WR250R flywheel weight / traction...

Discussion in 'Thumpers' started by thetubespoke, Sep 24, 2018.

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  1. thetubespoke

    thetubespoke Long timer

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    I went the 250cc route with a Super Sherpa and my Dad wants to follow. We drove down to a dealership with a WR250R and rode it around. Nice bike, all in all. Really impressive power.

    It was pretty apparent to me that the motor was very free revving and the throttle was a little twitchy off idle. Maybe it was this bike in particular being brand new, not certain. Anyway, after the ride we got to take it on a small trail in the back. It was somewhat sandy and rocky, and coming up sort of a steep, short hill, the tire was spinning quite a bit and I wasn't just going for it. It was predictable and all and I love that kind of throttle response on the street, but offroad it seemed excessive. I knew an old enduro rider who'd always harp on about flywheel weight, wanting a heavy flywheel, and I know from experience on say the Super Sherpa, with identical tires I wouldn't have spun the tire hardly at all.

    This isn't a concern in a casual setting, but if going up a notably steep hillclimb, it seems like the WR250R would just want to spin the tire on any loose surface. If the throttle were less twitchy and response were more docile off idle, I think it'd tractor up. Instead, it's really more road oriented wanting to spool up rapidly.

    Obviously, more aggressive tires can help but they aren't nearly as good on the road, so I'd rather not go down that route. I went through all kinds of stuff on my DR-650 with stock tires and regreted switching to TKC-80s for my kind of riding.

    The bike was pretty impressive all around (certainly compared to the other 250cc dual sports on the market), but the motor seemed like it was designed to look good on paper and not by anyone who'd ever been offroad before.

    Curious what more first hand time on the WR250R leads to. I'm betting that it doesn't get nearly the traction of say a Super Sherpa, XT-250, or XT-225 with equivalent tires. At least for going up hills, I'm sure downhill it'd do just fine and even better with vastly superior suspension.
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  2. Yinzer Moto

    Yinzer Moto Long timer Supporter

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    Tire pressure?
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  3. what broke now

    what broke now Petroleum Brother Supporter

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    Put an Mt 43 Pirelli on it and a 12 tooth counter sprocket for trails. The rims are drilled for rimlocks, and you can run the Mt 43 at about 6_8 psi with a rimlocks. Don't forget to raise the pressure for long pavement.
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  4. lamotovita

    lamotovita DAMN SNOWBIRD! Supporter

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    Lower gearing, rimlocks, a taller profile rear tire of your choice like a 120/90 instead of the 120/80 (at appropriate offroad pressure). You'll soon adapt to the higher reving power, it's not a hard bike to ride.
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  5. dhally

    dhally Hammerhead Supporter

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    I found the wrr to have tractable power. Tricky right off idle but gearing down fixed that. I wonder if your suspension needs to be adjusted? It sucks but can be adjusted for minimum suckage
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  6. Bitingdog

    Bitingdog That's not my dog

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    ???really??

    I have found the Wr250 (aka Whizzelberry) to be an awesome hill climber off-road. It's not very powerful, so keep the revs up. One finger on the clutch lever in case you need to fan it to avoid (Wade) Boggs. The Whizzelberry is quite nose heavy too, which combined with the low output motor makes looping out highly unlikely. You don't need to stand up in attack position, just sit and goose it
    20180925_000541.png
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  7. Plebeian

    Plebeian Scruffy-Looking Nerf Herder Supporter

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    Clutch.
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  8. 2WheelNeal

    2WheelNeal F'n Neal Supporter

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    Do this with the caveat that you will need to keep a close eye on proper chain tension, or risk having the chain eat the swingarm. I'd go up on the rear sprocket, before ever going to a 12 front.
    This will be for your dad or for you? I'd adjust tire pressures and ride it until things need replacing, then upgrade tires and chain and sprocket.

    Plenty of good information in the MegaThread.
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  9. what broke now

    what broke now Petroleum Brother Supporter

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    Sure, keep the chain adjusted. I rode mine for 3 -4k miles on a twelve before the rubber swingarm protector showed much wear.
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  10. thetubespoke

    thetubespoke Long timer

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    Thanks for the replies. The thing is, I don't have to air down the tire pressure on my Sherpa to get traction. Obviously I get more, but the lowest I've gone is 16/16 on Golden Boys and that's more for comfort than climbing traction.

    I suspect lower gearing would make it even easier to spin the tire on the WR250R. Unfortunately, most hill climb videos are not going to be stock tires at reasonable pressures. The general behavior of the WR250R motor just defies what I've learned about a good offroad motor.

    Are any of you in the Fort Collins / Boulder / Cheyenne / Denver area? I'd be really curious to take my Sherpa on Moody Hill and have a WR250R follow.

    WR250R would be for my Dad, although if he got one I might be tempted to as well.

    I think the WR250R motor would be fantastic in a street bike. I don't see the point in supermotos, I'm thinking more of a fully faired race bike. I bet it could hit 100mph, be street legal, and less than 300lbs. Not as fast or cool as an inline 4, but should be lighter and the peaky power response wouldn't be a problem.

    Edit: This was at a dealer, so I imagine tire pressure was at Yamaha's specs. Tires felt fairly firm. I don't think it was a suspension issue as it wasn't a rutted area and the bike felt fine on the road. It was mostly just loose material. I know lowering the pressure would help, but I still suspect PSI for PSI, tire for tire, a Sherpa or similar gets far better traction.
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  11. Navin

    Navin Long timer

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    117.457 MPH to be exact.
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  12. AceE

    AceE supermoco

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    think about climbing or at least attempting to climb those hills or navigate muddy conditions including hills with a slick tire. more fun than a barrel full of monkeys! also the best training tool, bar none for off roading because after you learn how to hang on with slicks. even the crappiest knobbie will feel like its glued to the surface. teaches throttle control, momentum, and wheelspin tactics like nothing else (which seems to be the area in which you are struggling)
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  13. CDN Rick

    CDN Rick Canoodia Eh?

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    The only way a WR250R is hitting 100mph is with really tall gearing, a strong tailwind, in freefall, after being ridden off a cliff.
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  14. thetubespoke

    thetubespoke Long timer

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    I care more about the 21" front and 18" or 17" rear in shape. I enjoy low traction situations, I did the Colorado BDR with a lot of mud on my DR-650 with the Trailwings, not aired down. A 17" front just behaves terribly offroad. I'd rather have a slick 21" and 18" than a knobby 17" set. 19" and 17" seems like an okay compromise.

    This is why I said a fully faired bike, so lower, more aerodynamic, taller gearing, less frontal area, etc. I'm pretty sure it could hit 100.
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  15. AceE

    AceE supermoco

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    not as much as supermoto junkies do or you would be one. it aint for everybody, but 17s with slicks will make anyone a better off road rider. since you wrote you "dont get it", perhaps you do now?

    FWIW TrailWings are actually very good rubber. I think the bad rap that gets mindlessly parroted came mostly from people with low skill levels (blaming the equipment) and those reviving old bikes that came with them (OEM) all rubber gets hard as it ages. but the rubber they use is the best out there for any given tread patern/style from my experience.
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  16. thetubespoke

    thetubespoke Long timer

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    I had a DRZ-400SM. I've found dual sports with 21" and 18" can go quick enough for my tastes. 17" is a little faster in the turns, but generally more relevant at higher speeds where you want a fairing anyways.

    I've had street bikes offroad. Honda Hawk GT up part way on Moody Hill, Seven Mile, BMW R50/5 offroad, R75/5 offroad, etc. I just think supermotos are kind of a silly niche, much worse offroad, a little better onroad, and not nearly as good as a sport bike on the road. I don't want a 35" seat height on the road and a high fender. They would be perfect for urban jump sort of riding, which I don't do.

    I found the trailwing dry traction was good, wet was so-so. But you're right, it was old rubber. I would fit them again. The pattern is not at all great for sand or mud, but it can do it which is good enough for me.
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  17. Plebeian

    Plebeian Scruffy-Looking Nerf Herder Supporter

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    So, will using MX tires on a road course make you a better track-day rider?
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  18. Yinzer Moto

    Yinzer Moto Long timer Supporter

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    I hit 100 once on the WRR, straight road, a few miles long, straight off the top of a mountain...

    There is no way that bike will do 100 on flat ground, I’ll get over 80 now and again but that is about it for that motor.
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  19. clintnz

    clintnz Trans-Global Chook Chaser

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    For the love of God No!

    The WRR has a low powered, rev happy motor & to get the most out of it offroad you will often need it to spin up quick, more flywheel weight would make it a pig IMHO.

    Cheers
    Clint
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  20. thetubespoke

    thetubespoke Long timer

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    Went down with my Dad to another dealer that had a 2018 WR250R that he had test rode before when it had zero miles on it. He said the throttle wasn't twitchy so I gave it a go.

    When the bike was cold, there was a very noticeable flat spot off idle. When it warmed up, it was gone. The throttle was much better than the first WR250R I tried, not at all jerky. The fuel injection and ignition mapping seems designed to make the motor less rev happy. Undoubtedly in my mind, it could be making more power but it would not be as good to ride on the street and likely in the dirt.

    All in all, the ride was impressive enough that I gave my endorsement, and he bought it. We should have it in the dirt soon. It is definitely taller than ideal for trail work for me, but a inch off the suspension and an inch off the seat might be just right. Would really have to push that suspension hard to bottom it out even lowered slightly. He'll ride it as is for now.

    Will report back when we have more time on it. I'll be riding my Super Sherpa and he'll be on the WR. Will be interesting keeping up with him at 5-7k feet.
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