Bultaco Pursang vs Astro Frame

[Tahitian_Red]

Besides steering head angle and rear frame loop, what are the differences between an Astro and Pursang frame?

I've always wanted an Astro dirt-tracker, but every one I find is pretty pricey (compared to vintage MX bikes).  I have an extra Model 135 frame leaning up against the house and the rear frame loop is already messed up (aren't 75% of them?), so if the differences aren't too numerous, perhaps I should get out the torch.
 

[jimg1au]

there is a cheap one on vtf at the moment
jim

[bullmad24]

There completly different i'll post some pictures to help you out the black frame is a #146 astro frame and the silver/rusty frame is a #135 / 136 frame which i borrowed off another forum member that he wont be gettin back.

[bullmad24]

[bullmad24]

[bullmad24]

The next photo is my astro tank and seat sitting on the pursang frame and it wouldn't take much work to make it fit or build a look alike also matchomick on the forum makes the tails and seat bases i'm sure he would look after you and make you one , i have bought some fibreglass stuff off him and it has been really good quality and the tails will fit alot of bikes the tail fits my 400 square barrel like a glove hope these photos help you out.

[bullmad24]

[bullmad24]

[Tahitian_Red]

Thanks BullMad!

I didn't know the difference was that dramatic.  My reason for asking was I had the spare frame laying around anyway and we have a once a year TT (Short Track) race, that I finally tried last year, but an MX bike doesn't fair so well (even though it just for fun).  It is "Open Traction" (knobbies allowed) and it is run in between Post-74 and a pre-75 races, at a two day event (Sat. evening).  Thought maybe I could put together a better running Pursang Short-Tracker.
 

[huskibul]

       Does the geometry look that much different between the two (other than the steeper steering) or is it more cosmetics/rider position ? Ive never noticed it on astros before but the different cradle do you think it would just be to stiffen it up ? Interesting thread keep us posted TR- great pics bullmad- cheers

[firko]

The original Bultaco Astro was introduced in 1971 with a Pursang frame. The later version of the Bultaco Astro introduced in 1974 had a fairly close copy of the Champion Frame that was was built by the Pioneer Equipment Co for Mike Kidd 1973. Pioneer Equipment was a Bultaco and Honda dealership located in Wincester, TN. The idea to create a flat track motorcycle for Bultaco to compete against the Ossa DMR came from the unbelievably named Royal Sherbet who worked under Bill Dutcher at Cemoto Bultaco. At the end of the 1973 season, Kidd’s Pioneer built Champion framed motorcycle was sent to Spain to be duplicated. At the same time Royal Sherbet and Mike Kidd designed the colorful Bultaco graphics. In 1974 the new Astro version based on the Pioneer/Champion design was introduced.

[Tahitian_Red]

So, how about tucking the stem in a degree or so and adding an Astro front end.  Keep the Petty blue tank and have someone build a matching seat/fender combo.  With flat track tires and handlebars it should be OK for a once a year event. (Pursangs were always great sliders anyway, right?)

On a side-note would it be a Purstro or an Assang? 

[firko]

So, how about tucking the stem in a degree or so and adding an Astro front end.  Keep the Petty blue tank and have someone build a matching seat/fender combo.  With flat track tires and handlebars it should be OK for a once a year event. (Pursangs were always great sliders anyway, right?)

Jay, the Pursang Betor's will be fine, just slide 'em up the triple's a little, pop on a 19" spooler, a pair of 12"-12.5" shocks, tyres to suit and off you go. You can buy glass dirt track seat/fender combos for little money on www.vft.org. Champion glass seat should come close.
If you're only riding dirt track once a year why spend dough you don't need to .

[Slider29]

Very interesting.  Great thread, i'love flat trackers especially Astros. Keep up the good work fellas.  Regards  Mark

[Moto]

That 136 frame came all the way from Arizona. It needs to be returned asap or your Astro and Squarie engines will remain expensive door stops.