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-   -   Dynohub + Drum: Sturmey-Archer or SRAM? (http://www.bikeforums.net/electronics-lighting-gadgets/518065-dynohub-drum-sturmey-archer-sram.html)

IanHelgesen 03-07-09 08:57 PM

Dynohub + Drum: Sturmey-Archer or SRAM?
 
Hello all,
I'm working on upgrading an old 3-speed to use as a low maintenance urban commuter. As part of this upgrade, I'm trying to decide between the Sturmey-Archer XF-DD (combined dynamo and drum hub) and the SRAM i-Light with an added i-Brake. My problem is that I have been able to find only a few reviews on the SA hub, and almost nothing on the SRAM products. The price and specifications seem quite similar for the two hubs (although the SRAM is easier to find in stock). So, does anyone here have experience with these hubs (or with the i-Brake on another hub)?
Thanks.

Unknown Cyclist 03-08-09 05:47 AM

Isn't there a shimano option ?

Nexus 7 or 8 with some sort of low maintenance brake ?

CaptCarrot 03-08-09 06:07 AM

Shimano Inter-L Hub Dynamo

Several options including roller and disc brake compatible.

The alfine is disc brake compatible too.


RE: the SRAM I-Brake, I looked into this a while ago. You will be lucky to find one, I think they are discontinued.

Unknown Cyclist 03-08-09 07:22 AM

Quote:

Originally Posted by IanHelgesen (Post 8488101)
I'm working on upgrading an old 3-speed to use as a low maintenance urban commuter.

Are you looking to upgrade the gears as well ?

CaptCarrot 03-08-09 08:59 AM

If so, Shimano Nexus Inter-8 or a Nuvinci would be my recommendations

quester 03-08-09 09:08 AM

http://www.bikeforums.net/electronics-lighting-gadgets/510817-generator-hub-vibration.html

Unknown Cyclist 03-08-09 09:13 AM

Quote:

Originally Posted by CaptCarrot (Post 8489858)
If so, Shimano Nexus Inter-8 or a Nuvinci would be my recommendations

Have you seen the weight and efficiency of the nuvinci ?

CaptCarrot 03-08-09 09:56 AM

the weight yes

the efficiancy - not too sure about

I know you cant accelerate quickly from bottom to top because it takes something like 3 full turns of the shifter,

But that aside, for a low maintenance urban commuter or leisure bike, the weight will not be an issue. Add the fact that you are rarely ever in the wrong gear and can adjust on the flie to compensate for the slightest headwind or incline.

I must admit though, my recommendation is blind, I have yet to use one - but I am keeping my eye out. The reviews I have read are very rpomising (unless you are a racer or crossing the alps).

Unknown Cyclist 03-08-09 10:10 AM

Quote:

Originally Posted by CaptCarrot (Post 8490123)
the weight yes

the efficiancy - not too sure about

Weight of a wheel with the hub in = 12 lbs.

Any idea of cost ?

What range of gearing does it approximate to ?

BTW. I've recently bought a Rohloff (bought blind) and though I wasn't initially keen on it, I'm converted now. :thumb:

Just need to save up and convert all my bikes to Rohloff, or replace them.

CaptCarrot 03-08-09 10:43 AM

Some interesting info snippeed form here

Quote:

...an infinitely adjustable gear ratio and a range of 350%...

...The range built into the hub is the equivalent of having an 11-38 tooth cassette...

...19t freewheel and a 38t chainring. With this combination, the lowest ratio available gives the equivalent of a 1:1 gear, in which the rear wheel rotates once for each crank revolution. On this bike, a Redline Monocog Flight with Rhyno Lite rims, this translates to a 26” low gear. With the 350% range of the hub, this means that the highest ratio is a 91” gear...

...For the record, the hub is just over 9 lbs...
And of course - Good ol Sheldon... http://www.sheldonbrown.com/harris/nuvinci.html

scroll down for Sheldon Brown's Internal Gear Calculator for Internal Gear Hubs.

Quote:

The lowest gear on most mountain bikes is around 22-26 inches. The highest gear on road racing bikes is usually around 108-110 inches.
Coming in at 26-91 ain't bad. Especially when you consider my 24/34/42 x 11-34 has a range of 18.4-99.3 inches

Unknown Cyclist 03-08-09 11:20 AM

CC price ?

CaptCarrot 03-08-09 11:43 AM

Google ;)

cheapest is 193.89

CaptCarrot 03-08-09 11:44 AM

Maybe this thread should be split, we seem to of kind of hijacked it

Unknown Cyclist 03-08-09 11:54 AM

Quote:

Originally Posted by CaptCarrot (Post 8490550)
Maybe this thread should be split, we seem to of kind of hijacked it

So you did !!

;)

Allen 03-08-09 01:36 PM

Shimano makes a dynamo front hub with a roller brake.
DH-2R30-E Dynamo Front Hub (for Roller Brake)

I would expect the drag to be much less with the Shimano than with the S-A. The Shimano dyno hubs are made with Ultegra level parts.

The Shimano hubs can also be fitted with a disk brake.

Allen 03-08-09 01:41 PM

Quote:

Originally Posted by CaptCarrot (Post 8490315)
Some interesting info snippeed form here

Quote:

...an infinitely adjustable gear ratio and a range of 350%...

...The range built into the hub is the equivalent of having an 11-38 tooth cassette...

...19t freewheel and a 38t chainring. With this combination, the lowest ratio available gives the equivalent of a 1:1 gear, in which the rear wheel rotates once for each crank revolution. On this bike, a Redline Monocog Flight with Rhyno Lite rims, this translates to a 26” low gear. With the 350% range of the hub, this means that the highest ratio is a 91” gear...

...For the record, the hub is just over 9 lbs...
And of course - Good ol Sheldon... http://www.sheldonbrown.com/harris/nuvinci.html

scroll down for Sheldon Brown's Internal Gear Calculator for Internal Gear Hubs.



Coming in at 26-91 ain't bad. Especially when you consider my 24/34/42 x 11-34 has a range of 18.4-99.3 inches

250% gear range with the NuVinci.
I have one.
+
Quote:

Originally Posted by Sheldon Brown (Post 5729037)
OK, so low gear is 100%, high gear is 350%.

350% - 100% = 250%. That's the _range_.

See also http://sheldonbrown.com/gears/internal

I just got one on my Greenspeed trike, but I've only had opportunity to ride it for a couple of miles so far. So far, I like it a LOT!

Sheldon "Digital Isn't Always Best" Brown


IanHelgesen 03-08-09 02:10 PM

Thanks for all the information. I knew Shimano had a disc version, but that means a new fork. I hadn't seen the roller brake option before, so I'll have to look into that.

As for the gears, I'm planning to stick with the vintage Shimano hub it came with. It's still working great, and we don't have much in the way of hills around here.

Allen 03-08-09 03:16 PM

No problem :thumb:

I've been running Shimano Dynos on all my bikes for a while.
They are great hubs.

K6-III 03-09-09 08:58 AM

The roller brake on the Shimano is nowhere near as good as the drum brake on the Sturmey. Efficiency is comparable on the Sturmey to mid-range Shimano.

The SRAM has excellent efficiency when on, not so good with the light off. The i-Brake is basically a drum brake with better cooling, so kudos there. The design, however, does require that you build a weaker dished front wheel.

All in all, I'm very happy with my Sturmey XFDD's. Drum brakes as good as these make it hard to ride with rim brakes ever again (you get used to stopping so quickly), provided you've adjusted your brakes properly and are running canti-specific brake levers.

IanHelgesen 03-11-09 01:13 AM

Exactly the sort of information I was hoping for. Looks like the SA is the way to go for this project. Many thanks for your advice.

robtown 04-10-09 11:00 AM

Quote:

Originally Posted by K6-III (Post 8495436)
The roller brake on the Shimano is nowhere near as good as the drum brake on the Sturmey. Efficiency is comparable on the Sturmey to mid-range Shimano.

The SRAM has excellent efficiency when on, not so good with the light off. The i-Brake is basically a drum brake with better cooling, so kudos there. The design, however, does require that you build a weaker dished front wheel.

All in all, I'm very happy with my Sturmey XFDD's. Drum brakes as good as these make it hard to ride with rim brakes ever again (you get used to stopping so quickly), provided you've adjusted your brakes properly and are running canti-specific brake levers.

Thats good information. I'm also building a 3 spd rear, generator hub front equipped bike (steel, track dropouts). I decided to go with drum brakes and non machined rims (different, and cheaper). I was a bit concerned about braking power. The SA rep confirmed that inverse bar-end brake levers work with the drums.

Anyone know where to pick up the SA S30 3 speed hub with drum brake? It seems out of stock everywhere.

JimBeans83 01-25-10 03:13 PM

Any more thoughts on reliability for the SA dyno drum brake hub? Sounds good - price reasonable, just concerned about reliability before building a wheel around it. A pointer to a PDF elsewhere describing the resistance graphs would be great - seems well done for the Shimano and Schmidt hubs, but not so much for SA. But I think I read somewhere that the electronics are outsourced for Shimano & SA (Panasonic?) , so in theory the same resistance charts? Cartridge bearings for the SA.

K6-III 01-30-10 12:28 AM

I have built up and used 3 bikes using Sturmey XFDD hubs and another 2 bikes using the XFD. No reliability concerns. Given that Pashley and Velorbis trust these hubs for their European-spec bikes, I wouldn't hesitate to use them.


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