so how tight are you getting those bolts?

[Ant]

I got my first set of aero bars, and slapped them onto my bars this afternoon. The bolts came
pre-prepped with loctite, I screwed them down hard, and then tried to move the aero bars. With not
much effort, I could move them up and down. This worried me a lot, so I pulled the bolts out,
greased them, and cranked them down hard. Then, when I tried again, with a strong shove, the
aerobars/handlebar rotate within the stem clamp (a coda threaded with a 2-bolt faceplate, i assume
aluminum). It does take a good bit of force to do this, but the fact remains that I can do it. From
on the bike, I can not push the bars down, but with effort can pull them up, rotating the entire bar
assembly within the clamp. I know I greased those stem bolts when I put the bars in a month ago, and
I've tightened them as much as I can with my 6" allen wrench and a good bit of muscling. I'm at the
point where im worried abotu stripping either the bolt threads or the allen hole in the bolt. The
allen key has already slipped out once under pressure.

What gives? Are aerobars always going to move if you try? If i push down on them really hard, the
bar assembly stays in place and the rear wheel lifts. But if i pull up on them with weight in the
saddle, I rotate the bar assembly up, and I dont want to think about that happening every time I
want to sprint.

what should I do?

 

[Sheldon Brown]

ant wrote:
> I got my first set of aero bars, and slapped them onto my bars this afternoon. The bolts came
> pre-prepped with loctite, I screwed them down hard, and then tried to move the aero bars. With not
> much effort, I could move them up and down. This worried me a lot, so I pulled the bolts out,
> greased them, and cranked them down hard. Then, when I tried again, with a strong shove, the
> aerobars/handlebar rotate within the stem clamp (a coda threaded with a 2-bolt faceplate, i assume
> aluminum). It does take a good bit of force to do this, but the fact remains that I can do it.
> From on the bike, I can not push the bars down, but with effort can pull them up, rotating the
> entire bar assembly within the clamp. I know I greased those stem bolts when I put the bars in a
> month ago, and I've tightened them as much as I can with my 6" allen wrench and a good bit of
> muscling. I'm at the point where im worried abotu stripping either the bolt threads or the allen
> hole in the bolt. The allen key has already slipped out once under pressure.
>
> What gives? Are aerobars always going to move if you try? If i push down on them really hard, the
> bar assembly stays in place and the rear wheel lifts. But if i pull up on them with weight in the
> saddle, I rotate the bar assembly up, and I dont want to think about that happening every time I
> want to sprint.
>
> what should I do?

This is a poor application for Loctite. The bolt heads and the undersides of the heads should be
greased. This will result in a greater tightening force for a given amount of torque, and reduce the
risk of stripping the threads.

Some handlebars, especailly heat treated ones, are slipperier than others.

A reliable fix is to sandwich a little piece of sandpaper inside the clamp area for better traction.

Sheldon "You Do NOT Want These To Slip!" Brown +-----------------------------------------+
| A ship in the harbor is safe, but | that is not what ships are built for. | --John A. Shedd |
+-----------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

[Kapers]

Hey Anthony. My solution would be to thoroughly clean all surfaces (inside of stem and clamping
surface of handlebar) to remove all grease/oil and oxidation.... then (if either of the surfaces are
smooth to the touch, such as painted or "clear anodised") sand the areas with really fine sandpaper
or steel wool. You don't want to remove material, or reduce the clamping area by knurling the
areas... just take the shine off like you would when scuffing a paintjob to apply another coat. My
easton EA-70 bars were extremely slippy until I did this (and even then I had to quit using my
favorite Titec Ti 1" quilled stem as the clamp still would not tighten firmly enough). Sheldon's
advice works good too... I used a similar technique on quite a few bars at the ITU event in Edmonton
last year when we did the tech inspections..... nothing ruins a triathelete's weekend like having to
remove his aero bars because they did not meet inspection or they stripped threads trying to get
them to stay put. Good luck and let us know how it turned out. Keith.

"The knack lies in learning to throw yourself
- at the ground and miss" Douglas Adams.

"ant" <[email protected]> wrote in message
news:[email protected]...
> I got my first set of aero bars, and slapped them onto my bars this afternoon. The bolts came
> pre-prepped with loctite, I screwed them down hard, and then tried to move the aero bars. With not
> much effort, I could move them up and down. This worried me a lot, so I pulled the bolts out,
> greased them, and cranked them down hard. Then, when I tried again, with a strong shove, the
> aerobars/handlebar rotate within the stem clamp (a coda threaded with a 2-bolt faceplate, i assume
> aluminum). It does take a good bit of force to do this, but the fact remains that I can do it.
> From on the bike, I can not push the bars down, but with effort can pull them up, rotating the
> entire bar assembly within the clamp. I know I greased those stem bolts when I put the bars in a
> month ago, and I've tightened them as much as I can with my 6" allen wrench and a good bit of
> muscling. I'm at the point where im worried abotu stripping either the bolt threads or the allen
> hole in the bolt. The allen key has already slipped out once under pressure.
>
> What gives? Are aerobars always going to move if you try? If i push down on them really hard, the
> bar assembly stays in place and the rear wheel lifts. But if i pull up on them with weight in the
> saddle, I rotate the bar assembly up, and I dont want to think about that happening every time I
> want to sprint.
>
> what should I do?

 

[Peter Cole]

"ant" <[email protected]> wrote in message
news:[email protected]...
> I got my first set of aero bars, and slapped them onto my bars this
>
> What gives? Are aerobars always going to move if you try?

> I dont want to think about that happening every time I want to sprint.
>
> what should I do?

Don't sprint on the bars. Seriously, you don't want to push or pull heavily on the ends of the
aerobars, they're not designed for that. Your weight should be balanced so that there is little or
no torque on the aerobars.

 

[Paul Kopit]

Idid neither of those things. When I hit the pothole on a slight downgrade, the ambulance took me to
the hospital for a broken hip, left wrist and thumb. I haven't had the nerve to use the bars since.

On Fri, 07 Mar 2003 14:58:52 GMT, "Peter Cole" <[email protected]> wrote:

>Don't sprint on the bars. Seriously, you don't want to push or pull heavily on the ends of the
>aerobars, they're not designed for that. Your weight should be balanced so that there is little or
>no torque on the aerobars.

 

[Ant]

Sheldon Brown <[email protected]> wrote in message
news:<[email protected]>...
> ant wrote:
> > Are aerobars always going to move if you try? If i push down on them really hard, the bar
> > assembly stays in place and the rear wheel lifts. But if i pull up on them with weight in the
> > saddle, I rotate the bar assembly up, and I dont want to think about that happening every time I
> > want to sprint.
> >
> > what should I do?
>

Sheldon replied:

> This is a poor application for Loctite. The bolt heads and the undersides of the heads should be
> greased. This will result in a greater tightening force for a given amount of torque, and reduce
> the risk of stripping the threads.
>
> Some handlebars, especailly heat treated ones, are slipperier than others.
>
> A reliable fix is to sandwich a little piece of sandpaper inside the clamp area for better
> traction.

Thanks for the replies.

Sandpaper? shoudl the texture face in or out or it doesnt matter? The bar is scored with those
little lines, so im guessing the stem is the slippery part of this equation, ill try roughing it up
a little first, as the second poster suggested.

And good call on the loctite. I feel the same way, thats why i pulled the bolts and greased after my
initial try.

Thanks.

 

[Michael James A]

Hello all,

So I'm doing some training that requires me to climb some hills at 3%, 5% and 7%. O.K., so we all
know how to calculate the grade of a hill IF we know the elevation gain and the distance. Since I do
not know the elevation gains of my local hills, I was wondering if anyone has a better method of
finding out what the percent grade is of any hill?

I have heard that race officials get a topo map and calculate each hill, is there a better way? It
would be great if there was a county map that shows the percent grade of each street; is there
such a map?

Thanks for the help, Michael

 

[Peter Cole]

"Paul Kopit" <[email protected]> wrote in message > On Fri, 07 Mar 2003
14:58:52 GMT, "Peter Cole"
> <[email protected]> wrote:
>
> >Don't sprint on the bars. Seriously, you don't want to push or pull heavily
on
> >the ends of the aerobars, they're not designed for that. Your weight should
be
> >balanced so that there is little or no torque on the aerobars.

> Idid neither of those things. When I hit the pothole on a slight downgrade, the ambulance took
> me to the hospital for a broken hip, left wrist and thumb. I haven't had the nerve to use the
> bars since.

So, what happened to cause the crash? Did the bars rotate? Did you lose balance and control? Did
your wheel get shmushed? Was the pothole concealed under a puddle?

I pretty much ride aerobars any place I'd ride no-handed, it's only a bit more controllable
than that.

 

[Terry Morse]

Michael James Anderson wrote:

> I have heard that race officials get a topo map and calculate each hill, is there a better way? It
> would be great if there was a county map that shows the percent grade of each street; is there
> such a map?

Whny not measure them yourself? See how this inventive person did just that:

http://graphics.stanford.edu/~lucasp/bike-grade.html#Build
--
terry morse Palo Alto, CA http://www.terrymorse.com/bike/

 

[Jobst Brandt]

Michael James Anderson writes:

> So I'm doing some training that requires me to climb some hills at 3%, 5% and 7%. O.K., so we all
> know how to calculate the grade of a hill IF we know the elevation gain and the distance. Since I
> do not know the elevation gains of my local hills, I was wondering if anyone has a better method
> of finding out what the percent grade is of any hill?

You could use a Specialized "Speed Zone Pro" altimeter that gives the gradient as well as other
altitude functions.

A less high-tech method is to measure it directly using a meter stick, a level and a mm rule to
measure the vertical distance to the road from the end of the level meter stick whose other end is
resting on the road. This is highly accurate if you pick a representative piece of road, mm being
0.1 percent.

> I have heard that race officials get a topo map and calculate each hill, is there a better way? It
> would be great if there was a county map that shows the percent grade of each street; is there
> such a map?

That no good. There isn't enough resolution to do that and roads generally do not cross contour
lines at right angles, so interpolation gets in the way as well.

Jobst Brandt [email protected] Palo Alto CA

 

[Ray Heindl]

[email protected] wrote:

> Michael James Anderson writes:
>
>> I have heard that race officials get a topo map and calculate each hill, is there a better way?
>> It would be great if there was a county map that shows the percent grade of each street; is there
>> such a map?
>
> That no good. There isn't enough resolution to do that and roads generally do not cross contour
> lines at right angles, so interpolation gets in the way as well.

Unless the road is tilted side-to-side it has to cross the contours at a right angle. You just have
to look closely to see how the contour bends to meet the road. As to resolution, most topo maps in
my experience show contours every 10 feet, so the resolution would be +/- 10 feet or so, depending
on how well you can interpolate. Whether that's good enough depends on how high the hill is and how
precisely you need to know the grade. For a 7% grade on a 1:24,000 map, the contours are 0.07"
apart, which should allow interpolation to half a contour at each end. If the hill is 100 feet high,
that would be +/- 10%.
--
Ray Heindl (remove the X to reply)

 

[Jobst Brandt]

Ray Heindl writes:

>>> I have heard that race officials get a topo map and calculate each hill, is there a better way?
>>> It would be great if there was a county map that shows the percent grade of each street; is
>>> there such a map?

>> That no good. There isn't enough resolution to do that and roads generally do not cross contour
>> lines at right angles, so interpolation gets in the way as well.

> Unless the road is tilted side-to-side it has to cross the contours at a right angle. You just
> have to look closely to see how the contour bends to meet the road. As to resolution, most topo
> maps in my experience show contours every 10 feet, so the resolution would be +/- 10 feet or so,
> depending on how well you can interpolate. Whether that's good enough depends on how high the hill
> is and how precisely you need to know the grade. For a 7% grade on a 1:24,000 map, the contours
> are 0.07" apart, which should allow interpolation to half a contour at each end. If the hill is
> 100 feet high, that would be +/- 10%.

I think you are imagining a resolution and map design that doesn't occur. Contour lines are not made
to include road benches but rather the natural contour of the terrain, just as they don't go up
sloping lines of building roofs. I think a typical map such as the following are a good example.

http://topozone.com/map.asp?z=10&n=4133352&e=620349&s=25

Jobst Brandt [email protected] Palo Alto CA

 

[Kinkycowboy]

On 6 Mar 2003 20:29:56 -0800, [email protected] (ant) wrote:

>I got my first set of aero bars, and slapped them onto my bars this afternoon. The bolts came
>pre-prepped with loctite, I screwed them down hard, and then tried to move the aero bars. With not
>much effort, I could move them up and down. This worried me a lot, so I pulled the bolts out,
>greased them, and cranked them down hard. Then, when I tried again, with a strong shove, the
>aerobars/handlebar rotate within the stem clamp (a coda threaded with a 2-bolt faceplate, i assume
>aluminum). It does take a good bit of force to do this, but the fact remains that I can do it. From
>on the bike, I can not push the bars down, but with effort can pull them up, rotating the entire
>bar assembly within the clamp. I know I greased those stem bolts when I put the bars in a month
>ago, and I've tightened them as much as I can with my 6" allen wrench and a good bit of muscling.
>I'm at the point where im worried abotu stripping either the bolt threads or the allen hole in the
>bolt. The allen key has already slipped out once under pressure.
>
>What gives? Are aerobars always going to move if you try? If i push down on them really hard, the
>bar assembly stays in place and the rear wheel lifts. But if i pull up on them with weight in the
>saddle, I rotate the bar assembly up, and I dont want to think about that happening every time I
>want to sprint.
>
>what should I do?

Maybe a good 4-bolt stem would be a good place to start, though another way to get your current
set-up to stay put might be black loctite (the one for permanent fixing, sometimes labelled for
studs and bearings). Bottom line is the stem clamp is not designed to take the large amounts of
torque which aero bars apply. Normal drop bars, straightish flat bars or even moustache bars have
the push/pull force axis running almost directly through the bar/stem clamp axis, and this is the
set-up for which the clamp was designed all those years ago. Having said all that, I never had a
problem with my off axis forces using a Cinelli 62 cowhorn bar, Profile Aero 2 and Cinelli Grammo
stem, without resorting to any special treatment. On the other hand, even top continental pros have
occasionally suffered aero bar rotation problems. This might be one of those cases, like slipping
seat posts, where the best solution is to have the clamp made of much harder material than the thing
being clamped.

Kinky Cowboy

*Your milage may vary Batteries not included May contain traces of nuts.

 

[Ant]

Paul Kopit <[email protected]> wrote in message
news:<[email protected]>...
> Idid neither of those things. When I hit the pothole on a slight downgrade, the ambulance took
> me to the hospital for a broken hip, left wrist and thumb. I haven't had the nerve to use the
> bars since.
>

i did not hear that. i did not hear that. i did not...

 

[David L. Johnso]

On Fri, 07 Mar 2003 12:32:27 -0500, Michael James Anderson wrote:

> Hello all,
>
> So I'm doing some training that requires me to climb some hills at 3%, 5% and 7%. O.K., so we all
> know how to calculate the grade of a hill IF we know the elevation gain and the distance. Since I
> do not know the elevation gains of my local hills, I was wondering if anyone has a better method
> of finding out what the percent grade is of any hill?

Take a yardstick and a level, or better yet a long level. I have one that is 4 feet. Put one end on
the road, hold it level, and measure down to the road with another yardstick. The ratio of these
measurements is the % grade (the tangent of the angle of the road).

--

David L. Johnson

__o | "Business!" cried the Ghost. "Mankind was my business. The _`\(,_ | common welfare was my
business; charity, mercy, forbearance, (_)/ (_) | and benevolence, were, all, my business. The
dealings of my trade were but a drop of water in the comprehensive ocean of my business!"
--Dickens, "A Christmas Carol"

 

[Tbgibb]

In article <[email protected]>, [email protected]
(ant) writes:

>I got my first set of aero bars, and slapped them onto my bars this afternoon. The bolts came
>pre-prepped with loctite, I screwed them down hard, and then tried to move the aero bars. With not
>much effort, I could move them up and down.

Perhaps the aero bar to handle bar interface would be a better place for the loctite, rather than
the bolt threads.

Tom Gibb <[email protected]

 

[Paul Kopit]

On Fri, 07 Mar 2003 18:09:56 GMT, "Peter Cole" <[email protected]> wrote:

>So, what happened to cause the crash? Did the bars rotate? Did you lose balance and control? Did
>your wheel get shmushed? Was the pothole concealed under a puddle?
>
>I pretty much ride aerobars any place I'd ride no-handed, it's only a bit more controllable
>than that.

I hit the depression and the handlebars rotated forward. I literally got slammed to the ground. The
bicycle sustained little damage as I took all the impact. The bars are TTT Prima and the stem is ITM
Ecylpse. Were I to use a clipon again, I'd use beefier bars, no grease, sandpaper, and whatever else
I could to stop anything from moving. I can't ride without hands but can do a track stand.

 

[Tim McNamara]

In article <[email protected]>, "David L. Johnson" <David L. Johnson
<[email protected]>> wrote:

> On Fri, 07 Mar 2003 12:32:27 -0500, Michael James Anderson wrote:
>
> > So I'm doing some training that requires me to climb some hills at 3%, 5% and 7%. O.K., so we
> > all know how to calculate the grade of a hill IF we know the elevation gain and the distance.
> > Since I do not know the elevation gains of my local hills, I was wondering if anyone has a
> > better method of finding out what the percent grade is of any hill?
>
> Take a yardstick and a level, or better yet a long level. I have one that is 4 feet. Put one end
> on the road, hold it level, and measure down to the road with another yardstick. The ratio of
> these measurements is the % grade (the tangent of the angle of the road).

Yah, but good heavens is it necessary to be so literal about hill training? Look for a mild, a
moderate and a steepish hill in your neighborhood and that will be close enough. I know Joe Friel
prescribes this stuff but IMHO at least it's just not a significant difference if the hill is
2.75% or 3.25%.

 

[Ray Heindl]

[email protected] wrote:

>> Unless the road is tilted side-to-side it has to cross the contours at a right angle. You just
>> have to look closely to see how the contour bends to meet the road. As to resolution, most topo
>> maps in my experience show contours every 10 feet, so the resolution would be +/- 10 feet or so,
>> depending on how well you can interpolate. Whether that's good enough depends on how high the
>> hill is and how precisely you need to know the grade. For a 7% grade on a 1:24,000 map, the
>> contours are 0.07" apart, which should allow interpolation to half a contour at each end. If the
>> hill is 100 feet high, that would be +/- 10%.
>
> I think you are imagining a resolution and map design that doesn't occur. Contour lines are not
> made to include road benches but rather the natural contour of the terrain, just as they don't go
> up sloping lines of building roofs. I think a typical map such as the following are a good
> example.
>
> http://topozone.com/map.asp?z=10&n=4133352&e=620349&s=25

Don't try this link if you use Opera; it starts an infinite series of error messages.

I wouldn't call that a "typical" topo map; it's way too small a scale to try to measure anything off
of. I imagine the original poster was referring to real, large-scale topo maps. Print your example
at 1.5 x 2 feet, like a USGS paper map, and you might be able to measure from
it.

On the USGS 7.5-minute topo map I'm looking at right now, every contour I checked that crosses a
road is perpendicular to it, as near as dammit. Many of the contour lines have little rectangular
jogs, showing where hills were cut out to put the roads through.

Here's a small part of the map: <http://members.nccw.net/rheindl/topo1.jpg> This represents a piece
of the map about 1.5 inches wide, or about 3000 feet on the ground. In the middle of the picture,
Washington Blvd has a grade of 1.8% as measured by a dial caliper. What's so difficult about that?

--
Ray Heindl (remove the X to reply)

 

[Cy Galley]

That would work. Just make sure the bars are positioned where you want them. "TBGibb"
<[email protected]> wrote in message news:[email protected]...
> In article <[email protected]>, [email protected]
> (ant) writes:
>
> >I got my first set of aero bars, and slapped them onto my bars this afternoon. The bolts came
> >pre-prepped with loctite, I screwed them down hard, and then tried to move the aero bars. With
> >not much effort, I could move them up and down.
>
> Perhaps the aero bar to handle bar interface would be a better place for
the
> loctite, rather than the bolt threads.
>
> Tom Gibb <[email protected]