Carbon Bars

I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be OK but no more two piece carbon setups for me. I guess this is why the pro's use the one piece bar/stem.

On 10/31/2019 4:16 PM, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be OK but no more two piece carbon setups for me. I guess this is why the pro's use the one piece bar/stem.


Glad you were not injured.

Modern light stems/bars, and not only carbon, need careful
setup with carbon paste, even torque to manufacturer
specified values and lubricated threads except where
manufacturer specifies dry or threadlock. Also, take care to
keep the faceplate evenly spaced top and bottom (and side to
side on a four-bolt) during torque sequence and especially
at final torque. Insufficient or uneven torque is bad but
overtorque is equally bad or worse. Get a proper scaled or
click wrench if you don't have one already.

To repeat, modern ultralight aluminum stems share many
foibles with carbon stems. The days of 'crank it tight and
go ride' have ended.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Thursday, October 31, 2019 at 2:16:37 PM UTC-7, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be OK but no more two piece carbon setups for me. I guess this is why the pro's use the one piece bar/stem.

What carbon bars do you have? Do they have a slick center-section? Are they undersized? I've had carbon bars on one bike or another for fifteen years with no problems. Slippage is not an inherent quality of carbon bars.

-- Jay Beattie.

On Thursday, October 31, 2019 at 3:01:18 PM UTC-7, AMuzi wrote:
On 10/31/2019 4:16 PM, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be OK but no more two piece carbon setups for me. I guess this is why the pro's use the one piece bar/stem.


Glad you were not injured.

Modern light stems/bars, and not only carbon, need careful
setup with carbon paste, even torque to manufacturer
specified values and lubricated threads except where
manufacturer specifies dry or threadlock. Also, take care to
keep the faceplate evenly spaced top and bottom (and side to
side on a four-bolt) during torque sequence and especially
at final torque. Insufficient or uneven torque is bad but
overtorque is equally bad or worse. Get a proper scaled or
click wrench if you don't have one already.

To repeat, modern ultralight aluminum stems share many
foibles with carbon stems. The days of 'crank it tight and
go ride' have ended.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

I am most certainly NOT a fan of precise torqueing. That was what I originally did with this bar and it promptly not only rotated on the first hard bump but it rubbed all of the grit on the bar interface off. Tightening it to what I felt was correct greatly improved the "hold" but it too slipped. Then I added carbon paste as directed and while it took a hell of a bump it too slipped though nowhere near as badly as the initially installed and torqued.

This is similar to what my tubeless carbon wheels were doing - they were walking all over the road whenever I got over about 25 mph. After talking about it and you suggesting that I get the wheel checked by the wheel pro here, he said that the spoke tension if anything was a bit high.

I came home and pulled out the wheel stand and spoke tools and doubled the spoke tension though they were still less than the almost identical carbon clincher wheels had. Now I don't have any steering problems at all with the tubeless wheels. And making 40 mph descents around turns is perfectly stable though these wheels appear to be more sensitive to cross winds than the clinchers with very high tension are. But I can't tighten these any more because the spokes are a bit too long.

On Thursday, October 31, 2019 at 5:35:23 PM UTC-7, jbeattie wrote:
On Thursday, October 31, 2019 at 2:16:37 PM UTC-7, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be OK but no more two piece carbon setups for me. I guess this is why the pro's use the one piece bar/stem.

What carbon bars do you have? Do they have a slick center-section? Are they undersized? I've had carbon bars on one bike or another for fifteen years with no problems. Slippage is not an inherent quality of carbon bars.

-- Jay Beattie.

I think that the real problem is that they are built to minimum weight more than anything else. I think I wouldn't have any problem with a bar built to these standards if it had a molded in stem. For awhile you could get those pretty cheap but now you're looking at $200 a pop.

On Friday, November 1, 2019 at 10:16:22 PM UTC+1, Tom Kunich wrote:
On Thursday, October 31, 2019 at 3:01:18 PM UTC-7, AMuzi wrote:
On 10/31/2019 4:16 PM, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be OK but no more two piece carbon setups for me. I guess this is why the pro's use the one piece bar/stem.


Glad you were not injured.

Modern light stems/bars, and not only carbon, need careful
setup with carbon paste, even torque to manufacturer
specified values and lubricated threads except where
manufacturer specifies dry or threadlock. Also, take care to
keep the faceplate evenly spaced top and bottom (and side to
side on a four-bolt) during torque sequence and especially
at final torque. Insufficient or uneven torque is bad but
overtorque is equally bad or worse. Get a proper scaled or
click wrench if you don't have one already.

To repeat, modern ultralight aluminum stems share many
foibles with carbon stems. The days of 'crank it tight and
go ride' have ended.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

I am most certainly NOT a fan of precise torqueing. That was what I originally did with this bar and it promptly not only rotated on the first hard bump but it rubbed all of the grit on the bar interface off. Tightening it to what I felt was correct greatly improved the "hold" but it too slipped. Then I added carbon paste as directed and while it took a hell of a bump it too slipped though nowhere near as badly as the initially installed and torqued.

Not a fan of precise torquing? What does that mean? You are a fan of imprecise torquing? That is weird for someone with a technical background. If my CF handlebars slipped and the grit of the interface was rubbed off I would consider the handlebar as not safe anymore and replaced it.
I build my bike with a CF handlebar 5 years ago. Torqued it precise to spec and it never slipped. Never touched it after the initial build


Lou

On Friday, November 1, 2019 at 10:18:50 PM UTC+1, Tom Kunich wrote:
On Thursday, October 31, 2019 at 5:35:23 PM UTC-7, jbeattie wrote:
On Thursday, October 31, 2019 at 2:16:37 PM UTC-7, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be OK but no more two piece carbon setups for me. I guess this is why the pro's use the one piece bar/stem.

What carbon bars do you have? Do they have a slick center-section? Are they undersized? I've had carbon bars on one bike or another for fifteen years with no problems. Slippage is not an inherent quality of carbon bars..

-- Jay Beattie.

I think that the real problem is that they are built to minimum weight more than anything else. I think I wouldn't have any problem with a bar built to these standards if it had a molded in stem. For awhile you could get those pretty cheap but now you're looking at $200 a pop.

If you get nervous about 200 dollar for a one piece CF handlebar-stem combo I wonder what CF handlebar you use now. A CF handlebar alone from a respectable manufacturer already cost over 200 euro on this side of the pond:

https://www.bike-components.de/en/co...aterial=carbon


Lou

On Saturday, November 2, 2019 at 9:42:01 AM UTC-7, wrote:
On Friday, November 1, 2019 at 10:18:50 PM UTC+1, Tom Kunich wrote:
On Thursday, October 31, 2019 at 5:35:23 PM UTC-7, jbeattie wrote:
On Thursday, October 31, 2019 at 2:16:37 PM UTC-7, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.

wrote:
On Friday, November 1, 2019 at 10:16:22 PM UTC+1, Tom Kunich wrote:
On Thursday, October 31, 2019 at 3:01:18 PM UTC-7, AMuzi wrote:
On 10/31/2019 4:16 PM, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem
with those super narrow front pieces that I was using with the carbon
bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next
time I hit a good bump the damn thing rotated again. I nearly lost
control when this happened but luckily I was able to retain enough
control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact
plate. The other day on a fast descent I again hit a large bump in a
turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and
got some and applied it as the shop recommended. This seemed to make a
difference until this morning: I was almost at my coffee stop and had
been pushing it so was fairly exhausted and I had a string of cars
behind me on a narrow section of road. I attempted to cut to the
inside of a turn to allow these cars to race by since they had to get
to the stop sign a block away in a hurry. On the inside of the turn
was one of those really rough spots that is hidden in bad asphalt and
as I hit it my bars rotated yet again. I kept control of the bike but
just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use
carbon bars. At the coffee stop the owner has a set of tools for the
bikes since he gets a lot of groups in there. (This morning was pretty
cold and my groves turned out to be too tight so my left hand had lost
feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then
tightened the bar I pushed on it and was quite surprised to see the bar flex.

Now they do make carbon bar/stem one piece combination that would be
OK but no more two piece carbon setups for me. I guess this is why the
pro's use the one piece bar/stem.


Glad you were not injured.

Modern light stems/bars, and not only carbon, need careful
setup with carbon paste, even torque to manufacturer
specified values and lubricated threads except where
manufacturer specifies dry or threadlock. Also, take care to
keep the faceplate evenly spaced top and bottom (and side to
side on a four-bolt) during torque sequence and especially
at final torque. Insufficient or uneven torque is bad but
overtorque is equally bad or worse. Get a proper scaled or
click wrench if you don't have one already.

To repeat, modern ultralight aluminum stems share many
foibles with carbon stems. The days of 'crank it tight and
go ride' have ended.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

I am most certainly NOT a fan of precise torqueing. That was what I
originally did with this bar and it promptly not only rotated on the
first hard bump but it rubbed all of the grit on the bar interface off.
Tightening it to what I felt was correct greatly improved the "hold" but
it too slipped. Then I added carbon paste as directed and while it took
a hell of a bump it too slipped though nowhere near as badly as the
initially installed and torqued.

Not a fan of precise torquing? What does that mean? You are a fan of
imprecise torquing? That is weird for someone with a technical
background. If my CF handlebars slipped and the grit of the interface was
rubbed off I would consider the handlebar as not safe anymore and replaced it.
I build my bike with a CF handlebar 5 years ago. Torqued it precise to
spec and it never slipped. Never touched it after the initial build


Lou


I didn’t build my bike myself but I bought it from a shop I trust. Never
had any problems with the bar slipping. Never really heard of this as an
issue...

On Saturday, November 2, 2019 at 9:39:06 AM UTC-7, wrote:
On Friday, November 1, 2019 at 10:16:22 PM UTC+1, Tom Kunich wrote:
On Thursday, October 31, 2019 at 3:01:18 PM UTC-7, AMuzi wrote:
On 10/31/2019 4:16 PM, Tom Kunich wrote:
I have a carbon bar on the Lemond. Initially I had an aluminum stem with those super narrow front pieces that I was using with the carbon bar. That was not a good idea.

I hit a good bump and the bar rotated.

So I got an Easton carbon stem with a wider contact surface and next time I hit a good bump the damn thing rotated again. I nearly lost control when this happened but luckily I was able to retain enough control to bring it to a stop.

Then I bought yet another Chinese stem that had a full frontal contact plate. The other day on a fast descent I again hit a large bump in a turn and again nearly lost it.

I remembered Andrew and Jay talking about "carbon paste" so I went and got some and applied it as the shop recommended. This seemed to make a difference until this morning: I was almost at my coffee stop and had been pushing it so was fairly exhausted and I had a string of cars behind me on a narrow section of road. I attempted to cut to the inside of a turn to allow these cars to race by since they had to get to the stop sign a block away in a hurry. On the inside of the turn was one of those really rough spots that is hidden in bad asphalt and as I hit it my bars rotated yet again. I kept control of the bike but just by the skin of my teeth.

Back to Aluminum bars for me. And I suggest that none of you use carbon bars. At the coffee stop the owner has a set of tools for the bikes since he gets a lot of groups in there. (This morning was pretty cold and my groves turned out to be too tight so my left hand had lost feeling and I couldn't shift - he asked me if I needed a hug (no he isn't))

In any case, after I loosened, rotated back into position and then tightened the bar I pushed on it and was quite surprised to see the bar flex.