A arm specs

[blanco]

I've read and searched countless threads for a basic all around set up for A arms. I'm not trying to build an all out track car just a trike that will handle good on the road. I understand the basics but everytime i look into it i goes over my head with all the figures and abbreviations, you guys are experts in this and i would very much appreciate your help or any input you may have. the bottom line is, im looking for is a spread sheet or drawing of a set of A arms with measurements for length, angle, hight. i dont know how to build this and really need some input from you guys.
Thank you,:tiphat:

[B-T]

Sorry, but that request is like asking how long a piece of string is. Your best bet is to get some suspension design books or the Locost book on how to build a Lotus 7 type car and follow that. There are several designs being used by various cars being built by people on this site, and they are chassis specific. If you are asking someone to give away their chassis design I don't see that happening.
:)
BT

[blanco]

No I don't need any one's design. I was only hopeing to get pointed in the right direction. Will the trike still track straight if I use equal length a arms top and bottom and perfectly centered to each other ? Will it handle the corners ok? What are your opinions? Are 21" long arms too long? Or close enough? I'm not looking for the right answer, I understand its a matter of opinion, what are you guy's opinions? I know you guys know a lot more than me on this subject, just looking for pointers and help. Thanks guys

[Alanstrike]

OK front end design for trike 101

I have been developing a fast track day capable trike over the last 3 yrs . We had our first track day back in march www.youtube.com/watch?v=2JaohD8FzTE - this setup was fun but not stable at hi speed. over the last 12mths and 2000km testing have tweaked and changed just about everything and am now very happy with the setup Mx5 front with entire bike built into a custom frame

Basic set up is - used an original subframe from a current NC MX5 as a reverse jig for pickup points and used the OEM wishbones and uprights (all forged alloy light and strong) or you can use this setup and make your own or use Solstice setup also seems OK

Alignment - rear MUST have positive swingarm angle and good rubber - watch if using OEM motorcycle rim a car tyre is not compliant with MC even though both are say 17" can be fixed and not too hard PM me if you need to go this way. Front - 10degree caster yes seems a lot, camber negative say just noticable ie max you can go with std OEM adjusters seems right, toe OUT 3-4mm will help hi speed stability

Handling - you can lift an inside wheel you can clip a ripple strip coming back on the track after oversteering in a sharp LH ( in your case RH ) corner and lift the whole trike up at 45degrees:run: - however this was at way too fast an entry speed and should not happen on the road at sensible speeds. Brake late and Turn sharp technique is NOT to be recomended smooth and you shouldnt be able to out drive the trike just be aware that a trike will not be as stable as a race car in corners - physics gets in the way....keep it light and weight low and don't over tyre the front.. mine is just under 500kg or 1100 lbs + FJR1300 at 109kw = FUN


Lastly just do it - best fun i have ever had designing - building - driving trikes should not be just about doing donuts.....http://i770.photobucket.com/albums/xx342/AlanLehmann/EdenandTrike.jpg

[Alanstrike]

Re Locost / seven front end yes good and all have UNEQUAL wishbones watch bump steer and when testing build up to high speed a well built a light trike can be a weapon for good and bad.

Alanstrike from Aust

[pook]

Will the trike still track straight if I use equal length a arms top and bottom and perfectly centered to each other ? Will it handle the corners ok?

Equal upper and lower arms would only work if the car would never ever lean...ever. One of the reasons we want shorter upper arms is for camber gain, sounds silly that the wheel needs to lean in as it travels up until you picture the chassis leaning over in a turn, pushing the upper arm outwards and the effect is the wheel stays vertical to the road so to speak (when its done right).
There is a great book by Allan Staniforth (may he RIP!)
http://www.amazon.com/Competition-Car-Suspension-Practical-Handbook/dp/1844253287
In it he shows how to make a simple cheap and hands on String computer to test your suspension ideas.

PooK

[blanco]

Alanstrike, Thank you so much for your help that's exactly what I needed to know. Sorry it took me so long to post a reply but I got all exicited and started looking into redoing the front end. When you say to use the nc mx5 are talking about the mazda miata mx5? What's nc? Thanks again you were a great help and I loved waching your video!

[blanco]

Pook, thank for your insight on the length of a arms much appreciated. I will keep this in mind as I try and figure out the suspension. And thank you for all the pics you've posted ,you do great work man!

[Alanstrike]

Alanstrike, Thank you so much for your help that's exactly what I needed to know. Sorry it took me so long to post a reply but I got all exicited and started looking into redoing the front end. When you say to use the nc mx5 are talking about the mazda miata mx5? What's nc? Thanks again you were a great help and I loved waching your video!

Yes Mazda MX5 is Miata - NC refers to the series is 2005 - current and has alloy wishbones and 5 stud rims - note - watch offset as 55mm is not a common spec also watch having too large a tyre on front compared to rear ( look at Lotus elise as eg - light car and i think uses a 16 x 6 front and larger rear ) i used a 16 x 6 compromotive ex UK custom made to suit .... Alan plus another video :spin::spin:http://s770.photobucket.com/albums/xx342/AlanLehmann/?action=view&current=0-1006sec0-16014sec.mp4

[Alanstrike]

Sorry - dont seem to be able to insert video link - try this - (speedo reads 10% low) http://s770.photobucket.com/albums/xx342/AlanLehmann/?action=view&current=0-1006sec0-16014sec.mp4