1965 Triumph Chopper

[Stephan]

It looks balanced...great result!

[gus96]

I used to have shitload of them Dave Mann posters on my walls many moons ago,
good to see you have sorted the rake problem

[Doug68]

So is the frame going to be modded to get the lower rails back horizontal?
The whole jacked up front end, tilted frame thing never worked for me, old school or not.

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[El Skitzo]

So is the frame going to be modded to get the lower rails back horizontal?
The whole jacked up front end, tilted frame thing never worked for me, old school or not.

Yes mate that is exactly the plan, as I don't like that look either.

With an extra pair of helping hands yesterday I got the chance to take a whole bunch of more accurate measurements, which I'll be needing to give to an Engineer to help explain to the Transport Department what we're proposing to do exactly.

You might find some of these interesting, especially if you imagine these numbers applied to your own bike:

* With the bottom frame rails parallel to the ground the ground clearance comes in at 105mm. The minimum legal height is 100mm, so we just scrape through there.

* Horizontal distance between a line dropped from the centre of the front axle to a line dropped from the centre of the neck comes in at exactly 549mm. The maximum legal distance is 550mm, so we just scrape in there. Once we redrill the front axle plates to increase the size of the front axle from 1/2" to 3/4", I think our measurement could come back to 548mm or even 547mm. So we should be safe, but it will be very close.

* Rake of the neck will need to be increased from the stock angle of 25 degrees, to 33 degrees. So an increase of rake angle of 8 degrees, which is very big change!

* The height of the neck relative to the bottom frame rails will need to be increase by 181mm. Although we'll probably aim for something a little less like 156mm to allow for suspension compression with the full weight of all mechanicals, a full tank of gas plus the weight of the rider. But still, imagine the top triple clamp on your front end sitting over 150mm higher than it does now!

[Doug68]

I think you know this already but just in case... with the girder fork there's no need for the links to be parallel or the same length, obviously there's limits on the geometry though.
By stuffing around with this you can make the geometry do things through movement like reduce or increase trail how you want rather than it just happening as it does on a telescopic fork.
The picture is Gunga Din (legendary bike) you can see the links are not parallel or the same length, the bottom inner pivot is on an eccentric it was run in either the forward or back positions and there was an optional different length top arm for use with a side car.


https://egli-vincent.net/2014/02/14/...the-limelight/

[Wozza]

* With the bottom frame rails parallel to the ground the ground clearance comes in at 105mm. The minimum legal height is 100mm, so we just scrape through there.!

You sure the above applies to motorcycles? AFAIK thats min ground clearance for cars. bikes in most states (Im in S.A) say "A motorcycle must have sufficient ground clearance so that no part of the body work or frame will contact the road when one or both tyres are deflated"
I couldnt find the WA online info, but here is the S.A one
https://www.sa.gov.au/topics/driving...r-requirements

[El Skitzo]

You sure the above applies to motorcycles?

I'm pretty sure. In WA we follow the guidelines as spelt our in the ADRs.