Backpack or pannier

On 4/11/2014 5:26 PM, jbeattie wrote:

I wonder how front bags would affect a bike with a steep front end (typical of short wheelbase bikes). I assume it would just make it sluggish rather than making it more twitchy. I never tried front bags on my racing bike because a rear rack worked and was convenient (plenty of room on the Cannondale drop-outs to drill and tap an eyelet). Kludging a front rack was far more difficult and would have required clamps.

Twitchiness is a problem with front bags on a touring bike. Following
Jim Blackburn's advice and mounting them as low as possible reduces the
twitchiness. But you still feel it on fast downhill runs when the bags
are fully loaded. Nothing much you can do about it.

Almost no road bikes have the braze-ons on the front fork for low-rider
rear racks. You don't want to be using U-Bolt clamps on anything but a
steel fork, and even then they're a kludge.

Panniers on a road bike are not for heavy loads for long distances, but
there are occasions when you want to carry stuff even on a road bike but
don't want to wear a pack.

Sir Ridesalot wrote:
On another thread someone was looking for a new backpack to carry his
commuting gear in it. Many people suggested panniers instead.

I use a backpack. But I don't wear it while riding. It goes in the milk
crate that is strapped on top of my rear rack.

--
K.

Lang may your lum reek.

On 4/12/2014 1:10 AM, Sir Ridesalot wrote: On Saturday, April 12, 2014
12:15:29 AM UTC-4, Frank Krygowski wrote:
On Friday, April 11, 2014 10:12:06 PM UTC-4, Sir Ridesalot wrote:



Front low rider bags can make a racig geometry bike very twitchy
especially in strong cross winds or gusts. Also, most racing bikes don't
have a way to mount low rider racks unleds you use U-clamps and
P-clamps. I don't think I'd want either on a racing fork.



I've never used them on a racing-geometry bike, but I've certainly
never had any problems with twitchiness or crosswinds on "sport touring"
or full-touring frames.
Snipped

- Frank Krygowski

Therein lies the difference. Pure racing bikes do handle differently
than sport
touring or touring bicycles. The lesser amount of fork rake on a pure
racing bike
can lead to a lot of problems if you hang panniers on a rack on the front.
One of your problems might very well be fot striking a pannier in a low
speed turn.

-----------

I certainly agree that racing bikes handle differently. But
mechanically speaking, I still can't see any mechanism that would cause
front panniers to increase twitchiness. Again, the mass slows the
steering response, which is the opposite of twitchiness.

BTW, I've used at least three different makes of front panniers over the
years. With every set I've used or seen, it's impossible for a rider's
foot to strike a pannier while riding. The panniers never reach anywhere
near the rear quadrant of the front wheel.

There's pretty good reasons why someone commuting on a pure racing
bike usually uses a backpack for their gear rather than trying to kludge
a rack and pannier(s) to fit where they were never designed to fit.

---------

It's fine by me if people prefer backpacks. The descriptions of
benefits and detriments should be realistic, though. I don't think
twitchiness from front panniers is realistic.

--
- Frank Krygowski

On Saturday, April 12, 2014 11:23:23 AM UTC-4, sms wrote:
On 4/11/2014 5:26 PM, jbeattie wrote:



I wonder how front bags would affect a bike with a steep front end (typical of short wheelbase bikes). I assume it would just make it sluggish rather than making it more twitchy. I never tried front bags on my racing bike because a rear rack worked and was convenient (plenty of room on the Cannondale drop-outs to drill and tap an eyelet). Kludging a front rack was far more difficult and would have required clamps.



Twitchiness is a problem with front bags on a touring bike. Following

Jim Blackburn's advice and mounting them as low as possible reduces the

twitchiness. But you still feel it on fast downhill runs when the bags

are fully loaded. Nothing much you can do about it.



Almost no road bikes have the braze-ons on the front fork for low-rider

rear racks. You don't want to be using U-Bolt clamps on anything but a

steel fork, and even then they're a kludge.



Panniers on a road bike are not for heavy loads for long distances, but

there are occasions when you want to carry stuff even on a road bike but

don't want to wear a pack.

ddddddddddddddddddd]]]]]]


?! no Europa Buick for SMS !

TWITCH

Give or cause to give a short, sudden jerking or convulsive movement:
[no object]: 'he saw her lips twitch and her eyelids flutter'

[with object]: 'the dog twitched his ears'


More example sentences {less humor}





Synonyms





1.1 [with object] Cause to move in a specified direction by giving a sharp pull:
'he twitched a cigarette out of a packet'


how forks twitch over a squashed contact patch ?

maybe with 140 pounds air front and 40 pounds of BS on the back....

Brandt's Disease ??

On Saturday, April 12, 2014 9:16:26 AM UTC-7, Frank Krygowski wrote:

snip


I certainly agree that racing bikes handle differently. But
mechanically speaking, I still can't see any mechanism that would cause
front panniers to increase twitchiness. Again, the mass slows the
steering response, which is the opposite of twitchiness.


You're right, I think. I think they've mischaracterized the effect
of loading the front end on bike handling. I agree with you that
it's the opposite of twitchiness.

And while it might be possible to find one perfect balance point
to put the mass up front that would allow for at least elegant
(if less readily responsive) handling, twitchiness is not inherently
bad; it's just a parameter. Some of us prefer it to sluggishness
(which becomes pronounced as relatively small amounts of mass are
added around and attached to the front end of a bike IME).

Worse than the sluggishness (for me) is the latent inertia added to
the steering, which, to be frank, I find scary.

On Saturday, April 12, 2014 12:16:26 PM UTC-4, Frank Krygowski wrote:
On 4/12/2014 1:10 AM, Sir Ridesalot wrote: On Saturday, April 12, 2014

12:15:29 AM UTC-4, Frank Krygowski wrote:

On Friday, April 11, 2014 10:12:06 PM UTC-4, Sir Ridesalot wrote:







Front low rider bags can make a racig geometry bike very twitchy

especially in strong cross winds or gusts. Also, most racing bikes don't

have a way to mount low rider racks unleds you use U-clamps and

P-clamps. I don't think I'd want either on a racing fork.







I've never used them on a racing-geometry bike, but I've certainly

never had any problems with twitchiness or crosswinds on "sport touring"

or full-touring frames.

Snipped



- Frank Krygowski



Therein lies the difference. Pure racing bikes do handle differently

than sport

touring or touring bicycles. The lesser amount of fork rake on a pure

racing bike

can lead to a lot of problems if you hang panniers on a rack on the front..

One of your problems might very well be fot striking a pannier in a low

speed turn.



-----------



I certainly agree that racing bikes handle differently. But

mechanically speaking, I still can't see any mechanism that would cause

front panniers to increase twitchiness. Again, the mass slows the

steering response, which is the opposite of twitchiness.



BTW, I've used at least three different makes of front panniers over the

years. With every set I've used or seen, it's impossible for a rider's

foot to strike a pannier while riding. The panniers never reach anywhere

near the rear quadrant of the front wheel.



There's pretty good reasons why someone commuting on a pure racing

bike usually uses a backpack for their gear rather than trying to kludge

a rack and pannier(s) to fit where they were never designed to fit.



---------



It's fine by me if people prefer backpacks. The descriptions of

benefits and detriments should be realistic, though. I don't think

twitchiness from front panniers is realistic.



--

- Frank Krygowski

Go borrow a racing geometry bicycle mount a lowrider rack on the front fork.. Put a pannier on it or two panniers (one on each side) and go ride that bike. You'll soon find that the handling is a lot more squirrely than if you did the same thing with a sport touring or touring bike.

Cheers

On 4/12/2014 4:47 PM, Sir Ridesalot wrote:


Go borrow a racing geometry bicycle mount a lowrider rack on the front fork.
Put a pannier on it or two panniers (one on each side) and go ride that
bike.
You'll soon find that the handling is a lot more squirrely than if you
did the
same thing with a sport touring or touring bike.

Well, I thought the claim was that the racing bike with front panniers
on low-rider racks would be more twitchy than without the load in front.
IOW, I thought the comparison was between the same bike, loaded and
unloaded. That's why I said adding mass would increase the polar moment
of inertia.

I don't doubt that a racing frame would be a bit twitchier than a
touring frame. But ISTM that was not the question being addressed.


--
- Frank Krygowski

On 13/04/14 02:16, Frank Krygowski wrote:


It's fine by me if people prefer backpacks. The descriptions of
benefits and detriments should be realistic, though. I don't think
twitchiness from front panniers is realistic.


My first full size bicycle was a Repco Superlite. Not very "lite"
actually. Just 4130 CroMo steel and cheap parts.

I joined the local touring club and went camping touring a few times on
that bike. It had eyelets on the drop outs.

Ok, it wasn't high end race, even for back in the 80's, but it handled
fine with heavy panniers, front and back and a handlebar bag.

--
JS

On Saturday, April 12, 2014 3:49:55 PM UTC-4, Dan O wrote:
On Saturday, April 12, 2014 9:16:26 AM UTC-7, Frank Krygowski wrote:



snip





I certainly agree that racing bikes handle differently. But

mechanically speaking, I still can't see any mechanism that would cause

front panniers to increase twitchiness. Again, the mass slows the

steering response, which is the opposite of twitchiness.





You're right, I think. I think they've mischaracterized the effect

of loading the front end on bike handling. I agree with you that

it's the opposite of twitchiness.



And while it might be possible to find one perfect balance point

to put the mass up front that would allow for at least elegant

(if less readily responsive) handling, twitchiness is not inherently

bad; it's just a parameter. Some of us prefer it to sluggishness

(which becomes pronounced as relatively small amounts of mass are

added around and attached to the front end of a bike IME).



Worse than the sluggishness (for me) is the latent inertia added to

the steering, which, to be frank, I find scary.



weight not mass....weight is force, mass is substance....

at extreme front weights , balance concerns when moving are frontal, when not moving more rearward...distributed evenly or not.\

I've tried recalling moments of tire grab or pull....not twitchy...but the motion isnot that the motion of pull is lack of forethought in balance...as the load(s) diminished or eliminated the bike geometry/physics of falling into a turn. There's no'fall'here the position is upright or crash.

32c Messengers on double wall Sunrims...maybe 50 pounds front...80 pounds rear I weigh abt 165.

On Saturday, April 12, 2014 5:15:17 PM UTC-4, Frank Krygowski wrote:
On 4/12/2014 4:47 PM, Sir Ridesalot wrote:





Go borrow a racing geometry bicycle mount a lowrider rack on the front fork.

Put a pannier on it or two panniers (one on each side) and go ride that

bike.

You'll soon find that the handling is a lot more squirrely than if you

did the

same thing with a sport touring or touring bike.



Well, I thought the claim was that the racing bike with front panniers

on low-rider racks would be more twitchy than without the load in front.

IOW, I thought the comparison was between the same bike, loaded and

unloaded. That's why I said adding mass would increase the polar moment

of inertia.



I don't doubt that a racing frame would be a bit twitchier than a

touring frame. But ISTM that was not the question being addressed.





--

- Frank Krygowski

Take a pure racing bike, ride it, add a front lowrider rack and load some stuff into panniers attached to that rack, ride that *SAME* bike again. Notice difference in handling. Cross winds and strong gusts will really affect the handling of a racing bike with panniers on a low rider rack. That wind is also why discsor disc covers are not a good idea on a road bike on the road but are okay on the rear wheel.

Cheers

Cheers