The 2025 Honda crf450 has a hard, spiky feel in the chassis. This attribute is of course exacerbated by hard edgy tracks BUT is always there and can even be felt just ridding in the pits. It seems to me there is an issue with this chassis, However I really like the way this bike handles and would very much like to find a fix or at least a solid reduction in the hard edgy quality.
I have been through extremes of adjustment out back (sag from 107-102, clickers from hard to soft etc), and the hard edginess out back is always there. Yes its reduced a small amount by soft comp damps BUT even with comp blown out te harshness is still obvious and of course now ya have no control. Anyway with damps that soft if there's still an edgy hard quality there almost has to be an uncontrolled wiggle in the frame or maybe the subframe?
My hope theres a fix that can tame this but not too hopeful at the moment.
If anyone is familiar with this issue and has some insight that might help it would be appreciated.
I have 3 bikes I use as references. 2022 SXF450, 2025 YZF450, and the 2025 CRF450. Interestingly the 2022 SXF 450 has a similar harshness in the rear that after multiple suspension mods/links/valving etc, was never tamed to a desirable level. BTW the 2025 Yamaha exhibits none of this trait and if the Yamaha handle like the Honda I would simply sell the Red bike and call it a day BUT the Honda simply handles in a way that fits my style better and Im sure many know what I mean here 
Anyway Help me fix the red head ! Shes far more fun BUT damn that kick in the ass has gotta be reduced or she will be kicked to the curb
I though going stiffer made the bike less hash. That is what Honda claims anyway.
Ive done a lot of development work with loudspeakers. You get your ass handed to ya in this arena with respect to how things flex and resonate. Often a too flexy structure (soft) will have major issues and a too stiff structure, while taiming some resonances will sing like a banshie when it finally does go off. Its a frustrating design problem as once ya tame one issue another pops up.
Looking at the Yamaha and the Honda frame the Yamaha is stiffer by quite a bit. All tubes and forgings are larger on the yamaha
However, the yamaha does not have as good a front wheel planted feel as the Honda and the honda IMO has better feedback due in part to its flexyer nature and perhaps its geometry
Anyway I hope honda is able in the future to calm that whip action AND keep the front end feel. Good luk on that BTW
I certainly dont expect to eliminate the issue but maybe there is a known remedy to calm it usefully? Suspension mods , motor mount stifness, etc??
Ive tryed a Gutts seat ( the stock honda seat is no good for anyone over 110 lbs unless ya like sitting on subframe rails. It was much better seat and no more butt bruse BUT no change in how chassis feels
I even tryed a makeshift tall" seat I made from an old KTM seat that was much thicker and softer. Still could feel he harshness . I hate the ergos of the tall seat too. Just doesnt handle right sitting up there
I guess you could weld some frame reinforcements in but where to add them I don't know. Changing frame feel is just about impossible. I have heard the 24+ Kawi turns really well and still has some comfort.
How much do you weigh? You might be too low in the stroke.
The Shop
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Free shipping: VITALMX
Luxon 4-Post Bar Mounts
$189.95 - $239.95
180
it does need to be a bit stiffer imo
BUT
this harshness is obvious at any speed. Its not just when your deeper into stroke
Its true. BUT the Kow has some serious vibration compared to the Honda and the Yamaha
that was a deal breaker for me
I am 160, I always go stiffer on Hondas (and the Yamaha) 250s. The 2024, I went stiffer on the Honda, and it worked much better.
Call Factory Connection, they are your best bet.
Fcp engine hangers & some Ti bro…all day long…. professional125 can back me on this…
Stock shock spring is a 5.3kg that is too light for 180lbs. I’m 185lbs and should be a 5.5 or 5.7 rear spring. preload close or over 10mm probably need stiffer spring.
With your background you would probably have a better understanding with resonance and transfer of energy but I have noticed the biggest difference between the Honda frames over the years and the Kawi/Yami frames are the relief holes. Kawi and Yamaha both have relief holes drilled in every section of the frame of varying sizes, underside of the swing arm each side, 2 holes where the linkage mounts, inside of the perimeter section each side and so on. The Hondas only have one hole in the cross member where the shock mounts. This is why I believe the Yamaha and Kawasaki frames have the more forgiving nature while actually being stiffer, the relief holes mitigate some of the “spike” or transfer from bumps or vibrations. The Hondas have a more direct feel but struggle with the balance of compliance in small chop and being stiff enough for high load situations hence why they came out and said their frame was the softest out of all the manufacturers but it can feel the harshest. I can only assume it is a production cost exercise cutting back on process in the manufacturing because their engineers would know these differences.
yea the older hondas say 2007 had a much flexyer upper shock mount. not sure if the spike was washed there ? It can be a nightmear in some structures to tame a wiggle and keep the performace iit had in all other areas
I have talked to FC and Fcp. They wont say straight up that they can eliminate the issue but of course they say it will be better.
Ive also contacted Keefer a few times on it and He says they have come to same conclusion. That its in the chassis not the suspension
I likley will be chopping up stock engine mounts ( cheap to replace) as a way to test before I dump that much $ on Fcp. And of course your into 1500-2000 at FC depending on how far ya go
Just hate to spend until i have evidence of what the issue is. Some crude experiments will try this spring I guess
If some Ti doesn't fix it, just add more.
Ha
More Ti bell
As CBE mentioned springs. At 195# Factory Connection went to .53. kg fork springs & a 5.7 on rear. FC recommended 108 sag, fork 2.5mm showing. last years shorter springs work with a spacer or FC machined a new clip in inner fork tube for lower spring seat.
I raised fork oil from the 340ml they sent it back with to 345 may go 350
re valved yes .The base valve is firmer than stock, mid is more progressive. oil up from 313ml .rebound stack is stiffer & more progressive than the stock stacks. Also they drilled a 1mm bleed hole in mid valve.
Shock ,I haven't opened it up to look at valving. but I feel they firmed up rebound stack & close to stock comp stack.
Stock forks do get worse with stiffer clicker settings. I had better luck with oil ,I tested up to 365ml stock everything.
Stock it rode low. Also key is front to rear balance / attitude of chassis.
Only other mod is the KX 450 clutch master cyl . engagement a bit wider, a bit less on & off. I wasted $195.00 on less noticeable stuff.
Coming off a 25 350 . I enjoy less vibration, less edgy chassis . Generally not a 450 guy but wanted a change.Also this bike is easy to ride.
interesting
yea I had a 2025 sxf350 for about a month. I didnt like having to rev it so on tacky or sandy tracks so I sold it
Also didnt care for the angle of the seat. It was a bit rear high and not a flatter slope. My 2022 sxf 450 and the 2025 yamaha and Honda All have a more level seat. Seems to me the new KTMs need the rear of the subframe lowered about 5mm. I was going to cut the subframe down BUT the 350 motor wasnt enough imo so never went that far with it.
I tryed lowering the rear by shortening the shock a bit (internal spacer) BUT that just raked the front out and didnt turn all that well
Sorry if this is a little off topic but would you mind sharing your thoughts between the 25 350 and the 25 crf450, mainly in the chassis and handling department?
Current hours on the bike? Having ridden both a 450R and RWE lately, can say they get noticeably better/softer feeling after 10+ hours. Also, 120/80-19 or 120/90-19 rear tire? Out west, the 120/90 and rolling turns a gear higher than usual assist this chassis a great deal. PT Evo bars and traditional glue-on grips go quite a ways too…
I’m keen to know as well!!
Pit Row
Your user name sounds like my life 🤣
Perhaps read up on the previous generation 20-24' CRF chassis adjustments. I think Honda tried to address them with the 25' chassis package but your mileage may vary.
Bars, triple clamps, chassis bolt torque specs, rear wheel distance, extra sag, etc...all played into making the 20-24' CRF chassis more compliant and comfortable. I have a 23' 450R I've been chasing some of this stuff on and it def makes a difference.
"hard spikey feel in the chassis" "can even be felt just ridding in the pits"
It sounds like you got one of the few '25's that received the TDA control assist technology. (Thunda Down Unda). Originally planned for 2025 they decided to spend another year developing, so I think we'll see it on the 2026 WE. It uses a directed electro magnetic frequency pulse up the lower orifice of the rider to correct their posture, leading to better balance and control. The factory riders all love it, claiming after they loosened up and gave into the technology it gives a more pleasurable riding experience; on the track and in the pits. It was originally developed by quad riders but Honda started applying the TDA to bikes after they stopped selling race quads.
Im not sure this question was directed at me, but heres my take on the compare between the 25 sxf350 and the 25 crf450
Ive been on ktms for the last 5 years and they are superior to any jap bike in these areas...
Breaks, the brembos really are usefully better. They are more linear and consistent. I didnt realize how much my corner entrance was influenced by the brembos. The jap brakes dont give that confidence. Not talking power here but finesss. That said the Hondas new front brake is better than the yamaha
Clutch, face it, the ktm clutch a heads and tail above the rest and yamaha is now nearly a direct copy. I have never gotten anywhere near as much life out of a clutch as the ktm design. Looking at it as a development engineer its a work of art
Components, the ktms are superior. better metalurgy, better design and they last. drop your honda and the weak cast levers will snap
Reliability, the ktm 4 strokes gave me 250 hrs on motors without an issue. I dont rev loud however. BUT I never came close to that life in any jap bike except the yamahas
Neutral handling. The ktms are bullseye at the center of nutrality. They turn well (not as sharp as the honda) but they have a forgiving nutral response to your inputs.
The new ktms did overcome the squat issue the older ones had in the rear BUT the height at the rear of the seat is off imo. it needs to be about 5mm lower. Many dont seem to have a problem with this BUT I see the ktm team is quietly dealing with this one.
THE 350SXF
I hate the air fork. Its a marvel of simple design thats biggest advantage imo is the ability to change the spring rate easily. Sand track? 2-3 more psi and a click or two and the bike is level again. However I grew tired of constantly chasing that pressure as it would change throughout the day with temp and I can easily feel 2 psi change. I eventually went with spring conversion and valving change (RT) and was happy and could get similar results on sand by simply changing comp clicker now. HOWEVER to my suprise I could feel that coils weight big time compared to the air cartradge. I suspect most wont have an issue with this but I do a lot of faster scrub whip type moves and trying to flick those bars around with 3 lbs added to the mix made a heavy feel. I got used to it BUT still miss it
The new motor definatly has better low to mid torque feel that the older 350. However that feel is really only good on dryer or harder surfaces. Once ya get into thicker power robbing stuff your right back to a big 250 feel. Ya gotta rev hard to keep it from falling on its face . Deal breaker for me as I like to ride in center of a wider 450 style power bubble
FI, the fuel injection on the 350 was a joke. It was herky jerky down low. sure stay away from that low a speed and its fine but at this stage there is no excuse for FI to be that unrefined. Strangely enough there were some days it didnt do this. I dont know why
Lack of "feel" of front end at corner entrance. Same as my 2022sxf450. this chassis doesnt have the feedback that the honda does. I dont like the vague feel out front and btw its similar on the yamaha
The Honda 450
Kind of cheezy and lower quality build than the ktm BUT not bad. Just not up to ktm quality and the plastics will eat holes in the frame. If ya buy pull plastics and put thick tape over those spots
Sharper handling. I love the way this bike almost feels like a pair of skis under me. I can angulate and carve and feel whats going on under me as I work the bike from my core. GOOD STUFF
Suspension, OK for novice but trouble if your at all fast or over 140 lbs. Forks have almost no comp damp and blow through stroke easily. Rear seems ok BUT front is the most plush I have ever felt so long as ya dont crush it
Chassis, theres a harshness in the rear of this bike. Some say its in the chassis. Some ay there is a usefull washing of this IF ya spend the money and suspension work. I have been round and round with contacts on this and so far it is looking like Factory Connection might be the best place to send the suspension too. However your looking at 1500 -1800 to find out. I will likley be sending mine out but wont have a report till spring as we are frozen solid here in NY now ha
Motor, this is a very good motor for the average guy. Its not a power house but has a well managed power profile that will work well for most. Its not the rush of the yamaha but thats a good thing for most
The stock seat is the all time fail of mx seats. its thin, too soft, and the frame rails are felt easily. Inexcusable design BUT having the intake air going up over the hock makes for so little room they were forced here. They should work on this
The new honda is defiantly less head shake than the older ones. They seemed to have fixed this a usefull amount.
FUN, I just have more fun on this bike than the 350. It feels lighter, has much better low end to mid usefulness, and it slices and dices corners. If the harshness in the rear can be fixed enough then I choose the lower quality honda over the higher quality KTM. The Honda isnt bad its just not up to the KTMs standard of quality, BUT she is way more fun imo
All that said the new 350 sxf is a great bike for many so long as ya arent asking it to torque through the thick stuff. If ya live out east and you are mid pack amature or faster I would not choose this bike
Sounds like pretty simple answer - you don't gel with an aluminum frame. I tried every jap bike and never been comfortable on an aluminum frame. KTM 350 now and once sorted the suspension and engine - did the factory programmer dialed up the torque settings as well as engine braking wow big difference. AER 48 forks with glide kit work beautiful now.
25 crf 450 vs 25 350 Chassis feel. first let me say this. I rode & wanted to like a 24 & older crf450 but up in the head tube & right under seat a shock tower I felt a stiffness or apparently" lack of" which gave a edgy harsh feel & twitchy .
Suspension changes you could do at home did not correct it.I have since rode a Factory connection set up with linkage ect. that is pretty good.also has.a Vortex with a very smooth map 24 & older.
Ok the 350 I have had a 25 ,2- 23's & various older years.I ran a WP6500 kit & good valve stack for the shock, sprung for my weight, pipe , vortex & fuel. The 25-350 feels like a 40 hour 24 & older frame from the start.
A buddy I ride with bought a 25 honda, He switched from a 24 kaw.& a 23 ktm 350. so I spun a lot of laps on it & thought man this is good.The clincher was . for the most part we are dead even in speed, once he was on the honda I had to go to 100% max effort to keep up.So I bought one to.
I say the 450 I turn it 5% better. possibly more consistent . I may of over rode the 350, too aggressive
350 actually had more throttle response
450 less vibration.
350 feels lighter but the 450 is not much of an adjustment as 450's usually are. Keep the 450 motor smooth & mellow.
350 easier to do maintenance on .450 shock swap & ignition box is a pita to remove.
Over all it's been easier to go my max speed on the honda 450 vs 350. technical Jumps out of corners if not hit perfectly significantly easier on the 450.
Also I stand up a lot when I ride so possibly this would lessen any extra chassis noise/ feedback . Correct springs were a huge improvement. held up in top of stroke felt plusher & better btm resistance. I tested 105 to 110 sag . I like 106-108 range.
Fwiw I feel more comfortable on the 450 & that surprised me. The guys I ride with have commented I look better on the 450 also.
While the 350 fun factor is great .The max effort is the undoing however, 90% effort same speed on the 450.
Note; I have full access to a great private track so I can ride & check things out . Make a change go back the next day. last summer I was riding 3 days a week. So you can get a lot done testing wise.
I generally get to ride all the bikes more than just a lap or 2. The 25 models I have rode so far is, ktm 350,FE 450, Honda 450 ,we 250 ,we 450, kx 450, yz450
The kick in the ass the op mentioned. I feel a stiffer rear spring with less pre load at 107-108 sag a click of rebound. Balance the fork ( springs & oil level) to match is 80% of the way there. A revalve is the last 20%. I raced mine this exact way and it was good . Then got around to the revalve.
That's enough ,too long already . I hope it helps.
I always thought those are just weep holes / protection against trapping moisture in the frame?
I dont believe its as simple as "dont like AL frame". My 2022 sxf has the same harshness in the rear as the 2025 crf450. As well Ive done decades of design and development work with these materials and its all in the exacution, not so much the material. Steel does afford more lattitude in what ya can do because of its resiliance( resistance to cracks) BUT you still have to overcome issue in overall design to tame unwanted resonances and oscillations.
If Honda gets this chasis figured out and cleans up a few areas this bike will be loved by most. The KTM are for sure better built but......
agree that the 350 seems to have better more "throttle response" BUT its a feel more than an actual in that as soon as ya get into any thicker gooy or deeper sand the 350 has to be reved hard to avoid a noise dive where the 450 easily plows through unfazed. Mostly east coast issue. The 350 was enough on hard dry dusty tracks but throw it down into a big soft berm and it will choke unless your spinning it hard and even then shes a tad weak
Pretty sure we shared some things awhile back on Thumper Talk. I was impressed with the deep dive you have done into these bikes. I am sure you are on a different level of speed than I am and sounds mostly Moto. I do 75% Moto when practicing and race 75% Harescrambles when racing. I did do amateur day in Millville and Glen Helen World Vets moto this year. I am always chasing comfort deep into 1 1/2 hours plus pushing hard. And just me but I have raced aluminum framed Honda's and after an hour they beat me up. I know they say 10 hours to break in a '23 KTM frame but in my experience it took more like 30. And I am a firm believer different brands just fit people better. I run my sag around 102 which helps me put more weight on the front, maybe my body position is wrong but that's where i am comfortable. Wish you were close by would love to spend a day testing different bikes and settings. Believe me it took awhile to get my KTM to where I am comfortable at race pace, now that I have I think I can share some settings that of course work good for me.
Too deliberate in placement plus the fact they are varying sizes is the tip of that they are more than just weep holes and like I said the Honda frames only have one in the shock tower which is at the top of the frame.
It is interesting that you notice this on the Yamaha/Kawi. I think most people would say those two brands have had the most comfortable frame feel for years.
Post a reply to: Honda CRF Chassis harshness