suspension yea or nay

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Stayt`ie
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Re: suspension yea or nay

Post by Stayt`ie » Sat Mar 29, 2014 6:44 pm

rgn wrote:Just say you were doing 150 mph but with twice as many deviation in the racing surface, or 75 mph with four times as many. :D

Motorcycle road-racing suspension these days is something special in itself. High-end rear shocks have low and high speed damper circuits, and separator valves that 'as much as possible' isolate the compression and rebound circuits from each other. I'll try to get some telemetry data off a friend who crews one of the top motogp riders. These bikes commonly do well over 200 mph these days. (lap after lap)

Sometimes you will see telly on-board footage, with a rear facing camera looking at the rear suspension working, it's quite amazing to see.

I really don't understand why it is perceived that LSR is any different to any other elite form of motor-sport? That it is thought the laws of physics that apply every where else in the world, don't apply on the salt.

Using treaded tyres, pumped up to whatever, (certainly beyond what they are supposed to run at) lead on swing arms, solid rear ends? Can someone please explain?

Anyway, as I said I'll try to get some data. I'm open to to doing some field research on the topic, on the salt.

Last year, our bike felt like it was running down a newly surfaced freeway. The only deviation experienced was soft salt on our last run when the bike bogged down, and I ended the run.

I've got to say we did pay attention to what was commonly said about slip etc, and geared far to tall, with only 2 runs after rookie licencing, it was obvious that our best speed would be achieved at beyond red line in 5th gear. So we let the tyre down to minimum recommend pressure, off the tyre warmers... (gearing change) and ran it like that.

I'm just providing anyone interested, with a different point of view for consideration.

uummmm, i seem to recall a multi million dollar funded F1 Team running at Bonneville a cuppla years back,, thay made no secret about the fact that thay were gunna show everybody "how to do it",, went home with their tails between their legs, have never come back, :? :lol: , apples and ummm, lemons,, :lol:
First Australian to ride a motorcycle over 200mph at Bonneville,,,

rgn

Re: suspension yea or nay

Post by rgn » Sat Mar 29, 2014 6:49 pm

if they owned the outright production motorcycle record in Australia, and the outright 1650cc PP record on salt to date in the the world, would you still forsake them?

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Greg Watters
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Re: suspension yea or nay

Post by Greg Watters » Sat Mar 29, 2014 6:58 pm

Brett is definitely the fastest, he is doing it with less hp and better aero, but the connection between his tyre and the salt is still only good for x hp and if he exceeds that he will get wheelspin,
The only way to better that connection is to tie it down better, on the blacktop you use better rubber , on dirt better knobbys
on the salt the best option i have seen is weight, , unlike most other forms of motorsport that are for the most part acelleration contests , we are not disadvantaged so much by a weight increase (unless its placed in the wrong spot and causes handling issues)

Stayt`ie
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Re: suspension yea or nay

Post by Stayt`ie » Sat Mar 29, 2014 7:05 pm

mate, im not forsakeing what you have done,, however in your inital post you make direct comparasons to well funded factory race teams racing on ashphalt circuts, achieving 200mph, allbeit for approx 10 seconds at best,, i do find it difficult to relate that to LSR on salt, where we are trying to put power to ground over three miles for approx a minute or more,, the F1 team i mentioned thought it was gunna be easy, didnt happen, why :?:
First Australian to ride a motorcycle over 200mph at Bonneville,,,

hawkwind
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Re: suspension yea or nay

Post by hawkwind » Sat Mar 29, 2014 8:15 pm

Edit: one question is do you need 400 hp? Wheel spin is fine if you want to spin your wheels. Lead is fine if you want your rear wheel to be in contact with the racing surface 1/2 of the time of each bump. I believe Brett runs with around or less than 200 rwhp, and he is the fastest bloke on a sit on in this country.[/quote]

Rgn.....why 400hp..... physics :D its the relationship between drag /velocity as drag increases to the square of velocity and the power to overcome that drag is to the cube.......In Brett's case as Greg stated its the superior aerodynamic package of his bike .....he will hit the wall at some stage and will require more power or better aerodynamics to go faster ....If he uses more power he will experience traction issues ....In my case im chasing 230mph in the naked class so I don't have the benefit of an aerodynamic advantage so I must rely on brute HP yes in excess of 400 :shock: to put that to the ground I need bulk weight ....what im trying to ascertain is will suspension help ...hinder ... or be neutral in this task? ......As there are teams that have achieved high speeds and records with and without suspension ...if I can get there without I can invest my very limited funds to other areas i.e. making HP.
cheers
Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
Rider......................... Tardus Vetus Inflatio

Stayt`ie
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Location: Mackay

Re: suspension yea or nay

Post by Stayt`ie » Sat Mar 29, 2014 9:49 pm

Garry, i had the pleasure of crewing with/for Richard Assen at Bonneville 2008, 2009 and 2011, something like 20 days of valuable experience on a bike that ran consistant 240 and 250mph's, eventually taking the FIM World Record at 262+ at the 2011 Shootout, at the time the fastest siton bike on salt(two ways),, there was a period in 2011 where Richard was struggling to find more speed and we discussed at lenght how to rectify it, suspenshion was one topic covered, i will not say what was eventually done to get the bike up to speed, but, "his bike had suspension", i believe that it would go faster without, but having said that, its a matter of personal openion, whatever one feels happy with, and it was his gig, :D ,
have gone on from there and applying lessons learnt into my project,, one thing to be "very aware of", is just how "fast" a bike is when one gets up into those speeds over 220, there are forces at play(faired and naked) that until you have "experienced" them, you cannot begin to imagine,, Bonnevilles air is noticably thinner than Gairdner, that is, "on the body", so one very important design feature i would suggest in your build is to get yourself out of the wind as much as possible, work towards no body/head movement once you start getting anywhere north of 180,, at G13 i went for 6th (approx 190), in the instant that i slowly opened my hand and relaxed my leg (weight eased on peg), the wind caught my hand, and my knee area, luckily i grabbed the very end of the handlebar with thumb and forefinger, then had to work my (hand) fingers up the bars, meanwhile fighting to keep my leg from getting torn off the footrest, couldnt just pull the knee in against the wind because of my hand situation,, i now have an air shifter fitted,, i know you have been over 200 on a faired bike, mate, that is like sitting in your favourite armchair at home compared to these naked bikes,, as you have rightly stated above, not only is so much extra power in the motor required to go faster,it also relates to the rider,, 200 is a long way from 100, 230 is so much further , :wink:
First Australian to ride a motorcycle over 200mph at Bonneville,,,

David Leikvold
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Re: suspension yea or nay

Post by David Leikvold » Mon Mar 31, 2014 9:17 pm

Has anyone considered building a bike like Dan Gurney's Alligator? It sure looks strange but it gets the rider well out of the slipstream and it is FF. A frame could easily be built to give the bike a tiny frontal area and very good aerodynamics.

Cheers
Dave :D
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David Leikvold
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Re: suspension yea or nay

Post by David Leikvold » Mon Mar 31, 2014 9:38 pm

Or something like this but without the roll cage.

http://www.gizmag.com/suprine-exodus-re ... cle/28398/

Cheers
Dave :mrgreen:
Good, Fast, Cheap, pick any two!

hawkwind
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Re: suspension yea or nay

Post by hawkwind » Tue Apr 01, 2014 6:22 am

By golly Dave I do believe you are on the right track :)......Yes I have those and many more designs in my designers chest, I'm pretty much set on an FF layout as having the best chance of success.....a still born Royce Creasy concept is where I'm placing most of my eggs at present.

cheers
Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
Rider......................... Tardus Vetus Inflatio

rgn

Re: suspension yea or nay

Post by rgn » Tue Apr 01, 2014 5:53 pm

Groupthink is something you are going to have to look up yourselves. It’s a danger to progression and direction.

I’m not saying I have the answers, but in the same way I’m not dismissive of anything any one does in this sport to make a greater result, to achieve a better outcome.

What I have been doing is sharing what the team did to achieve what we achieved. In all of the Australian Production classes (all) no one has gone faster than us in Australia. On salt in the world, 1650 PP, we have the fastest recorded record.

We stopped while we were on our way to Mt Ive Station, for the Black-Ice team, who’s trailer axle had broken in half.

They had attempted a repair with the homesteads help but it had failed. So we sorted it out for them and got them home I believe.

During the conversation, he asked us whether our recorded record speed was a mistake. What an ungrateful bastard? Well, I wonder about all of yours as well.

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Greg Watters
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Re: suspension yea or nay

Post by Greg Watters » Tue Apr 01, 2014 7:20 pm

You think ours was low ..... ;)

Ralph in some respects you stepped in on a good platform, better than most start with ,
Part of that was you and your team made some good choices in your prep, that suited the salt on the day, but its not always like that
come back 3 yrs in a row and see if you can replicate the results , or try and step up to the next level , modify the bike and try for 220
you will probably find you go slower

Half the challenge is the moving target :)

rgn

Re: suspension yea or nay

Post by rgn » Tue Apr 01, 2014 7:54 pm

Greg Watters wrote:You think ours was low ..... ;)
No. in no way. ( i think your gps data would console you) Greg I respect your mind and your advice as you know.

When I first looked at the GPS track there were massive black skid marks at it's beginning running for meters. I thought there is traction here, so continued with the strategy.

I know what wet salt feels like, and my advice would be to walk the track early morning to see what you are racing on. if doesn't suit you, don't put your balls on the line.

I would love to see a pre-dawn walk (drive take place)

(salt on the day in the first 3 miles was hard as concrete, and we had that tail wind... (but it was soft beyond, and two bikes went down)

I will bring shot next time I race believe me, but it will be the last thing I do. I have to know how it pans out.

I respect that which everyone does. That is what racing is about.

http://en.wikipedia.org/wiki/Groupthink

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ROSS BROWN
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Re: suspension yea or nay

Post by ROSS BROWN » Tue Apr 01, 2014 9:13 pm

OK
Gary is slowly let the cat out of the bag.. 3 threads to watch :shock:

SUMARY .. 15inch land racing tyres ..
............ 1- 3/8 x 2.6 wall tubing..
........... feet forward configeration..
............ rear engine ..
........... fly by wire..
............ wheel base in excess of 2400mm

Yep there has been some pretty cool FF road bikes built .. and at least 3 salt bikes that I know of..
The road bikes are virtually all using a high bar chassis technique.. thus necessitating the use of rear shock absorbers.
Currently our rules dont allow this technique ... So the chassis from steering head to the front engine mounts will have to go under the rider.. trellis four bar would be the thinking.. the chassis will be active in this aera..suspension could be a toss of the coin..
Any drawings yet ... :P
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TIME WAITS FOR NO ONE.

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hawkwind
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Re: suspension yea or nay

Post by hawkwind » Wed Apr 02, 2014 6:04 am

Ross ...sharp :P
If I was going down that road it may well have some of these features
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Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
Rider......................... Tardus Vetus Inflatio

hawkwind
Posts: 272
Joined: Fri Dec 17, 2010 3:50 pm

Re: suspension yea or nay

Post by hawkwind » Wed Apr 02, 2014 6:06 am

Or maybe more like this :mrgreen: yes I think more like this
preliminary target L= 4000mm...H= 800mm.....W= 600mm .....weight 800 -900 kg.....Cd= 0.4 ..... A= 0.48 m2....blown fuel busa engine 500-600 hp =300mph ????????
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Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
Rider......................... Tardus Vetus Inflatio

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