Converting a 1959 VBA from 8 inch to 10inch wheels

[wink]

Hi all, I am planning the above, can anyone advise on what options are available and the simplest most effective way to do it. Thanks in advance Chris

[henri]

a new fork leg for a start ,as theres more distance from bearing to bend on a 10" leg ,if ya just swap rims the tyre rubs on mudgaurd under suspension travel ,some just fit a p200 bearing race under the bottom race to drop axle height but that messes up the headset to chassis gap/clearance ,an you have to tilt the mudgaurd an re-drill fixing holes on side so wheel wont rub .
easiest way is to look for a rally/sprint or some supers fork leg as there 10" drum brake an a straight swap ,tho ya will have to still tilt ya mudgaurd n re-drill if using a vbb 8" mudgaurd .or swap to the smoother/no bodyline gs type of guard,an a drum dust guard ,bigger 5 stud hub,bigger brake shoes ,thats the front mostly . easiest way is a whole second hand rally set of forks,or if ya dont mind not looking original front suspension altering early p series forks to take a vbb headset .
at rear if its a early vbb lump with single pivot brake shoes its major engineering work to cases to go up to 10" ,if its a vbb2t later they can have 2 pivot shoes an its a bigger backplate/shoes an hub/rim/tyre . which just leaves ya with a 3 speed box with ratios to drive 8" wheels ,you need to swap out to a 4 speed later xmas tree n loose gears/output shaft an swap if memory serves the clutch basket to get the primary ratio's right .thats why most swap to a later engine if 10" is whats wanted ,theres quite a bit involved in it ,an i dont think ive remembered it all ,but thats the basics .Henri

[sbwnik]

...and then they look out of proportion.

[wink]

Hi there, apologies for the delay in responding but I have been flat out at work.

At this stage, rather than a full blown period restoration I was looking at pretty much leaving it as is and just sticking a P200 engine into it and upgrading the forks to 10 inch (i'll retain the original engine and forks, loom etc, thus giving me the option of putting it back to original spec later, if I wanted to).

I've got a recently rebuilt P200 engine to go into it, so realistically what I'm looking at is a new set of 10inch forks to match the engine wheel size and a new loom etc.
I suppose what ideally need some advice on, is:

Are there any major issues in doing this conversion ie modification to steering lock, frame etc.

What forks will fit without any major changes/modifications to the frame, I'm guessing PK, most old large frame models and the advantages/disadvantages of each type. I'm not too worried if they are the older type or the new PK,it's more about their performance and ease of fitting etc. Also if anyone knows where I can get a set of the forks, it would really helpful. Is there anyone on the forum who would sell me a set (hopefully not at EBay silly prices).

I've restored many PX's and Lambrettas over the years, but this is the first older large frame vespa I have attempted, so any help would be appreciated.
Thanks again in advance
Chris

[henri]

pk forks if like other smallframe forks ,an memory says yes (not always reliable),the steering stop on fork is different so you'd need to change either the frame or forks to match, an pk's headsets are same fitting as px so top of fork wud need altering to take a vbb headset, earlier v90/100 primavera/et3 forks wud take a vbb headset, i think pk/px steering locks are different to vbb type too.an earlyer smallframe fork wud fit but theve got the smaller axle/link set up that isnt favoured,smaller brakes aswell,
as a straight swap super/sprint/rally forks are the only option, slightly better drum brake/handling but needin little work p series drum, much improved brakes px disc but more work ,fitting a master cylinder,i think ya can get kits , ive managed to get complete "rally" forks before for well under a 100, there always listed as rally but most are super/sprint ,an have even got super 1's for 50,theve got 8" rims but everything else is 10", p series bout 50 an px disc with brakes on seem to go for 100-150,an a new?leg n link needing backplate/drum/shoes mudgaurd n bearings is 120quid with other bits needed bout a 100. any off the second hand forks will prob need re-building ,for rallys 55quid for bits less spring/shoes ,p series 30quid plus 20?mech cost changing link pivot,
trawl the bay an check classifieds in mags an scooter trader.com. an the for sale/wanted on forums ,
if your tryin to make a gs copy like nic said it will always look out of proportion on 10" ,an whilst also likin an owning 8"vbb's i also like there look on 10" , am also just finishing a abandoned vbb project with a px engine ,lookin forward to some reliable miles in style, H

[henri]

sprint fork leg 10" item number 141385639575 on flea bay 30quid or if near kettering 281188045725 for 4 legs ,1 on right is a 10" all for 18quid ,H