Inverted front forks?

[wildpudding]

Hi everyone,

I am a little bit curious, what are the reasons why some bikes have inverted front forks? Are there any benefits with regards to handling etc? Or is it just bike manufactures trying to be different?

Thanks,

Stefan

[ZorsT]

It reduces unsuspended weight...... which helps with corners...... and stuff

[nudemetalz]

Inverted forks are generally a lot more stiffer due to be significantly thicker. The slider (narrower part) is a lot shorter then normal ones.

This aids in deflecting or twisting less under braking in racing conditions.


My 2c worth.

:)

[WINJA]

It reduces unsuspended weight...... which helps with corners...... and stuff
REALLY , WHEN I SPLIT THE FORKS THE STEEL BITS FELT HEAVIER TO ME THAN THE ALUMINIUM BITS .
UPSIDE DOWN FORKS ARE USUALLY STIFFER

[Hitcher]

Yeah. They're stronger. And you need inverted oil to stop them leaking...

[nudemetalz]

And you need inverted oil to stop them leaking...

That's oil with bubbles at the bottom,. ay.....

[ZorsT]

REALLY , WHEN I SPLIT THE FORKS THE STEEL BITS FELT HEAVIER TO ME THAN THE ALUMINIUM BITS .
UPSIDE DOWN FORKS ARE USUALLY STIFFER
whoops, my bad

[TwoSeven]

As everyone says - stiffness. I have a problem with flex on my 600 using RSU forks. Sometimes under a decent amount of braking the forks bend far enough back that the wheel almost hits the headers. Pain in the ass.

[WINJA]

As everyone says - stiffness. I have a problem with flex on my 600 using RSU forks. Sometimes under a decent amount of braking the forks bend far enough back that the wheel almost hits the headers. Pain in the ass.
A GOOD FORK BRACE CAN STOP THEM WALKING

[thehollowmen]

I was explained it like this..

Think of a normal shock like a long fishing rod. If ya hold it by the thin end and get someone to give it a jiggle it wobbles a lot in your hands but if you hold it by the thick end the vibrations are well reduced to almost nothing.

So, it all depends on what end you want to stay still and what end you want to jiggle.. handle bars vs the wheel. That's why dirt bikes had upside down shocks first, the wheel had enough give to find its own grip.

Anyways...dunno if that makes sense to you, it doesn't to me when I re-read it.

I hear upright shocks are easier to make / service.

[cowpoos]

lighter unsprung weight,stiffer...externally tune-able

[Wolf]

That's oil with bubbles at the bottom,. ay.....
And water floats on it, I hear...

[Biff]

It's a fashion. Independent bikie type testers claim no difference in handling to rightwayupforks, alledgedly.

[Kickaha]

lighter unsprung weight,stiffer...externally tune-able

Exteranly tunable can be built in to any forks, I'd go for fashion as Biff said
(much as I hate to agree with anything he says)

[Marmoot]

the main reason is Bling factor to help sales.
"See, my bike is better than my neighbour's uncle's"

While doing that, they also discover extra stiffness.
"My stiffy is bigger than yours"

The bad thing is, if you smack your bike to something, the frame (in particular, the steering head part) is more likely to take a bend because the impact got transmitted to it instead of being soaked by normal fork which acts as a crumple zone......imagine, your fork crumpling.... :whistle:

[SARGE]

It reduces unsuspended weight...... which helps with corners...... and stuff


less unsprung weight means the suspension can react faster.. ie: throwing a shot-put v. throwing a softball

[wildpudding]

Ok sweet, thats just what I was after :niceone:

Cheers,

Stefan

[Beemer]

Oh, and I thought my bike had upside down forks just to look cool!

[cowpoos]

Exteranly tunable can be built in to any forks, I'd go for fashion as Biff said
(much as I hate to agree with anything he says)



It's a fashion. Independent bikie type testers claim no difference in handling to rightwayupforks, alledgedly.

well arn't those WSBK and motogp guys just fashion nuts then....

its lighter unsprung weight and stiffness....and externally tune able...

and yes kickaha...conventional forks can be made external adjustable...but it adds quite abit of weight to them....and limits the volume of oil that can flow because you are taking up more internal space and its increadably finicky to set up....thats why it isn't done

[Marmoot]

well arn't those WSBK and motogp guys just fashion nuts then....


They are, afterall, a moving billboards. Aren't they? :blip:

[Kickaha]

well arn't those WSBK and motogp guys just fashion nuts then....

its lighter unsprung weight and stiffness....and externally tune able...

and yes kickaha...conventional forks can be made external adjustable...but it adds quite abit of weight to them....and limits the volume of oil that can flow because you are taking up more internal space and its increadably finicky to set up....thats why it isn't done

Wasn't it the Honda 600 in Supersports using conventional forks until a year or two ago and doing quite well?

Wank factor same as underseat exhausts :bleh:

[laRIKin]

From what I under stand.
It's because it gives the treble clamps more to grip.
Because of the larger diameter giving a bigger surface area.
So when a MX bike drops out of the sky the forks stay in place and do not slide up the clamps.
And when you crash the forks do not twist in the clamps.
So they are stronger but there are pros and cons for both, so the std type are still used.

Rik

[Biff]

well arn't those WSBK and motogp guys just fashion nuts then....

Ooo get you. Time of the month sweetie? Apologies for (pretty much) quoting so called experts.

[cowpoos]

Wasn't it the Honda 600 in Supersports using conventional forks until a year or two ago and doing quite well?

Wank factor same as underseat exhausts :bleh:

well neat.....it didn't win a championship though did it....it probally got updated to up side downs because they wern't stiff enough....reducing the front end feel and control...

[cowpoos]

Ooo get you. Time of the month sweetie? Apologies for (pretty much) quoting so called experts.

bitch slap.....you are soooo sleeping on the couch tonight...........



OH and by the way......you never made me cum






:nya:

[Kickaha]

well neat.....it didn't win a championship though did it....it probally got updated to up side downs because they wern't stiff enough....reducing the front end feel and control...

All very nice on the track but for 99.9% of riders on the road :zzzz:

You could just as easily say they probably got updated so the fashion police wouldn't get them :bleh:

[Hitcher]

lighter unsprung weight,stiffer...externally tune-able
Surely the suspension system is "sprung" weight? I thought "unsprung" weight was rims and tyres? i.e. beyond the springs?

[cowpoos]

All very nice on the track but for 99.9% of riders on the road :zzzz:

You could just as easily say they probably got updated so the fashion police wouldn't get them :bleh:

you would notice more understeer with convetional forks...tendecy to run wide...and less confidence in the front end.... most sport bike riders would notice the difference

[cowpoos]

Surely the suspension system is "sprung" weight? I thought "unsprung" weight was rims and tyres? i.e. beyond the springs?

the sliders are unsprung...the tubes are sprung....

[Pixie]

And water floats on it, I hear...
Slightly off the subject,....when someone does a serious face plant,their brain smashes into the BACK of their skull

[gav]

Personally I'd take any information offered regarding suspension and handling from a TL1000S owner, with a grain of salt. How good is that rotary rear shock, mate? Why does the R1 have underseat exhausts yet Rossi doesnt get it?
AS for a claim that your capable of flexing the front forks enough so theynearly hit the headers? :whistle: (your forks are bent, if thats the case...)
Its all marketing hype.....

[cowpoos]

Personally I'd take any information offered regarding suspension and handling from a TL1000S owner, with a grain of salt. How good is that rotary rear shock, mate? Why does the R1 have underseat exhausts yet Rossi doesnt get it?
AS for a claim that your capable of flexing the front forks enough so theynearly hit the headers? :whistle: (your forks are bent, if thats the case...)
Its all marketing hype.....

Obviouly your one of these low intelligence types that are name callers to hide the fact their brain on regesters total lack of thought and consequences....okay...my TLs runs ohlins rear shock + robert taylor rebuilt front end with taxxion valves and the correct rate springs for my weight and bikes weight....inside of the tubes is coated with very low drag ceramic coating for less stiction...and low drag ohlins fork seals and dust seals...
So when you remove your foot from your mouth...why have u accused me of posting that I can brake hard enuff to make my front wheel nearly hits the headers??? I didn't post that.....
and yes....it is very very possable with conventional forks
do a rolling stoppie from about 50-60 kmph...and get some one to video tape those conventional forks on your honda....and watch it...you might be very surprised



Ps:underseat exhaust are power robbers common knowledge... :niceone:

[gav]

Thanks for your reply, however note that I didnt "quote" you, the flexing forks is another post, funny how these same forks are good enough to run on the WSS stage, AMA and BSB for many years, but not good enough for the road. Yes the forks may flex, but who says this is a bad thing? And why would I feel I had to do a rolling stoppie from 50-60kp/h? You may be aware that alot of the GP and WSBK teams are now trying to dial in controlled flex, but maybe these riders arent as hard on equip as some of the posters on here? Suprising that Suzuki couldnt find fault with rotary rear shock to start with and bin it before it ever made production.
ps Name callers? Me? check my post again sunshine, no name calling necessary :calm:

Oh what the hell....

Last edited by cowpoos : Today at 22:32. Reason: spelling
You want to have another go? Low intelligence indeed....... :dodge:

[cowpoos]

Thanks for your reply, however note that I didnt "quote" you, the flexing forks is another post, funny how these same forks are good enough to run on the WSS stage, AMA and BSB for many years, but not good enough for the road. Yes the forks may flex, but who says this is a bad thing? And why would I feel I had to do a rolYou may be aware that alot of the GP and WSBK teams are now trying to dial in controlled flex, but maybe these riders arent as hard on eqip as some of the posters on here? Suprising that Suzuki couldnt find fault with rotary rear shock to start with and bin it before it ever made production.
ps Name callers? Me? check my post again sunshine, no name calling necessary :calm:

Oh what the hell....

You want to have another go? Low intelligence indeed....... :dodge:

the flex they are after is from the head stock...for feel as the 16.5 inch rim reduces feel...as does 6o profile tyres seen on a few bikes in recent years..
suzuki's problem is they came up with a brillent concept for the TL...but when everything needed to be engineered they ran out of space for a conventional shock linkage...so thats why they had a small diameter spring place along the side of the engine and used the rotary shock for damping...the spring and linkage provided the digressive control required of a road bike and the rotary damper was a damping device for use in a small space so it got the tick...as none of the usual suspension companies had at the time a solution for suzuki...[showa.kyb,etc]...they were aware of its down falls...they tryed to improve it in the tlr...because it has far to much internal friction...so changing direction is a harder task...and they are near imposible to valve correctly...as they can't flow large volumes of oil quick enough to cop with large and or high speed impacts [also know as the blow off effect]
Fork flex is a bad thing as it induces understeer....which is a very bad thing...it causes people to ride off the side of the road into hard objects when they over cook it and freak out....panic....etc....look at the first hard object they see and hit it....
as for the time it takes to filter down to production motorcycles...well we can only guess...my bet is on manifacturing costs...but thats only a guess

[Marmoot]

wow....quite a heated debate and tomato-throwing......all just on a simple Bling-Factor object :whistle:

[Biff]

......all just on a simple Bling-Factor object :whistle:

That's so not true. Everyone with half a brain (that's me in) knows that USD forks help to reduce world poverty and make Jessica Simpson want to rub you down with the juice from the musk gland of a Guatamalan lesser spotted tree frog.

I like beer. :drinkup:

[Ixion]

Oh. are they supposed to be that way? I thought someone had stuffed up the putting together process. Uh, must go make an apology.

Then I' think I'll work on this brilliant idea I've had. If turning the forks upside down is a good thing, why not extend it and reverse the forks? Put the back wheel (and swing arm) at the front and the front wheel (and forks) at the back, Don't laugh, they laughed at the Earles fork too. And just ask any BMW nut how good they were.

[Aiolos]

Put the back wheel (and swing arm) at the front

http://www.motorcyclecruiser.com/newsandupdates/news031026/

Damn, that thing is ugly.

[Windy]

They are, afterall, a moving billboards. Aren't they? :blip:
And the bilboard owners want their bilboard to win the race.

All very nice on the track but for 99.9% of riders on the road :zzzz:

You could just as easily say they probably got updated so the fashion police wouldn't get them :bleh:
I'd say 100% of road riders, but development comes from the track where factories want that extra 0.1% to win. If it wins on the track people think it will make them faster so they will buy that bike.

USD skrof are better for a bikes handling, but RWU forks are plenty good enough for the majority.

Think about slipper clutches. They have a definate advantage for good racers, but none whatsoever for a road rider "Ooh the back wheel locks when I change down too many gears". Ever heard of a clutch :whistle: , or sympathy with your gearbox. Yet road bikes are appearing with slipper clutches, just because the racers can utilise that technology.

Simple equasion: (T*Rw)/m=s

T = Technology
Rw = Race wins
m = marketing
s = Sales

:laugh:

[dangerous]

my TLs runs ohlins rear shock + robert taylor rebuilt front end with taxxion valves and the correct rate springs for my weight and bikes weight....inside of the tubes is coated with very low drag ceramic coating for less stiction...and low drag ohlins fork seals and dust seals...
bling bling bling....... but can you ride it :mellow:


front wheel hits the headers??? yes....it is very very possable with conventional forks
:clap: :lol: :woohoo: :sleep: :doobey: :rolleyes:

[Mental Trousers]

Slipper clutch?? Who needs a slipper clutch?? Just wind the idle up to 2500rpm for zero engine braking :dodge:

[cowpoos]

Oh. are they supposed to be that way? I thought someone had stuffed up the putting together process. Uh, must go make an apology.

Then I' think I'll work on this brilliant idea I've had. If turning the forks upside down is a good thing, why not extend it and reverse the forks? Put the back wheel (and swing arm) at the front and the front wheel (and forks) at the back, Don't laugh, they laughed at the Earles fork too. And just ask any BMW nut how good they were.

earles were way a head of there time...and is a better system than any forks...same with girder type arrangments on the britten and a triumph factory racer I remeber seeing...and has also been seen on other bikes....the system used on the yamaha gts and bimota tesi is also good [better for braking] but lacks the adjustability of the girder type arrangments...bmw tele lever also has some very good merits....

[cowpoos]

And the bilboard owners want their bilboard to win the race.

I'd say 100% of road riders, but development comes from the track where factories want that extra 0.1% to win. If it wins on the track people think it will make them faster so they will buy that bike.

USD skrof are better for a bikes handling, but RWU forks are plenty good enough for the majority.

Think about slipper clutches. They have a definate advantage for good racers, but none whatsoever for a road rider "Ooh the back wheel locks when I change down too many gears". Ever heard of a clutch :whistle: , or sympathy with your gearbox. Yet road bikes are appearing with slipper clutches, just because the racers can utilise that technology.

Simple equasion: (T*Rw)/m=s

T = Technology
Rw = Race wins
m = marketing
s = Sales

:laugh:

okay....slipper clutches arn't nessicary at all...your right....but my god they are good...have you every ridden a big V-twin hard???? tip over a v-twin into a corner while using alot of engine braking your will probally end up in the weeds or cause a massive wooble....the have a lot of use for road riders....especially for attacking corners agressivly...

All I can think of here is that there are alot of people arguing against usd forks...that probally havn't got much feel when riding a bike...I can feel the diffderence between rwu and usd...you can hold a far tighter line with usd coz you don't have anywhere near the flex...hence less understeer...mid corner adjustments are far more accurate...

think about it....modern sports bikes of today would beat racer bikes of 5yrs ago around a race track....

[cowpoos]

Slipper clutch?? Who needs a slipper clutch?? Just wind the idle up to 2500rpm for zero engine braking :dodge:

hmmm......that was ment to be funny right?????

[limbimtimwim]

Hi everyone,

I am a little bit curious, what are the reasons why some bikes have inverted front forks? Are there any benefits with regards to handling etc? Or is it just bike manufactures trying to be different?Aside from the good things people have posted, USD forks do apparently have the disadvantage of more total weight. Apparently you have to have a stonger/less bendy (Re: heavier) top of the forks to get the advantage of the less bendy bottom bit. This can push cost up as well as more raw materiels and possibly and extra weld or four for the extra bracing. Or instead 'better' materials (Re: expensive) for construction to not increase the weight.

Apparently.

[cowpoos]

bling bling bling....... but can you ride it :mellow:



you wanna race !!!!! or a game of corner chicken old man???? :whistle:

[cowpoos]

Aside from the good things people have posted, USD forks do apparently have the disadvantage of more total weight. Apparently you have to have a stonger/less bendy (Re: heavier) top of the forks to get the advantage of the less bendy bottom bit. This can push cost up as well as more raw materiels and possibly and extra weld or four for the extra bracing. Or instead 'better' materials (Re: expensive) for construction to not increase the weight.

Apparently.

yes the are heavier...conventional forks are lighter than rwu cartridge...and usd cartridge forks are a little heavier still....but the unsprung weight is lighter on usd than either of the other two

[Wolf]

Then I' think I'll work on this brilliant idea I've had. If turning the forks upside down is a good thing, why not extend it and reverse the forks? Put the back wheel (and swing arm) at the front and the front wheel (and forks) at the back.
Elf's bikes had a parallel swing arm on the front to reduce diving under deceleration/braking.

My old Zundapp had a trailing link suspension on the front so it was almost like a swing arm, albeit a very short one. Used to rise on braking (rapid deceleration due to engine braking never occured, it being a blue-smoke).

[Mental Trousers]

Telelever was a single A arm that still used forks. It was a kludge and was more expensive and less efficient. Really the only thing it had going for it was the inherent anti-dive properties.

The Duolever is BMW's name for the Hossack. The Hossack frontend is essentially what the Britten V1000 etc use. It's a parallelagram style arrangement that uses unequal upper and lower A arms. Changing the lengths, angles and place they're attached gives a huge amount of control over the front end, including the ability to change the caster angle (rake) dynamically and tunable anti-dive behaviour.

The Hossack *should* be what all bikes use if you ask me. Economically they're cheaper to produce than forks, they offer superior performance and handling characteristics and can be adjusted to suit a wide variety of riders and styles. Unfortunately, forks do what people want well enough, they're already entrenched in the industry and Hossack style frontends can be a complete bitch to get right. They take a large amount of time to set up correctly compared to forks.

[Mental Trousers]

hmmm......that was ment to be funny right?????

Only partly. I used to do that when riding hard. Took a bit of fiddling to get the right idle speed so it wouldn't push when braking, but I was able to get into corners a hell of a lot smoother as it was more like a smoker under brakes, ie no engine braking.

[aff-man]

I noticed After riding zxr400 with usd forks and going to the cbr600 and now gsxr600 with RWU's, that the usd were a lot more firm. This lead to two/ a few tank slappers. The cbr and gixxer are softer but I dunno which i prefer more. If i was racing probably USD but on the road my experience (although very limited) has pushed me to RWU (this being said i have only ever ridden properly bikes 98 and younger, had a few goes on a k3600 and a 03 636 but not enough to really comment on the suspension)

[cowpoos]

I noticed After riding zxr400 with usd forks and going to the cbr600 and now gsxr600 with RWU's, that the usd were a lot more firm. This lead to two/ a few tank slappers. The cbr and gixxer are softer but I dunno which i prefer more. If i was racing probably USD but on the road my experience (although very limited) has pushed me to RWU (this being said i have only ever ridden properly bikes 98 and younger, had a few goes on a k3600 and a 03 636 but not enough to really comment on the suspension)


your feeling the damping...its nothing to do with the type of forks...its to do with how the internals are valved and spring rates

[Ixion]

Elf's bikes had a parallel swing arm on the front to reduce diving under deceleration/braking.

My old Zundapp had a trailing link suspension on the front so it was almost like a swing arm, albeit a very short one. Used to rise on braking (rapid deceleration due to engine braking never occured, it being a blue-smoke).

Ariel Arrow/Leader had a trailing link front too. Was quite common once

[vifferman]

yes the are heavier...conventional forks are lighter than rwu cartridge...and usd cartridge forks are a little heavier still....but the unsprung weight is lighter on usd than either of the other two
Yeah, that's what they say, and what I thought, but are they? :spudwhat:
Right-way-uppers: Unsprung weight is the alloy sliders, a few hundred ml of oil, cartridges/damper mechanism, and springs (I guess).
USD: Unsprung weight is the fork tubes, the piece at the bottom that the axle attaches to, springs. Oil is in the upper bit?? Damper stack etc too??

What's the weight of steel fork tubes plus bracket thingos compared to sliders?
Is there somewhere on the interdweeb that gives this sort of info?

[Marmoot]

That's so not true. Everyone with half a brain (that's me in) knows that USD forks help to reduce world poverty and make Jessica Simpson want to rub you down with the juice from the musk gland of a Guatamalan lesser spotted tree frog.

I like beer. :drinkup:

oh, now we're debating whether the debate is really worth debating or not.
:whistle:

[Wolf]

That's so not true. Everyone with half a brain (that's me in) knows that USD forks help to reduce world poverty and make Jessica Simpson want to rub you down with the juice from the musk gland of a Guatamalan lesser spotted tree frog.

Well, I won't be buying a bike with USD forks then - I don't want a sudden divorce.

[limbimtimwim]

The Duolever is BMW's name for the Hossack. The Hossack frontend is essentially what the Britten V1000 etc use. It's a parallelagram style arrangement that uses unequal upper and lower A arms. Changing the lengths, angles and place they're attached gives a huge amount of control over the front end, including the ability to change the caster angle (rake) dynamically and tunable anti-dive behaviour..BMW's latest frontend is adjustable electronically too. Aparently it's very good. Can't remember the model.

And, dare I say it, that same bike sounds fantastic down the pit straight of manfield..

[badblackbuell]

Had both road and trail, usd all the way, they take the big hits!

[Windy]

USD's have less unsprung weight. This is very important to handling. You want as little unsprung weight as possible as it makes the job of suspending your bike easier for your forks and shock.

[laRIKin]

I asked a suspension guy today a few questions today, only a few as he was busy.
One the main advantage with USD forks are strength, that is stiffer and better clamping in the treble clamps.
I asked about the unsprung weight. He just said that it is not a easy question to answer and did not even want to think about it, at the moment.
We for a joke got a few different forks and put them on our finger in the middle, to see the balance.
To our surprise, they balanced about in the middle of the length on the forks.

Rik

[Marmoot]

that's not true. He only wants to promote the USD fork for sales, and it works.
Real proof that it has great Bling factor and sex appeal.

:whistle:

[gav]

How about something like this then? Still got RWU forks, betcha there aint too much flexing going on with this setup?
An early CBR600 does have fairly spindly forks agreed, but also has a fairly basic steel frame too. However if lets say Honda chose too, I'm sure they could produce a bike with RWU forks that would satisfy 99% of the riders on this forum, who wouldnt be able to fault it. However as its deemed unfashionable then this is unlikely, but Honda were one of the last manufacturers to switch, the Fireblade for a long time ran RWU forks, never read of anyone complaining of the forks hitting the header pipes did ya?

[Biff]

Then I' think I'll work on this brilliant idea I've had. If turning the forks upside down is a good thing, why not extend it and reverse the forks? Put the back wheel (and swing arm) at the front and the front wheel (and forks) at the back, Don't laugh, they laughed at the Earles fork too. And just ask any BMW nut how good they were.

Been done good sir. By Benelli I think...on some new fangled concept come production machine. They sold in the UK for around 30K GBP new if mammories serve me correct. Tesla, Telsar...something like that.

First one to confirm I'm not barking gets bling......please.:mellow:

[gav]

Bimota Tesi?

[Biff]

Bimota Tesi?

Thanks Gav. Bling in the mail.

Looks more like a telilever (sp??) front end to me?

[inlinefour]

My new bike has then and I've never had a bike with them before. Feels a whole lot better than anything else Ive had but thats probably cause its new tecknaloligy. :mellow:

[laRIKin]

How about something like this then? Still got RWU forks, betcha there aint too much flexing going on with this setup?
An early CBR600 does have fairly spindly forks agreed, but also has a fairly basic steel frame too. However if lets say Honda chose too, I'm sure they could produce a bike with RWU forks that would satisfy 99% of the riders on this forum, who wouldnt be able to fault it. However as its deemed unfashionable then this is unlikely, but Honda were one of the last manufacturers to switch, the Fireblade for a long time ran RWU forks, never read of anyone complaining of the forks hitting the header pipes did ya?

As I said before, (in a round about way) their is nothing wrong with RWU forks.
In some way they are better. (cheaper and easy to tune)
The only real advantage in USD forks is their strength and for an off road bike I would go more for the USD forks because of that.
But for a road bike I would not care, its down to the tuning of the forks.

Rik
:brick:

[gav]

Yip, dead right there!

[Motu]

My FA 50 had USD forks,that was some seriously quality front end - when you carry an 11 plate battery in the front basket on gravel roads you want the strongest front end money can buy - I reckon I'd be dead now if it had conventional forks....I'm sold on USD forks now....

My BSA Bantam had USD forks too,you had to grease them with a grease gun,and black pus ran down the forks - way ahead of their time were BSA Bantams,the public just didn't understand.

[Ixion]

..
My BSA Bantam had USD forks too,you had to grease them with a grease gun,and black pus ran down the forks - way ahead of their time were BSA Bantams,the public just didn't understand.

:killingme :killingme :rofl: rofl:

they did too. so much for the "latest trend". So all these sprotsbikes are falling over themselves to emulate the handling of a bezza bantam :killingme :killingme

(I never broke 'em but, and Gawd knows I tried hard enough.)

[Brian d marge]

That would be the mighty D1 ,,,,a few here may have been emplyed by the post office riding one ....
The damping in those forks were constant AND they suffered little from seal stiction

Technology indeed

Stephen
I had a D7 with a 185 big bore kit and epoxyed transfer ports ,,,,,its still being seen round london !!!

Stephen

[Brian d marge]

The 2nd moment of Inertia changes from just under the bottom clamp to the axil ( gets smaller ) so in the place of Max bending they are the stiffist ...and as the seals are placed at a part of the fork with the largest area the seal suffers from stiction WHich is NOT friction but a product of friction .
So the RSU fork has a lower area But is not as stiff So in EXTREME circumstance they will bend more for a given force ...translated unless you are doing a stoppie ,,or are running slicks that are up to temp ...or are called rossi ....or just a legend in your own life time ( me ) you wont notice much if any difference forks under heavy loads actually walk in a figure eight AND I have been watching ,,,but havent seen them do it yet ..must be when I am asleep .......
The damping controll is similar ,,,crude

but at the end of the day ,,,I like USD forks they look nice ,,,,,,,

Stephen

[cowpoos]

As I said before, (in a round about way) their is nothing wrong with RWU forks.
In some way they are better. (cheaper and easy to tune)
The only real advantage in USD forks is their strength and for an off road bike I would go more for the USD forks because of that.
But for a road bike I would not care, its down to the tuning of the forks.

Rik
:brick:

are you talking about rwu cartridge or conventional with emulaters?

USD forks are a cartrage fork mounted usd...and all catridge forks have far better/easyer tunablility than conventional forks