why internal hubs?
« Reply #15 on: March 17, 2011, 01:59:05 pm »
Does anyone have any comments on the shifting range on a Rohloff hub?  Can a Rohloff setup match having a compact mountain crank in the front (22/32/43) with say an 11-32 in the rear?

http://www.rohloff.de/en/products/speedhub/gear_range_comparison/index.html

http://www.sjscycles.com/pdfFiles/LivingWithARohloffWeb.pdf

Above are a couple comparisons of Rohloff gearing to regular gearing.  The second link shows a 44-32-22 11-34 gearing.  You can then pick out a Rohloff gear combination that matches it on either the high or low side.  The Rohloff has a narrower range of gears than a mountain bike with a wide ranging cassette.  If you make the low side equal, then you give up about 15 gear inches on the high side.  Personally I don't spend a whole lot of time in the highest gears, so giving them up would be nothing to me.  But if you are always grinding away in the highest gears on your bike, then it may mean the world to you.

Offline Tourista829

Re: Why internal hubs?
« Reply #16 on: March 17, 2011, 09:44:32 pm »
Paddleboy how are you? I hope your weather is warming up in Michigan. I will adress only the low to high range. The set up you gave, I assume you are taking about a 700c wheel. I believe the range is 19" gear to 107" gear. More than a wide enough range. The Rohloff is not shabby either, I believe you can vary the set up. A popular one is 38 front and 18 rear cog, you may be looking at a 17.2" low gear and a little over 90" top gear. Some may think a little to low at the top. I know two people with the Rohloff set up and love it. If I were setting up an expedition bike, it would be my first choice.

Offline Pat Lamb

Re: Why internal hubs?
« Reply #17 on: March 17, 2011, 10:09:40 pm »
Does anyone have any comments on the shifting range on a Rohloff hub?  Can a Rohloff setup match having a compact mountain crank in the front (22/32/43) with say an 11-32 in the rear?

Check out http://www.rohloff.de/en/products/speedhub/gear_range_comparison/ -- down at the bottom they have a direct comparison of gear range.

Recommend you poke around on the site; I seem to recall they have a gear inch calculator somewhere on there that lets you compare various chain ring/sprocket combinations.

Offline paddleboy17

Re: Why internal hubs?
« Reply #18 on: March 24, 2011, 12:03:19 pm »
Paddleboy how are you? I hope your weather is warming up in Michigan. I will adress only the low to high range. The set up you gave, I assume you are taking about a 700c wheel. I believe the range is 19" gear to 107" gear. More than a wide enough range. The Rohloff is not shabby either, I believe you can vary the set up. A popular one is 38 front and 18 rear cog, you may be looking at a 17.2" low gear and a little over 90" top gear. Some may think a little to low at the top. I know two people with the Rohloff set up and love it. If I were setting up an expedition bike, it would be my first choice.
I am fine.  Michigan was fine last week. :)  In the winter I mostly ride the mountain bike with carbide studded snow tires.  I pulled them off last week thinking spring was finally here.  Things even got nice enough over the weekend that I got the Waterford out. 

As for today, I think I would need the carbide studded snow tires out again. :(

The Rohloff set up is looking sweeter every day.  If I were doing the Waterford again, I would probably go with the Rohloff.
Danno

Offline Tourista829

Re: Why internal hubs?
« Reply #19 on: March 25, 2011, 12:08:35 am »
Weather this time, in Michigan, can be tricky to predict. I like Rohloff, if one wants to find out "why internal hubs," ride a bike with one of these. Planning any good tours this summer? This year, we travel to visit the family in Memphis, St. Louis, Cincinnati, Greensboro. I am going to try to get to ride to Ft. Myers Beach and take the ferry to Keywest. I am glad you are doing well.

Offline paddleboy17

Re: Why internal hubs?
« Reply #20 on: March 25, 2011, 12:43:30 pm »
I did not want to drift too far off list, so I continued back with an email.  I don't always get notified when I get an email from this site, so I thought I would give you a heads up.

Yes, Rohloff hubs look sweet.

There I am back on list.
Danno

Offline Lowly Swale

Re: Why internal hubs?
« Reply #21 on: March 31, 2011, 03:37:23 pm »
One other thing not mentioned, having a hub gear can allow symetrical spoke dishing in the rear wheel giving greater strength and reliability.

Offline DaveB

Re: Why internal hubs?
« Reply #22 on: April 01, 2011, 09:16:18 am »
One other thing not mentioned, having a hub gear can allow symetrical spoke dishing in the rear wheel giving greater strength and reliability.
Theoretically, this is correct but modern 135 mm hubs with 8/9/10-speed freehub bodies laced to good quality rims with 32 or more spokes are so strong and durable these days that the advantage isn't worth the weight, efficiency loss and cost of an IGH just for that reason.

Offline Pat Lamb

Re: Why internal hubs?
« Reply #23 on: April 01, 2011, 09:25:25 am »
One other thing not mentioned, having a hub gear can allow symetrical spoke dishing in the rear wheel giving greater strength and reliability.
Theoretically, this is correct but modern 135 mm hubs with 8/9/10-speed freehub bodies laced to good quality rims with 32 or more spokes are so strong and durable these days that the advantage isn't worth the weight, efficiency loss and cost of an IGH just for that reason.

Perhaps true, but only if you haven't had a spoke break recently, leaving you with once-a-wheel-revolution brake drag for 10 miles home where you discover the broken spoke...

I haven't quite drunk the Kool-Aid yet, but I can see the attraction of Co-Motion's Americano wheel.  Tandem hub, un-dished, 48 spokes, ready for any (not-too-unreasonable) load.  How's that wheel plus two derailers compare to an ordinary wheel with an IGH for weight?

Offline whittierider

Re: Why internal hubs?
« Reply #24 on: April 01, 2011, 02:38:00 pm »

Use an off-center rim, ie, rim with the holes off center, to eliminate the dish on a wheel with a freehub and cassette, like the Velocity Aerohead O/C:

 

Going with a deep-V rim also increases the strength of the wheel a lot.  One of our sons has a Velocity Deep-V aluminum rim on the back of his commuting bike on which he has loaded up to 60 pounds (all on the rear rack) of tools and supplies, all with no give at all, so when he hits bumps on our poor roads, it is truly brutal on the wheel.  Yet after several years of this now, it has been perfect, maintenance-free, trouble-free.  Deep-V also increases the surface area to get rid of braking heat which would be more of a consideration when your gross weight is very high, regardless of the kind of hub.

Offline DaveB

Re: Why internal hubs?
« Reply #25 on: April 02, 2011, 09:59:19 am »
Perhaps true, but only if you haven't had a spoke break recently, leaving you with once-a-wheel-revolution brake drag for 10 miles home where you discover the broken spoke...

I haven't quite drunk the Kool-Aid yet, but I can see the attraction of Co-Motion's Americano wheel.  Tandem hub, un-dished, 48 spokes, ready for any (not-too-unreasonable) load.  How's that wheel plus two derailers compare to an ordinary wheel with an IGH for weight?
No, I haven't had a spoke break lately, not since my 1985 Bridgestone 400 with 36H 4X wheels with cadmium plated 14 ga no-name spokes which started to break after about 8500 miles.   

Since then I've ridden 32H 3X wheels with stainless steel 14 ga or 14/15 db Wheelsmith or DT spokes and haven't broken one in 150,000 miles which included several wheels with 30,000 miles on each.

And before you accuse me of only riding on smooth roads with an unladen bike,  I live in the  home of some of the worst roads in the USA and I've toured with moderate loads on these wheels.

Whittierider is correct deeper section rims increase wheel strength a lot without a major weight penalty,
« Last Edit: April 05, 2011, 07:19:26 pm by DaveB »

Offline RussSeaton

Re: Why internal hubs?
« Reply #26 on: April 05, 2011, 05:09:38 pm »

Use an off-center rim, ie, rim with the holes off center, to eliminate the dish on a wheel with a freehub and cassette, like the Velocity Aerohead O/C:

The off center rear rim helps even spoke tension and reduce dish.  But it does not eliminate it.  I think the Rohloff wheel is almost completely symmetrical.  I've built wheels with the Velocity Aerohead off center rim.  Spoke tension was closer between drive and non-drive.  But still not equal.  And less dish.  The off center feature moves the spoke holes about 5mm to the non-drive side.  Not terribly fond of Velocity's rim quality.  Required quite a bit of tweaking to get the hop out of them.  No where near as round as DT rims.  The DT rim was a dream to work with.  Unfortunately DT does not make any off center rims.

Offline Nubo

Re: Why internal hubs?
« Reply #27 on: July 19, 2011, 12:11:26 am »
One other thing not mentioned, having a hub gear can allow symetrical spoke dishing in the rear wheel giving greater strength and reliability.
Theoretically, this is correct but modern 135 mm hubs with 8/9/10-speed freehub bodies laced to good quality rims with 32 or more spokes are so strong and durable these days that the advantage isn't worth the weight, efficiency loss and cost of an IGH just for that reason.

Additionally, not having to shift the chain means narrow chains are not necessary and you can use a single-speed (more durable) chain.  Also it allows practically the entire chainline to be enclosed and protected from grime.  Those two are what might eventually sway me to a Rohloff for commuting.  Chain maintenance is my least favorite part of cycling.

Offline paddleboy17

Re: Why internal hubs?
« Reply #28 on: July 25, 2011, 12:51:40 pm »
There is a blog on CGOAB about a couple that did a big loop through eatern Europe, Asia, and the Middle East for their honeymoon.  The husband had a conventionally geared bike, and the wife had a Rohloff hub.  The act of flexing a chain to accommodate a cassette, greatly reduces the life of the chain.  This was a big deal for them, as they bought some convincing looking Shimano imposter chains that went after a couple of days of riding.

The Rohloff hub was not issue free.  Rohloff replaced the hub under warranty when it failed (in Lebanon?).  She covered an amazing number of miles before the hub failed.

I wish that I had known about Rohloff hubs when I built up my Waterford.  My net cost to use a Rohloff setup instead of Shimano XT might have only been $300.
Danno

Offline Old Guy New Hobby

Re: Why internal hubs?
« Reply #29 on: July 30, 2011, 11:25:21 am »
If you're going to spend all that money, why stay with a chain? I have heard a belt drive doesn't need to be lubricated, doesn't come off the sprocket, and in general is more reliable with less maintenance.