250 Chott Fork Yokes Fitted to a Monty

Gbarnes3

Junior member
Guy's I have laying around a set of Chott yokes that I intend to fit to my spare monty to sharpen up the steering but now that I am fast approaching the project I have a couple of questions to anyone who has undertaken this mod before. The Chott yokes are physically narower than the Std ones hence there should be a difference in the wheel spindle and I assume the wheel spacers and front mudguard. As a heads up can anyone who has done this before let me know what the issues are and what they did to overcome them.
Thanks Glenn
 
Hi Glenn - Haven't used the Chott yokes as the preferred mod was to use the 250 2TR scrambler (think that's the right model - but may be the LZ250?) yokes - direct replacement - but did have very little off set so steering lock was v limited -Regards - Phil
 
Hey Phil,

The 2 TR is a Chott, the 2T and 2TR share the same forks.

LZ250 must have been a prototype???


Marnix
 
Hmm - It was definately an orange 250 scrambler sort of thing - nice looking tool - perhaps someone else can throw more light on it? -  - doesn't help Glenn though! - Regards - Phil
 
Appears to require a different top nut from the monty Std one and as I said before the fork spacing is slightly narrower!
Glenn
 
For the uninitiated LZ of course means Laverda-Zundapp, LH means Laverda- Husqvarna. As far as I know Laverda never made a specific scrambler/motocross or indeed a trials bike. Laverda specialised in enduro and regolarita machines. In the sixties the definition between scramblers and other off roaders was a bit more blurred and examples of the both the 100cc Regolarita machines and the later 125cc four strokes did appear in scrambles type events in Italy.

Glenn, the Chott yokes won't necessarily sharpen up your steering, they will simply reduce the offset and increase the trail which will provide more high speed stability. In theory your steering could become slightly heavier because you will have introduced a stronger self centreing tendency. In practice this doesn't happen on the 500s, I suspect this is because the reduced offset also reduces the wheel base by a small amount and this could help quicken the steering counteracting the deadening effect of the increased trail.

The standard F500/Alpino/Montjuic yokes have a large offset which gives a trail of around 72mm [I haven't got my notes handy but I know it's in this ballpark] This is the sort of measurement you'd find on a grasstrack bike, a genre of machine not renowned for stability! When the F500s competed on the Island in the early 80s some riders complained of instability at high speed and Spondon offered yokes which Slaters fitted to the team bikes and later offered as an option to customers. Originally these yokes were fabricated from steel and later ones were alloy. I have a set of the original Spondon alloy yokes and the offset is 22mm which provides a healthy 100mm [give or take a couple of mm] of trail.

I'd heard of the 2TR yoke mod but didn't realise the yoke centres were narrower. As Phil says this could create a clearance and lock problem , especially if you are using clip ons. You might need to move the tank back to give a sensible clearance for road use. Having a restricted lock can be a royal pain in the arse , even on a racer, and should be avoided if possible. You'll curse it every time you try to park the bike in a limited space, move it around the garage or try to load it in a van.

 
 
I'd heard of the 2TR yoke mod
  You're at it now Bob! - it was the LH250 mod - it did quicken up the steering - along with the longer swinging armed Saxon/Motodd monoshock conversion - the handling was ace - Yes the small steering lock was a PITA. Gary Holman - who you know - fitted a set to his 600 i believe - Regards - Phil
 
Here's a picture of the Spondon box section yokes:
LF
 

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