Suspension Smith in Canberra, Australian Capital Territory | Motorcycle repair centre

Suspension Smith

Locality: Canberra, Australian Capital Territory

Phone: +61 407 903 652

Address: Unit 1 100 Maryborough st fyshwick 2609 Canberra, ACT, Australia

Website: http://www.suspensionsmith.com.au

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24.01.2022 Making good progress on the conversion. first thing I did was make a lower rear engine mount plate...this is a temporary mount but it allows be to get the motor into position as shown in the CAD Pic and squared in the frame and then see where things need to be modified to make it fit. Its a pretty good fit considering. The front engine to frame mounts need to be cut away and the bottom middle of the frame rail cut back to clear the top of the two upper carburetors. The frame... area around the clutch cover needs to be cut back for clearance there. The upper rear engine mount in the frame will need to have a hole cut just above the present engine mount in the frame to allow this bolt to go through the frame into the new engine/frame mount....that hole will probably be the most difficult part to do. The front engine mounting arrangement will be a steel cradle bolting onto the engine mount under the engine....this cradle will bolt onto the lower rear engine mounts on the frame which I have milled back to allow this....the front of the cradle will bolt onto the new mount which I have milled into frame at the front. See more

23.01.2022 Now a K-tech suspension dealer

23.01.2022 Ok so the first round of welding on the frame of the RSV/RG500 conversion is done....now to fabricate the rear engine mounts...starting with the rear upper mount. This one requires setting up on the mill with engine and frame setup square on the bed....then mill a blind hole in line with the engine mount...starting with a small pilot hole and then adjusting the alignment of this hole with the engine mount until alignment is found and the final hole size bored. Then machine up the aluminium boss that is to be welded in once that is done then fabricate the other side with a simple plate.

22.01.2022 The stock Demo 29 expert rear suspension is fitted and pleased to say it fits up perfect....the only change I have made is to turn the rear shocks piggy back reservoir so its positioned downwards instead of upwards of the shock.....this allows me to mount the datalogger in a lower and more central position in the bike just above the rear shock.

21.01.2022 Resumed testing on the dual front suspension bike with Nick as my test rider........this is Nicks first ride on the bike and presently just spending time dialing the bike in to suit him. So just taking things easy to start with and working our way up to more aggresive riding in the future.

21.01.2022 Just finished a day testing with ADB....expect it in the next Issue

21.01.2022 Making some really good progress on the Dual front suspension on the DH MTB. Gradually sorting the bike out as a whole and getting the bike setup to suit Nick the rider and at the same time Nick making friends with the bike and the unusual front suspension and its weight :-). To begin with we had it setup quite soft and were testing it through some rock gardens to test the suspensions compliance and reaction to large high frequency bumps and how the steering felt through sa...me....with some very interesting data collected on the datalogger. Now we are starting to do some faster downhill sections and are now stiffening the suspension through stages....with Nick liking each stage we go harder.....Nick describes the bike initially as being understandably too soft and lacking in the stiffer more playful feel of the bikes he is used to riding. What is really interesting is what the data is showing in terms of how the two front suspensions interact with each other and how changing one such as upping the air pressure in the Ohlins forks or reducing the spring preload in the secondary shock....effect the action of the other and the suspension overall. What is really intriguing is how the dampers are performing.....it appears that when the suspension hits a large obstacle which moves both dampers simultaneously you are getting a combined damping effect of the bump energy being put into the suspension...same can be said of the following rebound control ....this means that the teleforks damper can be tuned to be very fast in compression and rebound and achieve a greater level of critical damping ... with the secondary damper then providing extra damping in those situations where the telefork would usually struggle to maintain control ...a regular telefork suspension tuned like this on its own would be considered flighty and unstable with poor chassis stability....but in this case the secondary damper is providing the extra damping when needed. See more

20.01.2022 A quick look at the extremes of adjustment available in regards to steering angle /trail and wheelbase by adjusting the top rod end link. First pic shows front adjusted all the way inwards...shortening wheelbase/steepening steering angle and reducing trail too figures of around 22.2 degree steering angle.....1240mm wheelbase and 110mm of trail....a very quick steering agile single track setup. Second pic shows it adjusted all the way out lengthening wheelbase...a slacker steering angle and increased trail giving a very stable DH setup with figures of around 28 degree steering angle.....1300mm wheelbase and 140mm of trail. What is neat is that this can be adjusted on the trail with a few tools and a few minutes.

19.01.2022 I want to describe to people a new facet of the TwoEvo dual suspension system I have been testing. Its to do with the springs and their interaction with the systems dampers...basically how it has a spring system that is partially velocity sensitive. Conventional systems to date are a simple spring and Damper combined...the spring is position sensitive and generates spring force by spring rate x suspension travel and the damper is velocity sensitive...both combined working to...Continue reading

19.01.2022 New frame in the works.......

18.01.2022 Finally finished the RG500/RSV Aprillia conversion.....should make a good basis to further pursue the viability of the conversion.

18.01.2022 Heres a few screen shots of some of the stress analysis I did on the frame...the 6mm frame. I saw a Vid of Santa cruz doing a destruction test on one of their Carbon frames and this analysis is trying to replicate that. So its where you were to drop short off a big jump and land into the face of the following ramp face for example and the front wheel is pushed into the bike...their frame fails at 2050lb or 931kg which is impressive. My test is at 10.000N or roughly 1000kg The... pics shows the frame with a large solid lever in place of the forks and linkage...its not a perfect representation but close enough. The first pic shows total deflection represented in colour....there is a colour chart too the left...so at the bottom of the lever it shows 9.7mm in red......if you look at the colour of the frame it is a lightish blue at its highest deflection which is around 2.5mm. The next pic shows the level of stress...this is yield stress....the point at which permanent deformation takes place.....7075-T7 has a yield stress of 435mpa....so this shows where the frame is stressed and how it is stressed across the frame....again shown by colour and shown in the chart on the left side.....max stress is at 270mpa...so not real close to bending....if this was made in 6061-T6 it probably would bend at this point. The next pic shows fatigue stress....7075-T7 has a fatigue stress of 150mpa....so if you stress a part for 1 cycle at 150mpa max then you can acheive 500,000,000 fatigue stress cycles before it fails.....this pic shows a lot of fatigue stress at 150mpa and higher.....so you couldnt do this test many times before it broke. Next pic shows where the frame is stressed the most at 270mpa.....at the centre of the top of the frame....there is a small patch of red.... So overall it shows the frame would not fail at this stress level...but would fail after repeated tests..... See more

18.01.2022 A quick look at the mods done to the WP AER Air forks for the TwoEvo...travel reduced too 250mm with new internal spacers...the spacers actually only shorten the forks by 16mm.....just enough to pull the main piston seals up short of the cross over port. The rest of the travel reduction is done my installing a set of 34mm thick bottom out spacers and bumpers to stop the fork short of its original full travel. The other Mod is installation of a set of two seals from a SKF Glid...e seal kit ...these are low drag seals which lower stiction considerably.....the original air seal is a single lip seal designed to only contain high air pressure in one direction/or side....the main air spring chamber side..........now with the balance chamber being also a high pressure side...by this I mean I can now set the balance chamber too a higher pressure than the main air spring chamber when the forks are fully extended....normally the balance chamber never sees a higher pressure than the main chamber...only a equal pressure when fully extended.....hence the single lip seal. The other Mod is the installation of a Schrader valve in the base nut in the bottom of the fork...this pressurizes the balance chamber. It appears to work very well. See more

18.01.2022 I have just done a quick test to see how hard this new mountain bike can brake.....The software simulations I designed the bike with were telling me a max of around .7 to .75G braking force which seemed fair enough....its a short wheelbase with a very high CofG...a typical motorcycle sports bike can acheive around 1.1G with a longer wheelbase and lower CofG. I did this test in a car park with a level smooth asphalt surface...pedaled up to around 26KPH and braked hard....funn...y thing was the main limitation was the front MTB brakes barely had enough braking power to bring the bike too its max braking potential and lift the rear wheel clear of the ground...front tire grip with MTB knobbies was fine...no problem there. Anyways I was surprised to find that I could acheive a braking force of .96G...Max front telefork travel was 170mm out of the total travel of 200mm and secondary suspension max travel was 57mm out of a total travel of 70mm.... so its showing good brake dive characteristics by preserving enough suspension travel to deal with bumps etc whilst braking hard. Ok so why the discrepancy between what the software is telling me and whats happening real world as far as max achievable braking force. I think what is happening is the software is not taking into account the MTB rider and how he/she will change their weight bias on the bike when braking. I as I was braking on the bike was shifting my weight further too the rear as I was braking harder....thus delaying the point of rear wheel lift and allowing a higher max brake force. A MTB rider is a number of times heavier than the bike they are riding so body weight shift has a massive effect....plus being able to drop the seat out of the way also helps. Any experienced MTB rider will subconsciously without really thinking about it will auto shift their weight further over the rear as they brake and brake harder...its just one of those things we learn as we ride....same can be said riding moto dirtbikes....although road/race motorcycles not so much...the seating position is more static and the weight of the rider has less overall effect on a much heavier bike. As far as the software goes in future I will need to measure and take into account this effect/variable. The traces in the pic show 4 data traces. The pink bottom trace is rear suspension travel....at the point of max braking it shows the rear suspension topped out as shown by the flat part of the trace at the very bottom. The red trace is the secondary suspension. The blue trace is the telefork...where it is peaking in the vertical is the point of max braking. The black trace is the Inline acceleration...this is measuring and showing braking force The small box in the far righthand top corner is showing the max values for each trace in this pic.

18.01.2022 Problem with Girder forks is they have a lot of steering inertia as the links etc place the upright and shock etc far from steering centre so they tend to flop from side to side....and they can be more prone to the negative effects of head shake. I have already experimented with a Girder fork version of my Dual suspension on the Kawasaki KX450F and it worked pretty good...we even raced it once in MX.....this new version is a follow on from that incorporating lessons learned.......the main one is building a much more compact design with much less steering inertia and structurally more rigid. https://www.facebook.com/Suspensionsmith/photos/2222407511183854 https://www.facebook.com/Suspensionsmith/photos/2222407324517206 https://www.facebook.com/Suspensionsmith/photos/2222406491183956 https://www.facebook.com/622479384510016/videos/2268837433366624

18.01.2022 Currently working on a new version of my Dual suspension system....the previous version is a Hybrid between a Telefork and Hossack type link suspension...problem is it requires substantial modification of the bikes frame to fit it. This new version is a Girder fork /Telefork Hybrid....because its a Girder fork it simply bolts too the standard bikes steering head and so requires far less modification and doesnt require a steering linkage......it should still give all the advantages of the previous design...maybe the steering will be a little different in feel and performance...only building and testing one will find out.

17.01.2022 Clutch cover cutout almost done.....

17.01.2022 Started work on a customers conversion of putting a RG500 Suzuki motor in a Aprilia RSV V4. So my task is to get the motor into the frame in a tidy fashion. So a detailed look at it shows it can be done and without too much bother....tidy it should be. The main thing that needs to be done is get the 500's countershaft into the same position as the stock RSV....that way it will have good rear squat geometry etc. First thing I did was take some high resolution pics of the naked... bike..... RG engine and RSV frame.....side on and square too the bike from as far away as possible using the cameras zoom lense to reduce parallax error. Then load the pics into CAD on the computer.....now I am able to layer the Bike...Engine and Frame onto each other and move them around to get stuff in the correct orientation and get best fit. Its accurate to within less than a mm and makes this easy as. So now I have the best fit orientation and have worked out the config of the engine mounts etc. Now to start modifying the frame to suit.....now for some milling time. See more

16.01.2022 A future project I am tinkering with...Taking a Specialized Kenevo Comp E bike and doing a dual front suspension setup and plate frame similar too what I have done on the Downhill bike. This would be geared towards better control of weight...so would use a 160mm or 180mm single crown Fox fork with the 75mm travel secondary suspension...and use a lighter version of my plate frame design.....Mmmmmm

16.01.2022 These pics show the front suspension with both the fork and secondary suspension working together....both traces being shown together and the suspension travel traces in equal proportion too each other. The fork travel trace is in red and the secondary suspension trace is in pink. Here maximum fork suspension travel is 115mm and at 24 degrees gives a vertical height of 105mm......over the obstacle height of 110mm. The secondary suspension which is now moving...is moving with... a maximum travel of 39mm....it is moving back at a angle of around 45 degrees. The next pic shows the suspension speed or velocity that the two suspensions are moving. The peak speed that the fork is moving at is 2813mm/s and the secondary suspension is moving at a peak of 1489mm/s. See more

15.01.2022 Started proper testing of the dual front suspension on the MTB.....test went very well...bike feels great...steers and feels normal and the front suspension is super plush and sensitive.. Had the data logger in operation so lots to think about. Biggest thing I noticed was after getting to the bottom after doing Skyline and the Luge down to the carpark was my hands and arms felt great....usually I feel a bit pumped and cramped up in the hands and arms....but the front is so plush and controlled through the stroke that its allowing me to stay much more relaxed in my upper body.

14.01.2022 With the setup of the suspension...and by setup I mean how the secondary suspension is balanced against the Ohlins telefork....I have gone for a very active lightly damped telefork....its running a quick rebound and a soft (fast) compression damping in both low speed and high speed comp....so it has very good small bump compliance/sensitivity and so able to react very quickly to trail obstacles and rebound very quickly to help keep the tire in contact with the trail and hence... give good traction. The air spring pressure of the Ohlins telefork is set for my weight etc to give 50mm of rider sag....but the air chambers secondary chamber pressure which controls the progressiveness of the air spring is set quite high...so the forks air spring is quite progressive through the stroke....so the spring is tending towards a high frequency setup. Now this would normally give a fork whilst being quite active too bumps etc also tends to give a nervous or flighty feel too the front suspension over much rougher stuff because it is lightly damped etc. So I have setup the secondary suspension so its damper is quite strong in high and low speed compression damping and good rebound control...at the slower end of the spectrum. So the idea is that the softer Ohlins telefork takes care of the small to intermediate bumps where the suspension needs high sensitivity and gives very good ride quality and traction......and the secondary suspension is set on the firmer well damped side....and it tales care of the bigger hits and so gives the necessary damping control that the forks are missing....so the two suspensions are working in Harmony. In the two vids you can see this difference...the telefork working very quickly with high frequency and amplitude and the secondary suspension moving with less sensitivity and a lower amplitude but still with comparable frequency....so they are well matched against each other...staying in step together .... In the included Pic this shows a datatrace which shows exactly this....of the two front suspensions working together....the blue line is the telefork wheel movement and the pink trace is the secondary suspension movement.....this shows what I mean in detail.....the blue telefork trace is moving very quickly with high sensitivity and frequency and moving very far up and down showing high amplitude.....the pink trace of the secondary suspension is moving with less sensitivity and less amplitude.....but is moving with much the same frequency as the blue trace...which is very important....they are almost a perfect copy of each others movements. See more

14.01.2022 Ok so the first pic is the suspension travel data trace of the Fork in the Fork only test. It shows a series of four distinct trace bumps. The first bump which is a very sharp vertical trace is the front forks hitting the first obstacle.....the next smaller more rounded bump is the effect on the front fork of the rear wheel then hitting the first obstacle.....the next trace bump is again a sharp vertical bump which is the front fork hitting the second obstacle....and again th...e next smaller bump trace is the effect on the fork of the rear wheel hitting the second obstacle. All of the following pics will show the same event replicated in each test and showing suspension travel and suspension movement speed.....so the data traces will be similar in shape and so can be interpreted the same as what is shown in the first pic. Now in the pictures I will be concentrating on the first bump trace which is the front fork/wheel hitting the first obstacle. In the first pic it shows the suspension reacting too that first obstacle with a very vertical moving trace...this shows the fork/wheel moving very quickly up and over the face of the first obstacle which is very square. The maximum distance that the front fork/wheel moves is 135.5mm ....this is at a 24 degree angle too the bump and so gives a vertical height of 124mm...the bump is 110mm high so the wheel is over reacting too the bump by 14mm...... probably because its moving so quickly its momentum is carrying it above the height of the bump. The next pic shows the suspension speed or velocity it is getting when hitting these bumps....again i am concentrating on that first bump trace. This first trace shows the front fork is achieving a peak speed of 3343 millimeters per sec...which is reasonably fast. The next series of pics will show the next test done with the fork working with the secondary suspension and its effect on these parameters just described.

13.01.2022 A quick pic of the engine cradle design for the RG500.....the engine first bolts into the cradle first which then also acts as a engine stand then the two are either together bolted up into the frame or frame onto engine/cradle.

11.01.2022 Heres a data trace of both front suspensions and the rear suspension....as being ridden down an eroded forest track....somewhat bumpy. Notice the two upper traces .... pink which is the secondary suspension and the black trace is the front fork....both are very active and the upper pink trace is a smaller amplitude copy of the lower black fork trace....these two working together are giving the front suspension an amazing level of small bump compliance ....it just glides over stuff....amazing....Its basically two layers of compliance working together. The cool thing about the two front systems is they seem so far to be working in harmony with each other....but I am sure that at certain higher frequency and or amplitudes they may start to work against each other......

10.01.2022 Almost there....

10.01.2022 Following on from the previous post in regards to spring rates/forces. This describes another Facet of the dual suspension system. One of the things felt by most riders who have ridden this suspension is the great balance and feel between small/medium bump compliance and response and bottoming control/resistance...it has a balance between the two not felt or even possible by conventional front suspensions to date. Part of it is the velocity sensitive nature of its spring for...ce as noted in the previous post. Another as is being described now is its increased level of suspension position sensitivity and how this increases spring rate and force as the two dual suspensions move and interact (the Telefork and the secondary link suspension ). In the first pic it shows two conventional rear swingarm and link suspension systems....the top swingarm is long and this gives a certain leverage ratio over the shock through the linkage and so a certain vertical spring rate at the wheel ( the red arrow ) The second lower suspension has a swingarm that is shorter...everything else remains unchanged from the top suspension...only the swingarm is shorter....this shorter swingarm gives this suspension a stiffer vertical spring rate ( red arrow ) just by shortening the swingarm and lowering its leverage ratio...it has less leverage over the shock and hence is stiffer. The dual suspension works on a similar principle to this. This is shown in the second pic...showing two dual suspensions...the left suspension is unloaded and the telefork is mostly extended as is the secondary suspension...the this gives a certain vertical spring rate at the wheel as shown by the red arrow. The second suspension to the right shows the same suspension in a highly loaded position....the telefork has mostly compressed and the secondary suspension is partially moved through its travel ( it being much stiffer ).....this is where the dual suspension system is replicating the effect of the longer shorter swingarm in the previous pic ....the telefork goes from extended (long) too compressed (shorter) and this changes the leverage length over the secondary suspension....as the telefork gets shorter the leverage over the secondary suspension lessens and so the secondary suspension gets stiffer....this combined with the velocity sensitive facet described in the previous post.....gives the dual suspension superb bottoming control....but without the harshness normally associated with this level of bottoming control...

09.01.2022 Seat post tube is done.....

09.01.2022 The Issue with my dirtbike front suspension test article is out now

08.01.2022 Testing the dual front suspension....this a run through the bottom section of the Luge trail....steering feels great...good feel and agile and stable..very good traction...the steering geometry is in the middle of its setting range so a more trail orientated setup.

08.01.2022 Pretty well finished the main frame....the rear suspension is fitted up and ready to go.....just need to finish making the two new front suspension links and it should be all ready to go. Frame weight is 3.8kg in its rough form versus 2.2kg for the original frame.

07.01.2022 Making god progress on the new MTB frame.....plates are cut and drilled/tapped etc..... I mounted the two plates one on the other then drilled them on the Mill for perfect alignment....and made the new bottom bracket shell and successfully fitted the bearings....so far so good.

07.01.2022 Just completed a small redesign of the DH mountain bikes front suspension...... The ideas was a couple of things...main one was to get rid of the lower ball joint which was giving me some grief once some wear was upon it...a little too much friction in the steering when the bike is loaded up in a berm and taking away some degree of steering precision and feel. So I have designed in a mini steering head to replace the ball joint...it uses a typical MTB steering headset so give...s comparable ( normal ) feel and response.....so this also requires a conventional steering stem and triple clamps to suit....the triples required some very precise machine work as they mount the forks at a 3 degree offset from the steering stem and I was very relieved upon assembly to find they fit and align perfectly....another benefit is this arrangement is somewhat more laterally rigid. I also redid the linkage ratios and this gives two things....a more curved wheel path to the secondary suspension....it still starts at a 45 degree angle but then curves into a more vertical wheelpath....in turn giving lot less prodive deeper in the travel and so better braking feel when hard on the front brakes. I have retained the upper adjustable rodend link so this retains the ability to adjust the length of the link and so adjust steering angle...wheelbase....trail etc etc....I can also adjust the height of the rodend where it bolts into the top of the steering stem...thus giving me adjustable secondary wheelpath angle as was also done on the previous setup. So now I need to repeat all the testing and datalogging I did previously and see how this setup compares. See more

06.01.2022 Shows the suspension working through a rock garden section and working well.

05.01.2022 Just finished some testing of the latest TwoEvo KTM conversion against the TwoEvo KXF....wow....the KTM is seriously good in every way...transformational as a Trail/Enduro bike. Riding it in wet slippery trail conditions and it excels...nothing more to do except get some bums on seat so other people can see for themselves. Too which we have some "prominent" dirtbike riders lined up to have a ride in the next few weeks...stay tuned. A big thanks goes to Terry Hay of Shock Treatment for working his magic on a custom modified rear PDS shock for the bike...the last piece of the puzzle in making a great overall bike.

05.01.2022 Yesterday me and Bernie did a trip up to Hampton NSW to visit Geoff Ballard on his property. We had arranged for Geoff to do some test riding of the recently built TwoEvo KTM 350 and get his opinion on how it was developing. Big thanks to Hugh Litchfield for arranging the meeting. Geoff has some Enduro/MX track of varying levels cut in next to his home amongst Lush High mountain forest ( especially lush with all the recent rain ) He came away very impressed with the front sus...pension. Commenting on how well it steered and gave very good front grip...he was especially enamored with how it soaked up tree roots and ruts at any speed. As Geoff got to know the bike and was getting more aggressive with it the front was a little too soft and he started to notice the extra weight of the front suspension. The bike is running the open chamber WP forks and they were fading noticeably. With that in mind we are going to trial a set of WP AER air forks which are much lighter and have tunable air spring rate...they also use a closed chamber damper which should solve the fade issue. Make a few tweeks to the rear PDS shock and then give Geoff another go on the bike. For me this is a great affirmation of my work...its such a relief to know that my thinking and method is matched too real world performance and results... Next week we have Ben Grabham swinging a leg over the bike and will be interesting to hear what he has to say. Happy days. See more

05.01.2022 The next two pics show the combined data traces of the two tests just shown....making for a direct comparison between the two. The first shows the combined suspension travel and shows how much less the fork combined with the secondary suspension needs to travel compared to the fork by itself. The next pic shows the combined suspension speeds and shows how much less fast the fork combined with the secondary suspension needs to move compared to the fork by itself.

03.01.2022 A good day testing the bike with Nick at Stromlo....now with the shuttle bus again running we are starting to do some downhill run testing.