Unchain my bike... or so I thought...

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Originally Posted By: Shannow
You do good work.
A frame carved out of billet would be awesome


IMPOSSIBLE...CAN'T BE DONE!!
OK Larry now you have the incentive to make the chips fly.
Good luck
Smoky
 
Originally Posted By: Shannow
You do good work.
A frame carved out of billet would be awesome


Thanks... an carved from billet frame would be awesome but
unfortunately it would be stiff as marble and lack feel... the trick
is design a degree of tune flex quality to the chassis employing
billet and extruded aluminum pieces... allow me to elaborate because I
know this all sounds alien to someone use to 4 wheels...

In the 1980 as tires improved and engine outputs increased, the forces
involved in braking and accelerating started to overwhelm the old
flexy steel chassis and so frame builders started to make their new
aluminum frames stiffer and stiffer thinking there was no limit to the
degree of stiffness a rider could handle... thats why some riders
prefer the stiff as marble feel of the RC30 chassis but it comes at a
cost of nervousness...

In the 1990s the chassis builders started to encounter the oppostie
problem of flex as their frames got stiffer and stiffer, the bike
started chattering and vibrating, making handling terrible, especially
when leaned over, when the suspension of a bike ceases to work, being
in the wrong plane. And so the concept of flex was introduced, adding
sufficient flexibility to allow the bike to absorb some of the bumps
while leaned over, but still stiff enough to keep the chassis stable
in a straight line and under braking. Since the late 1990s, and
especially since the four-stroke era began, a huge amount of work has
gone into engineering in exactly enough flexibility in specific areas,
while retaining the stiffness in the planes where it is needed.

As tuneable flexibility has become increasingly important, the
attractiveness of alternatives to aluminium has also grown.
Traditional aluminium has the benefit of being light and easy to work
with, but as chassis designers push the limits, they also run into a
few limitations. Engineering in flex is a matter of designing chassis
elements with a specific thickness and shape, but the underlying
properties of aluminium mean that at some point, achieving the precise
amount of flexibility required means sacrifices strength. The way to
get around this problem is to by making elements longer, allowing a
mass (usually, the mass of the engine) to use the greater leverage
provided by a longer element (such as an engine spar connecting the
engine to the main chassis beam) to provide the flexibility without
sacrificing rigidity. The RC45 got the benefit of this latest
engineering in tune flex which is why it still feels modern...

1988 RC30 Short ridged front engine mounts
18753559201_cb062f15fd_b.jpg


1994 RC45 long flexible front engine mounts
NakedRC45JPG.jpg


2015 RC213VS long flexible front engine mounts... The goal of tuned chassis flex is very much in evidence in MotoGp today...
7217d3b1-fa06-4a91-b176-6d2e0735d2b3-720x480.jpg
 
Originally Posted By: LoneRanger
Can you build one for my Ducati, LoL.


I'd be happy too... chains are a pain... belt spells relief... but I
can not convince Gates to market the 11mm pitch belt like they market
the 8mm and 14mm pitch belts... they say I'd have to finance the
tooling for the mold myself at the going rate of $65K... they don't
see the possibility of their 11mm pitch belt capturing a serious share
of the chain market... oh what can I possible say to Gates to change
their minds???
 
Originally Posted By: BusyLittleShop
they don't see the possibility of their 11mm pitch belt capturing a serious share of the chain market... oh what can I possible say to Gates to change
their minds???

Say what you want about Harley, but they got their drive lines right. 75,000-100,000 maintenance free miles. Why don't more manufacturers use belts?

Very impressive work you did.
 
Originally Posted By: whip
Say what you want about Harley, but they got their drive lines right. 75,000-100,000 maintenance free miles. Why don't more manufacturers use belts?


I wonder the same thing, but if they performed that well they'd be using them in racing. Whether it's about absolute power handling, parasitic drag or some other factor there must be a reason most manufacturers stick with chains.
 
Originally Posted By: whip
Originally Posted By: BusyLittleShop
they don't see the possibility of their 11mm pitch belt capturing a serious share of the chain market... oh what can I possible say to Gates to change
their minds???

Say what you want about Harley, but they got their drive lines right. 75,000-100,000 maintenance free miles. Why don't more manufacturers use belts?



Chains are cheaper and belts have a few issues. Get one decent sized rock in between that belt and pulley and you can bust the belt. There are also concerns over just how much power a belt can reliably hold.

There is no perfect system sadly.
 
Originally Posted By: whip

Say what you want about Harley, but they got their drive lines right. 75,000-100,000 maintenance free miles. Why don't more manufacturers use belts?

Very impressive work you did.


Thanks whip...
My research into belts included talking with a Harley Engineer at
Daytona about their 14mm pitch belt... I wonder why the engineers
decided on a 38mm wide belt width good for 156 HP instead of the
recommended 22mm good for Harley's meager 56 HP???


The engineer cited a study done by marketing which found "it would be
a question of strength if the belt on the bike was smaller than the
belt width on a prospective customers pants...

Gates Rubber holds all the patents that matter for belts so the
Japanese are reluctant to invest in belt drives... they rather support
their own chain manufactures...
 
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Originally Posted By: Robenstein

Get one decent sized rock in between that belt and pulley and you can bust the belt. There are also concerns over just how much power a belt can reliably hold.


I can address your concerns about rocks and strenght...

One day I noticed a rock hole my Belt-0-Cepter's belt... so I ordered
a new one and went out riding... came upon a Harley rider and we compared
belts... I express concerns that my belt might not make it back but it was
one heck of nice day for a ride... Harley biker said heck I've had a rock
hole in my belt for a year now... What??? sure enough his belt had a
ragged hole that my finger fit... 10 months later and about 4K miles
my belt snapped in the parking lot of American River College... so a rock hole
is not instantaneous death like you're thinking...


Belts are stronger than most people believe... take 37mm wide 14mm
pitch Gates Poly Chain... it is strong enough to handle a 502 HP 425
Ft lb Boss Hoss... in fact most of the Boss Hoss product line employs
belts because they last longer than chains...

gallery_3131_51_24711.jpg

gallery_3131_51_101719.jpg
 
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Originally Posted By: Brad_C

I wonder the same thing, but if they performed that well they'd be using them in racing. Whether it's about absolute power handling, parasitic drag or some other factor there must be a reason most manufacturers stick with chains.


Eddie Lawson raced 250 Gp on a belt drive Kawasaki... the reason most stick with chains is
gear ratio changes but I believe that can be solved with more engineering...

2595761411_8399f95334_b.jpg
 
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Originally Posted By: BusyLittleShop



Belts are stronger than most people believe... take 37mm wide 14mm
pitch Gates Poly Chain... it is strong enough to handle a 502 HP 425
Ft lb Boss Hoss... in fact most of the Boss Hoss product line employs
belts because they last longer than chains...





They also know that they are very rarely ridden in any kind of anger which might strain the belt. They spend most of their time being subjected to lots of stationary revving of the engine, and on low-speed poser runs from one Bar to the next.
 
Originally Posted By: BusyLittleShop
Originally Posted By: whip

Say what you want about Harley, but they got their drive lines right. 75,000-100,000 maintenance free miles. Why don't more manufacturers use belts?

Very impressive work you did.


Thanks whip...
My research into belts included talking with a Harley Engineer at
Daytona about their 14mm pitch belt... I wonder why the engineers
decided on a 38mm wide belt width good for 156 HP instead of the
recommended 22mm good for Harley's meager 56 HP???


The engineer cited a study done by marketing which found "it would be
a question of strength if the belt on the bike was smaller than the
belt width on a prospective customers pants...

Gates Rubber holds all the patents that matter for belts so the
Japanese are reluctant to invest in belt drives... they rather support
their own chain manufactures...


Seriously?! One of the FIRST belt-drive bikes was a Suzuki. Most of the bigger Japanese bikes (going back 30+ years) are shaft drive.
 
Kawsaki had a belt drive cruiser back in the 80's as well. My friends new Star has one as well.

As for belts breaking from debris....I said you CAN snap your belt, not you always WILL. Look around and you can see cases of instantaneous breaks and failures like you had.

I do not underestimate the strength of belts...I have been around belt driven superchargers that sit on methanol and nitro methane fed engines for most of my life. A top fueler supercharger sucks almost 900HP off the engine at full throttle.Use a big enough belt and you can put a ton of power to it. But belts on final drives of bikes go only so big before they get bulky.
 
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Originally Posted By: Robenstein

I do not underestimate the strength of belts...I have been around belt driven superchargers that sit on methanol and nitro methane fed engines for most of my life. A top fueler supercharger sucks almost 900HP off the engine at full throttle.


There are a bunch of variables that affect how much power it takes to drive the Supercharger. But it can take far more horsepower than that to drive.
 
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Originally Posted By: 02SE
Originally Posted By: Robenstein

I do not underestimate the strength of belts...I have been around belt driven superchargers that sit on methanol and nitro methane fed engines for most of my life. A top fueler supercharger sucks almost 900HP off the engine at full throttle.


There are a bunch of variables that affect how much power it takes to drive the Supercharger. But it can take far more horsepower than that to drive.


I pulled the 900 HP figure from an ANDRA sponsored article on the cost of racing a top fueler. Of course I know that variables such as engine compression and the state of under/overdrive has a ton to do with how much power it takes to spin a supercharger.
 
Originally Posted By: Robenstein


As for belts breaking from debris....I said you CAN snap your belt, not you always WILL.


Debris were no longer a problem after I fabricated a rock guard in between the belt and the rear tire... no more problems with rock holes...
 
Harley has a decent belt guard too. It's rare to get something caught in a H-D. The worst scenario I hear of is when riders are traveling down tar and gravel roads. The fine gravel can get in there and start rattling around, chewing up the belt.
 
Originally Posted By: Jarlaxle
I have seen stories of belts with rock holes that still went another 10,000+ miles.


Pretty much this, as long as the hole is not on the edge of the belt or bigger than 1/4". I have seen countless customers ride out a normal service life on debris damaged belts.
 
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