1972 Jackpiner sprocket swap

[Ken Faro]

I tried search but no answer.........Im building a 72 Jackpiner...need the change sprocket ratio and want to go to 520 or even 428 chain instead of the 530....any idea where to locate what Im looking for?..the rear hub is the full width 6 bolt version....Is the hub the same as a SIX DAY 125?...that would solve my rear sprocket issue...front on the KTM 175 maybe also the same as SIX DAY (Sachs)...isf not can the gurus steer me in right direction?....new or used sprockets are fine....thanks in advance..K

[slvrbrdfxr]

Hi Ken,
A 520 chain is the popular replacement on the 175 Jackpiner. I'm sure there are probably some folks out there that have gone to a 428 chain but I personally have not tried that. Maybe someone else will chime in on how the 428 chain works on the 175 bikes. As far as the front sprockets, the Sachs countershaft sprocket will not fit the KTM engine as the Sachs uses a non-splined tapered design whereas the KTM engine uses a splined sprocket. On the rear, the early Jackpiner bikes did use the same hub and six bolt sprocket carrier as the 125 six day. At some point however during the production run on the 175 bikes, there was a change to the rear hub to incorporate a larger rubber cushion for the sprocket carrier to engage the hub. Either the small or large cushion hub will work on the 72 Jackpiner and would use the exact same 6 bolt sprocket. Just be sure you have the correct sized rubber cushion for the hub/sprocket carrier combo you have on your bike. You might call Al Buehner from the supplier page on the site to see what sprockets he has in stock. If he does not have what you are looking for, then maybe contact Sprocket Specialists as they can make you either 428 or 520 front and rear sprockets in whatever tooth count you desire. Hope this helps. Take care !
Dave McCullough

[Ken Faro]

Thanks for the info....I use Al's advise and he sold me a 6-day rear 428 and a front 428 from a 77 MC125 KTM thats puts out alot of HP and ridden harder works great..I used a  125  a quality name brand 428HD never had a problem...its so far so good on mine...thanks

PS...I have some excellent condition 530 sprockets for sale...the rear is a 60T !

[Ken Faro]

1972 Jackpiner rear 2 feet of the OEM pipe,correct 2 port spark arrestor end cap,perforated stinger core and 1/2 the coned outer section ready to weld to your damaged or missing rear section...$200? shipped in the 48

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