Author Topic: 1947 T35  (Read 3351 times)

0 Members and 1 Guest are viewing this topic.

Offline jerycmitch

  • Member
  • *
  • Join Date: Nov 2014
  • Posts: 4
  • Location: Newmarket
1947 T35
« on: 17 Nov 2014 at 16:39 »
Hello everyone,  I have recently purchased a 1947 T35  in need of reassembly.  The frame has just been nicely powder coated and the engine is back in.  I am now putting the rear suspension back together and have noticed the torsion bars have coloured marks, one red one green.  I have noticed a reference to coloured marks on torsion bars in the literature but no explanation.  Could anyone help?  I would be much obliged.   Kind regards  Jeremy Mitchell

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4250
  • Location: Glen Mills, PA, USA
Re: 1947 T35
« Reply #1 on: 17 Nov 2014 at 17:15 »
Jeremy,

You will want to get yourself a copy of the handbook.

The painted mark is assembled to the front of the machine. The left-hand torsion bar will have a red band, which switched to yellow paint on later machines. The right-hand torsion bar was always marked with green paint. The torsion bars are handed, in that they get use to loading in a certain direction, so ensure that they get reassembled the proper orientation.

Powder coating makes an excellent insulator, so you may find you need to run grounding wires between the electrical devices. The extra thickness may make it difficult to assemble fasteners.   

-Doug

Offline jerycmitch

  • Member
  • *
  • Join Date: Nov 2014
  • Posts: 4
  • Location: Newmarket
Re: 1947 T35
« Reply #2 on: 18 Nov 2014 at 07:50 »
Hi Doug,
Many thanks for the information.  I have a photocopy of the original handbook but can't find any specific reference to the markings.  I will buy a copy of the book by Neville Heath to compliment the other literature.   When I removed the torsion bars I made a note that green was on the left (port or near side, in England ) and red on the opposite,  so I wonder whether it would be sensible to put them back as was, or go for the  'correct'  port / starb'd  marking since they have  'memory'.  Don't know when they were last out of the machine.   All good fun !   Many thanks, Doug.    Jeremy

Offline eddie

  • Master Member
  • ****
  • Join Date: Mar 2006
  • Posts: 1659
  • Location: Hampshire, UK
Re: 1947 T35
« Reply #3 on: 18 Nov 2014 at 09:43 »
Jeremy,
         When springs (or torsion bars) are loaded, they take a 'set' in that direction. Torsion bars are different to most coil springs in that the load can be reversed, so that when a torsion bar is subjected to (say) an anti-clockwise twist and then it is reversed, it is likely to settle again by an amount equal to twice the 'set'. For this reason, Mr Douglas colour coded the torsion bars so that they could be identified as either LH or RH, very necessary if a bar was being swapped from one machine to another, but if you swapped the torsion bars side for side on the same machine, the worst they would do is settle equally and need to be re-adjusted for ride height. The big problem occurs when replacing just one bar that is not identified, as this bar could then settle and create excessive loads on the opposite bar.
  Whilst we are on the subject of suspension - have you looked at the front forks? Mr Douglas provided 2 options for front fork springs - a parallel (heavy duty) spring and a lighter duty tapered spring. Now the tapered spring is effectively a multi-rate spring, and Mr Douglas shows it fitted in the forks large diameter upwards - I think this is wrong, as it is normal practice to fit multi-rate springs with the strong end taking the shock load (to prevent the weak end becoming coil bound - a major cause of springs breaking). In recent years, quite a few Mark series machines have suffered spring breakage - could it be due to incorrect fitting of the spring? I have always inverted my springs - and had no problems - even on my Comp which has 'bottomed' the front forks many many times!!
  Regards,
                Eddie.

Offline jerycmitch

  • Member
  • *
  • Join Date: Nov 2014
  • Posts: 4
  • Location: Newmarket
Re: 1947 T35
« Reply #4 on: 18 Nov 2014 at 14:50 »
Hi Eddie,
I am very much obliged for your information.  As with all things simple there is always more to it than meets the eye!!  Having spent a while understanding how the torsion bars and links, swing arm etc. all fit together I am now not so worried about having to re-set the bars having let them settle once in situ, knowing that they have been correctly reinstalled.  We haven't stripped down the front forks, yet, indeed I am not sure whether we will, but it would be reassuring to know which way up the springs are and what 'weight'  they are.  I now have to find a couple of felt washers and face washers to fit inside the rear of the torsion bar links.  Many thanks again for your assistance.  Kind regards   Jeremy

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4250
  • Location: Glen Mills, PA, USA
Re: 1947 T35
« Reply #5 on: 18 Nov 2014 at 15:29 »
Jeremy,

The above color coding was taken from the Mark series handbook. I am not sure if it appears in the T35 handbook.

-Doug

Offline jerycmitch

  • Member
  • *
  • Join Date: Nov 2014
  • Posts: 4
  • Location: Newmarket
Re: 1947 T35
« Reply #6 on: 19 Nov 2014 at 07:50 »
Doug, 

Many thanks for that.   We're making progress here,  step by step !   

Jeremy.

 

motorcycle