Suspension history of USDs?

[Blackflagged]

Hi been looking for suspension history, in particular usd`s. First started when, on what models, but google not that helpful, mentions upside down forks on say wiki not no really specific.Anyone have any links or info.

[pete376403]

Possibly not quite what you mean but speedway bikes have had USDs just about forever.

Ivan Maugers gold plated bike from 1970

[Motu]

The BSA Bantam....and that means probably on the DKW as well. So that's pre WWII.

[Blackflagged]

Considering there reasonable recent on volume production bikes, you would think there would be more info.There seems more History published on earlier styles.

"Just on more searching looks like WP claim to be first volume producer on MX models.Found a little (Very) info

[Motu]

Seeing as they are just a reinvention of what has gone before, you'll probably find only manufacturers blowing their own trumpet.

[Blackflagged]

Close the Patent Office!

Was more trying find Adjustable USD Fork use , before say 1990.
Some Huskys, Ktms, Ducati (Racebikes) ,Kawasaki ZXR250 anything else spring to mind ? Who reinvented them around there.
WP say 1986 on above mx models, and they did some GP bikes aprox early 90`s

[TLDV8]

...before say 1990.


Did Simons do a USD fork,can't remember.? early 1980's or late 70's ?
My 1986 Husqvarna has had 86 40mm WP USD's (off a KTM Rotax 600) since 1990,non externally adjustable though.

[Hitcher]

Is there a history of RWUs?

[Blackflagged]

According to Wikipedia."The first production motorcycles with hydraulically damped telescopic forks were the German BMW R12 and R17 in 1935"

[TLDV8]

The first USD forks by todays standards did not come on a brand motorcycle,they were a brand and in off road.
Looks like that was around 1982 as per the post already.

[Blackflagged]

Which Simons? Can`t find any info, maybe using wrong search terms

[TLDV8]

Simons was a US fork maker,first with a conventional fork then a USD.
They like Fox Shox are sought after these days (eBay)
Apparently (1934) Nimbus was the first manufacturer to produce a motorcycle with hydraulically damped telescopic forks.

[F5 Dave]

Brad Lackey was running them (Simons) on his RM500 when he won the 500 MX title, that was 82 I'm pretty sure (quick google) yup 82.

[jellywrestler]

Close the Patent Office!

Was more trying find Adjustable USD Fork use , before say 1990.
must be tough having a closed mind eh?

[manxkiwi]

There's an early picture in this thread, in the Racing section.


http://www.kiwibiker.co.nz/forums/showthread.php/160408-Pacific-Club-Endurance-Races-5-October-Manfeild/page3

[fridayflash]

in their modern form i remember production mx and enduro bikes having them from 1989 onwards...mostly the 125's and 250's. i remember the 'new at the time' rmx250 had them

[fridayflash]

and of course they became de rigueur throughout the '90s, their main advantage being the lack of underhang below the front axle...although i cant recall the last time i was thrown over the handlebars due to my rwu forks snagging me to a halt in a rut:sleep:
im sure dr robert could fill us in on any technical advantages of them over rwu's

[ellipsis]

...my earlier bikes all had upside down forks at some point in their lives...nearly always ended up with broken ribs or shit like that, just after they turned USD..

[T.W.R]

Close the Patent Office!

Was more trying find Adjustable USD Fork use , before say 1990.
Some Huskys, Ktms, Ducati (Racebikes) ,Kawasaki ZXR250 anything else spring to mind ? Who reinvented them around there.
WP say 1986 on above mx models, and they did some GP bikes aprox early 90`s


The first USD forks by todays standards did not come on a brand motorcycle,they were a brand and in off road.
Looks like that was around 1982 as per the post already.

WP in 1983 1st mass supplier of USD for KTM :msn-wink:

[F5 Dave]

Suzuki FA50 std fitment from 1980, but heaps of examples before that. The woeful Bantam has been mentioned before, and there's not much arguing that wasn't mass produced. Can't be bothered to check if the DKW the design was stolen from was usd.

[Crasherfromwayback]

Considering there reasonable recent on volume production bikes, you would think there would be more info.There seems more History published on earlier styles.

"Just on more searching looks like WP claim to be first volume producer on MX models.Found a little (Very) info


The first USD forks by todays standards did not come on a brand motorcycle,they were a brand and in off road.
Looks like that was around 1982 as per the post already.


Which Simons? Can`t find any info, maybe using wrong search terms


Brad Lackey was running them (Simons) on his RM500 when he won the 500 MX title, that was 82 I'm pretty sure (quick google) yup 82.

Yep. Simons UDX60's. Worth big money now. Was a new set on TM a while back. Similar to the sort of money Fox Factory Forx fetch..sometimes more.

[jellywrestler]

henderson fours went to usd's before WW1

[manxkiwi]

im sure dr robert could fill us in on any technical advantages of them over rwu's

I'm under the impression that the main difference is that USDs have a slightly lower unsprung weight. I don't think there's much in it with regard to rigidity. Would be interested to hear if that's not the case and/or what else there might be.

[F5 Dave]

Why would you think that?

What are the differences in the tube sizes comparatively? & would you think that would make a difference?

[manxkiwi]

Why would you think that?

What are the differences in the tube sizes comparatively? & would you think that would make a difference?

Just the impression I was under, I did say 'unsprung weight'. I would have thought an USD lower was lighter than a RWU lower. They're normally quite chunky cast aluminium (RWUs). I think USDs might well be lighter overall too. They're like eggshells on wall thickness. RWU stanchions are usually pretty heavy walled steel. Though there is the caliper mounting system difference too to consider.

Just my thoughts, I don't know if it's actually the case. As I said I'd be interested to hear if this is correct or myth.

[F5 Dave]

Just like frames. Bigger tubes = more rigidity. The smallest diameter tube is also the shortest instead of the longest.

As with monoshock rears (the increased size helped), but they conincided with proper shimmed damping.

[T.W.R]

Suzuki FA50 std fitment from 1980, but heaps of examples before that. The woeful Bantam has been mentioned before, and there's not much arguing that wasn't mass produced. Can't be bothered to check if the DKW the design was stolen from was usd.

Bantams and a few other makes at the time were direct copies of the DKW RT125 and the Royal Enfield flying flea was a copy of the RT100 but with rigid suspenders


henderson fours went to usd's before WW1

mmm nah they had two variants of a springer front end either trailing or leading linkage even when Schwinn brought he brand in 1917 they stuck with the same design; even the 1925 1300cc De Luxe was springer front end

[pete376403]

Bigger diameter upper tube means more contact area between tube and triple clamps, which apparently means a more rigid assembly.

Among other reasons.

[malcy25]

Close the Patent Office!

Was more trying find Adjustable USD Fork use , before say 1990.Some Huskys, Ktms, Ducati (Racebikes) ,Kawasaki ZXR250 anything else spring to mind ? Who reinvented them around there.
WP say 1986 on above mx models, and they did some GP bikes aprox early 90`s

Being that I am of the suspicious type, I'll ask the question of "why do you you need to know?" Are you you specifically asking for your own general interets and furthering your knowledge base, or given the date you have noted in the your post above of "before say 1990", are you heading in a pre 89 race bike legality question?

If the later, you'll want to pay particular attention to the the specific pre 89 rules around forks that can be used, and when. It's very much a case of just because USD forks existed pre 1990, doesn't mean that any USD fork can be used. Period Ohlins and WP forks can be used where there is proof they were used on a specific model (ie Olins on Bimota YB4, 888 Corsa OW01, YZR500), or appropriately old enough WP's on say a AF1 250 Aprilia GP bike. ZXR400 are the only obvious USD fork /OEM production model and the rules are such that these are allowed, but only on a ZXR400. Essentially to stop every bike arriving with a set of ZXR400 forks on them.....

[F5 Dave]

Sweet! Due to this post I can now pull out my Ex Lawson YZR & legally use USDs in Posties.


Now it was around here somewhere. . .

What's under this sheet? Drat an XZ400.

Hmm. . .CX500 Custom, no. . .

MVX250, no. . . .hmm.

Ohh, GPz305, but no,

Hey I didn't remember this Hesketh,

bah,

it'll show up I'm sure.

[husaberg]

Yep. Simons UDX60's. Worth big money now. Was a new set on TM a while back. Similar to the sort of money Fox Factory Forx fetch..sometimes more.

Simons "invented LOL" inverted forks and were used during the 1981 season on the Suzuki 250's in the us MX series i have a pic here in a book.
My 1954 James captain has them too......

[Crasherfromwayback]

Simons "invented LOL" inverted forks and were used during the 1981 season on the Suzuki 250's in the us MX series i have a pic here in a book.
My 1954 James captain has them too......

Yeah think they mean birth of the modern USD unit eh.

[MVnut]

In the jungle we just make our own

[Waihou Thumper]

Close the Patent Office!

Was more trying find Adjustable USD Fork use , before say 1990.
Some Huskys, Ktms, Ducati (Racebikes) ,Kawasaki ZXR250 anything else spring to mind ? Who reinvented them around there.
WP say 1986 on above mx models, and they did some GP bikes aprox early 90`s


My 1989 aprilia Tuareg has them, aprilia boasted that they were state of the art..HUH?

[malcy25]

Sweet! Due to this post I can now pull out my Ex Lawson YZR & legally use USDs in Posties.


.

if ya got the right "period legal USD's that were used on it, yep, bring it on!! :yes:

[F5 Dave]

Still looking. Sure we'd left it here somewhere between the Bimoto Mantras (5 of), Robert Stark Aprilia 650 & CB250Ns. :blink:

[Crasherfromwayback]

Bad Brad on the charge.

292330

[ktm84mxc]

I believe the first over the counter USD's were fitted to some 1983 KTM models in a production bikes as OEM parts. They offered more rigidity and less/no fork over hang but were deemed to harsh and lead to unnecessary triple clamp and frame flexing/breakages.
The Simons were an after market supplier similar to FOX with there air shocks and fork kits.

[Jay GTI]

I read somewhere ages ago that the main reason for the mass adoption of USDs over conventional/RWUs was way more to do with fashion than the claimed benefits. Once they started turning up on the factory MX'rs, the public started demanding them and, as with alloy frames and fuel injection more recently, it soon got to the point where you couldn't sell a MX bike if it didn't have USDs. Nothing dated a bike visually more than the old RWU forks...

Suspension guys of the time apparently could easily get RWU's to perform as well, if not better than USDs (can't remember off-hand, but seem to recall that RWU's have some of their own advantages).

[Robert Taylor]

In terms of road racing and the development that never ceases USDs have overall more benefit than RWU forks. In the roadbike world as much is owed to marketing and all the spin applied by salesmen.

[F5 Dave]

Underseat Exhausts anyone?


. . .Well ok 3MA(reverse TZR), & RG/RZ500 its permissible, but they are technically superior to 1/2 time engines so they can cope.

[mr bucketracer]

the honda NR500 was the first roadracer i think had the start of a modern looking USD forks

[manxkiwi]

the honda NR500 was the first roadracer i think had the start of a modern looking USD forks

Maybe looked like USDs, pretty sure they weren't on the NR or the NS. You have to get to around '89 or so for USDs, in 500 GP anyway.

Interesting what Robert said about the racing advantages, care to expand Dr Bob?

[F5 Dave]

. . ., care to expand Dr Bob?
Put him on a diet of Pies & fizzy drink, that should do the trick.

[mr bucketracer]

Maybe looked like USDs, pretty sure they weren't on the NR or the NS. You have to get to around '89 or so for USDs, in 500 GP anyway.

Interesting what Robert said about the racing advantages, care to expand Dr Bob?http://www.google.co.nz/imgres?imgurl=http://www.motorcyclespecs.co.za/Classic%2520Racers/Honda%2520NR%2520500%2520GP%2520Racer.jpg&imgrefurl=http://www.hondatwins.net/forum/viewtopic.php?f%3D23%26t%3D21161%26start%3D90&h=500&w=800&sz=66&tbnid=wTvdWWnXm7DvBM:&tbnh=90&tbnw=144&zoom=1&usg=__zbS0snKJF2nE07QunPTSy0RD_a4=&docid=y9cCg8qeDlQMnM&sa=X&ei=8erWUtO9JcHIkwWz94HwDQ&ved=0CFUQ9QEwBw

[husaberg]

the honda NR500 was the first roadracer i think had the start of a modern looking USD forks

I have a write up somewhere the bike had a lot of firsts on it side mounted rads etc etc.
it also had some bloody silly things as well. Ron Williams (manxton) sorted out the MK2 versions with a conventional chassis with conventional size wheels etc etc.

[ktm84mxc]

The first NR500 was a racing disaster but was a designing master piece oval pistons, 8 valves per cylinder, side mount radiators, monologue chassis etc.
It was so slow a TZ350 or KR350 would give it a serious hurry up. The first NSR same thing fuel tank under the engine , pipes were the tank should be , super fast engine but it would not turn corners. For a long time engines out performed the chassis they were fitted in.

[manxkiwi]

http://www.google.co.nz/imgres?imgurl=http://www.motorcyclespecs.co.za/Classic%2520Racers/Honda%2520NR%2520500%2520GP%2520Racer.jpg&imgrefurl=http://www.hondatwins.net/forum/viewtopic.php?f%3D23%26t%3D21161%26start%3D90&h=500&w=800&sz=66&tbnid=wTvdWWnXm7DvBM:&tbnh=90&tbnw=144&zoom=1&usg=__zbS0snKJF2nE07QunPTSy0RD_a4=&docid=y9cCg8qeDlQMnM&sa=X&ei=8erWUtO9JcHIkwWz94HwDQ&ved=0CFUQ9QEwBw

Bugger me! I bow to your superior knowledge. Next question; did they race with that set up?

[manxkiwi]

Now look what you've made me do! Had to spend an hour searching pictures of NR500s, he he. Not that I mind.

Looks like Grants' Silvestone bike had that set up. Though there are versions with conventional forks too.

You get a stripe on your anorak Mr. Bucketracer.

[F5 Dave]

The first NR500 was a racing disaster but was a designing master piece oval pistons, 8 valves per cylinder, side mount radiators, monologue chassis etc.
It was so slow a TZ350 or KR350 would give it a serious hurry up. . .
That's because the engine had one design fault they couldn't overcome. - It only worked 1/2 the time. Every alternate downstroke failed to produce any power.

[ktm84mxc]

True the rules of the time rendered it a failure eg maximum 4 cylinders, 500 cc max capacity.
Honda tried to build a V8/V4 using oval pistons etc.
Remember all of this happened some 35 yrs ago when the best street bike was a GS1000s or CB900f, remarkable achievement and lead to the VFR series and RC30/45, RCV etc.

[mr bucketracer]

That's because the engine had one design fault they couldn't overcome. - It only worked 1/2 the time. Every alternate downstroke failed to produce any power.but did make a amazing 120hp double that is 240hp like a moto gp engine

[mr bucketracer]

Now look what you've made me do! Had to spend an hour searching pictures of NR500s, he he. Not that I mind.

Looks like Grants' Silvestone bike had that set up. Though there are versions with conventional forks too.

You get a stripe on your anorak Mr. Bucketracer.oh lol my first stripe :woohoo:

[Robert Taylor]

That's because the engine had one design fault they couldn't overcome. - It only worked 1/2 the time. Every alternate downstroke failed to produce any power.

Yes, these 1/2 time engines need capacity to produce similiar power. Look at MX. Problem is when they spill their guts ( and they do ) its mortgage your house material. Progress?

Less is more

[husaberg]

Now look what you've made me do! Had to spend an hour searching pictures of NR500s, he he. Not that I mind.

Looks like Grants' Silvestone bike had that set up. Though there are versions with conventional forks too.

You get a stripe on your anorak Mr. Bucketracer.

I will post an article as it appears i are getting usurped in the Anorak stakes.:sweatdrop
I am surprised you guys spend so long on the net without posting this though (will add later)


You can have it as a ringtone here.....
http://world.honda.com/MotoGP/history/RC166/ringtones/index.html
The other galleries section show and sound the NR500 the nsr500 http://world.honda.com/MotoGP/history/NSR500/video/02/index.htmlrc211v rc166,rc142 etc.


They would get by because they have no options. When the FIM brought in the rules for how many cylinders limiting at first the 50's (later 80cc's)to one. The 125's to two (later one) and the 250's and 350's to two 500's two four the one common rule was gearbox's with no more than 6 gears were allowed.
Remember the speed (155 to 160mph) i posted for the Yamaha 250V4 it took years for that to be matched with the more restrictive rules.
Suzuki when they pulled out in the 60's had been testing the 50cc/3 with god know's how many gears(at least 18) The riders were faster on the twin though.

http://world.honda.com/MotoGP/history/NR500/
You can hear it as well on the site same as the NSR and the RC166 etc etc great site
scanning story as i type.
As you will see in the article the origional was a V8 and was legal because it had only 4 combsution chambers honda wouldn't race it even though it was legal as they didn't want to be accused of being dodgy........
The 250 twin Turbo they built for Freddy was also oval pistoned and made more power i posted some stuff about it a while back can't remeber where but i will link it later.The rule allowing its use never evenuated so it was shelved.

[pete376403]

I read a really good article by Gordon Jennings (or maybe Kevin Cameron) about the NR500, the writer predicted the whole engine layout based on viewing and measuring 1 conrod, combined with the rumours that had gone around about the bike. The predictiony turned out to be remarkably close when Honda released details of the engine.

The NR could have been something if Honda hadn't felt the need to combine so many untried ideas in one hit.

[husaberg]

I read a really good article by Gordon Jennings (or maybe Kevin Cameron) about the NR500, the writer predicted the whole engine layout based on viewing and measuring 1 conrod, combined with the rumours that had gone around about the bike. The predictiony turned out to be remarkably close when Honda released details of the engine.

The NR could have been something if Honda hadn't felt the need to combine so many untried ideas in one hit.
all the engineers were bloody young and were blooded on the NR500 given free reign as it were.
Afterwards once Honda got it going good..... they did what they could have done all along and built the NS500 and won with it.......
Corporate version of jerking off.... they did the same with the EXP2
Anyway last page of the NR500 i also have a write up of the 750 (not the road one) but the Endurance racer that Mal Cambelll raced in the Swan series or what not.
The NR500 write up was in Classic Racer in 1987.........

[ktm84mxc]

Yes a great article I remember a large article in Cycle World in I think 1980 on the NR500 with pxts of the engine internals and dual conrods etc a in depth story. the technology used was beyond even F one cars at the time engine wise. Hell the engine could run to almost 19000 rpm etc on a normally aspirated engine.

[husaberg]

Yes a great article I remember a large article in Cycle World in I think 1980 on the NR500 with pxts of the engine internals and dual conrods etc a in depth story. the technology used was beyond even F one cars at the time engine wise. Hell the engine could run to almost 19000 rpm etc on a normally aspirated engine.

they ran them past 22000 according to some up to 28000 the tacho was not numbered at times.
Cameron mentions octane does funny things at ultra high RPM like it doesn't need over 80 octane etc and won't detonate at all.
I have another one somewhere with the 500 but no idea what Mag it was in.

[manxkiwi]

Back to the subject of forks for a moment. Robert, when you say USDs have a slight advantage in racing, are you meaning to work on? From a sus. tech. point of view.

As I said earlier in this thread, I don't think there's a massive performance/rigidity benefit over RWUs. Does it have anything to do with unsprung weight? Would love to hear your wiewpoint on them.

[haydes55]

Back to the subject of forks for a moment. Robert, when you say USDs have a slight advantage in racing, are you meaning to work on? From a sus. tech. point of view.



As I said earlier in this thread, I don't think there's a massive performance/rigidity benefit over RWUs. Does it have anything to do with unsprung weight? Would love to hear your wiewpoint on them.










My understanding with USD forks, is the lighter, skinnier part of the forks are now the parts moving, so move faster, easier.

[Ocean1]

My 1954 James captain has them too......

My first store-bought (second hand) bike was a James. 250 scrambler. Forks were conventional though.



Fuck I'm old...

[husaberg]

I will post an article as it appears i are getting usurped in the Anorak stakes.:sweatdrop
I am surprised you guys spend so long on the net without posting this though (will add later)



http://world.honda.com/MotoGP/history/NR500/
You can hear it as well on the site same as the NSR and the RC166 etc etc great site
scanning story as i type.
As you will see in the article the origional was a V8 and was legal because it had only 4 combsution chambers honda wouldn't race it even though it was legal as they didn't want to be accused of being dodgy........
The 250 twin Turbo they built for Freddy was also oval pistoned and made more power i posted some stuff about it a while back can't remeber where but i will link it later.The rule allowing its use never evenuated so it was shelved.


My first store-bought (second hand) bike was a James. 250 scrambler. Forks were conventional though.



Fuck I'm old...
they went to FB AMC forks later. i think the usd "grease dampened" forks only were up to 53 or 54 they we almost exactly the same as Bantam likely same gaiters and all....

[Ocean1]

they went to FB AMC forks later. i think the usd "grease dampened" forks only were up to 53 or 54 they we almost exactly the same as Bantam likely same gaiters and all....

Don't know what year mine was, I bought it in bits and there was no indication anywhere. Was the later frame they made for scramblers (the non-Cotswold one?) but it had the Villiers which I don't think was usual for the 60's scramblers.

The forks were shit of course, but everything was shit compared to current stuff. And the tracks weren't anywhere near as aerial, so I was quite happy. Was surprisingly quick when you got it right.

[gavinnz]

Moto Guzzi used upside down forks on their singles from about 1948 until 1967.
I think Scott might have had the first? I remember reading a "first" article in Classic Bike years ago and the first telescoping fork was on a Scott in about 1908 and it was USD.

Check out this picture of a 1913 Scott....

http://en.wikipedia.org/wiki/File:Scott_550_1913.jpg

Regards
Gavin

[ktm84mxc]

Didn't Honda's CB350F have USD forks or was it just they looked like modern USD's ?
There have been many a design to MC front ends Earls, Springer, Canta lever, BMW's para system etc. Almost as many as rear suspension designs.

[husaberg]

Didn't Honda's CB350F have USD forks or was it just they looked like modern USD's ?
There have been many a design to MC front ends Earls, Springer, Canta lever, BMW's para system etc. Almost as many as rear suspension designs.

nah they were the rwu same as these twins (one with shouds the other with rubber gators for the SS look)
they had shrouds either to cover the external springs or the unplated sliders or sometimes both (ie Norton BSA etc) like a lot of other bikes mentioned....
the Z50s and so forth plus a lot of Scooters were also USD.....or Male Slider because they could be made cheaply as a fabrication exactly like the James USD fork.
A lot of the early 90 forks were about looking hi tech and they were no better then the conventional forks they replaced most were not even cartridge.


My understanding with USD forks, is the lighter, skinnier part of the forks are now the parts moving, so move faster, easier.
with the slider mounted below they can be made with less unsprung weight
they can aslo be stiffer as the most stress is in the area below the fork yoke. Which is why those 80's fork braces were just a fashion accessory, what you needed was a deeper yoke.

[TLDV8]

Yep. Simons UDX60's. Worth big money now. Was a new set on TM a while back. Similar to the sort of money Fox Factory Forx fetch..sometimes more.

Off topic but it seems a lot of those parts in general are spendy these days.
I brought a RM125S new from Colemans in 1976 (in box's now) some time in the 1990's (iirc) I was at Mount Eden Motorcycle Wreckers when you could just wander around looking for parts (H2 parts) and what did I find,a mint DG radial head for said model RM125 asking price $15.
I could probably double my money.

The BSA (DKW) Bantam had a USD of sorts but its a stretch,based more on cost and ease of manufacture perhaps.

[Crasherfromwayback]

Off topic but it seems a lot of those parts in general are spendy these days.
I brought a RM125S new from Colemans in 1976 (in box's now) some time in the 1990's (iirc) I was at Mount Eden Motorcycle Wreckers when you could just wander around looking for parts (H2 parts) and what did I find,a mint DG radial head for said model RM125 asking price $15.
I could probably double my money.

The BSA (DKW) Bantam had a USD of sorts but its a stretch,based more on cost and ease of manufacture perhaps.

Nice find mate! And double your money? Fuck me...a mint DG head for your RM would fetch around 4-5 hundred US on Ebay I'd think mate.

[husaberg]

Nice find mate! And double your money? Fuck me...a mint DG head for your RM would fetch around 4-5 hundred US on Ebay I'd think mate.

Go back a few pages on the ESE thread.
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130724331#post1130724331