Author Topic: Carbonda fm936 Thoughts  (Read 372314 times)

Vipassana

Re: Carbonda fm936 Thoughts
« Reply #615 on: July 31, 2020, 02:10:04 AM »

carbonazza

Re: Carbonda fm936 Thoughts
« Reply #616 on: July 31, 2020, 04:00:24 AM »
...Given I ride a LARGE CS-218, should I consider a MED. or LAR. FM936?  That reach on the FM936 really worries me......
I learned here from David Arthur that you should get your normal size. The frame is for short stems only. The reach seems long, but as the seat angle is very steep you won't have such a long reach in real life. Just check eff. top tube. Also Carbonda recommends a seatpost without setback on this frame.

I made my drawings, I ride L for my MTB's but this time took a M, and should get the same effective top tube length with a 50mm or 60mm stem. I'm 5'10" with 35" legs.

carbonazza

Re: Carbonda fm936 Thoughts
« Reply #617 on: July 31, 2020, 04:07:15 AM »
... I went with what I know which is the XT...  But I heard the newer models have issues?...

What issues did you hear about ? I was planning to use the new version(Light, cheap and maybe more modularity than before), until your comment...
I built my previous bike about the same time as yours if I remember well, and have the Hope Race Evo X2 that still run fine.
I was hesitating between reusing or getting a new set of Hope's brakes, or the XT.

Colt__Seavers

Re: Carbonda fm936 Thoughts
« Reply #618 on: July 31, 2020, 08:02:47 AM »
Carbon or Aluminium rims?

Carbon
Then it's quite obvious this happened. With an electrically conducive medium like tubeless milk (electrolyte) there is a electrochemical corrosion going on. The Aluminum has a lower valence than the carbon so there is a constant ions transport from aluminum to carbon. Ths makes the aluminum corrode. It really dissolves. This can even lead to a complete nipple head failure and the ripping apart of nipple head and rest of nipple. This also happens with water, but it takes longer as water is faster evaporating like the persistent milk.
ALWAYS use brass nipples when buildung carbon rims you want to run tubeless and you want to ride your bike also in wet weather conditions. Salt from the winter times, even help the corrosion.
The avaiation learned it the hard way, as they were placing aluminum ribs on bare carbon. Nw they are using a insolation layer between the both like glassfiber.
« Last Edit: July 31, 2020, 08:09:37 AM by Colt__Seavers »

carbonazza

Re: Carbonda fm936 Thoughts
« Reply #619 on: July 31, 2020, 08:31:58 AM »
...wouldn't it be nice to have a huge database with all available component options to choose from? with all weights? ...
r2-bike.com weight themselves almost all what they sell , and you can sort by weight.
Say you look for a stem, sort it by weight, and go down, until you reach what your wallet is ready to pay.
bike24.com, and bike-component.de have generally the constructor's weight, but no sorting option.

For older or second hand components, there is a list of components on Weight Weenies' site, but I'm not sure it is updated regularly.


Then it's quite obvious this happened. With an electrically conducive medium like tubeless milk (electrolyte) there is a electrochemical corrosion going on. The Aluminum has a lower valence than the carbon so there is a constant ions transport from aluminum to carbon.
Can't the quality of anodisation help ?
Along the years, I've had dissolved PILAR nipples, but the black SAPIM never did that.


Colt__Seavers

Re: Carbonda fm936 Thoughts
« Reply #620 on: July 31, 2020, 09:05:48 AM »
...wouldn't it be nice to have a huge database with all available component options to choose from? with all weights? ...
r2-bike.com weight themselves almost all what they sell , and you can sort by weight.
Say you look for a stem, sort it by weight, and go down, until you reach what your wallet is ready to pay.
bike24.com, and bike-component.de have generally the constructor's weight, but no sorting option.

For older or second hand components, there is a list of components on Weight Weenies' site, but I'm not sure it is updated regularly.


Then it's quite obvious this happened. With an electrically conducive medium like tubeless milk (electrolyte) there is a electrochemical corrosion going on. The Aluminum has a lower valence than the carbon so there is a constant ions transport from aluminum to carbon.
Can't the quality of anodisation help ?
Along the years, I've had dissolved PILAR nipples, but the black SAPIM never did that.

Do you think I'm new in the business ;)
Sure thing I know about r2 and bike24. Great resources. But again an overall database like a "bike configurator" would be neat.

Yeah anodization helps! It all comes down to the method and to the thickness of the aluminum Oxyd layer which gets created by the method.

lRaphl

Re: Carbonda fm936 Thoughts
« Reply #621 on: July 31, 2020, 09:32:13 AM »
Yeah anodization helps! It all comes down to the method and to the thickness of the aluminum Oxyd layer which gets created by the method.

No holes in rim bed also help a ton. A bit of a bitch to build or change spokes/nipples when they break but also no need to tape the rim and no chances of sealant going between the tape and the rim up to the nipples.

Colt__Seavers

Re: Carbonda fm936 Thoughts
« Reply #622 on: July 31, 2020, 10:22:11 AM »
Yeah anodization helps! It all comes down to the method and to the thickness of the aluminum Oxyd layer which gets created by the method.

No holes in rim bed also help a ton. A bit of a bitch to build or change spokes/nipples when they break but also no need to tape the rim and no chances of sealant going between the tape and the rim up to the nipples.
That's for dang sure. I wanted those rims this time, but as I build them my own, I prefer not to have to fiddle that much with all those nipples. As brass nor aluminum are magnetic, this won't help you here

Vipassana

Re: Carbonda fm936 Thoughts
« Reply #623 on: July 31, 2020, 11:34:10 AM »
What issues did you hear about ? I was planning to use the new version(Light, cheap and maybe more modularity than before), until your comment...
I built my previous bike about the same time as yours if I remember well, and have the Hope Race Evo X2 that still run fine.
I was hesitating between reusing or getting a new set of Hope's brakes, or the XT.

Nothing specific, so don't change course based on my comment.  I was getting that from a local Facebook group (of mostly gravity guys) when we were discussing brakes.  People mentioned XTs and there was a lot of comments suggesting alternatives and belly aching about the XTs.  Which surprised me because my older set has been honestly flawless.  So I was left wondering if later versions missed the mark.

Vipassana

Re: Carbonda fm936 Thoughts
« Reply #624 on: July 31, 2020, 11:43:12 AM »
Then it's quite obvious this happened. With an electrically conducive medium like tubeless milk (electrolyte) there is a electrochemical corrosion going on. The Aluminum has a lower valence than the carbon so there is a constant ions transport from aluminum to carbon. Ths makes the aluminum corrode. It really dissolves. This can even lead to a complete nipple head failure and the ripping apart of nipple head and rest of nipple. This also happens with water, but it takes longer as water is faster evaporating like the persistent milk.
ALWAYS use brass nipples when buildung carbon rims you want to run tubeless and you want to ride your bike also in wet weather conditions. Salt from the winter times, even help the corrosion.
The avaiation learned it the hard way, as they were placing aluminum ribs on bare carbon. Nw they are using a insolation layer between the both like glassfiber.

Awesome info.  Any you're right.  The tips of the nipples were nearly gone.  Putting a screw driver in them was not possible as the slot was missing in most cases.  I'm surprised I had not had complete failures up to that point.  I think the stainless steel washers used were the only thing holding them in.  These were black Sapim aluminum.  6 years old.  Maybe 2-3 rim tape failures in the time I had them, so plenty of sealant contamination opportunities.

Brass ones arrived Monday and brass ones will be used on all future wheels as well.  Because this was a PITA and cost me $114 in spokes.

That's for dang sure. I wanted those rims this time, but as I build them my own, I prefer not to have to fiddle that much with all those nipples. As brass nor aluminum are magnetic, this won't help you here

I read that people thread a tiny steel bolt into the nipple and then use a magnet to pull them into the holes.  Seems like a PITA.  But I might try hole-less with the next set I built up.
« Last Edit: July 31, 2020, 11:49:19 AM by Vipassana »

Colt__Seavers

Re: Carbonda fm936 Thoughts
« Reply #625 on: July 31, 2020, 11:54:43 AM »
Then it's quite obvious this happened. With an electrically conducive medium like tubeless milk (electrolyte) there is a electrochemical corrosion going on. The Aluminum has a lower valence than the carbon so there is a constant ions transport from aluminum to carbon. Ths makes the aluminum corrode. It really dissolves. This can even lead to a complete nipple head failure and the ripping apart of nipple head and rest of nipple. This also happens with water, but it takes longer as water is faster evaporating like the persistent milk.
ALWAYS use brass nipples when buildung carbon rims you want to run tubeless and you want to ride your bike also in wet weather conditions. Salt from the winter times, even help the corrosion.
The avaiation learned it the hard way, as they were placing aluminum ribs on bare carbon. Nw they are using a insolation layer between the both like glassfiber.

Awesome info.  Any you're right.  The tips of the nipples were nearly gone.  Putting a screw driver in them was not possible as the slot was missing in most cases.  I'm surprised I had not had complete failures up to that point.  I think the stainless steel washers used were the only thing holding them in.  These were black Sapim aluminum.  6 years old.  Maybe 2-3 rim tape failures in the time I had them, so plenty of sealant contamination opportunities.

Brass ones arrived Monday and brass ones will be used on all future wheels as well.  Because this was a PITA and cost me $114 in spokes.

That's for dang sure. I wanted those rims this time, but as I build them my own, I prefer not to have to fiddle that much with all those nipples. As brass nor aluminum are magnetic, this won't help you here

I read that people thread a tiny steel bolt into the nipple and then use a magnet to pull them into the holes.  Seems like a PITA.  But I might try hole-less with the next set I built up.
Holy moly, these are looking bad. You had black sapim aluminum spacers under the nipple heads? And these looking great? Are you sure they are aluminum? You could try a magnet on them to find out.

lRaphl

Re: Carbonda fm936 Thoughts
« Reply #626 on: July 31, 2020, 12:03:06 PM »
I read that people thread a tiny steel bolt into the nipple and then use a magnet to pull them into the holes.  Seems like a PITA.

This is exactly what I'm doing and it's working well as long as you have a strong magnet. You need to remove the valve stem to insert the nipples in the rim but you would have to do that also if you were to remove the tape to change a nipple so it's no big deal.

Vipassana

Re: Carbonda fm936 Thoughts
« Reply #627 on: July 31, 2020, 12:06:14 PM »
Holy moly, these are looking bad. You had black sapim aluminum spacers under the nipple heads? And these looking great? Are you sure they are aluminum? You could try a magnet on them to find out.

I wasn't very clear on that point.  Nipples were aluminum, black Sapim.  But under them were some stainless steel washers/spacers; definitely steel, probably stainless given that they had zero corrosion and could be removed from the nipples easily.

Should I reuse these spacers on the new brass nipples?

Colt__Seavers

Re: Carbonda fm936 Thoughts
« Reply #628 on: July 31, 2020, 01:19:59 PM »
Holy moly, these are looking bad. You had black sapim aluminum spacers under the nipple heads? And these looking great? Are you sure they are aluminum? You could try a magnet on them to find out.

I wasn't very clear on that point.  Nipples were aluminum, black Sapim.  But under them were some stainless steel washers/spacers; definitely steel, probably stainless given that they had zero corrosion and could be removed from the nipples easily.

Should I reuse these spacers on the new brass nipples?
Only if the rim recommends those. Normally the case with thin aluminum rims

adroitrider

Re: Carbonda fm936 Thoughts
« Reply #629 on: July 31, 2020, 02:12:09 PM »
XL SL frame came in at 2,012g. Everything was removed except for the cable liners.

Here are the weights of the attached items.

I will consider a RWC Shock Eye Needle Bearing Kit

Frame, shock, and all frame bits is 2,329g.
« Last Edit: July 31, 2020, 02:16:19 PM by adroitrider »