Loading ...
Sorry, an error occurred while loading the content.

Re: Sturmey classic AW explanatory video (Was: Sturmey S3X)

Expand Messages
  • Tom Hart
    Dan, great video. In engineering terms, is there any benefit, or disadvantage, from overdrive vs underdrive? Tom.
    Message 1 of 24 , Mar 1, 2013
    View Source
    • 0 Attachment
      Dan, great video.

      In engineering terms, is there any benefit, or disadvantage, from
      overdrive vs underdrive?

      Tom.
    • Dan Burkhart
      Well, not being an engineer, I can t really put it in engineering terms. Are you talking in terms of function and efficiency or durability?
      Message 2 of 24 , Mar 1, 2013
      View Source
      • 0 Attachment
        Well, not being an engineer, I can't really put it in engineering terms.
        Are you talking in terms of function and efficiency or durability?

        --- In Geared_hub_bikes@yahoogroups.com, Tom Hart <tomhart92@...> wrote:
        >
        > Dan, great video.
        >
        > In engineering terms, is there any benefit, or disadvantage, from
        > overdrive vs underdrive?
        >
        > Tom.
        >
      • Andrew Curl
        Well, I am an engineer, and if I understand your question correctly, it depends on which gear you spend the most time in. I was once a speed freak, so I
        Message 3 of 24 , Mar 1, 2013
        View Source
        • 0 Attachment
          Well, I am an engineer, and if I understand your question correctly, it depends on which gear you spend the most time in. I was once a speed freak, so I configured my gearing so I spent most of my time in 3rd gear on a four speed hub. This meant that fewer of the internal parts were whirring around, which in turn meant less wastage in terms of my energy, spinning gears unnecessarily; also if the bits in the hub weren't working against each other, logically they'd wear out less quickly as well.
           
          As I understand things, the new generation of SA hubs (my specialty) are better than they used to be, (in terms of dimensional correctness, ergo, efficiency) so the question is more of mechanical drag as opposed to longevity. "Overdrive" as I understand it means that each tooth of each gear takes a higher torque loading, "underdrive" means that each tooth will meet each other tooth more often, 'cos more gears are spinning around. I cannot see that there's really much in it. That said, I did wear out pivot pins, but I never stripped any gear teeth.
           
          -Andrew UK
           
           
          ----- Original Message -----
          From: Tom Hart
          Sent: Friday, March 01, 2013 2:58 PM
          Subject: [Geared_hub_bikes] Re: Sturmey classic AW explanatory video (Was: Sturmey S3X)

           

          Dan, great video.

          In engineering terms, is there any benefit, or disadvantage, from
          overdrive vs underdrive?

          Tom.

        • Thorsten Ostrander
          Hi Dan, I just picked up a 1970s AW a few weeks ago. Hope to build a bike with it later this year and your video will undoubtedly be a help. Kind regards,
          Message 4 of 24 , Mar 1, 2013
          View Source
          • 0 Attachment
            Hi Dan,
            I just picked up a 1970s AW a few weeks ago.  Hope to build a bike with it later this year and your video will undoubtedly be a help.
            Kind regards,
            Thorsten

            On Fri, Mar 1, 2013 at 12:33 AM, dannyrobinson1962 <dannyrobinson1962@...> wrote:
             

            I thought that was a really useful video. Thanks for posting.

            --- In Geared_hub_bikes@yahoogroups.com, Benjamin Nead wrote:
            >
            > Hi Dan . . .
            >
            > As with Anwar, I'm another recent arrival here and appreciate anything
            > that can help explain the mechanical properties of IHGs and other
            > bicycle technology. This morning, before I had to run off to work, I
            > watched the first few minutes of your AW video. As time permits over the
            > next few days, I'll give this one and others in your series a complete
            > viewing, as I'm sure it will answer quite a few questions I have but
            > might not even know how to properly ask. Please don't assume that
            > any/all on this particular site are uninterested in this sort of thing.
            > Thanks.
            >
            > Ben in Tucson
            >
            > ----------------------------------------------------------
            >
            > Anwar Rahim wrote:
            > >
            > > Hey Dan,
            > >
            > > Great videos! That AW one is super. Thanks for making the effort to
            > > make these videos and posting them online (subscribed to your channel
            > > some time ago with the plan of watching more of the hub videos!). I
            > > love it that there are enthusiasts out there who are keen to share
            > > their knowledge with others.
            > >
            > > Fairly new to the group, found out about it when someone mentioned it
            > > on the yahoo Moulton Bicycle forum. Had no idea it existed but being a
            > > fan of internal hub gears I thought I'd join. It's a shame that the
            > > yahoo group it's not more widely known or mentioned (on blogs etc, you
            > > could mention it in the description for your IGH videos (just a
            > > thought), may generate a few new members). Must admit that although I
            > > had been a member of the yahoo Moulton group for a while, I would
            > > never have thought that such a group existed in yahoo too!
            > >
            > > Despite loving IGH my knowledge is largely based on appreciation of
            > > them and having used a few, rather than how they work, however,
            > > looking to change that. Have a couple of hubs I want to `service' (F&S
            > > duomatics) and am looking to add some Sturmey hubs to my stable. Did
            > > dismantle and reassemble a Sram Dual Drive II a little while back. Had
            > > a lot of fun doing it, and gave me a lot of confidence to want to do
            > > it with another hub, but somehow haven't found the time yet. Fingers
            > > crossed I can get round to it over the summer. May post with my
            > > progress… Or with questions when I've stuffed things up!!!
            > >
            > > Anwar
            > >
            > > --- In Geared_hub_bikes@yahoogroups.com
            > > , "pj" wrote:
            > > >
            > > > Dan wrote in part:
            > > > > I am the creator of that video. I no longer bother posting
            > > > > those here, because as you can see, there is pretty much
            > > > > zero interest among this group in how they actually work.
            > > >
            > > > Maybe everyone here on this enthusiast's list is just afraid to
            > > admit they don't already know how a basic planetary hub works! Imagine
            > > the embarrassment of someone who has posted hundreds of times here
            > > upon watching your wonderful new classic AW video
            > > >
            > > > http://youtu.be/o6v5K-2zWMI>
            > > >
            > > > and saying, "Oh, NOW I get it"!
            > > >
            > > > pj
            > > >
            > >
            > >
            >


          • dannyrobinson1962
            Hi Thorsten, I assembled a set of useful AW resources for another website, a Raleigh Twenty enthusiasts site.
            Message 5 of 24 , Mar 1, 2013
            View Source
            • 0 Attachment
              Hi Thorsten,

              I assembled a set of useful AW resources for another website, a Raleigh Twenty enthusiasts site.

              http://raleightwenty.webs.com/apps/forums/topics/show/8400316-a-collection-of-sturmey-archer-aw3-resources?page=last

              There's some good stuff on this group too, of course.

              All of which will make your work easier.

              Danny

              --- In Geared_hub_bikes@yahoogroups.com, Thorsten Ostrander <ttostr@...> wrote:
              >
              > Hi Dan,
              > I just picked up a 1970s AW a few weeks ago. Hope to build a bike with it
              > later this year and your video will undoubtedly be a help.
              > Kind regards,
              > Thorsten
              >
              > On Fri, Mar 1, 2013 at 12:33 AM, dannyrobinson1962 <
              > dannyrobinson1962@...> wrote:
              >
              > > **
              > >
              > >
              > > I thought that was a really useful video. Thanks for posting.
              > >
              > > --- In Geared_hub_bikes@yahoogroups.com, Benjamin Nead wrote:
              > > >
              > > > Hi Dan . . .
              > > >
              > > > As with Anwar, I'm another recent arrival here and appreciate anything
              > > > that can help explain the mechanical properties of IHGs and other
              > > > bicycle technology. This morning, before I had to run off to work, I
              > > > watched the first few minutes of your AW video. As time permits over the
              > > > next few days, I'll give this one and others in your series a complete
              > > > viewing, as I'm sure it will answer quite a few questions I have but
              > > > might not even know how to properly ask. Please don't assume that
              > > > any/all on this particular site are uninterested in this sort of thing.
              > > > Thanks.
              > > >
              > > > Ben in Tucson
              > > >
              > > > ----------------------------------------------------------
              > > >
              > > > Anwar Rahim wrote:
              > > > >
              > > > > Hey Dan,
              > > > >
              > > > > Great videos! That AW one is super. Thanks for making the effort to
              > > > > make these videos and posting them online (subscribed to your channel
              > > > > some time ago with the plan of watching more of the hub videos!). I
              > > > > love it that there are enthusiasts out there who are keen to share
              > > > > their knowledge with others.
              > > > >
              > > > > Fairly new to the group, found out about it when someone mentioned it
              > > > > on the yahoo Moulton Bicycle forum. Had no idea it existed but being a
              > > > > fan of internal hub gears I thought I'd join. It's a shame that the
              > > > > yahoo group it's not more widely known or mentioned (on blogs etc, you
              > > > > could mention it in the description for your IGH videos (just a
              > > > > thought), may generate a few new members). Must admit that although I
              > > > > had been a member of the yahoo Moulton group for a while, I would
              > > > > never have thought that such a group existed in yahoo too!
              > > > >
              > > > > Despite loving IGH my knowledge is largely based on appreciation of
              > > > > them and having used a few, rather than how they work, however,
              > > > > looking to change that. Have a couple of hubs I want to `service' (F&S
              > > > > duomatics) and am looking to add some Sturmey hubs to my stable. Did
              > > > > dismantle and reassemble a Sram Dual Drive II a little while back. Had
              > > > > a lot of fun doing it, and gave me a lot of confidence to want to do
              > > > > it with another hub, but somehow haven't found the time yet. Fingers
              > > > > crossed I can get round to it over the summer. May post with my
              > > > > progress… Or with questions when I've stuffed things up!!!
              > > > >
              > > > > Anwar
              > > > >
              > > > > --- In Geared_hub_bikes@yahoogroups.com
              > > > > , "pj" wrote:
              > > > > >
              > > > > > Dan wrote in part:
              > > > > > > I am the creator of that video. I no longer bother posting
              > > > > > > those here, because as you can see, there is pretty much
              > > > > > > zero interest among this group in how they actually work.
              > > > > >
              > > > > > Maybe everyone here on this enthusiast's list is just afraid to
              > > > > admit they don't already know how a basic planetary hub works! Imagine
              > > > > the embarrassment of someone who has posted hundreds of times here
              > > > > upon watching your wonderful new classic AW video
              > > > > >
              > > > > > http://youtu.be/o6v5K-2zWMI>
              > > > > >
              > > > > > and saying, "Oh, NOW I get it"!
              > > > > >
              > > > > > pj
              > > > > >
              > > > >
              > > > >
              > > >
              > >
              > >
              > >
              >
            • Dan Burkhart
              There are no gears that have fewer parts whirring around as these hubs are all constant mesh. The only gear not rotating at any given time while a hub is in
              Message 6 of 24 , Mar 1, 2013
              View Source
              • 0 Attachment
                There are no gears that have fewer parts whirring around as these hubs are all constant mesh. The only gear not rotating at any given time while a hub is in use is whatever sun gear is coupled to the axle .
                The power path through those gears can have an impact on efficiency however.

                --- In Geared_hub_bikes@yahoogroups.com, "Andrew Curl" <methuselah@...> wrote:
                >
                > Well, I am an engineer, and if I understand your question correctly, it depends on which gear you spend the most time in. I was once a speed freak, so I configured my gearing so I spent most of my time in 3rd gear on a four speed hub. This meant that fewer of the internal parts were whirring around, which in turn meant less wastage in terms of my energy, spinning gears unnecessarily; also if the bits in the hub weren't working against each other, logically they'd wear out less quickly as well.
                >
                > As I understand things, the new generation of SA hubs (my specialty) are better than they used to be, (in terms of dimensional correctness, ergo, efficiency) so the question is more of mechanical drag as opposed to longevity. "Overdrive" as I understand it means that each tooth of each gear takes a higher torque loading, "underdrive" means that each tooth will meet each other tooth more often, 'cos more gears are spinning around. I cannot see that there's really much in it. That said, I did wear out pivot pins, but I never stripped any gear teeth.
                >
                > -Andrew UK
                >
                >
                > ----- Original Message -----
                > From: Tom Hart
                > To: Geared_hub_bikes@yahoogroups.com
                > Sent: Friday, March 01, 2013 2:58 PM
                > Subject: [Geared_hub_bikes] Re: Sturmey classic AW explanatory video (Was: Sturmey S3X)
                >
                >
                >
                > Dan, great video.
                >
                > In engineering terms, is there any benefit, or disadvantage, from
                > overdrive vs underdrive?
                >
                > Tom.
                >
              • Dan Burkhart
                OK, I guess it s clear now that I must retract my earlier statement and apologize. Clearly, I leaped to an incorrect conclusion, and for that I am sorry.
                Message 7 of 24 , Mar 1, 2013
                View Source
                • 0 Attachment
                  OK, I guess it's clear now that I must retract my earlier statement and apologize.
                  Clearly, I leaped to an incorrect conclusion, and for that I am sorry.
                  Please know that I am always open to suggestions and critisism with regard to my videos, so feel free to jump in and say what you think.
                  I have plans for several future projects, and I will post them here as I complete them.
                • pj
                  ... Another common misconception is the belief that the gears still spin when the rider coasts on an IGH. Actually, the gears are locked to the driver - cog
                  Message 8 of 24 , Mar 2, 2013
                  View Source
                  • 0 Attachment
                    Dan wrote in part:
                    > There are no gears that have fewer parts whirring
                    > around as these hubs are all constant mesh. The only
                    > gear not rotating at any given time while a hub is in
                    > use is whatever sun gear is coupled to the axle .

                    Another common misconception is the belief that the gears still spin when the rider coasts on an IGH. Actually, the gears are locked to the driver -> cog -> chain -> cranks. If the cranks aren't turning, the little gears aren't turning. When coasting, only the hub shell is rotating [and the little drive pawls on the output of the gears (the IGH's freewheel) are clicking in and out].

                    pj
                  • pj
                    ... I m surprised that in all the time since it was released, the Alfine 11 hasn t been analysed by anyone.
                    Message 9 of 24 , Mar 2, 2013
                    View Source
                    • 0 Attachment
                      Dan wrote in part:
                      > There are hubs out there that will take a lot more
                      > head scratching before I can explain them to anyone else.

                      I'm surprised that in all the time since it was released, the Alfine 11 hasn't been analysed by anyone.

                      <http://john-s-allen.com/gears/hubratios.htm>

                      Shimano has yet to post a "Structure and Function" (or overhaul instructions!) on their tech tips page. With no direct drive gear, the Alfine 11 must make use of a fair amount of multiple stage compounding.

                      pj
                    • Tom Hart
                      I wasn t differentiating, Dan, as I m an ignoramous on the subject! I seem to remember, though, in a discussion on whether the Alfine 11 challenged the Rohloff
                      Message 10 of 24 , Mar 3, 2013
                      View Source
                      • 0 Attachment

                        I wasn't differentiating, Dan, as I'm an ignoramous on the subject!

                        I seem to remember, though, in a discussion on whether the Alfine 11 challenged the Rohloff hub, that how many gears were achieved by undergearing and overgearing, was relevant. So, I'm interested to know if that's correct and, if so, why.

                        Tom.

                      • Dan Burkhart
                        On reflection, I realize this statement is not universally correct. I had my head stuck in the 3 and 5 speed hubs when I wrote it. In the Sturmey Archer 8
                        Message 11 of 24 , Mar 3, 2013
                        View Source
                        • 0 Attachment
                          On reflection, I realize this statement is not universally correct. I had my head stuck in the 3 and 5 speed hubs when I wrote it.
                          In the Sturmey Archer 8 speed for example,planetary gears in the stages not engaged in any particular gear, just go along for the ride and do not rotate relative to the sun and ring gears.
                          As this video demonstrates.
                          https://www.youtube.com/watch?v=kJIh64i9IAY
                          --- In Geared_hub_bikes@yahoogroups.com, "Dan Burkhart" <boomer5319@...> wrote:
                          >
                          > There are no gears that have fewer parts whirring around as these hubs are all constant mesh. The only gear not rotating at any given time while a hub is in use is whatever sun gear is coupled to the axle .
                          > The power path through those gears can have an impact on efficiency however.
                          >
                          > --- In Geared_hub_bikes@yahoogroups.com, "Andrew Curl" <methuselah@> wrote:
                          > >
                          > > Well, I am an engineer, and if I understand your question correctly, it depends on which gear you spend the most time in. I was once a speed freak, so I configured my gearing so I spent most of my time in 3rd gear on a four speed hub. This meant that fewer of the internal parts were whirring around, which in turn meant less wastage in terms of my energy, spinning gears unnecessarily; also if the bits in the hub weren't working against each other, logically they'd wear out less quickly as well.
                          > >
                          > > As I understand things, the new generation of SA hubs (my specialty) are better than they used to be, (in terms of dimensional correctness, ergo, efficiency) so the question is more of mechanical drag as opposed to longevity. "Overdrive" as I understand it means that each tooth of each gear takes a higher torque loading, "underdrive" means that each tooth will meet each other tooth more often, 'cos more gears are spinning around. I cannot see that there's really much in it. That said, I did wear out pivot pins, but I never stripped any gear teeth.
                          > >
                          > > -Andrew UK
                          > >
                          > >
                          > > ----- Original Message -----
                          > > From: Tom Hart
                          > > To: Geared_hub_bikes@yahoogroups.com
                          > > Sent: Friday, March 01, 2013 2:58 PM
                          > > Subject: [Geared_hub_bikes] Re: Sturmey classic AW explanatory video (Was: Sturmey S3X)
                          > >
                          > >
                          > >
                          > > Dan, great video.
                          > >
                          > > In engineering terms, is there any benefit, or disadvantage, from
                          > > overdrive vs underdrive?
                          > >
                          > > Tom.
                          > >
                          >
                        • Dan Burkhart
                          I seem to remember seeing a study somewhere that actually measured efficiency of various gearhub and derailleuer drive trains in all their possible ratio
                          Message 12 of 24 , Mar 3, 2013
                          View Source
                          • 0 Attachment
                            I seem to remember seeing a study somewhere that actually measured efficiency of various gearhub and derailleuer drive trains in all their possible ratio combinations, but I can't find the link to it right now.
                            Common sense, and my own subjective observations lead me to believe there are some efficiency losses when transmitting power through an oerdrive train, but for my purposes, it's never been significant enough to worry about.

                            --- In Geared_hub_bikes@yahoogroups.com, Tom Hart <tomhart92@...> wrote:
                            >
                            > I wasn't differentiating, Dan, as I'm an ignoramous on the subject!
                            >
                            > I seem to remember, though, in a discussion on whether the Alfine 11
                            > challenged the Rohloff hub, that how many gears were achieved by
                            > undergearing and overgearing, was relevant. So, I'm interested to know if
                            > that's correct and, if so, why.
                            >
                            > Tom.
                            >
                          Your message has been successfully submitted and would be delivered to recipients shortly.