Author Topic: Straight pull twistgrip  (Read 4735 times)

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Offline Les Mills

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Straight pull twistgrip
« on: 04 Jan 2015 at 09:55 »
I have had the good fortune to get hold of the above, sadly it is missing the vital part IE: the bit that holds the cable and follows the spiral.  Does anyone please have a photo, a drawing preferably with dimensions or even one I may borrow to copy.

                Yours in hope,
                                          regards,
                                                           Les


Offline eddie

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Re: Straight pull twistgrip
« Reply #1 on: 04 Jan 2015 at 12:31 »
Les,
       When I first got my Dragonfly, I had a similar problem in that the throttle slider was in 2 pieces - they were made of a zinc based alloy and were prone to disintegrating with age. I made a replacement from phosphor bronze which is still working well (43 years on!). I'm afraid that, without dismantling mine, I cant come up with any dimensions, but you should be able to work them out from the mating parts that you have. From memory, the block is a shallow inverted 'T' shape that is curved to fit the diameter of the 'bars - the centre being angled to match the helix in the twistgrip sleeve. The centre of the block has a square hole to accept the 1/8" x1/8" cable nipple, and also about a 1/16" wide slot running out one end for the actual cable.
  I found it was better to fit the twistgrip with the cable at the top - with the cable underneath, water got in and settled around the slider, causing it to be very stiff to operate (probably also hastening the demise of the original slider!).

  Hope this helps,
       Regards,
                      Eddie.

Offline Chris

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Re: Straight pull twistgrip
« Reply #2 on: 04 Jan 2015 at 13:59 »
Hi Les
Some years ago I made a batch of these, now sadly exhausted, by turning a ring in brass with the bore being the diameter of the handlebar. I then slit this into segments and then was able to file the sides to the "T" shape and the angle to match the helix on the top and drill and counterbore each segment to suit the 1/8" x 1/8" nipple. A final saw cut to permit entrance of the cable completed the job.
Chris.

Offline Doug

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Re: Straight pull twistgrip
« Reply #3 on: 04 Jan 2015 at 15:18 »
Les,

Do you mean the prewar one? It is a stamped piece of steel sheet metal, though could be fabricated from multiple bits and silver-brazed together.
If of the prewar Bowden type, then I can probably pull the twistgrip off and get you photo/dimensions. Though most of the dimensions can be figured out via the other components.






-Doug


Offline Les Mills

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Re: Straight pull twistgrip
« Reply #4 on: 05 Jan 2015 at 14:36 »
Hi Eddie and Chris,

                                Many thanks for your suggestions, I thought I may be making one from scratch.      Another "nice little project".

           A happy and healthy 2015 to you both, with some good riding thrown in.

                         Best regards.
                                                Les



Offline Les Mills

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Re: Straight pull twistgrip
« Reply #5 on: 05 Jan 2015 at 14:42 »
Hello Doug,
                      Thanks for replying, mine is the post war type and differs from your picture,.

          A happy and healthy 2015 to you.

                   Regards,
                                     Les