Manky Monkey Motors

hi guys, would like a second opinion,,, im building a reliant trike i have recently bought some slab alloy yokes that are 39mm my fzr600 front end has 38mm fork stanchions i have been told i would be able to use a spacer to shim them by using pieces of tubing with a slit in, been told this will do the job and be safe,,, i need some re assuring im afraid as its the forks we are talking about here,,, what do you guys think
regards
tony

No idea, but welcome to the madhouse forum Tony

Not sure where you will find tube with 0.5mm (0.019") wall thickness.
Personally I would prefer flanged spacers inserted from below and bonded into place, but your wall thickness would make this difficult.

you could hav some top hat spacers made to suit the forks diameter and bore the yokes out to suit or try getting fork legs the right dia

Half a mill thick would mean a strip of ali or steel about the thickness of a Coke can wrapped around the fork legs then clamped by the yokes. Probably safe enough if it's slightly thicker than needed so the yoke clamps down tight onto it, but not good engineering.
As the clever ones have said, better to get the holes bored out to a bigger size if you can & some thicker shims made, preferably with a flange on them so they can't drop out of the holes, & slit so they can grip the forks tight as the yokes bolts are tightened.
In the real world of backyard builds, the Coke can shim would probably work fine, but your MOT man might not like it & it might be worth the 50 quid an engineering firm might charge you for the work, for the peace of mind of knowing it's done right.

Or you could get yourself a pair of 39mm fork legs,
Yamaha TZR250 1987-91 are 39mm.

There ya go. Problem solved!  ;D

make the slot where the clamp bot goes 1mm wider the tolerance your talking of will be taken up and an easy fix

the above reply is incorrect as every 1mm  reduction in dia  needs 3.142mm taking off this is the rule of pye  which is 
circumferance =dia x pye(3.142) at the end of the day the forks are keeping you up off the road surface

The mathematics are of course correct, so if you must use the stanchions and yokes as they are, use 20thou. 'shims' in each yoke, and torque the clamp bolts up, you should be fine, Morrag

thank you very much for all the suggestions and advise above,,,, i would like to keep it on three wheels and not end up with it a snowplough for tarmac,,,,, the tzr forks sound the safest bet,,, suprised realy there 39mm and a 250,,, my forks are 38mm and from a fzr600,,, hopefully bits might interchange, ie wheel callipers etc, yamaha to yamaha,,,
once again many thanks guys
much appreciated
best regards
tony

If you need any more dimensions for the TZR forks i have a set here that i am using.

hi hunter, actually that wouldnt be a bad idea as my trike is more than half built with the fzr600 front end in,,, whats the height / lenth of the tzr legs inc wheel,,, what size front wheel you on,,,, any idea if tzr and fzr might be interchangeable ie wheel callipers etc,,, thanks for your help
much appreciated
tony

Going over the workshop later,Will measure everything.

Any chance of some pics Tony ?  Of the trike that is. :)
You may have noticed, we like pics. :D

i started the build on the 31st of may , it was stood on its wheels in 4 days , cracking on with it , and when this is built i have a kawasaki gt550 to trike , best regards tony

(http://i888.photobucket.com/albums/ac90/skyeices/IMG_2429_zpsd130d3f0.jpg) (http://s888.photobucket.com/user/skyeices/media/IMG_2429_zpsd130d3f0.jpg.html)

(http://i888.photobucket.com/albums/ac90/skyeices/IMG_2436_zps31e9dd7d.jpg) (http://s888.photobucket.com/user/skyeices/media/IMG_2436_zps31e9dd7d.jpg.html)

(http://i888.photobucket.com/albums/ac90/skyeices/IMG_2457_zpsfc751816.jpg) (http://s888.photobucket.com/user/skyeices/media/IMG_2457_zpsfc751816.jpg.html)

(http://i888.photobucket.com/albums/ac90/skyeices/IMG_2467_zpse59ec45d.jpg) (http://s888.photobucket.com/user/skyeices/media/IMG_2467_zpse59ec45d.jpg.html)

(http://i888.photobucket.com/albums/ac90/skyeices/IMG_2473_zps4e1c3925.jpg) (http://s888.photobucket.com/user/skyeices/media/IMG_2473_zps4e1c3925.jpg.html)
(http://i888.photobucket.com/albums/ac90/skyeices/IMG_2472_zps98c266cb.jpg) (http://s888.photobucket.com/user/skyeices/media/IMG_2472_zps98c266cb.jpg.html)

OK here we go,
The full length of the forks is 31.1/2in,  They are single disc.

Wheel spindle dia 12mm.

The right bottom spindle hole has a steel sleeve in it to reduce hole size for spindle.
if removed the hole would be 24mm.So bigger spindle no problem.
The other leg has a 12mm threaded hole,This could be bored out and re-tapped to around 18mm.
The wheel size is 2.15x17.You could use the 600 wheel if the yoke spacing would allow you.

love the tank Kwaka ,it will be a nice trike and very fast work well done

thanks scannerzer,,, i like old school,,, maybe because im 50yrs old and allways had that type of thing,,,,,, everything old ends up going full circle and back in fasion at some point,,,
cheers
tony,,,,, isle of skye,,

Fast work indeed.
I wonder how many prism tanks from the 70s are out there. Seen a few recently :)

one hung up in my garage ,,

i bought the coffin tank initially for my next build gt550 kwaka but it was too short,,,,, need another for my gt550 but might have to have one made special,
cheers
tony

Youve been busy Tony. Im still sourcing parts for next build :)

what you needing pete mate,,,  ;)

mini chrome speedo, l/h & r/h switchgear for 7/8th bars, headlight, 120/70/17 front tyre, bag of tenners :)

hi mate,, i can help you with switches, in a fashion i can give you some off a quad, there 7/8th but no indicator switch, but theres the kill switch, start button and lights on the one cluster,,, im needing some 1" switches and a mini speedo also,,,,, and a pair of regal half shafts and flanges,,,
best regards
tony,,,,,, skye

thanks for offer tony but would like matching set with indicators etc etc. good luck in sourcing halfshafts. thinking about it contact bruce at bb customs down in dorset on mainland, tell him i sent you  :)

thanks very much pete i will follow your suggestion up,,, these regal ones are hard to find..... when you very first made contact with me when i had my reliant trike unleaded abandoned project on ebay for sale £300 about 2 years ago that was a regal axle i let go with that,,,, it went to orkney isles,,,,,
cheers mate
tony,,,

These days a abandoned project is probably the cheapest way of getting a good early axle.