Refurbing Greenspeed GT3

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   The Young Lady complained today that the rear end snaked around on a downhill when using the Carradice recumbent panniers for a shopping run. Something like 14kg in each pannier apparently.

As noted previously, "The folding hinge has noticeable play and tightening the QR doesn’t remove the play in the hinge pin, unlike a Birdy, Dahon or Brompton hinge. Is there some trick to removing hinge play that I am missing?” I haven't yet found the solution to this issue. Do I need to replace the hinge pin, fit bushes somehow or something else? The hinge pin appears to non-removeable without serious metalwork.

Edited by LWaB - 02 July 2024 at 10:50pm

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LWaB Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 13 August 2016 Status: Offline Points: 277	Post Options Post Reply Quote LWaB Report Post Thanks(0) Quote Reply Posted: 02 July 2024 at 1:41pm
	The Young Lady complained today that the rear end snaked around on a downhill when using the Carradice recumbent panniers for a shopping run. Something like 14kg in each pannier apparently. As noted previously, "The folding hinge has noticeable play and tightening the QR doesn’t remove the play in the hinge pin, unlike a Birdy, Dahon or Brompton hinge. Is there some trick to removing hinge play that I am missing?” I haven't yet found the solution to this issue. Do I need to replace the hinge pin, fit bushes somehow or something else? The hinge pin appears to non-removeable without serious metalwork. Edited by LWaB - 02 July 2024 at 10:50pm

LWaB Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 13 August 2016 Status: Offline Points: 277	Post Options Post Reply Quote LWaB Report Post Thanks(0) Quote Reply Posted: 10 July 2024 at 3:49pm
	I have had replies from WizWheels (the new owners of Greenspeed) and Trisled (purchaser of most Greenspeed spares when the business was sold) and neither have any idea how to reduce play in the frame hinge. WizWheels is getting some replacement hinge assemblies but they have no idea if those spare parts fit the obsolete GT3. Other than getting some replacement metalwork done by a pet machinist, what is my next option? The frame fold is the major reason this trike was purchased, so brazing the hinge solid is not a solution. The GT3 frame was fabricated in Taiwan. Does anybody know who was the frame manufacturer, Pacific Cycles or somebody else? Getting hold of the detail drawing of the hinge assembly would help in machining replacement parts. Edited by LWaB - 10 July 2024 at 3:52pm

Anthony-C Members Profile Send Private Message Find Members Posts Add to Buddy List Visitor (new) Joined: 11 April 2023 Location: South east UK Status: Offline Points: 6	Post Options Post Reply Quote Anthony-C Report Post Thanks(0) Quote Reply Posted: 27 July 2024 at 6:57pm
	I haven't seen one of these hinges but would it take up the slack if you shut some JB-Weld in the hinge, after greasing one face so that it still opens? (edit) Hope this suggestion isn't wildly out of step with the forces at play. Edited by Anthony-C - 28 July 2024 at 7:57pm

Martin Kiszel Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 05 October 2022 Location: Mansfield Status: Offline Points: 24	Post Options Post Reply Quote Martin Kiszel Report Post Thanks(0) Quote Reply Posted: 29 July 2024 at 12:10pm
	Is there any chance you could provide pictures or links to show the hinge? It could be re-pinning the hinge may take up some slop, but also there could be some stretch on the arms. So as suggested refacing may work for a short time, I was going to say stop gap solution! An engineer could get the parts clamped up and ream the hinge hole slightly bigger, by say 0.1mm~0.2mm. I don't know the size but they do go up in small increments. Then a new bespoke pin would need making and fitting.

LWaB Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 13 August 2016 Status: Offline Points: 277	Post Options Post Reply Quote LWaB Report Post Thanks(0) Quote Reply Posted: 29 July 2024 at 1:53pm
	I will try to put up some hinge photos once I get home. Scroll down in Greenspeed GT3 (atob.org.uk) and there is a good folded hinge shot. Folding the Greenspeed GT3 Recumbent Trike (youtube.com) shows the hinge in action. The short-term plan is to clamp up the hinge with Jubilee clips to prevent any movement. Long-term, hopefully Geoff Booker will do some interesting metalwork to permanently replace the hinge pin with something a little bigger and to de-ovalise/ oversize the locking pin holes. Edited by LWaB - 29 July 2024 at 5:44pm

Anthony-C Members Profile Send Private Message Find Members Posts Add to Buddy List Visitor (new) Joined: 11 April 2023 Location: South east UK Status: Offline Points: 6	Post Options Post Reply Quote Anthony-C Report Post Thanks(0) Quote Reply Posted: 30 July 2024 at 10:47pm
	Could you do me a small favour and try shutting a strip cut from inner tube in the hinge and doing it up really hard? I'm so intrigued... I think the hinge pin and QR pull it together until the side edges nestling in their cutouts resist play in the pin and form a tetrahedron. If the sides aren't springy enough the high spots can be asymetrical, then the tetrahedron's edges wouldn't be perpendicular and would make a narrower axis less resistant to frame flexing. A compressible strip that crosses those edges (i.e. longer than the width of the frame) should centre it up a bit vertically, and also help horizontally if there's play in the pin. So IIUC without rubber it needs doing up even tighter. Edited by Anthony-C - 30 July 2024 at 10:48pm

LWaB Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 13 August 2016 Status: Offline Points: 277	Post Options Post Reply Quote LWaB Report Post Thanks(0) Quote Reply Posted: 31 July 2024 at 5:59am
	Pacific Cycles have responded that I should contact Greenspeed for hinge details as confidentiality prevents them giving out information. I think that the hinge relies on the tolerances around the hinge pivot pin, the hinge clamping pin and their surrounding holes. There doesn’t seem to be any face-to-face contact of the main hinge components themselves. Wear of powdercoating quickly increases clearances, which can’t help. https://flic.kr/p/2q7ky87 https://flic.kr/p/2q7is1x Edited by LWaB - 31 July 2024 at 6:20am

Anthony-C Members Profile Send Private Message Find Members Posts Add to Buddy List Visitor (new) Joined: 11 April 2023 Location: South east UK Status: Offline Points: 6	Post Options Post Reply Quote Anthony-C Report Post Thanks(0) Quote Reply Posted: 31 July 2024 at 10:27am
	The strip of inner tube is to replace the worn powder coating. Edited by Anthony-C - 31 July 2024 at 10:32am

LWaB Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 13 August 2016 Status: Offline Points: 277	Post Options Post Reply Quote LWaB Report Post Thanks(0) Quote Reply Posted: 31 July 2024 at 4:17pm
	The main issue is torsion along the main tube, allowing the rear wheel to lean sideways slightly in both directions. The hinge pivot pin is quite a loose fit at both ends (rusty section on the RHS of the photo) and in the middle of the hinge. I am not convinced that a rubber washer would improve torsion resistance sufficiently but I will give it a go over the next day or two. Edited by LWaB - 31 July 2024 at 5:28pm

LWaB Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 13 August 2016 Status: Offline Points: 277	Post Options Post Reply Quote LWaB Report Post Thanks(0) Quote Reply Posted: 01 August 2024 at 9:39am
	Pacific Cycles has replied asking for some pictures or video showing the problem. Hopefully they can provide a detail drawing of the joint (to aid remanufacture of the worn joint) or diagnose the cause. Edited by LWaB - 01 August 2024 at 1:46pm