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View Full Version : Different MX racing setups....I have questions



ironchop
02-05-2015, 03:04 PM
I hesitated to post this because I`m sure it was covered some time but searching for all those postings has become a nightmare.

SO when I built my first 200X, the idea was for a flattrack/ TT setup as that is what most tracks here are setup to run.

After blindly dumping cash into this machine I figured out that I`m happy with the result but I don`t think its set up for flattrack very well. I never lowered the forks or rear end with a strut. I just threw on some Duro`s and a 38t sprocket and called myself ready.....SMH.

After reading a lot more postings and determining that I don`t want to do just one type of racing, I also discovered I know little or nothing about race setups AT ALL.

SOOOOOO........I realize just in this forum we have desert racers, ice racers, MX racers, Hare Scramblers, Flat trackers on dirt, flat trackers on syrup covered concrete, TT racers, drag racers, and armchair racers (I`m really good at this one and have my setup dialed-in)

Fast forward to TF14......no flat track... good MX track.....great drag strip....great trails. So I guess since I have the time to race maybe once a year and since once a year I`ll be at TF, I decided to setup for racing MX at TF once a year and if I can find the time maybe do the one indoor MX race in KY that Ray and those OTC fellars like to go to.

SO here it goes and if you don`t want to reveal your winning setups, I get it. It won`t hurt me asking questions, though. Its been thirty years since I read a howto in 3&4 Wheel Action magazine and I don't remember a thing.

1)Engines.......got it covered....moving on
2)Swingarms.....longer, shorter, stock?....and why would you want a shorter lenght than stock swinger?
3)Nerfs....I realize what they do but do they have any drawbacks or is it a no-brainer?
4)Suspension.....is longer travel better for MX or is it all about rebound and compression and dampening mostly?
5) Sag front and rear.....any explanation of why this needs to be addressed would be a tremendous help to me. Thanks ahead of time.
6) Tires.....I know lateral sliding ability would be important and I know that taller and farther apart lugs are for soft and loamy and tight short lugs are for hard pack. Is there anything else to consider?
7) Clutch use.....I ride a four stroke 200X so mine is either engaged or not. I don`t feather it ever because I`m not sure why I should. With my CRs and more powerful bikes, I feathered it because I hated trying to keep the front wheel down but again, I`m not an experienced racer so I don`t know crap. My armchair has a clutch handle for raising and lowering the footrest.
8) Rear Axle width....I have a Durablue 3+3 I think it was and I know wider= more stable but why would they make it adjustable? is there a reason you would want to make it narrower than 6 over?
9) adjustable shock mounts on swingarm.....like a westcoast has a whole array of mounting holes on the 250R model so what situations would you need to raise/lower it?

I apologize if these have been covered before and aggravate the more seasoned veterans but I`m just trying to learn and I can think of no other way than the proverbial Dumb Question. Thanks in advance and I will warn you that at some point I will ask all the same questions about setups for all the other types of trike racing but for now, just MX answers are good for me. Too Much Too Fast and my head will explode.

Samjp22
02-05-2015, 07:30 PM
I'm no expert in this but I think I understand some concepts.
Swingarms: A shorter swing arm would allow you to make tighter turns
Nerfs: Everyone either likes them or don't like them, I have them and enjoy them alot! gives me a much wider area to put my feet and if my legs coming off I know it most likely get sucked under the rear wheel.
Rear Axle: A downfall of the wider axle is it's harder to keep it in a straight line going through whoops. Advantages can take corners a lot harder without having to worry as much about raising your inside tire. I guess they're adjustable just for riding style, some people like them wider some narrower but still a little over stock. And maybe just for the consumers, riding trails through the trees all day, narrower is probably the answer but fast sharp turns on an open trail or track wider.

other than that im not too knowledgeable, ill be reading more experienced answers from the experts.

oscarmayer
02-10-2015, 11:42 AM
recommendation, get the front forks redone and setup for you as a rider also sue the emulators to allow for rebound/dampening adjustments (stock never had that just dampening), the rear shock on the 200x is not really rebuildable or modifyable. I would look into an aftermarket one. expect to spend around $450-$650 on a rear shock but it will make a BIG difference.

rear axle you want a +1-+2 swinger. your going to be hitting jumps and such, you need more stability int he air and leverage for the jumps. so that is about all you need over stock as well as it helps keep the front planted better. rear axle, i would get an adjsutable rear axle that allwos a +2-+4 adjustment. LSR or someone else makes them. there are several out there. Fleebay has several different models you cna choose from, but the stocker will bend on jumps after a bit. a good aftermarket billet axle is what you want. billet bearing carrier is also something you must have. Stock ear out to fast on the track.

SS braided brakelines and new pads are a must as well at a minimum but you can loot to see what adapters you can make to install larger brakes if ya want.

engine, you will definatly have to spend a lot on the motor. Remember a MX race is nothign like a CX race. MX is a full 20-30min sprint at WOT 80% of the time. so you need a powerful and relyable motor. Stroker and bore is fine, but rememebr you will need to ensure you have an oil cooler. Also do not go to the max on the bore or you will regret it on the track. In a 100* day you will overheat very fast ruining the top end. I suggest a Mickey stroked bottom end kit and use a wiseco 12:1 piston. Make darn sure you properly prep that piston. Also you want 1-2* cooler spark plugs. NGK the higher the # the cooler the plug and also tighten the gap to .028 - .030 for gap and no more. you chance sparkknock if you go more on the track.

fuel, run only 100octaine. I recommend the leaded vs the unleaded. minimum is 97. 103 may work ok, but the highrer the octaine you run you will end up loosing power. so 97-100 is what I recommend.

run a 28mm mikuni carb. use the factory air box with the lid removed.

use a good clutch kit. Wiseco makes a good kit. if you cna find one, run a billet clutch basket if not, find a newish looking one as the stock baskets will give out over time.

most important, Take your time, and HAVE FUN!!!!!!

Joseph Farrow
02-10-2015, 12:47 PM
To me your suspension and bike set up way out weighs the motor mods when you are talking a 200x racing moto cross. I ran a 350x front fork set up with a +2 West Coast swing are and a "Sparks" Fox Twin Clicker rear shock. You could float over stuff someone with a stock suspended 200x would die in. Rear tires I would suggest some type of flat track / lawn tire vs a knobby unless you are talking extreme mud or sandy type track. On the axle I ran a 3x3 Finish Line with non off set wheels. Back in the day no one ran nerf bars on mx. I saw a few run them on TT's.
Here is a pic of how I had my bike set up in the 80's

210120

90nut
02-10-2015, 01:56 PM
As posted above you can have the baddest 200x engine on planet earth but without suspension upgrades you are not going to gain a thing on the,track. Suspension is one of the first things to address on any mx bike. As for your swingarm, that's kind of rider preferance. Everyone always claims a longer swinger is needed on a first gen T3 (my main ride) I had a +3 on it and hated it. Back to a factory length on now. All in all in boils down to rider preferance, track conditions, and skill level. Need seat time and don't be,afraid to change things to figure out what suits you the,best.

xrider
02-10-2015, 02:54 PM
I agree with Joseph. Turn your focus first on getting your suspension rebuilt and set up for your weight before diving into other mods

aramid
02-10-2015, 08:04 PM
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1. since you say you have the engine area covered, i would only say that you can buy an adjustable timing gear so you can advance or retard the cam a bit if you want a slightly higher or lower power band.


2. Lengthening the swing arm 2 inches will make the rear noticeably softer, so if it is a little soft for you now, you will need to increase the shock damping and possibly get a stiffer rear spring, but you can simply try adding preload to your current spring first.

You can get a custom front and rear springs made here.

http://eibach.com/america/en/powersport

It will also cause it to slide more easily and controlably . . it will put more weight on the front wheel which is good for short track . . I would .look at around 2” longer for your app and 3” at the most . . longer is not always better and will make the front tire push or plow in turns if you are not sliding it.


4. the trike fest track is actually a TT or Scrambles type track as opposed to a true MX style track, but the way it is set up, I would be hesitant to lower your bike by reducing suspension travel because you only have around 7 .5 inches in the front and around 6.5 inches in the back as it is . . also, the more you raise the bike, the more tippy it will be in the turns . . I would say that unless you are pretty fast that you don’t raise it up any more than stock for that track, but the rougher the track, the longer the travel should be up to a point . . on a smooth short track, lower is better.

the rear racing tires are often lower than the stock ones, especially on that bike, so shorter tires will automatically lower the rear which might be just low enough for one of your apps.

If you lower the rear, I would lower the front the same amount to keep the factory steering geometry which is pretty good imo . . a low rear and high front will cause it to be more stable at high speeds but it will turn more slowly and since this is not a high speed desert race, i would lower the front the same amount as the rear or maybe leave it up to 1” higher than the rear until you get used to it . . as was mentioned, you simply need to try different things to see what best suits you.

There are a few different ways to approach lowering the front, here’s just a few.

Remove the fork springs and lower the front end until it bottoms out.

Measure the clearance between the tire and the fender . . if you have more than around 3/8”, you can raise the tubes in the triple clamps to lower the front until you calculate that you have 3/8” of clearance . . if you can raise the tubes around 1 – 1 ½”, this may be enough to match the amount the rear tires lower the rear.
If you can not lower it that much in front, and need to lower it more, you can do so by disassembling the forks and removing the top out spring from the damper rod and the short spring in the top of the fork tube and swap them with each other . . this should lower it around 2” which only leaves you with around 5.5” of front wheel travel . . this is great for smooth flat tracks but not so good for the trike fest track.

Another option is to go to the hardware store and get a spring similar to the id of the top out spring on the damper rod and cut it to around 1 1/2” long . . this will lower it by around 1” and will make the forks slightly stiffer at the same time and if your springs are original, they might be sagged out a little anyway.

Another option is to go to the hardware store and get a spring around the same od as the spring in the top of the fork and around the same size wire and coils per inch . . then cut this around 1” shorter than the stock one and see how much that lowers . . continue to cut until it is where you want it.

If you want to lower the rear more for short track, one easy way is to pull it down with a tie down or chain . . some tracks might not allow this and it’s not really ideal but it will work in a pinch.

one place to try for a rear shock is works performance.

http://www.worksperformance.com


one place to try for general suspension parts is racetech . . contact them directly for info . . rockymountain may have fork springs

http://racetech.com/index.aspx


In the end, you might even consider just raising the rear back up to stock height if the new tires lower it.

I would shorten the steering stops as much as possible

An adjustable steering damper is nice to have


5. the rougher the track, the more sag and travel you want . . the max amount of sag desired is around 1/3 . . I would use a little less on a smooth track.


6. tire choices are many so I would narrow it down with these suggestions . . yes, rubber compound and ply amount are important factors . . softer compounds work better on a lot of terrains, but they wear a lot faster . . some people have a set of racing tires and wheels and trail riding tires and wheels . . 6 ply tires weigh a ton and 2 ply often roll under too much under hard cornering . imo, 4 ply is a happy medium.

For all around budget trail tires shredders are the best deal I have seen . . if you like to slide a lot the itp holeshots . . 20” tall on 10” rims

flat track tires should be almost perfectly flat across the top with a slightly short sidewall to minimize roll under in the turns.

A semi affordable tire for both trike fest track and flat track is duro hf245 sport . . it will allow you to slide easier than most but will have good forward traction . . I have never used them but I have heard they are a bit heavy and the height is possibly a little bigger than advertised but they are the only flat track tire I know of with horizontal cuts in it . . if you are rich, just buy soft compound hoosiers or similar and get a tire grooving tool and cut slots in them like the duros have . . the 20’s will lower your bike around 1” from stock and the 18” will lower it around 2” from stock . . pick your poison on tire size for this one but I would not rule out 18’s . . the duro HF245’s are also 2 ply but that’s all they make in that model.

Duro HF245 Sport
http://www.oponeo.co.uk/Temp/duro-hf245-7193-t-f-l125-sk1.png


7. you will know if you need to slip or feather it once you get there . . I would practice starting in second gear, rev it to maybe just over 1/2 way, then pretend the flag drops and roll the throttle on as you let the clutch out fairly slowly . . some people peg the throttle and then let the clutch out . . getting a good start is helpful . . it’s easier to work your back from the front than it is to work your way to the front from the back, plus the track can be hard to pass on.

Flat track . . if you are a slow starter, start on the inside . . always hug the inside . . if you drift out just a foot you might get pushed out by a rider . . it's better to go slow in the inside than it is to try and go fast on the outside unless you are better than everyone else.


8. a wider axle or wheel spacers is a must for most types of racing . . if you are used to leaning off the bike, I would try 2” wider on both sides of the rear axle for the trike fest track and no less than that, and 3” wider on both sides for flat track or you can go standard width on the left and 3” wider in the right . . some people do this but I never have , but you can mess with different widths when you get there.

hawaiirider
02-10-2015, 08:48 PM
a cheap alternative is put 83-84r suspension front and rear on, i found a junker so this was cheap. youll have to modify the rear shock mount to fit. all in all i personally liked the stock 200x suspension once setup for your weight, i used to jump it extremely big for what it was and it always rode away with me and the trike in one peice.

Dave8338
02-10-2015, 11:55 PM
Be able to land the flight first, then worry about the launch speed.........................

GREAT thread ! ! ! ! ! :Bounce

onformula1
02-11-2015, 01:10 AM
To me your suspension and bike set up way out weighs the motor mods when you are talking a 200x racing moto cross. I ran a 350x front fork set up with a +2 West Coast swing are and a "Sparks" Fox Twin Clicker rear shock. You could float over stuff someone with a stock suspended 200x would die in. Rear tires I would suggest some type of flat track / lawn tire vs a knobby unless you are talking extreme mud or sandy type track. On the axle I ran a 3x3 Finish Line with non off set wheels. Back in the day no one ran nerf bars on mx. I saw a few run them on TT's.
Here is a pic of how I had my bike set up in the 80's

210120

That there is the coolest 200X, sick just sick! Great job!