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Long Brake Levers



 
 
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  #11  
Old March 22nd 18, 11:17 AM posted to rec.bicycles.tech
John B.[_3_]
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Posts: 3,967
Default Long Brake Levers

On Wed, 21 Mar 2018 19:44:01 -0700, Jeff Liebermann
wrote:

On Wed, 21 Mar 2018 21:20:19 -0400, Frank Krygowski
wrote:

That probably sounds terribly risky to some people, as in "But what if
the lever breaks at the repair???"


I'm sure the TIG welding will hold together if there's sufficient
penetration. The epoxy glue job is a bit risky depending on
temperature. The difference between the coefficients of thermal
expansion for aluminum at 23 PPM/C and epoxy[1] at 95 PPM/C could
easily tear apart the glue joint when hot or cold.

Looks like Masterbond has several low CTE range epoxies:
https://www.masterbond.com/properties/epoxies-low-coefficient-thermal-expansion
which are a bit too low but should work. If that's too much work,
just mix in some powdered aluminum into the epoxy mix, and it should
bring the CTE of the epoxy down a little. If that's still to much
work, use the largest diameter roll pin as possible.

But in any normal use, the force on a brake lever is quite small. A
strong person can bend many designs fairly easily. I did that on the
levers on my wife's touring bike, to better fit her smaller grip. They
don't have to be super-strong because you'd go over the bars if you
squeezed too hard.


Agreed. I don't think grip force is going to bend or break the levers
(under normal use). More likely, impact damage from dropping the
bicycle on the brake levers will break the joint. Epoxy is rather
brittle and will crack before it bends. If that's a problem, a thin
strip of aluminum, glued over the joint, should help protect the glue
joint.

[1] MG Chem 9200 structural epoxy adhesive:
https://www.mouser.com/ds/2/265/tds-9200-2parts-1149953.pdf


A set of epoxy adhesive 832FX-450ml costs $46.03. A set of XLC brake
levers Brake Lever set for V-Brake BL-V05, at Amazon is $12.59 :-)
--
Cheers,

John B.

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  #12  
Old March 22nd 18, 01:58 PM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 8,281
Default Long Brake Levers

On 3/21/2018 3:41 PM, Jeff Liebermann wrote:
On Tue, 20 Mar 2018 13:45:06 -0700, sms
wrote:

On my DaHon Speed TR folder, it had brake levers, branded DaHon with a
longer handle than other levers I've seen, about 1" longer. One of the
levers broke in half and I haven't been able to find a suitable replacement.


No clue on a replacement, but if you still have the remains of the old
lever, it can be repaired in various ways. I had one I fixed by
drilling both sides of the break. On the thick side, I drilled it for
an interference fit for a roll pin. On the other side, I drilled it
loosely because it's very difficult to get the holes aligned on the
same centerline. I then filled the hole and mating surfaces with
structural epoxy and allowed to harden for over 24 hrs. I'll see if I
can find it and take a photo. However, there's not much to see. Just
a crack that goes around the lever.

Another way is to TIG weld the two pieces together. I haven't done
this, but have seen the results. If it's done professionally, it
should look good and hold together quite nicely. You'll probably need
to know the Al alloy. My guess(tm) is forged 6061-T6.


I don't have them anymore. But there is just no way you could have fixed
these given the small surface area and the large amount of force put on
levers. I suppose that welding some sort of reinforcing bar would work
but be kludgy.

Now that I know the description "four finger brake levers" I should be
able to find something. These are for linear pull brakes.

As someone said, "four finger" is not a very accurate way to specify the
length. Looking at pictures online is about the best I can do. The ones
that look the best are not available anywhere, the EVO, E-Force Park V.




  #13  
Old March 22nd 18, 03:48 PM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,826
Default Long Brake Levers

On Thu, 22 Mar 2018 18:17:37 +0700, John B.
wrote:

On Wed, 21 Mar 2018 19:44:01 -0700, Jeff Liebermann
wrote:

On Wed, 21 Mar 2018 21:20:19 -0400, Frank Krygowski
wrote:

That probably sounds terribly risky to some people, as in "But what if
the lever breaks at the repair???"


I'm sure the TIG welding will hold together if there's sufficient
penetration. The epoxy glue job is a bit risky depending on
temperature. The difference between the coefficients of thermal
expansion for aluminum at 23 PPM/C and epoxy[1] at 95 PPM/C could
easily tear apart the glue joint when hot or cold.

Looks like Masterbond has several low CTE range epoxies:
https://www.masterbond.com/properties/epoxies-low-coefficient-thermal-expansion
which are a bit too low but should work. If that's too much work,
just mix in some powdered aluminum into the epoxy mix, and it should
bring the CTE of the epoxy down a little. If that's still to much
work, use the largest diameter roll pin as possible.

But in any normal use, the force on a brake lever is quite small. A
strong person can bend many designs fairly easily. I did that on the
levers on my wife's touring bike, to better fit her smaller grip. They
don't have to be super-strong because you'd go over the bars if you
squeezed too hard.


Agreed. I don't think grip force is going to bend or break the levers
(under normal use). More likely, impact damage from dropping the
bicycle on the brake levers will break the joint. Epoxy is rather
brittle and will crack before it bends. If that's a problem, a thin
strip of aluminum, glued over the joint, should help protect the glue
joint.


[1] MG Chem 9200 structural epoxy adhesive:
https://www.mouser.com/ds/2/265/tds-9200-2parts-1149953.pdf


A set of epoxy adhesive 832FX-450ml costs $46.03. A set of XLC brake
levers Brake Lever set for V-Brake BL-V05, at Amazon is $12.59 :-)


9200 - Dual cartridge 25 mL (0.8 fl oz) 1:1 STRUCTURAL EPOXY ADHESIVE
https://www.ebay.com/itm/MG-Chemicals-9200-Structural-Adhesive-25-mL-Dual-Syringe-/132476402539
$13.50 for 25 mL. However, you do have a point. Considering the tiny
quantity needed for gluing the lever back together, a less expensive
adhesive might be a better choice. Unfortunately, I couldn't find a
cheaper low CTE and low shrinkage epoxy.



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #14  
Old March 22nd 18, 04:41 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 6,042
Default Long Brake Levers

On 3/22/2018 6:02 AM, wrote:
On Thursday, March 22, 2018 at 12:42:05 AM UTC+1, Joy Beeson wrote:
On Wed, 21 Mar 2018 07:05:36 +0100, Tosspot
wrote:

4 finger is longest I've seen these days, but be careful, mileage varies
and some are closer to 3 than 4.


Now that is weird. Thanks to two engineers and a Dremel Moto-Tool, I
have child-size brake levers on my bike, and I can put six fingers on
the lever. (Not while riding, of course.)

How things can change in only thirty or forty years.

--
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/
The above message is a Usenet post.
I don't recall having given anyone permission to use it on a Web site.


Because brakes/cables and housing got so much better that only two fingers are needed to apply enough pressure on the pads to get you over the bars.


Technology is marching ever onward. Some day, we'll just have to THINK
the word "brake" and we'll go over the bars.

Won't that be wonderful!


--
- Frank Krygowski
  #15  
Old March 22nd 18, 05:13 PM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,826
Default Long Brake Levers

On Thu, 22 Mar 2018 12:41:39 -0400, Frank Krygowski
wrote:

On 3/22/2018 6:02 AM, wrote:
On Thursday, March 22, 2018 at 12:42:05 AM UTC+1, Joy Beeson wrote:
On Wed, 21 Mar 2018 07:05:36 +0100, Tosspot
wrote:

4 finger is longest I've seen these days, but be careful, mileage varies
and some are closer to 3 than 4.

Now that is weird. Thanks to two engineers and a Dremel Moto-Tool, I
have child-size brake levers on my bike, and I can put six fingers on
the lever. (Not while riding, of course.)

How things can change in only thirty or forty years.

--
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/
The above message is a Usenet post.
I don't recall having given anyone permission to use it on a Web site.


Because brakes/cables and housing got so much better that only two fingers are needed to apply enough pressure on the pads to get you over the bars.


Technology is marching ever onward. Some day, we'll just have to THINK
the word "brake" and we'll go over the bars.


Right. With electrically actuated brakes, you can probably do that.
Just wear a colander instead of a helmet while riding. The colander
picks up signals from various parts of the brain. When it detects the
brain wave pattern for "fear" or "panic", it applies the brakes.
Patent pending.

Won't that be wonderful!


Yep, but you don't need to wait until cycling catches up with modern
technology. ABS (anti-skid brakes) and anti-lock bicycle brakes are
available today.
https://www.bikeradar.com/us/road/news/article/pinarello-blubrake-abs-system-launch-48819/
https://www.bikeradar.com/us/road/gear/article/abs-bicycle-brakes-for-e-bikes-first-look-48000/
https://www.cnet.com/roadshow/news/bosch-brings-anti-lock-brakes-to-bicycles/
http://www.sabs-global.com/product.html
https://www.youtube.com/watch?v=Xe-U2E6Cw8w
https://www.youtube.com/watch?v=ipwu-J9LElI
http://road.cc/content/tech-news/213546-italian-company-blubrake-develops-electronic-anti-lock-braking-system
I like the ones with the built in vibrator (mechanical modulator).
There's nothing like a good massage after a hard days ride.

After the safety fanatics have given up pushing mandatory helmet laws,
they can easily switch to ABS brakes as the next required safety
feature.

Full disclosu I've never actually gone over the handlebars. More
often, my flight is interrupted by the stem hitting a very sensitive
part of my anatomy. Yep, I can definitely see myself installing ABS
bicycle brakes.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #16  
Old March 22nd 18, 05:13 PM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 8,281
Default Long Brake Levers

On 3/22/2018 8:48 AM, Jeff Liebermann wrote:

9200 - Dual cartridge 25 mL (0.8 fl oz) 1:1 STRUCTURAL EPOXY ADHESIVE
https://www.ebay.com/itm/MG-Chemicals-9200-Structural-Adhesive-25-mL-Dual-Syringe-/132476402539
$13.50 for 25 mL. However, you do have a point. Considering the tiny
quantity needed for gluing the lever back together, a less expensive
adhesive might be a better choice. Unfortunately, I couldn't find a
cheaper low CTE and low shrinkage epoxy.


Do you really believe that given the tiny surface area and the large
forces applied to brake levers that any adhesive could possibly work?

You would have to reinforce the repair with some sort of splice. Way too
complicated to try to save zero dollars.

  #17  
Old March 22nd 18, 05:24 PM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,826
Default Long Brake Levers

On Thu, 22 Mar 2018 10:13:11 -0700, sms
wrote:

On 3/22/2018 8:48 AM, Jeff Liebermann wrote:

9200 - Dual cartridge 25 mL (0.8 fl oz) 1:1 STRUCTURAL EPOXY ADHESIVE
https://www.ebay.com/itm/MG-Chemicals-9200-Structural-Adhesive-25-mL-Dual-Syringe-/132476402539
$13.50 for 25 mL. However, you do have a point. Considering the tiny
quantity needed for gluing the lever back together, a less expensive
adhesive might be a better choice. Unfortunately, I couldn't find a
cheaper low CTE and low shrinkage epoxy.


Do you really believe that given the tiny surface area and the large
forces applied to brake levers that any adhesive could possibly work?


Yes. The glue joint won't be as strong as the original aluminum
forging, but should hold together as long as you don't crash the
bicycle. If the levers are hollow, a steel reinforcing rod down the
center cavity should provide sufficient strength. If solid, drilling
and adding a steel roll pin should do the same.

The strength is not in the glued butt joint, as you seem to suggest.
It's in the roll pin or center rod. Simply slopping on some glue to
the broken area and butting them together, isn't going to hold.

You would have to reinforce the repair with some sort of splice. Way too
complicated to try to save zero dollars.


Well, if it's too thin for a pin through the center of the lever, then
tacking the pieces together, milling several slots across the broken
area, and pounding in a roll pin, should be sufficiently strong.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #18  
Old March 23rd 18, 12:00 AM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 8,281
Default Long Brake Levers

On 3/20/2018 1:45 PM, sms wrote:
On my DaHon Speed TR folder, it had brake levers, branded DaHon with a
longer handle than other levers I've seen, about 1" longer. One of the
levers broke in half and I haven't been able to find a suitable
replacement.

DaHon was no help in getting a replacement, ever since Pete Mole passed
away the company has been in decline in the U.S..

I replaced both of the levers with
https://www.bikenashbar.com/cycling/nashbar-deluxe-mountain-bike-brake-levers-ns-adbl-base
but the levers are too short.

Where can I find longer brake levers?


Pretty amazing to search for brake levers.

I have seen 2 finger, 3 finger, 3.5 finger, and 4 finger models.

It's very hard to find a 4 finger V-Brake/Linear version that is
purchasable. Most are caliper and cantilever only.

I found two that claim to be 4-Finger:
1. XLC-BL-V05
2. Saccon Shimano Nexus V-brake 4-finger silver / bl (not available in
U.S.).

  #19  
Old March 29th 18, 07:50 PM posted to rec.bicycles.tech
Tosspot[_3_]
external usenet poster
 
Posts: 1,167
Default Long Brake Levers

On 03/23/2018 12:00 AM, sms wrote:
On 3/20/2018 1:45 PM, sms wrote:
On my DaHon Speed TR folder, it had brake levers, branded DaHon with a
longer handle than other levers I've seen, about 1" longer. One of the
levers broke in half and I haven't been able to find a suitable
replacement.

DaHon was no help in getting a replacement, ever since Pete Mole
passed away the company has been in decline in the U.S..

I replaced both of the levers with
https://www.bikenashbar.com/cycling/nashbar-deluxe-mountain-bike-brake-levers-ns-adbl-base
but the levers are too short.

Where can I find longer brake levers?


Pretty amazing to search for brake levers.

I have seen 2 finger, 3 finger, 3.5 finger, and 4 finger models.

It's very hard to find a 4 finger V-Brake/Linear version that is
purchasable. Most are caliper and cantilever only.

I found two that claim to be 4-Finger:
1. XLC-BL-V05
2. Saccon Shimano Nexus V-brake 4-finger silver / bl (not available in
U.S.).


That was my experience. It's not that I don't think 2/3 finger brakes
work, but when it's -15 and I'm wearing ski gloves they become 1/2
finger brakes. Added to which, I *like* 4 finger levers :-(
 




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