Author Topic: Carbonda fm936 Thoughts  (Read 505080 times)

SlappinBerms

Re: Carbonda fm936 Thoughts
« Reply #1440 on: February 22, 2021, 08:24:52 PM »
It's called a "Sex bolt" You should be able to find them online if your local hardware store doesn't have them. 

I know, I thought it was a joke the first time I read it in another thread here somewhere about 6 months ago but that is genuinely what you will find them listed under.  https://en.wikipedia.org/wiki/Sex_bolt

Heck yeah! thank you very much emu26!

Medico

Re: Carbonda fm936 Thoughts
« Reply #1441 on: February 23, 2021, 09:43:07 AM »
Soooo.... Year later...
I was thinking to remove the bottombracked because of a creak since the last 2 rides.
But no...hell no...not the same shit!
A lot of play at the lower pivot point, drive side. Can move it almost a cm(0,5 up and same down)

ilyamaksimov

Re: Carbonda fm936 Thoughts
« Reply #1442 on: February 23, 2021, 09:53:05 AM »
Soooo.... Year later...
I was thinking to remove the bottombracked because of a creak since the last 2 rides.
But no...hell no...not the same shit!
A lot of play at the lower pivot point, drive side. Can move it almost a cm(0,5 up and same down)

Did you feel any backlash while driving?

Medico

Re: Carbonda fm936 Thoughts
« Reply #1443 on: February 23, 2021, 09:57:41 AM »
Did you feel any backlash while driving?

First I tought it was because of a soft rear tire, but wasn't. Didn't care much, because it was a bit muddy... But now I know it, it al make sence...last year I did notice it because of because of wobly tail.

ilyamaksimov

Re: Carbonda fm936 Thoughts
« Reply #1444 on: February 23, 2021, 10:02:30 AM »
First I tought it was because of a soft rear tire, but wasn't. Didn't care much, because it was a bit muddy... But now I know it, it al make sence...last year I did notice it because of because of wobly tail.

Is the frame still warranted?

and another question, can you film the backlash?
« Last Edit: February 23, 2021, 10:34:37 AM by ilyamaksimov »

Medico

Re: Carbonda fm936 Thoughts
« Reply #1445 on: February 23, 2021, 10:50:00 AM »
Is the frame still warranted?

Hopefully...its 1,5yr old

wfl3

Re: Carbonda fm936 Thoughts
« Reply #1446 on: February 23, 2021, 12:44:47 PM »

Pull the pivot pin out of the frame and measure the length, if it's much over 80mm you'll get play.   I got that info from Adam when I had a creak (thought it was BB as well) and found a bit of play in the lower pivot.  I just filed mine down to maybe 81mm and then everything snugged up and no play.  Been solid ever since.   I did order some new lower pivot hardware, but haven't needed to touch it yet.

Medico

Re: Carbonda fm936 Thoughts
« Reply #1447 on: February 23, 2021, 12:48:42 PM »
Pull the pivot pin out of the frame and measure the length, if it's much over 80mm you'll get play.   I got that info from Adam when I had a creak (thought it was BB as well) and found a bit of play in the lower pivot.  I just filed mine down to maybe 81mm and then everything snugged up and no play.  Been solid ever since.   I did order some new lower pivot hardware, but haven't needed to touch it yet.

Will check when @home...but the pics will tell otherwise I think..



wfl3

Re: Carbonda fm936 Thoughts
« Reply #1448 on: February 23, 2021, 02:46:10 PM »

Mine has the pivot pin inserted the other way, the bolt piece is on the non-drive side on mine - and that's where I had a small amount of play that was causing the creaks.

The problem was the pivot pin was too long so even with the bolt side tightened to the max there was still movement. I rode it for about 4-6 months before it started making noise and then I noticed the pivot had some play AFTER redoing the BB and the creak was still there.  Once I shortened the pivot pin (just filed it down to length) I could then tighten the bolt to spec and actually feel it was apply pressure, the pivot play was gone and so was the noise.

Of course your issue could be completely diff, but an easy check.  The spare pivot pin I ordered was exactly 80mm, I guess some of the frames went out with out of spec hardware?

zilcho

Re: Carbonda fm936 Thoughts
« Reply #1449 on: February 23, 2021, 03:06:32 PM »
Mine has the pivot pin inserted the other way, the bolt piece is on the non-drive side on mine - and that's where I had a small amount of play that was causing the creaks.

The problem was the pivot pin was too long so even with the bolt side tightened to the max there was still movement. I rode it for about 4-6 months before it started making noise and then I noticed the pivot had some play AFTER redoing the BB and the creak was still there.  Once I shortened the pivot pin (just filed it down to length) I could then tighten the bolt to spec and actually feel it was apply pressure, the pivot play was gone and so was the noise.

Of course your issue could be completely diff, but an easy check.  The spare pivot pin I ordered was exactly 80mm, I guess some of the frames went out with out of spec hardware?

I think this is the source of my occasional creaking, too.  Did you order the spare from Carbonda or source it elsewhere?  When I was trying to find the creak I had pulled every bolt out but was unable to get the pin to move laterally, only spin in place, and then stripped the bolt head reinstalling.  It holds for now but needs replacing.

wfl3

Re: Carbonda fm936 Thoughts
« Reply #1450 on: February 23, 2021, 03:24:17 PM »

I ordered it from Carbonda - like $15 shipped.  Mainly ordered it because I was afraid I was gonna strip my bolt head out as well trying to get it tight enough, mine would spin too when tightened to almost the point of stripping.  I could feel the movement in the pivot still if I squeezed the non-drive crank arm against the chainstay and put my finger on the pivot.  Once I shortened that pivot pin like Adam suggested it fully tightened with ease and didn't spin and most importantly didn't creak anymore.

Medico

Re: Carbonda fm936 Thoughts
« Reply #1451 on: February 23, 2021, 03:58:59 PM »
I ordered it from Carbonda - like $15 shipped.  Mainly ordered it because I was afraid I was gonna strip my bolt head out as well trying to get it tight enough, mine would spin too when tightened to almost the point of stripping.  I could feel the movement in the pivot still if I squeezed the non-drive crank arm against the chainstay and put my finger on the pivot.  Once I shortened that pivot pin like Adam suggested it fully tightened with ease and didn't spin and most importantly didn't creak anymore.

I do so hope you're right...I was so fedup about it...I allmost ordered a tranition spur frameset ::)

theirishrider

Re: Carbonda fm936 Thoughts
« Reply #1452 on: February 23, 2021, 04:07:07 PM »
I have exactly the same issue. The male of the bolt was entering from the driveside. The bolt is aluminum so it doesn't bite as much as a steel bolt. The solution was to make the female enter from the drive side, locktite the male bolt with plumber's ptfe tape. If this bolt comes out during a ride, say goodbye to your frame ahaha

Futhermore, I believe the female side should be a little longer. It doesnt extend all the way into the interference fit area of the chainstay hole. You can see this in the photo.

I would like to install a stainless bolt however I'm struggling to find one. If anyone find a source please do let me know! Thanks
« Last Edit: February 23, 2021, 04:09:07 PM by theirishrider »

adroitrider

Re: Carbonda fm936 Thoughts
« Reply #1453 on: February 23, 2021, 04:24:45 PM »
I’m gonna pull my bolt and measure it. I hope they started shipping the frame with the shorter bolt at some point and we all don’t have this problem.

victorike

Re: Carbonda fm936 Thoughts
« Reply #1454 on: February 24, 2021, 02:45:44 AM »
Today I have reviewed and also movement here on this axis ... I will clean and disassemble ... any solution?