Jackshaft Sick Bike Parts jackshaft issue

[wolframore]

That’s what I thought. What do you think about 0.624 nom with +/-.001 tolerance. I would rather sand it down if it’s too tight. Unless you can get tighter tolerance at a reasonable cost. Does the material seem a little soft to you? I work on motorcycles and this sort of stuff just wouldn't last or happen on them. Haven’t seen Chinese motorcycles yet and hope I never do.

 

[5-7HEAVEN]

Back in the 1950s, anything junk was misnamed as "made in Japan".

Decades later, anything junk was misnamed as "made in Korea".

And now it's China.

 

[Wrench]

HUH?

The shafts are from the USA. Please. Some people take this stuff seriously

Excuse me Brah I've never ordered one and just assumed. My Bad.
But the question still remains. Why @wolframore shaft is .005" undersized?

 

[wolframore]

I have 3 shafts that are 5 under... very consistently off, purchased quite a bit apart.

 

[Wrench]

Back in the 1950s, anything junk was misnamed as "made in Japan".

Decades later, anything junk was misnamed as "made in Korea".

And now it's China.

Of course, Americans were used to Made in America products and it lasting a lifetime .
Japan, Korea, copied American stuff and it was junk at first. So yea, they got a bad rap for decades. Japan and Korea now make good stuff. China is still learning. China products are known as disposable products. I'm sure to keep the cost of their products low it's inferior.

I buy Made in China crap all the time, Ya can't avoid it in this day and age. Some stuff I know how and what's gonna break on it before I even use it. I'll modify the Dam thing just to make it last longer.
It's not a myth China makes alot of JUNK and they have NO QUALITY CONTROL

After WW2 Japan was making toys from (trash) tin cans. Their worth alot of money today if ya can read the tin can label.
Yes, it took Decades for Japan to loose the bad rep that they make stuff from what they find in the trash.

I thought Korea just made sneakers

 

[Pablo]

.005" Under would surprise me. Are you measuring with an actual in calibration micrometer? If that is the case, those are .001" out of specification.

Remember, the material specification is 0.625" +.000 and -.004". I've yet to measure a shaft that is out of tolerance.

 

[5-7HEAVEN]

and cellphones and big screen TV's.

 

[wolframore]

Thats a large tolerance, no I used a vernier, I didn’t break out my mic. So I’m sure it could be 0.001 off. Either way 0.621 is pretty bad. I can dig out my Starret if that’s important. What’s fact is that the shaft has spun because theyre undersized. It’s so bad I can rock it back and forth on the shaft, when I see bearings like this they get tossed and replaced on motorcycles. When I machine I use the bearing to get the perfect fit. It is now perfect. Does it cost much more to get +0.000/-0.002? I would rather order it 0.624 nom with +/- 0.001 that way they will aim for a tighter clearance. So what Jim was saying that it was in tolerance means it can be 0.004 under?

 

[Pablo]

The shafts are not undersized. Please they are within specification. Why do you struggle with that? .621 is the minimum so suppliers are good enough in 2020 to control right at that line and save material. Goes the same with most all material items.

Vernier caliper? Easily off .001" yeah.

There is no standard 0.624" keyed shaft, custom made will be expensive.

I am getting quotes now on .625 +000 -002", TGP 1045 Steel The process is not instant and some places were off for Columbus Day

 

[wolframore]

True Ive worked for a stainless steel mill and when material is sold by weight it seems the distributors (I won’t mention names) cheat by going to the absolute minimum within the gauge. But the manufacturers who care about their products had tighter requirements. We didn’t mind they purchased enough and they got a great price. I handled these contracts as well as all the spec reviews. Negotiate with annual projections and past volume. Good luck.

1045 with 2 under sounds like a great. I’m assuming 1045 will he heat treated. I hope it works out. Spread out over all the kits you will sell, a few bucks extra would be something I would pay for.