Topic: Lightening stock 750 K forks !

[754]

Dont know if anyone realizes, but if you turned off 4mm of aluminum on the OD of a K3 and later leg it would still be as thick as a 72 or earlier   .. a bit of weight there..may help..

 Take a wild guess how thick a Ceriani roadrace fork leg is at the turned down areas, I was    SHOCKED.. when I measured it..

[lordmoonpie]

I'd guess thinner as in thinner = lighter = better for racing but did they go the other way and beef it up for the stresses of the track?

[Ricky_Racer]

Just a quick question, then.... With it's somewhat lighter weight and lower tube bushing, is the earlier fork considered superior to the K3-6?  RR

[754]

That what I am starting to wonder, which is considered to have better handling?

 I am asking, because I have figured out a way to rebuild the early fork legs, using new style tubes & damper rods..

[turboguzzi]

a bit unsure here, but arent ceriani legs forged = more consistent material qualities = no internal defects = can be thinner?

am a weight saver myself but there are certain areas that I wouldnt touch.

 in order not to create any stress raisers, you'd need very nice fillets all around. considering the big caliper boss, it will be more of  CNC job rather than mounting it on a lathe.

there's so much weight to remove from the front wheel and calipers, would leave that as a really last resort

TG







 

[voxonda]

a bit unsure here, but arent ceriani legs forged = more consistent material qualities = no internal defects = can be thinner?

am a weight saver myself but there are certain areas that I wouldnt touch.

 in order not to create any stress raisers, you'd need very nice fillets all around. considering the big caliper boss, it will be more of  CNC job rather than mounting it on a lathe.

there's so much weight to remove from the front wheel and calipers, would leave that as a really last resort

TG

+1 (especially the last bit), front wheel and calipers, easier and much safer!



 

[754]

 They may be forged, or cut from billet.. I am pretty sure they are made from 7075 Aluminum considering how thin they are.

 I was mentioning the stock forks could be trimmed simply to make later ones, closer to the thickness, of the early stock ones. Its all unsprung weight..

[754]

 The thinned areas on the Ceriani road race or GP fork are...
 3mm thick.. 120 or so thou.. ....     .120

[mystic_1]

mystic_1

[754]

I could not count on my fingers how many of those forks, ended up on fuel bikes   .. a lot of them double engine Harleys..       

[turboguzzi]

I could not count on my fingers how many of those forks, ended up on fuel bikes   .. a lot of them double engine Harleys..       

sounds good, just not sure how bumpy 1/4 mi strips are 

[Old Scrambler]

AND NO CORNERS OR Ssssss

Good discussion for me to consider.......I have a few sets of early and late forks........also, would be curious about a comparison with Betor forks........They sure worked magic for Bultaco!

[Zaipai]

mystic_1

I am with you Mystic_1 its all over my head.. All I know for sure is they are talking front forks..

[754]

The reason I mentioned the double engine bikes, is..
 not that they have a rough ride..

 its the wheelies, if it hooks up, and comes down hard (wheelie bars not always set right & not all bikes have them)

 or like Ray Prices bike where the front wheel, didnt touch down till 90 or 100 mph..

 to put it in perspective.. the stock 750 Steel fork tubes are probably thicker than the lower aluminum fork legs of the Ceriani 

[mystic_1]

1/8" wall thickness is crazy, bet you can get away with it because the loading is all compression forces, no (little) lateral forces from cornering etc.

mystic_1

[bucky katt]

i may try this with one of the spare sets of forks i have. does anyone have any pics of a set of forks that have been lightened?