Project 350x MX Suspension

[inv3ctiv3]

So in the past week I've ridden my 350x at a motorcross track twice and absolutely love it. But the suspension seems to be a little lacking in terms of jumping so I am turning to you guys to help me build up my suspension to take jumps. DC said someone named Bill on .org had a good set up and I'd like to hear more about it.

I'd love to get inverted forks on my 350x, has anyone ever done this before? I've seen it on R's but never a 350x.

My suspension after some big jumps (maybe 5-6ft high and 15ft across)

http://farm3.static.flickr.com/2723/4236978197_e6c68dc2b3.jpg

http://farm5.static.flickr.com/4038/4236978361_98da11bfc0.jpg

http://farm5.static.flickr.com/4011/4237763854_d311d57597.jpg

[leviblue]

I just got a rear shock built by a guy not too far from you. My 250R is a total MXer and the shock that I just got is perfect. Didn't pay an outrageous price either, $320. so give Evan Schmidt a shout eschmidt@clearwire.net . As for the forks try some new springs.

[Dirtcrasher]

I would not rebuild a 350X shock. My reply was about MR ATC AKA - BILL running an 850 pound progressive rear shock and the valve kit they offered.

I WOULD rebuild/revalve a 250R shock and run a linkage suspension/450R on my 350X. I plan on running all 450R gear aside from the shock (which will be 250R or????) The 450R stuff is just so cheap that you can't ignore it. I got a swinger/axle and hubs for under 100$ The rear caliper brand new is only about 50$ BRAND NEW!! (HOW can ya beat that??)

I have all the parts and it's next on my list after the 200X brake mount issue. BUT, you have to be handy!!

It DOES require welding 2 tabs onto the 350X but allows you to run linkage suspensions. Which is what all dirtbikes run and what you need for the rear to work on that track.

The front? Your cheapest route is to run a 250R front with progressive springs and heavier oil. I'm not sure what articles are out there about the rebound damping which is too fast in stock form.

If your shaking your head about welding and fabricating those 2 tabs for a linkage suspension, let me remind you that you WILL break even a stock 86 frame and especially a stock 85 frame. You may not feel it, but one day you'll look down and say "OH SHIYAT!!"

You did great on that track, I look forward to seeing a better suspension on there!

[inv3ctiv3]

Cool thanks man I emailed him.

[Billy Golightly]

The 350X is definitely somewhat limited with a no-link setup on the rear. You can get a PEP guts valving kit and respring for $350 that will help immensely. On the front end you might be best boring the triples and using 3rd gen 250R forks. Or if I recall correctly you can use the dampening rod and springs out of the 83-84 250R in the 350X forks to get some additional travel. You are extremely limited with compression and rebound on the conventional forks though. On the later model 250R forks you can use Race Tech gold valve emulators which is more or less a spring tensioned check valve that you can adjust how much pressure it takes to open. That monitors your compression dampening. That and springs is about the best mod you can do for regular forks until you go to inverts. There is hoopla about inverted forks being too stiff and the frame not being able to handle the additional pressure from the rigidity but I happen to think its crap. If the forks are valved right and arent A: so soft that it is pounding the bottom every time or B: So stiff that its like riding a rigid, then the suspension action is going to work up and down and do its job with as little feedback as possible past it.

This is one area that everyone has different opinions though. My advice is to ask yourself a couple of questions to determine what you should do:

What is my total budget for front and rear suspension modifications and upgrades?
How much performance difference, am I expecting when the modifications are complete?
What are my mechanical, and fabricating abilities limited to?

[Billy Golightly]

Also, and this isn't in any way a dig (Just trying to help) but where are you landing at on the jumps? It looks like in the one picture your in the middle of a table top. The best suspension money can buy is going to be harsh landing flat. You need to land on a downhill, where your force and energy can be rolled out in a forward motion instead of flopping straight down like a rock.

[Dirtcrasher]

^ Well put Billy.......... Nothing lands flat well. And IDK if your a 20 something YO guy or a 30 something YO guy but you need the balls to hit that table top wide open and hit the downside which is far less taxing on the suspension and that heavy 350X motor will break that frame givin enough abuse and time. I can fix that with some Gussets/bracing (and weld on the linkage suspension tab) if your interested though :D We do it all here at DC's motosports, lol..............

I have the 84R damping rods in mine and spacers which does help. It also helps if your not 212lbs like I am and if your 175 and under, I bet you can clear allot of stuff you may not think you can!

What always bothered me was doubles, it's either make it or get hurt bad (both you and the trike....) But, if you can clear a table top, it tells you which doubles you can hit and which you should avoid.

Jensen (Jensen racing) on the board did some SILLY ILL jumps on his 350X, I'd hit him up to see whats up!

This was what became a problem to me. I want a motor like a 350X but with suspension like a 250R:

I absolutely LOVE the broad power of a 350X, but it's suspension suffers.

I absolutely LOVE the suspension of a 250R, but I ride them like an animal and get hurt in the process. I am NOT 2 stroke friendly.....

So, along came my 250F idea. Use a lighter motor with great power and match some linkage suspension with it.

I do not have 5K to play with a project like that at this point. In time, I'll build EXACTLY what I want.

But for now, I do plan on putting a whole 450R rear end on my 350X (using a less stiff shock than the 450R though). And for the front end, I'll have to bore a 250R lower clamp to accept a 350X shaft, then I can run any of the 85/86 250R forks and triples which are larger in diameter and I can toss a progressive spring in there too....

IDK if steering stops need to be made but I'm fairly certain that just boring the 250R clamp allows you to run the 250R forks. I also don't know how much fatter those forks are than the 350X..... Remind me (or I'll try to remember to check) and I'll post every friggen OD from a 200X to a 250SX to a 350X and a 250R - I've got all of them to check :D

I have the 200X brake pedal to do, ATC70 suspension to design/build and then the 450R rear end conversion. I have 80% of all the parts I need for those projects and the machines/half-a-brain to get it done.

If you haven't done anything by then, I'll have a nice post outlining what it took ME in MY case. Everyone's situation is different..........

If I get the suspension nailed down (steering stops maybe??), you guys ought to ship a crapola used 350X frame direct from EBAY/other members/Craigslist and I can do all the welding and fabrication. Then I can ship it to you, your PC or paint guy and then the finished product goes back to you and saves you shipping $$$$$ and time.

Trust me, I'm very particular (OBSESSIVE) so nothing leaves my shop/hands/me unless it's 100% or it runs away :lol:

[inv3ctiv3]

Yea those pics were from my first few laps ever on an MX track so I wasn't clearing everything. This last time I went I was clearing 15ft + doubles (5-6ft in the air) and landing super clean so don't totally base it off those two pics haha.

And DC I'd love to work with you on some suspension stuff (sending you a frame or something). Everyone tells me to get a quad but F that! I ride trikes and want to make this old track last with how hard I ride it.