New suspension 70 build

[1979ATC110]

My 70 frame snapped in half a while back so I've now rounded up most of the parts to build my suspension frame. I'll post more pictures here as the build progresses.

I'm using a pit bike frame, making my own swingarm and triples.





Today I've been sizing everything up on the bench, trying to work out what wheelbase length I want to go for. I don't know how the extra length, width and rake affects the ride so it's really hard to decide. Maybe some of you guys can help me out here; The A+ frame looks about right to me - it obviously has a longer wheelbase than stock, can anyone tell me exactly what it is (or the length of the A+ swinger) and did the A+ use wheel spacers to increase the width to keep the overall geometry the same?

[Sparkplugkid]

This will be a sick build!

[Yamaha_Rules69]

Nice start to a good build! Keep up the good work, and keep the pictures coming! I really like seeing the 70's with suspension, and even more of them being jumped! It must be a riot.

[BIGREDGUY]

Looks like a pretty solid project.

[cox]

thats pretty sweet. me likey

[1979ATC110]

Thanks for all your help...

Made a bit of progress on the swing arm today:











All I need to know now is the what length it needs to be - anyone???

[krazykane]

well iam just thinking outside the box but a little longer is prob better just like a extended swingarm.i dont have one but iam diff going to watch this build cause i have everything in the making to do this so .in due time i will be doing this .and i mean longer then the stock length on the stock 70 .

[KASEY]

ONE THING TO LOOK AT, the neck is alot shorter and the top clamp will hit the tank right in the middle.. so adjustsments will have to be made there,,,

[1979ATC110]

Thanks Kasey, I hadn't thought of that. Just looked at a few pictures of 70's on pit bike frames, they seem to have moved the tank back far enough to avoid them hitting, without it looking odd. I'll watch out for it.

[1979ATC110]

Got a bit more work done on the swingarm and frame this afternoon - swingarm is 13 inch / 330mm





I'll be making the yokes this weekend from these slabs of billet ali:



Front forks and rear mono shock are new pit bike parts:



Should hopefully be a roller by the end of the weekend.

[thestud25]

Keep us in the loop!

[1979ATC110]

I got the swingarm spot welded together, didn't want to weld it all in case I need to make changes. Also lowered the rear shock mount on the frame because it was in the way of the seat.



Marked out the bottom clamp ready for drilling and cutting.

[Dirtcrasher]

I like it :

There are 1000 ways of building a suspended 70..........

What do those forks cost? and where can I grab a set, I was gonna chop down some 200X forks but those look pretty trick!

I think you may be angling that shock back a hair. Like you said, thats why it's just tack welded. The same reason I do it that way too.............

Nice work so far!!

[1979ATC110]

Thanks Dirtcrasher, it's nice to get some feedback......

The forks are Marzocchi non-adjustables - Goggle it. They're Italian high quality forks, a proper adjustable set costs about $700!!!!!!!
These are only sold as part of of pit bike but occasionally they turn up on ebay form new bikes that have been dismantled for about a $100.

The rear shock is only 11 inches long, and the seat height as it is now, is 26 inches. I'll see how it rides, but you may be right.

[1979ATC110]

In my haste to get the triples done I made a stupid mistake on the setting out, luckily I spotted it before I messed up the 2nd one. Managed to make a couple of 1 inch wheel spacers out of the centre part of the 1st but it meant I had to drive all the way out to the metal supplier today to get a replacement. Hopefully I'll get her rolling later this week.