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-   -   LBS says no Dyno Hub on Disk Brake bike - Is that right? (http://www.bikeforums.net/commuting/928577-lbs-says-no-dyno-hub-disk-brake-bike-right.html)

Giant Doofus 01-04-14 04:28 PM

LBS says no Dyno Hub on Disk Brake bike - Is that right?
 
I'm starting to zero in on a new commuter I think might work for me. It's the KHS Green 8 step-through frame. Here's a link to the specs: http://khsbicycles.com/bikes/2014-kh...ls/green-8-14/.

I'm trying to get away from rim brakes, and the guy at the LBS says that this bike can be equipped with a disk brake on front. Problem is, I also want dyno hub lighting. The guy at the shop says that there's no way to use a generator hub on a wheel with a disk brake. That doesn't sound right to me, but I don't know a lot about brakes or dyno hubs. So, all-knowing forum members, help me out here. Is that right, or is this guy confused?

Wanderer 01-04-14 04:34 PM

There was one posted on here within the last week. I think it was from a German wheelbuilder, a big one.

mrbubbles 01-04-14 04:42 PM

Dynamo disc hub search says there's plenty of dynamo disc hub on the market. I have 3 disc dynamo hubs myself, all different models.

Wanderer 01-04-14 04:47 PM

http://www.bikeforums.net/showthread...s-or-lbs-build

follow the link on the first post in the string

Giant Doofus 01-04-14 04:52 PM

Quote:

Originally Posted by Wanderer (Post 16382882)
http://www.bikeforums.net/showthread...s-or-lbs-build

follow the link on the first post in the string

Thanks! I didn't think that sounded right.

My problem now is that Memphis doesn't have a culture of transportation cycling, so I'm having trouble finding an LBS that can answer basic questions like this. Even if I figure out on my own which wheel/hub to order, I'm going to have a heck of a time finding a shop I trust to install it.

unterhausen 01-04-14 05:00 PM

ya, you're limited to Shimano, SON and Shutter Precision. And maybe a few more

tsl 01-04-14 05:03 PM

I use the Shimano Alfine DH-S501 dynamo hub on my disc brake bike. I liked it so much, I bought one to use on my rim brake bike. See the installation sheet at techdocs.shimano.com It's available in either black or silver. There are probably others out there, but this is the one I own and have experience with.

Your LBS can also order a prebuilt wheel with that hub from QBP's Handspun Wheels division--either the stock WE7246 or one built to your specification. My LBS ordered to my spec when I got the one for the rim brake bike. Velocity A23 hoop (black), DH-S501 hub (black), DT Revolution spokes laced 3-cross, with brass nipples. Came in two days later.

The picture of the WE7246 shows the rubber cover in place over the rotor mount. It just pops off and you put on your rotor.

EDIT: The installation sheet I linked to above, also shows how to do the wiring. With luck, your bike will have a hole on the front of the fork crown for mounting a caliper brake or fender. Your light will mount there. (There are also handlebar mounts available.) Shimano shows wrapping the wire around the fork. I used Jagwire's stick-on cable guides (or was it the stick-on hydraulic brake hose guides?) on the inside of the fork leg instead. A little neater installation. On one bike I use those to run the taillight wire. On the other I just used zip ties

surreal 01-04-14 05:58 PM

Quote:

Originally Posted by unterhausen (Post 16382921)
ya, you're limited to Shimano, SON and Shutter Precision. And maybe a few more

And SRAM. And the other SP clones, like Supernova. Pretty much I think there's no Sanyo-branded disc generator hub, but the oft-repeated rumour is that Sanyo makes the internals for several other manufacturers anyway.

I guess, technically, the LBS guy is right b/c, technically, these hubs create alternating current so they're generators. Dynamos produce direct current. So, yeah, he ain't lying... he's just wrong.

grolby 01-04-14 06:10 PM

Quote:

Originally Posted by surreal (Post 16383055)
I guess, technically, the LBS guy is right b/c, technically, these hubs create alternating current so they're generators. Dynamos produce direct current. So, yeah, he ain't lying... he's just wrong.

Is this a technical distinction? Merriam Webster says dynamo is synonymous with generator, which is how I've always understood it. Dynamo is more common in British English and generator in American English, or so I've been led to believe. http://www.merriam-webster.com/dictionary/dynamo

Whatever the case, I think it may be harder to get a generator/dynamo hub WITHOUT a disc mount than the other way around.

surreal 01-04-14 06:23 PM

Generators produce AC; dynamos produce DC. The dictionary would be a lot thicker if they got into every minute technical distinction. To the lay-person, either one is a thing that produces energy. To those of us who frequent online forums to get pedantic about bike components, it makes a difference... Although every bike geegaw I've ever seen that isn't running on batteries takes AC...

Don't get me started on the "cog" thing....

mrbubbles 01-04-14 06:28 PM

Quote:

Originally Posted by tsl (Post 16382928)
I use the Shimano Alfine DH-S501 dynamo hub on my disc brake bike. I liked it so much, I bought one to use on my rim brake bike. See the installation sheet at techdocs.shimano.com It's available in either black or silver. There are probably others out there, but this is the one I own and have experience with.

My hubs.

1. SP PD-8 with Mavic Open Pro, sapim spokes.
2. Shimano Deore XT dynamo with Mavic A319, pillar spokes.
3. Shimano Deore LX dynamo with Alex ACE18, DT swiss champion spokes.

All silver in colour except the shimano hubs are black. All of these are disc hubs.

Also have a Shimano capreo dynamo hub for a folding bike (it was hard finding somebody who could cut really really short spokes).

They all run great.

Quote:

Originally Posted by tsl (Post 16382928)
EDIT: The installation sheet I linked to above, also shows how to do the wiring. With luck, your bike will have a hole on the front of the fork crown for mounting a caliper brake or fender. Your light will mount there. (There are also handlebar mounts available.) Shimano shows wrapping the wire around the fork. I used Jagwire's stick-on cable guides (or was it the stick-on hydraulic brake hose guides?) on the inside of the fork leg instead. A little neater installation. On one bike I use those to run the taillight wire. On the other I just used zip ties

I just use electrical tape and tape the wire inside the fork.

Giant Doofus 01-04-14 06:46 PM

Quote:

Originally Posted by tsl (Post 16382928)
I use the Shimano Alfine DH-S501 dynamo hub on my disc brake bike. I liked it so much, I bought one to use on my rim brake bike. See the installation sheet at techdocs.shimano.com It's available in either black or silver. There are probably others out there, but this is the one I own and have experience with.

Your LBS can also order a prebuilt wheel with that hub from QBP's Handspun Wheels division--either the stock WE7246 or one built to your specification. My LBS ordered to my spec when I got the one for the rim brake bike. Velocity A23 hoop (black), DH-S501 hub (black), DT Revolution spokes laced 3-cross, with brass nipples. Came in two days later.

The picture of the WE7246 shows the rubber cover in place over the rotor mount. It just pops off and you put on your rotor.

EDIT: The installation sheet I linked to above, also shows how to do the wiring. With luck, your bike will have a hole on the front of the fork crown for mounting a caliper brake or fender. Your light will mount there. (There are also handlebar mounts available.) Shimano shows wrapping the wire around the fork. I used Jagwire's stick-on cable guides (or was it the stick-on hydraulic brake hose guides?) on the inside of the fork leg instead. A little neater installation. On one bike I use those to run the taillight wire. On the other I just used zip ties

Thank you. I may just print out your response and take it in with me!

grolby 01-04-14 07:04 PM

Quote:

Originally Posted by surreal (Post 16383097)
Generators produce AC; dynamos produce DC. The dictionary would be a lot thicker if they got into every minute technical distinction. To the lay-person, either one is a thing that produces energy. To those of us who frequent online forums to get pedantic about bike components, it makes a difference... Although every bike geegaw I've ever seen that isn't running on batteries takes AC...

Don't get me started on the "cog" thing....

A quick look on Wikipedia suggests that dynamos are a class of generator, and produce DC. No mention of generators being AC-specific at all. I've been pedantic about bike parts for years, and I've never heard anyone else make this distinction. Not that I'm trying to start an argument over this, I was just curious.

tcs 01-04-14 07:28 PM

Quote:

And maybe a few more
To get away from rim brakes, you could even go with a Sturmey-Archer X-FDD Dynohub with its drum brake or a Shimano dynamo hub with a roller brake.

surreal 01-04-14 08:12 PM

Quote:

Originally Posted by grolby (Post 16383199)
A quick look on Wikipedia suggests that dynamos are a class of generator, and produce DC. No mention of generators being AC-specific at all. I've been pedantic about bike parts for years, and I've never heard anyone else make this distinction. Not that I'm trying to start an argument over this, I was just curious.

You're probably right... to be a dynamo, it's gotta produce DC.... but there's no reason to believe that a dynamo isn't a generator. It's like, a Dachshund is a specific type of dog, but it's still a dog....

Still, none of the generator hubs mentioned on these threads are dynamos, though. And none of my bikes have any cogs on 'em. :lol:

surreal 01-04-14 08:14 PM

Quote:

Originally Posted by tcs (Post 16383258)
To get away from rim brakes, you could even go with a Sturmey-Archer X-FDD Dynohub with its drum brake or a Shimano dynamo hub with a roller brake.

I love my x-fdd hubs. Wanna build the next around the 90mm drum-equipped xl-fdd....

hueyhoolihan 01-04-14 09:21 PM

Quote:

Originally Posted by grolby (Post 16383199)
A quick look on Wikipedia suggests that dynamos are a class of generator, and produce DC. No mention of generators being AC-specific at all. I've been pedantic about bike parts for years, and I've never heard anyone else make this distinction. Not that I'm trying to start an argument over this, I was just curious.

psst!.... i think the post might have a generator and an alternator mixed up. along with the difference between a producer of energy and something that changes its form. in this case from kinetic energy to electrical energy. it's called a transducer, i think. but 'nuf said.

it's really not important on a bike forum, is it? really.:)

Reynolds 01-04-14 10:20 PM

Generator=produces current
Dynamo=produces DC current
Alternator=produces AC current

acidfast7 01-05-14 02:49 AM

full wheel

700c

front wheel dynamo (Alfine DH-S501)

disc brakes (also works with rim brakes)

€88 for the machine built and hand-trued front wheel

€20 for shipping and customs to the US from Germany

€108 total which is roughly $130 (not sure how much you're getting charged but this is a very nice off the shelf solution from a very reputable site)

http://www.bike24.de/1.php?content=8...;product=62193

Walter S 01-05-14 06:44 AM

Quote:

Originally Posted by Reynolds (Post 16383664)
Generator=produces current
Dynamo=produces DC current
Alternator=produces AC current

I beg to differ. I have a Shimano dyno. It produces AC. My lights are designed to run off AC. But to charge my iPhone and other electronics I need DC and that requires a power converter to rectify the voltage.

Magnets have a north pole and a south pole. On each rev of the wheel the coils move past the north or south pole and "alternately" produce positive and negative voltage on each side of the circuit. By definition, alternating current.

acidfast7 01-05-14 07:11 AM

Quote:

Originally Posted by Walter S (Post 16383998)
I beg to differ. I have a Shimano dyno. It produces AC. My lights are designed to run off AC. But to charge my iPhone and other electronics I need DC and that requires a power converter to rectify the voltage.

Magnets have a north pole and a south pole. On each rev of the wheel the coils move past the north or south pole and "alternately" produce positive and negative voltage on each side of the circuit. By definition, alternating current.

Certain models are AC and certain models are DC.

TT sells a 5V USB transformer.

Walter S 01-05-14 07:22 AM

Quote:

Originally Posted by acidfast7 (Post 16384026)
Certain models are AC and certain models are DC.

TT sells a 5V USB transformer.

A little research shows me that it is not entirely unambiguous because some of the terminology is confusingly similar. According to Wikapedia I was surprised to find that they say a "Dynamo" by definition produces DC http://en.wikipedia.org/wiki/Dynamo. "A dynamo is an electrical generator that produces direct current with the use of a commutator."

But reading further that article also says "A small electrical generator built into the hub of a bicycle wheel to power lights is called a hub dynamo, although these are invariably AC devices,[SUP][1][/SUP] and are actually magnetos."

We're obviously talking about a "hub dynamo" on BF. I'm not aware of hub dynamos that output DC. Are you?

acidfast7 01-05-14 07:48 AM

Quote:

Originally Posted by Walter S (Post 16384038)
A little research shows me that it is not entirely unambiguous because some of the terminology is confusingly similar. According to Wikapedia I was surprised to find that they say a "Dynamo" by definition produces DC http://en.wikipedia.org/wiki/Dynamo. "A dynamo is an electrical generator that produces direct current with the use of a commutator."

But reading further that article also says "A small electrical generator built into the hub of a bicycle wheel to power lights is called a hub dynamo, although these are invariably AC devices,[SUP][1][/SUP] and are actually magnetos."

We're obviously talking about a "hub dynamo" on BF. I'm not aware of hub dynamos that output DC. Are you?

Not hub dynamos (nabendynamo) ... but some "bottle generators" are 6V DC (LiteSpin for example).

Walter S 01-05-14 08:06 AM

Quote:

Originally Posted by acidfast7 (Post 16384070)
Not hub dynamos (nabendynamo) ... but some "bottle generators" are 6V DC (LiteSpin for example).

When you say "not hub dynamo" what is your point? You disagree that hub dynamos generate AC?

Edit: I misunderstood. You're saying hub dynamo is AC, bottle is DC I guess...

likebike23 01-05-14 08:09 AM

Maybe the confusion stems from the naming of generator hubs by Sturmy Archer. They called them "dynohubs" which is technically a misnomer, but the name stuck. It's kind of like calling a cola a coke or a cotton swab a Q-tip.


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