Posts
185
Joined
9/2/2013
Location
Little Elm, TX
US
Fantasy
9th
Edited Date/Time
8/23/2021 10:43am
After almost a year of riding the RMZ250 I’m thoroughly enjoying the bike. Before I start documenting the build process, I figure I’d share some observations I’ve made regarding this bike.
-It corners phenomenally. Every now and then I get spoiled and forget how good it does this, and a friend rides it and that is one of the two things they always say.
-The other thing they always say is “I thought it would be slow?” The shootouts haven’t done this thing any favors, but Vital’s own shootout had a dyno graph that I think explains it: up until 11k rpm it is even with a Yamaha, and frankly not many of us utilize power after that often.
-If you find yourself wanting in between gears 2 and 3 for corners, try a 13/52 gearing combo. One of the BarX mechanics recommended this, and I thought it was nuts, but for tracks with a lot of corners that are kind of “in between” 2nd and 3rd, this gearing works great. Just roll 3rd.
-This thing and it’s 450 sibling are built significantly tougher than any other bike I’ve owned. (red, orange/white, blue, and especially green ones). I pulled the OEM top end at 15 hours because with other OEM’s I’ve cracked pistons in that timeframe, so I wanted to see how it would look. Perfectly fine. I pulled the stock clutch and installed an aftermarket one at 30 hours (reasoning to come) and the oem one was still pulling just as strong.
-The stock bars are low if you’re 6’5” (I am). On this 250 I think I installed the linkage at the same time as the taller bars, but on my 450 I did bars first and call me crazy, but I think by pivoting my torso a bit more upright it got enough weight off the front to eliminate the front end twitch on corner entry (I only noticed this on sand tracks and high speed small chop on corner entry).
-The shootouts all seemed to favor the lean coupler, which does make for a livelier feeling at low to medium throttle openings, however if you would prefer more over-rev or run an oxygenated fuel I’ve found I like the rich coupler. Looking at some screen grabs of the GET maps on the iPhone app backed this theory up. (Although I’m still waiting for SMAI to release the GET WiFI tuner for these so I can copy their “reach map” which combines the best of both worlds)
-It corners phenomenally. Every now and then I get spoiled and forget how good it does this, and a friend rides it and that is one of the two things they always say.
-The other thing they always say is “I thought it would be slow?” The shootouts haven’t done this thing any favors, but Vital’s own shootout had a dyno graph that I think explains it: up until 11k rpm it is even with a Yamaha, and frankly not many of us utilize power after that often.
-If you find yourself wanting in between gears 2 and 3 for corners, try a 13/52 gearing combo. One of the BarX mechanics recommended this, and I thought it was nuts, but for tracks with a lot of corners that are kind of “in between” 2nd and 3rd, this gearing works great. Just roll 3rd.
-This thing and it’s 450 sibling are built significantly tougher than any other bike I’ve owned. (red, orange/white, blue, and especially green ones). I pulled the OEM top end at 15 hours because with other OEM’s I’ve cracked pistons in that timeframe, so I wanted to see how it would look. Perfectly fine. I pulled the stock clutch and installed an aftermarket one at 30 hours (reasoning to come) and the oem one was still pulling just as strong.
-The stock bars are low if you’re 6’5” (I am). On this 250 I think I installed the linkage at the same time as the taller bars, but on my 450 I did bars first and call me crazy, but I think by pivoting my torso a bit more upright it got enough weight off the front to eliminate the front end twitch on corner entry (I only noticed this on sand tracks and high speed small chop on corner entry).
-The shootouts all seemed to favor the lean coupler, which does make for a livelier feeling at low to medium throttle openings, however if you would prefer more over-rev or run an oxygenated fuel I’ve found I like the rich coupler. Looking at some screen grabs of the GET maps on the iPhone app backed this theory up. (Although I’m still waiting for SMAI to release the GET WiFI tuner for these so I can copy their “reach map” which combines the best of both worlds)
The bike had been used as a test/backup bike for dirtbikemike’s arenacross team and had Race Tech gold valves installed for that. After inputting a new code, I was ready to go with an outdoor setting. It was super intimidating the first time when I helped DBM do his team’s stuff, but a quick call to the support line got me squared away. Quick tip, if you’re doing arenacross or supercross let Race Tech know when you order so they can supply the thicker shims necessary.
I took the opportunity to re-grease all the pivot points and stripped the paint off the triple clamps (so they look like a 2020) as well as from the ignition cover. The clamps were lightly polished with some of those blue steel wool pads, and the ignition cover was etched with Mag Wheel Etching by Eagle1.
Next up was replacing the Wiseco Racer Elite 14.5:1 piston I’d been running. It had 15 hours on it, but wasn’t showing any signs of needing replacing, I just figured I might as well with this free time. I was concerned going into trying the Racer Elite piston that I would gain a bunch of bottom-mid, but lose over-rev. Thankfully, that wasn’t the case! I did gain a much stronger bottom and mid, BUT was pleasantly surprised that it pulled strong into the top end as well. It made gear selection less important, and the 13/52 combo plus the piston made 3rd gear feel like riding a 450. I did run this piston 50/50 with 110 octane and pump gas or straight U4.4 to be safe with the compression. Below are some before and after pics. Note there was zero wear on the skirts!
If I had one complaint with the Wiseco Racer Elite piston, it would be there was a good bit of added engine braking. For some, that'll be no biggie, others might not like that feel. For me, the juice was worth the squeeze.
-Holeshot device. Duh, who doesn’t. They’ve got a simple one that I’ve never had a failure with.
-Elite Clutch Perch. This might be an unpopular opinion, but I’d take a cable clutch with this perch over any hydraulic set up. I’ve never appreciated the hydraulic “feel” or lack thereof, in my mind. Plus, this looks super trick.
-Skid Plate. Occasionally my friend talks me into doing a harescramble, which in Arkansas means rocks the size of your head everywhere. This is to negate those rocks. *A keen eye will notice I got bored and drilled the OEM engine guards to match. No, it doesn’t serve a purpose, I just think it says “attention to detail,” or maybe just “he needs a hobby”
The Shop
I’ve got a Pro Circuit and Ride Engineering link. No reason why for the mismatch, just one popped up on eBay cheap, and the other was given when a friend switched brands. If I had to buy one, I’d get a DeVol transformer pull rod, since they use a similar adjustment system as another, but for the price of the non-adjustable ones.
Both appear to be the same length according to my calipers, and 1mm longer than the OEM link.
I actually have 30 hours on my 450 as well, but haven’t put a link on it yet, as I haven’t felt a need really. I will when I re-grease the chassis.
*also pictured is the yellow UFO slider (chain guide to match). The stock one wasn’t worn, I just thought the yellow was snazzy. More UFO updates to come.
I’ll be running Pirelli MX32 Mid-Soft’s, and a larger 110-90 on the rear. Here’s my breakdown of the tires I’ve tried in the last year.
Dunlop MX33: came on the bike. Good grip in straight line, rear has good grip on lean, front not quite as good, still better than most. When you push these tires outside of their intended use window the front has more of a “cartoon banana slip” moment than a gradual smear like the mx3s. The rear was destroyed after a few rides. My wallet didn’t appreciate that.
Dunlop MX3s Front: better than the MX33, it will “smear” across hardpack rather than just sliding right out from under you.
Bridgestone Battlecross 40’s: these came on the 450 and were hot garbage. They have a super narrow window of where they work well. It’s a decent set for hardpack. The front gives you a little warning before you’re on your head on hardpack, but constantly seemed searching in sand.
Kenda Millville 2 & Washougal 2 DC: There’s a lot to mention about these. They are popular in my local off road community, because it’s almost impossible to tear a knob off... that said, I’ve ran tires missing knobs that hooked up better. These tires work ok on straight line traction in their intended conditions. They haven’t figured out the lean angle traction, and they give way with little to no warning. The sidewalls have a very stiff feel. If you used on tire as a baseline, say Dunlop’s, these would feel like 2-3 clicks stiffer on your suspension.
Pirelli MX32’s: straight line AND lean angle traction on par or better than the Dunlop MX3s & MX33. These have the most forgiving operating window, so when I ride hardpack and break too hard or turn too aggressively, I feel a gradual “smear” and not a “whoops, I’m on my head”. Additionally, these have the best (in my opinion) “bump absorption”. Remember the Dunlop baseline I mentioned? This would be like going 2-3 clicks softer BUT not sacrificing any actual travel because it’s all sidewall. Supposedly these are rather light too, but I don’t get hung up on that stuff. Pirelli recommends running these at 14 psi, I’d been running them at 12 and the front lean angle traction improved when I went up to 14. I have been riding this set once a week or more on my 450 since New Years. The front carcass is breaking down, but the rear has really surprised me durability wise.
When I buy an extra wheel set, I’ll be mounting up MX -Extra’s from Pirelli on the stock 450 set to use as a practice set.
There’s about 4” of overlap between the rear fender and air box, and a bunch as well between air box and side panels, so I drilled the redundant air box plastic. I didn’t let my OCD plot out the holes since they won’t be seen, but if you do something seen I’d recommend taping graph paper on, plotting your hole centers, and making a pilot hole (I use a heated up dental pick).
Occasionally while practicing on tight turn tracks I will boil the front brake fluid. To aid in cooling, I drill a couple of holes in the caliper. As for pads, my front pad of choice is DP for “initial bite” and I don’t care about the rear as long as they aren’t too touchy.
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I kind of wanted to utilize the blue to do something like the Suzuki MotoGP or MotoAmerica teams, but I couldn't quite find something I was happy with. This is what I would up with:
They were printed by a local sign company that's owned by a moto guy, Pro Signs and Graphics in Hot Springs, AR. They've been super helpful since I started handing them notebook sketches back in 2009, and now they let me have a copy of the design software so I can tinker at home.
You may notice the head is still off the engine in the previous posts. Well I sent my cams to WebCamshafts and unfortunately they only have office staff til the 30th, so my cams will have to wait until then to be reground. They were super helpful over the phone and in email helping me find the right set up as well as a safe valve train. The head has some light work done to it, mostly just to smooth out the short side radius on the intake where the casting meets the machining marks above the valve seats.
Dirt Bike Mike's is awesome. It has elevation change, some sand, a few turn tracks, a full scale arenacross track, and 10 miles of trails. Honestly, the hardest part about riding in Arkansas is getting in with the people who have private tracks, otherwise it's slim pickings.
That bike in stock trim is a great bike for the second half of the day. For instance, doing the Texas Winter Series they gave one of my classes pretty long motos. I'm pretty slow for that class, but as the tracks got beat and I got tired that bike shines. Pretty mellow down low, very torquey mid, not too much over rev, the chassis turns well with little input. I never experienced any issues with the shock (it's still stock) despite shootouts claiming I'd endo seat bouncing that bike. In fact, I never went further than 3/4 turn softer than stock on the shock, and never touched the forks. I've been running the forks flush with the top clamp, and 110mm of sag on the rear. When I put the linkage on, I'll go to 105-108 as I've been running on my 250 with a link.
My eventual plans for the 450 are:
-High compression piston and slip-on exhaust. I want two things, a smidge more "snap" rolling 2nd gear on in really tight 180 turns, and more over-rev for when I get too lazy to shift.
-Try LTR450 clutch springs and removing the judder spring, before a Rekluse TorqDrive. I don't get any extra free play with the stock clutch, but some friends who abuse them more do.
-Race Tech gold valves (I did these on a friend's bike, they're too easy not to do)
-Linkage (just to allow a little more adjustment with fork height if I ever need better turning for arenacross or a really tight track)
-Extra set of wheels, I think I'm going to go with ProWheel, just haven't settled on colors.
As for the Works Connection perch, I don't know if it's just tighter tolerances, or the quality of the bushings, the lever ratio, whatever, but it always feels a little smoother than a well oiled brand new stock perch. The adjustment wheel is easier to spin as well while riding. Lastly, they look cooler than Christmas and you can pick the color of each component.
Mx bike a 1972 husky 250 wr this rmz really is Great bike ! As reviews state it is sprung like a SX bike and I only weigh 148 lbs so I’m planning on going softer on springs...
What have you changed on your suspension? Also at the price of 4999.00
I couldn’t find anything less than about 9-10
Grand ! For the other makes Thanks for your write up on your build..stay Safe
Warren
Pit Row
I’m 6’5” and 195 lbs, so I run stiffer springs with the Race Tech gold valves. I would try a lighter spring rate front and rear for starters and depending on your mechanical ability, either installing some gold valves yourself, or having a reputable shop perform a revalve and re-spring as necessary.
With the stock valving and springs it was a bit harsh on small chop during the break in period, but after a few hours I noticed I wanted more bottoming resistance and the suspension had softened up on the small chop.
Thank you for the kind words regarding the build, the virus precautions have caused some delays in some of the parts to complete it.
Next came my search for valve springs to handle these bad boys. I noticed only Pro Circuit had springs listed specifically for the 19-20 RMZ250, but PC likes to keep their specs to themselves, so without 100% certainty they'd be compatible, I decided to keep searching. Still with no aftermarket ones for the 19+ turning up, I did a little cross referencing of the OEM springs. Not only have the valve springs on the 2020 RMZ250 been used for over a decade (meaning aftermarket ones should be compatible), but the intake springs are also from a GSXR750, and the exhaust springs are from a GSXR1000! So, I did a quick search to see what kind of lift those springs could handle in GSXR models and was confident the stock valve train would handle it. It also made me feel better knowing the OEM springs are also the springs that survive tens of thousands of miles with dudes screaming down the highway. One final call to Webcam to confirm my findings and once again Ms. Melissa was very helpful and we determined it was good to go.
So I did the final assembly on the head, set the valve clearances and torqued everything down Wednesday night. Thursday I loaded up to go to a race. In first practice as I was taking it kind of easy to break it in, I felt like the bike was very snappy. I liked it, but was worried it might be lacking over-rev simply because bikes that usually are snappy seem to lack up top. NOPE! This sucker screamed. It honestly felt like I was always in the power. High RPM, low RPM, it was going to pull. Another added bonus of the cams was it eliminated the heavy engine breaking feel of the Wiseco Racer Elite 14.5:1 compression piston.
With so many variables changed over the course of this, I also went back to the stock gear ratio (13/50) to better get a feel for what the changes were doing compared to stock. Honestly giving the bike more power on both ends made me feel like I could run any gearing just fine. As I broke in the bike and began "givin' her the berries" to realize the over-rev was awesome, I decided to go back to the lean coupler. My logic was that the high RPM power was awesome regardless, might as well give it some more razzle dazzle down below.
Now for the sad news. After being absolutely thrilled with not only the performance, but equally the customer service from Webcam, I hopped on Instagram and found that Melissa had passed away according to webcam's account. My heart goes out to them, she was great to deal with even as a total stranger, I can only imagine how nice she must have been to have as part of your work family.
I cannot recommend Webcam enough for your cam needs. To have your cams reground it retails for $623. That's about $200 more than a set of cams from the cheap company that gets used in every build video put out by Mr. Clark, but the performance is night and day better. There are other high-end cam grinders too, but none have been as easy to deal with and informative as the good people at Webcam in my experience.
Also, I went with a different exhaust than I initially planned. The company I was planning on using had been a longtime supporter, and I was simply waiting for their newest iteration to become available. Unfortunately, once it was available, they cut their rider support program, citing COVID as a reason for declining sales. Odd, since every other aftermarket company and OEM is busier than they've been since 2008-9. Hope all goes well and returns to normal for them, as I've heard that shop has some overhead problems. At any rate, vital member dirtbikemike recommended I try the FMF system his team used in arenacross. I tried the slip-on first, and noticed a little more snap down low, and maybe a little over-rev too. When I tried the header as well, I felt the top end was about equal to stock, but the bottom end gain was more pronounced. I noticed the Bar-X team uses the slip-on with stock header on their race bikes.
The next, and likely last thing to come will be a vortex ecu. They finally released one for this bike, and the gains posted on Vortex's website from the ecu are huge.
Pics to come!
You just kinda disappeared; wanted to check on ya.....
Michael
Vortex arrived and if I were to do it all over again that may be the first thing I did! The added rpm is a HUGE help. The stock ecu only revs to 13200, which is a significantly lower than other oem’s. Additionally, the stock ecu cuts fuel 200 or 300 rpm before that. With a stock ecu, mapped using the get WiFI tuner, I could get incredible throttle response and midrange out of that engine package, but it just quit pulling earlier than my previous 250 (fc250). With the vortex installed I noticed it kept on pulling way longer. Rhythm sections where you’d land one jump wide open and wonder if you should ring one gear out or shift up you’d be fine to just let it scream. Perhaps most beneficial was straightaways where you’d debate shifting up right before letting off. No need for the shift with the vortex. I even slapped the vortex ecu on one of dirtbikemike’s stock rmz250’s to see what kind of improvement it made. Down low it was comparable to the snappy map in the Suzuki app, but mid range and up it was way better. I feel like the simple ecu swap is all it takes to be on par with other oem’s bikes. Hopefully for Suzuki fans, they’ll raise the rpm limit. The valve train components can certainly handle it, the springs are from GSX-R models!
Cautionary tale for those considering the GET ecu:
Dirtbikemike had a rider that ran one on his arenacross team. The bike repeatedly broke the kickstarter shaft. Several rm army kids who were using the ecu found the same problem. The oem and vortex ecu’s have a certain protocol built in that cuts the spark if you don’t kick it hard enough, which prevents the kickback that was snapping the shafts. The GET unit did not have this, nor did it have anyway to program it in. I asked the jgr guys if they had that issue, assuming they actually ran the GET ecu’s, and they told me they ran a works unit.
As for a general life update, I no longer work for Suzuki so I moved to the Dallas and made the switch to gasgas bikes. Brian Storrie at adventure moto in McKinney was a great dealer to deal with when I owned Austrian bikes before, so he had already earned my business. My first ride on the gasgas 450 I actually thought I made a mistake, my rmz450 was dialed! I’ll post a build thread soon on those bikes, my goal is to gain some excitement in pretty much any area of the power band on the 450, as it’s super linear feel is probably faster for my untalented self, but I want some ooomph somewhere. I’ve already had Fastlap set up an old set of cone valves and trax shock for one bike, and revalve a set of oem forks and install the mx tech tank kit on the oem shock. Thinking I’ll send the 250 head and vortex ecu to racetech for their engine spec that Blose and Robin are using, as it’s surprisingly affordable!
Question: you mentioned the GSXR valve springs... So you stuck with the stock valve springs on your RMZ250 because they were the same as the GSXR springs or got a set of GSXR springs for your 250??
I have the GET and kinda wish I had the Vortex. I'm gonna get with Derrick at HP Performance about my GET, he's suppose to be really well versed on the GET systems! So, we'll see.
Congrats on a successful Loretta’s!
So, did you feel like they could keep up with your Web cam set-up?
Thanks on Loretta's! I'm pretty happy with my results considering my lack of preparedness! I needed a couple more months to train and ride. Staying healthy this year will help me tremendously for '22!! Top 5 is my goal and run with those fast boys....!!!!
Were you at LL this year?
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