Who is Sherri Cruse and why are we testing her bike? Sherri is a 17-year-old motocrosser from Bakersfield, California who is coming up fast in the ranks in both the WMA series and WORCS, where she is currently leading in points in the women's A class over defending champion, Maria Forsberg. Aside from this amazing feat, what is truly unique about Cruse's bike is the ergonomic set up. Her ZipTy/Montclair Yamaha YZ250F has been modified and fabricated to fit her 5'1" frame and 105lb weight. We took a closer look at this small-person setup from the ZipTy team, and got to race test it recently at round five of the WORCS in Adelanto, California.
ZipTy Racing's feather- weight setup suits Sherri's 5'1" frame very well.
Click here to find out more about Sherri Cruse.
As a 5'8" 135lb female rider, I am much closer to the average rider's size than Cruse herself, but can still certainly appreciate how difficult it is for smaller, lighter people to ride full-sized bikes. It is that much harder to stay in control when you're struggling to compensate for too-tall seat height, or overly stiff suspension. The rider-to-bike weight ratio is another factor to consider. Someone my size muscling around a 220lb motocross bike is the equivalent of the average 200lb rider trying to manhandle a 335lb KLR650 (there's some food for thought)!
Since I commonly jump on bikes with stock set-ups—which usually want to spit me off like a sunflower seed—I was thrilled to have the chance to ride Sherri Cruse's YZ250F, and maybe even experience what "too soft" feels like for a change.
The modifications made the ZipTy bike included taking a 10mm chunk out of the subframe, cutting down the seat foam 10mm, raising the forks in the triple clamp, modified lower handlebar risers and Race Tech suspension with softer springs. Seeing how well her 5'1" frame worked with the bike made me think I'd be a behemoth on it, but I was very pleasantly surprised when I finally got to throw a leg over the "Cruse Control" YZ250F.
The key in making these ergonomic modifications is balance, and that's what the Zip Ty team paid such close attention to. The overall smaller size was noticeable, but the bike's dimensions were carefully kept in proportion. The shortened subframe is countered by the raised forks, preventing the bike from feeling raked-out. The Renthal bar is lower thanks to the modified risers in the rear off-set position and a low-rise bar bend. 3/8" was also taken off each end of the bar, making it narrower for Cruse's short wingspan. The Race Tech suspension didn't feel too mushy, even with the softer springs. Cruse hits hard enough to require pretty aggressive suspension, so it felt just right for me. The bike received these modifications along with the long list of other ZipTy team goodies (full parts list below).
Softened Race Tech suspension and 10mm removed from the subframe helped fit Cruse's 5'1" 105lb build. | 
The subframe mod was carefully balanced by the front end setup, with a lowered triple clamp and low-rise bar bend. | 
The bar mount is in the rear off-set position and 3/8" are cut off each end of the bar. The damper is a big help, too! |
I rolled up to the line on Saturday afternoon without any practice on the bike, or on the course for that matter, and thought, "This should be interesting." But I found out right away that the bike and I took to each other with ease as I grabbed the holeshot. I knew a good test of the Cruse YZ250F's setup would be on the off-road section of the course, which was fast, sandy and whooped-out.
Just as Sherri advised, I held it open, leaned back and just sailed through the rough desert course. The Renthal bar and Scotts Stabilizer made the front end very comfortable and forgiving. The softened suspension helped me conserve a lot of strength, since I did not have to work my legs as much to counter for stiff settings. The overall smaller size of the YZ-F had an advantage I hadn't previously realized; it allowed me more room to move around, and also let the bike move under me when it needed to. The lower height also meant a lower center of gravity, which made it quick and easy to lean over in turns.
With everything kept in such careful proportion, the all-over smaller size of the bike was subtle.
Even in my limited time on the Cruse YZ250F, I was quickly figuring out its advantages, most of which simply allowed me to conserve energy. Not being as ergonomically spread out as usual allowed me to use leverage instead of strength to control it.
The suspension and stabilizer made life easier as well, and also allowed me a lot more latitude in my precision (or lack thereof). As a package, the bike was remarkably comfortable and confidence inspiring, and oh yeah... hit like a hammer!
The strong motor and supple suspension handled the rough course without wearing me out.
I could ride as aggressively as I dared without the usual fear of punting myself with one false move. It was easy to keep under control and it let me get away with everything. Well... almost everything. Just when I was wondering why I'm still riding a two-stroke, I locked up the 250F into a sandy turn and stalled it. Kick, kick, kick for nearly a minute before it gave any sign of life. I lost the lead before I got going again. On my way to regain the lead, I stalled again in the scoring chute, where I spent nearly another minute kicking, which now put me in third. I finally got going again, regained the lead (stalled one more time) and finally crossed the finish line.
Despite my apparent disability to keep the little thumper lit, I was in love with the Cruse YZ250F, and contemplated stashing it in the bushes rather than returning it to the ZipTy pit. Small, quick and nimble, I could put it anywhere I wanted. It just felt so easy to ride it aggressively. And what's more fun than that?
Whoops were no problem. Lean back and apply throttle. | 
With more room to move around, the bike was easy to manipulate. | 
Note the size difference between myself and the average rider. Not a dramatization! |
I then had a chance to do a comparison by racing another ZipTy YZ250F, this one with a stock setup, on Sunday morning. This one was sprung for a 200+lb rider, as bikes I ride often are. The bike itself was still amazing; the Zip Ty porting gave it great power, but required much more effort and caution from me to ride. I did not feel nearly as aggressive. I had to watch my speed in the rough straights to keep from swapping, the front end wanted to push in the soft sand, and at the stock height, even though I could still easily touch the ground, the bike wasn't as easy to get leaned over in the turns.
This bike required much more effort to control and wore me out much quicker.
About 40 minutes into the race, my legs, butt and lower back were killing me from working the stiff suspension in the whoops. Rather than contemplating stashing this bike in the bushes, I was longing to see a white flag.
Though both bikes were fun to ride, with many of the same great characteristics, it brought to light how important proper set-up can be. As a lighter rider, I've always known that, but never truly understood how much it could help until having ridden with it.
It wasn't about outright speed; my strongest lap times on each bike were very comparable. A proper set-up is about comfort, confidence and conserving your energy, which can be just as important as speed on your way to the finish line.
Sherri Cruse ZipTy Yamaha YZ250F Parts List
ZipTy FR and RR wheel spacers
ZipTy quick-release RR axle adjuster kit
ZipTy caliper/sharkfin unit
TM RR chain guide
TM counter sprocket guard
TM swingarm/chain slider
Carbon skid plate
DID chain
TCR coated hubs
Pirelli MT450 tires
Renthal RC fat handlebar with 3/8" cut off each end
CHT sprockets 13T-48T
ODI glue-on grips
ARC rotating perch/lever combo
Scotts steering stabilizer
ZipTy billet stabilizer post
ZipTy triple clamp kit modified lower risers with rear offset position
ZipTy fuel screw
ZipTy jetting kit
Barnett clutch basket
Am-Pro oversized brake disc
Fastway footpegs
ZipTy magnetic oil drain plugs
ZipTy magnetic float bowl plug
RR subframe cut approx. 10mm @ frame junction
Seat shaved approx. 10mm
Dirt Digits graphics
Polisport body plastic and hand guards
Jardine complete exhaust
ZipTy FR axle pull handle
ZipTy extended brake pins
ZipTy FR axle nut
ZipTy radiator race coolant
ZipTy air filter cage ring and billet mounting bolt
ZipTy neutral switch cover
ZipTy hotstart nut
Seal Saver thumb donuts
CV4 radiator hoses
Too2cool oil additive
VP race fuel
All Yamalube oils and lubricants
ZipTy cylinder head plug
Intake and Exhaust Hot Cams
ZipTy radiator braces
Race Tech suspension
ZipTy aluminum valve retainers
ZipTy head and motor work
K&N filters
Parts List Contact Info
ZipTy Racing - www.ziptyracing.com
Race Tech - www.racetech.com
Jardine - www.jardineproducts.com
Scotts Performance - www.scottsperformance.com
Polisport - www.polisport.com
Dirt Digits - www.dirtdigits.com
Fastway Performance - www.fastwayperformance.com
VP Racing - www.vpracingfuels.com
K&N - www.knfilters.com
Seal Savers - www.sealsavers.com
CV4 - www.cv4.net
Yamalube - www.yamaha-motor.com
Barnett - www.barnettclutches.com
Am-Pro - www.amproracing.com
Hot Cams - www.hotcamsinc.com
Sunline ARC - www.sunlineracing.com
ODI Grips - www.odigrips.com
Renthal - www.renthal.com
Pirelli - http://www.us.pirellimoto.com
D.I.D. - www.didchain.com