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130mm OLD rear hub into a narrower frame without cold setting... too risky?

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  • dannyrobinson1962
    I have a steel frame bike which currently takes a 118mm OLD Sachs T3. The hub shell needs to be replaced and I was considering installing a more modern rear
    Message 1 of 9 , May 18, 2014
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      I have a steel frame bike which currently takes a 118mm OLD Sachs T3. The hub shell needs to be replaced and I was considering installing a more modern rear hub, a Sturmey Archer XL RD5 W which has an OLD of 130mm.


      I asked my LBS (Evernden Cycles of Paddock Wood, a very well respected and professional outfit) if they could cold set the frame to a wider setting. They can’t... for the very same reason I won’t attempt it myself. It’s too risky, you have to get it right, you only get one chance at it and they don’t have the training or the equipment. In fact it’s one of the only jobs they will not take on. Framebuilders have the equipment but there are fewer and fewer of them around. Unfortunately cheap imported frames are forcing these highly skilled people out of business. There isn’t one anywhere near me, apparently.


      So this leaves me with two options... either stick to a hub that will fit without being forced, or experiment and see if a wider hub can be coerced into the gap.


      The gap “naturally” sits at 125mm and by loosening the bolts holding the seat stays and rear rack the gap can be pushed outwards. By putting some nuts and washers onto some threaded rod and screwing the nuts outward along the rod I can coax the gap up to 130mm, enough to take the hub. That’s all very well as a feasibility experiment, but would springing it wider like that really be a risk I’d want to take long term and for actual riding, with a £160 ($270) hub in place? Instinct tells me no, don’t try it. Question One, am I right to be that cautious?


      I think plan B is less risky and it will be cheaper. Plan B is to get hold of a T3 hub with a coaster brake (Torpedo or MH 3115) and install that instead. These are very rare in the UK, but less rare on the continent. I’ll have a look on eBay but before I do, does anyone here have one they can sell me? To make the postage reasonable it would need to be sourced from somewhere in Europe. Question Two is, to all intents and purposes are a Torpedo hub and a T3 hub interchangeable?


      Incidentally I discovered something whilst looking for new hubs which could easily catch out the unwary. Sturmey Archer’s X RD 8 has its direct drive in the lowest gear. This means if you ever fit one in place of a hub where direct drive is in the middle of the gear range, you will almost certainly need to have a smaller chainring and/or larger sprocket. That is not something they make obvious.


      many thanks


      Danny

    • John Allen
      I find it hard to believe that widening any steel frame of reasonable quality would be risky.. Last year I widened three frames, no problem. I had to readjust
      Message 2 of 9 , May 18, 2014
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        I find it hard to believe that widening any steel frame of reasonable
        quality would be risky.. Last year I widened three frames, no
        problem. I had to readjust a few times before I got them right.
        Instructions on how to do this with the minimum in tooling are at
        http://sheldonbrown.com/frame-spacing.html .

        The dropouts also need to be realigned so they are parallel -- or
        else they will flex the axle and possibly damage the hub, bending the
        axle and misaligning the internals. simply springing the dropouts
        apart won't accomplish this, and also, will make the wheel very hard
        to install and remove. (I disagree with Sheldon about this, and
        especially for IG hubs.)

        At 05:43 PM 5/18/2014, dannyrobinson1962@... [Geared_hub_bikes] wrote:
        >
        >
        >I have a steel frame bike which currently takes a 118mm OLD Sachs
        >T3. The hub shell needs to be replaced and I was considering
        >installing a more modern rear hub, a Sturmey Archer XL RD5 W which
        >has an OLD of 130mm.

        >So this leaves me with two options... either stick to a hub that
        >will fit without being forced, or experiment and see if a wider hub
        >can be coerced into the gap.

        John S. Allen

        Technical Writer/Editor, http://sheldonbrown.com

        League Cycling Instructor #77-C

        jsallen *at* bikexprt.com
        http://bikexprt.com
        http://john-s-allen.com/blog
        http://bostonbiker.org/streetsmarts
      • Mark Stonich
        ... Clearly they either don t have a clue about working with steel frames or they assumed your frame is aluminum. Most people use some variation of the method
        Message 3 of 9 , May 18, 2014
        On May 18, 2014, at 4:43 PM, dannyrobinson1962@... [Geared_hub_bikes] wrote:

        I asked my LBS (Evernden Cycles of Paddock Wood, a very well respected and professional outfit) if they could cold set the frame to a wider setting. They can’t... for the very same reason I won’t attempt it myself. It’s too risky, you have to get it right, you only get one chance at it and they don’t have the training or the equipment.

        Clearly they either don't have a clue about working with steel frames or they assumed your frame is aluminum. 

        Most people use some variation of the method shown here. http://sheldonbrown.com/frame-spacing.html (Scroll down till you see a 2x4)

        Lots of frames have been spread this way with few failures. But why risk it? Brass isn't very good in tension, yet you are trying to bend the stays by pulling on the bridge joints. You are putting stress on the seat stay attachment to the seat tube. Plus the whole system is one big spring so it's hard to be precise about the amount you move the tips.

        After I had a seat stay come loose from the seat lug I figured there had to be a better way

        Regardless of method;

        Before spreading a rear triangle, fork or swingarm, carefully check existing alignment. If you need 5mm, you may find you need to move one side 1.5mm and the other 3.5mm. I moved the left side of my '72 Holdsworth Super Mistal out 2mm and the right out 8mm. Must have handled like a pig, which could account for the low milage.  

        You will save a lot measuring by creating a "Spreading Gauge". Tap one end of a hollow axle with 6mm x 1 threads and screw in a 6mm bolt with the head removed. Attach the other end of the axle to the other dropout with axle or lock nuts. If you need to come out 4mm, turn the 6mm bolt till 4 threads are past the outer face of the DO. Come to think of it; If you are only doing one or two frames, you could get by with 2 wingnuts, 2 washers and a piece of 1/4" threaded rod.


        After spreading the rear triangle the dropouts will no longer be parallel. Correcting this will bring them slightly inboard again. so take this into account when deciding how much to pull the DOs out.

        I usually cold set, but in such a way that any major force is isolated to the stays themselves. The simplest way to do this is to place a piece of soft pine or fir 2x4 at, or just aft of, the bridges and using it as a fulcrum for a long lever. The soft wood will deform before kinking the stays.

        I secure the frame to my table with split wooden blocks and C clamps. May not be absolutely necessary, but one less thing to worry about.  (I usually bungie the 2x4 to the stays. Don't remember why I didn't when the pix were taken.)

        My lever is a long piece of 1.25" mild steel tube with a hole drilled through one end. I use a section of threaded rod, long enough to pull the bottom side up if necessary, wing nuts and a piece of soft pine 1.25" dowel.

          Push down on the long end of the lever till you can't feel or see the tip of the spreading gauge. With cheap steel, when you lift the long end of the lever, the dropout will not return to it's original location. Remember to LIFT the long end of the lever to check, as it's weight will pull the stays outward. Good steel will spring right back. So push down just a wee bit further and check again. I find it easier to tell by feel than by eye where the DO is WRT to the tip of the gauge. Repeat as necessary. Without the spreading gauge you would have to measure after each attempt.  Good steels will bend quite some distance before taking a set. But still just keep adding a bit more force each time.

        If you go too far, flip the frame over to pull it back. Don't try to get too precise though by bending back and forth till it's perfect.

        With large diameter, thinwall, heat treated stays, or 753, I would use a different method. Warping them into position using a torch, 3 nuts and a piece of threaded rod. Ruining the paint. This is done at similar or lower temps than silver brazing, spread out over a longer area. More precise, especially with high strength steels. I've been doing this for a long time, so I can get within about 0.5 mm. I was taught this method as a way to align tubes in airframes back in the '60s. If the FAA thinks it's OK for airplanes I don't worry about it near the middle of a stay, where stresses are minimal. I won't go into details here, as this probably isn't something you can learn over the internet.

        BTW This is nothing like heating a tube to the point where you can easily bend it. No force is applied. Steel has practically no strength at brass brazing temps, but is still pretty tough at 1100F.



         Mark Stonich;    BikeSmith Design & Fabrication
           5349 Elliot Ave S. Minneapolis, MN 55417 USA
              Ph. (612) 824-2372   http://bikesmithdesign.com



      • dannyrobinson1962
        Thanks for the posts so far. In all fairness to Evernden Cycles, they weren t saying the job was impossible, they were simply saying they not prepared to take
        Message 4 of 9 , May 18, 2014
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          Thanks for the posts so far. In all fairness to Evernden Cycles, they weren't saying the job was impossible, they were simply saying they not prepared to take the work on because they couldn't guarantee it would be up to their usual standard. It is a steel frame, and the seat stays are bolted both ends, not brazed. 
        • prester_john_in_cathay
          Incidentally I discovered something whilst looking for new hubs which could easily catch out the unwary. Sturmey Archer’s X RD 8 has its direct drive in the
          Message 5 of 9 , May 19, 2014
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            "Incidentally I discovered something whilst looking for new hubs which could easily catch out the unwary. Sturmey Archer’s X RD 8 has its direct drive in the lowest gear. This means if you ever fit one in place of a hub where direct drive is in the middle of the gear range, you will almost certainly need to have a smaller chainring and/or larger sprocket. That is not something they make obvious."

            This is far from unique; indeed, Shimano, SRAM and MBI have also made or currently make hubs that have direct drive in first gear, and such hubs have been around for over one hundred years. Sturmey-Archer cannot possibly know the wheel size or the desired overall gear range for each and every customer, but they do clearly show the individual gear ratios for their eight speed hub on their website under 'Specifications' and in the spec sheet for the hub.

            pj
          • dannyrobinson1962
            Here’s the sequel to this query. In the end I went for the safe option. I decided to keep the frame as it was, and use new components with similar dimensions
            Message 6 of 9 , Jun 29, 2014
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              Here’s the sequel to this query.


              In the end I went for the safe option. I decided to keep the frame as it was, and use new components with similar dimensions to the previous ones. This was on the grounds that I could be confident I was fitting new parts that were going to be consistent with the tolerances that had been envisaged when the bike was originally designed. I built new wheels using a SA SRC3 (ii) coaster brake 3 speed, and a SA X-FD.


              The OLD of the SRC3 (ii) is 118.7, very similar to the T3 I was replacing. I might just have got away with squeezing in a SA S5C (OLD 127mm) but it would have been a risky business which would have involved spending over twice as much as I did on the SRC3 without any guarantee of compatibility.


              I wanted to order these parts from a local bike shop, purely to give them the option of the sale rather than my using an internet supplier. However they were not interested, explaining that they did not keep such parts in stock and if they ordered them and I chose to return the parts later they would not be able to resell them. I fear they are correct about not being able to resell the parts, so I understand why they declined my offer of business. It tells you a lot about the level of UK consumer demand for hub gears and drum brakes, but it is part of a vicious circle. In the end I used SJS Cycles, a large online retailer who provided excellent service. That’s where I got the spokes, hubs and fittings. I got the rims from Hollandbikeshop, as they could supply rims in size 28 * 1 5/8 , the same as the existing rims. It was not possible to get rims in this size from a UK supplier.


              This was the first wheelbuild I have ever done. I followed the excellent instructions in the Roger Musson e-book. The only thing I found difficult was gauging the correct amount of tension... it’s the sort of thing you have to do by feel and so it’s difficult to write that sort of explanation into a book. But I got there in the end.


              I’m very pleased with my new wheels. I particularly wanted to fit a coaster brake. I had ridden such bikes in the past but not often and not recently. So the coaster brake took a little getting used to at first but I am now finding it instinctive and I actually prefer it to other rear wheel braking systems. The SRC3 feels good and solid. It came with all cables and fittings, including an SLS 30 T thumbshifter lever which also has a reassuringly solid feel to its action.


              The X FD is perfect for the front. The reaction arm neatly fits into the loop that was already on the forks for the original Sachs drum brakes. I bought a new lever, an S80, made by SA. It goes well with the X FD. The new combination is a big advance on the original one. The X FD stops adequately and smoothly. I’d originally wondered about an XL FD but there would have been no need for the larger drums.


              The black rims and stainless steel spokes do look really good together. I feel that I’ve given the old bike a new lease of life.


              Photos are here...  

              https://plus.google.com/photos/110055669501444994025/albums/6025206619377484609


              One day I’m going to fit an X FD to my other big Dutch bike (the Puch Brilliant), and replace the Nexus 8 and rear roller brake with a coaster brake version. But at the moment there’s nothing wrong with what’s already there so I don’t plan to fix what’s not broken.

            • John S. Allen
              Correct spoke tension can be determined either using a tensiometer or by musical pitch. See http://www.bikexprt.com/bicycle/tension.htm On Sun, June 29, 2014
              Message 7 of 9 , Jun 29, 2014
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                Correct spoke tension can be determined either using a tensiometer or by
                musical pitch. See http://www.bikexprt.com/bicycle/tension.htm

                On Sun, June 29, 2014 5:21 pm, dannyrobinson1962@...
                >
                > This was the first wheelbuild I have ever done. I followed the excellent
                > instructions in the Roger Musson e-book. The only thing I found difficult
                > was gauging the correct amount of tension... it’s the sort of thing you
                > have to do by feel and so it’s difficult to write that sort of
                > explanation into a book. But I got there in the end.
                >
              • John S. Allen
                Correct spoke tension can be determined either using a tensiometer or by musical pitch. See http://www.bikexprt.com/bicycle/tension.htm On Sun, June 29, 2014
                Message 8 of 9 , Jun 29, 2014
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                  Correct spoke tension can be determined either using a tensiometer or by
                  musical pitch. See http://www.bikexprt.com/bicycle/tension.htm

                  On Sun, June 29, 2014 5:21 pm, dannyrobinson1962@...
                  >
                  > This was the first wheelbuild I have ever done. I followed the excellent
                  > instructions in the Roger Musson e-book. The only thing I found difficult
                  > was gauging the correct amount of tension... it’s the sort of thing you
                  > have to do by feel and so it’s difficult to write that sort of
                  > explanation into a book. But I got there in the end.
                  >
                • Irvine Short
                  I see it is a Batavus similar to mine except I think mine is from the 80 s My LBS in Cape Town cold set the frame to take a Sachs / SRAM 5 speed at 135mm. The
                  Message 9 of 9 , Jun 30, 2014
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                    I see it is a Batavus similar to mine except I think mine is from the 80's

                    My LBS in Cape Town cold set the frame to take a Sachs / SRAM 5 speed at 135mm.

                    The old Torpedo 3 speed is now in another frame that is being ridden so much the chap is getting through a front brake block every couple of months.

                    My Batavus now has a Shimano hub dynamo and rim brake in the front - after all my trips to Hamburg I got "LED and hub dynamo" envy.

                    It is the first time I have ever had a headlight so powerful. 2.4W retro-look LED ftw :-)






                    On Sun, Jun 29, 2014 at 11:21 PM, dannyrobinson1962@... [Geared_hub_bikes] <Geared_hub_bikes@yahoogroups.com> wrote:


                    Here’s the sequel to this query.


                    In the end I went for the safe option. I decided to keep the frame as it was, and use new components with similar dimensions to the previous ones. This was on the grounds that I could be confident I was fitting new parts that were going to be consistent with the tolerances that had been envisaged when the bike was originally designed. I built new wheels using a SA SRC3 (ii) coaster brake 3 speed, and a SA X-FD.


                    The OLD of the SRC3 (ii) is 118.7, very similar to the T3 I was replacing. I might just have got away with squeezing in a SA S5C (OLD 127mm) but it would have been a risky business which would have involved spending over twice as much as I did on the SRC3 without any guarantee of compatibility.


                    I wanted to order these parts from a local bike shop, purely to give them the option of the sale rather than my using an internet supplier. However they were not interested, explaining that they did not keep such parts in stock and if they ordered them and I chose to return the parts later they would not be able to resell them. I fear they are correct about not being able to resell the parts, so I understand why they declined my offer of business. It tells you a lot about the level of UK consumer demand for hub gears and drum brakes, but it is part of a vicious circle. In the end I used SJS Cycles, a large online retailer who provided excellent service. That’s where I got the spokes, hubs and fittings. I got the rims from Hollandbikeshop, as they could supply rims in size 28 * 1 5/8 , the same as the existing rims. It was not possible to get rims in this size from a UK supplier.


                    This was the first wheelbuild I have ever done. I followed the excellent instructions in the Roger Musson e-book. The only thing I found difficult was gauging the correct amount of tension... it’s the sort of thing you have to do by feel and so it’s difficult to write that sort of explanation into a book. But I got there in the end.


                    I’m very pleased with my new wheels. I particularly wanted to fit a coaster brake. I had ridden such bikes in the past but not often and not recently. So the coaster brake took a little getting used to at first but I am now finding it instinctive and I actually prefer it to other rear wheel braking systems. The SRC3 feels good and solid. It came with all cables and fittings, including an SLS 30 T thumbshifter lever which also has a reassuringly solid feel to its action.


                    The X FD is perfect for the front. The reaction arm neatly fits into the loop that was already on the forks for the original Sachs drum brakes. I bought a new lever, an S80, made by SA. It goes well with the X FD. The new combination is a big advance on the original one. The X FD stops adequately and smoothly. I’d originally wondered about an XL FD but there would have been no need for the larger drums.


                    The black rims and stainless steel spokes do look really good together. I feel that I’ve given the old bike a new lease of life.


                    Photos are here...  

                    https://plus.google.com/photos/110055669501444994025/albums/6025206619377484609


                    One day I’m going to fit an X FD to my other big Dutch bike (the Puch Brilliant), and replace the Nexus 8 and rear roller brake with a coaster brake version. But at the moment there’s nothing wrong with what’s already there so I don’t plan to fix what’s not broken.




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