Jump to content

10 mil CRANK


stroking

Recommended Posts

ok my boss has a vito's 10mil weld crank that has separated 3 times and working on the forth!!!

 

this is a full drag bike with everything except straight cut gears

 

and it happens after only 3-5 passes

 

 

 

 

what CAUSES these cranks to do this......compression/timing/rpms/pto gears/????????

 

do the billet cranks have the same problem

 

seems like 10mil is a unlucky stroke!

 

 

Link to comment
Share on other sites

  • Replies 62
  • Created
  • Last Reply

Top Posters In This Topic

Are you thinking its putting side load on the crank without straight cuts?What side seems to come apart and is it the same everytime?

both sides have come apart ... not at the same time

 

and whats the difference in a 115 and 120 rod 10mil ?

 

 

is the 120 stronger ? i know the case is trenched deeper for the 120

 

 

Link to comment
Share on other sites

Unless your crank is made of butter, there is an issue somewhere else.

I've seen more billets break than forged, and there's a LOT more forged out there.

 

If they are separating after being welded...either the welder isn't doing the job correctly, or there is a MUCH bigger problem in the motor, it's mating/bearing surfaces, something out of balance/true, etc.

 

Now a days, all the cranks come from pretty much the same place, just different names on the box.

 

A 120 rod is not as common for the 10 mil. There are a few 10 mil cubs with that rod, I'm not sure about the twister, and the super cubs (72mm bore) might use it.

 

The 120 rod is available in a big pin or small pin. If it's the small pin, no extra trenching is required. The big pin has a larger bearing so that's why it needs to be trenched a hair deeper.

 

That being said, Vito's doesn't offer the 120mm rod that I saw...

 

I have a Vito's 10 mil in mine. It's a quality piece. I watched my buddy unbox 4 of them, NONE of them needed to be trued. He just welds all the way around the pin.

I also like their new cub pistons....

 

While I don't agree with some of their marketing hype...I do think their products now a days are quality.

 

Separating a crank 3 times...it's possible you got a bad one, but I'd be looking else where to be honest.

Link to comment
Share on other sites

  • 2 weeks later...

Please don't take this as me being a smart ass...

 

If you put a different brand crank in the same set of cases with the same setup and it doesn't fail, I will 100% support you in saying the cranks you got from Vitos are junk.

 

Until then, I'm convinced it is something else...and any of the cranks coming out of Taiwan would have the same issue.

Link to comment
Share on other sites

here you go.....i didnt remove it yet but you can see whats going on here.......this is the 4TH time this year a vito 10mil has done this 3 times in a different motor and once in this one!

 

i was told the flywheel can cause this as well as over reving

IMG00443-20101116-1937-1.jpg

 

 

 

IMG00442-20101116-1937.jpg

 

IMG00443-20101116-1937.jpg

Edited by stroking
Link to comment
Share on other sites

I too agree that Vito's cranks are fucking junk. The one that went in my 10mm cub motor after I sold it to bbcmudtruck came apart twice. The first time we sent it back and they fixed it for free and sent it back for free. The second time he sold the motor and washed his hands of it. Vito's absolutely sells fucking junk 10mm cranks.

Link to comment
Share on other sites

Should never happen....

Are you guys rewelding them?

Have you tried different flywheels? What kind of bearings are on them?

 

I can see if they explode, but if they keep separating like that, different cranks no less, there is another problem.

 

Yes, flywheel and too much over rev could certainly cause that....

 

I only put 40 to 50 passes on my bike this year...I have my buddy weld all the way around the pin, and no issues like that.

 

Try another brand crank, but I have a feeling you'll be seeing the same thing again...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...