Feedback on Gearing . . .

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Jeb
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Feedback on Gearing . . .

Post by Jeb »

for those considering changes for the first time.

When I replaced my rear tire with a Pirelli MT16 110/100 I actually made my gearing a bit taller (that's sexy moto talk for less accel, more speed if you don't know). I didn't install the tire for that purpose, mind you, so it's sorta the price I paid for some awesome traction. BUT . . . since about the same time I bolted on RB-modified head/carb, the genuine increase in power completely buried any effects on apparent power from the ratio change (and then some, let me tell you).

Sidenote: I also pulled the airbox lid off with positive effects. I've got the CEK clip in the #4 spot and things seemed a bit rich since the colder season has rolled past and the absense of the lid squared things up pretty good (and added a little more punch all around, I'm happy to say). Diminished spooge. A/S is pretty close to 2.25. 'Still need to do a plug chop to be safe . . . OK, back to the topic.

So what would gearing changes do!? 'Bought a Renthal 12t counter-sprocket and replaced the stocker to find out. I'm figuring (SWAG) my gearing with the bigger tire is now betwen a 13/50 and a 12/47 . . .

I like the change - more than I thought I would. In my 30-minute ride I spent more time in a higher gear than normal. Meaning I'm faster. There's a tight, bermed curve I almost always took in 1st and now I'm in 2nd, coming out plenty hard and into 3rd pretty quick. Acceleration improvement is obvious. Lofting the front wheel is easier, making up for my LOFT (lack of freakin' talent). Almost looped it on my infamous-to-me little creek crossing / turn uphill (if you dial in the throttle enough the front wheel misses the rutted creek crossing BUT traction on the other side + some physics makes the bike tend to stand up, bad if you don't hit the uphill turn !) On the minus side is a bit more wheel spin in the mushy stuff - that's the CEK but I like it too much to change it :grin:

Overall, another nice improvement . . . it just keeps getting better !!
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

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UFS207
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Post by UFS207 »

I had the same tire on my 220 about a year ago. I noticed it was just a "tad" softer in 2nd, 3rd gear singletrack like-conditions in the lower part of the "power-band" but other than that the effective overall taller gearing didn't faze me. If anything I liked it better at first since it reduced unwanted wheel-spin in many situations. I did opt to go back to a stock 100/100 sized tire (Maxxis desert cross IT) because I found as I started riding singletrack faster that the ability to kick the rear-end out with some controlled wheel-spin helped me get around hairpins easier. My bike was and still is practically stock motorwise though (full FMF exhaust and airbox mods only).

Off-topic: how do you like your YZ forks? You may not remember me but I recently did a CR fork swap on my '00 220 and I really like them other than the fact that my steering radius is severely reduced. Going to have to come up with something different. I noticed you did something similar to what I did to fix the stop problem, is your turning radius noticeably narrowed? Mine has probably lost a good 8-10 degrees stop to stop which is all the difference in the world on tight stuff. Was looking at your gallery and your stops on the clamp seem much further apart.
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Post by Indawoods »

Rear wheel steering! :wink:
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Jeb
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Post by Jeb »

>|<>QBB<
UFS207 wrote: . . . as I started riding singletrack faster that the ability to kick the rear-end out with some controlled wheel-spin helped me get around hairpins easier. My bike was and still is practically stock motorwise though (full FMF exhaust and airbox mods only) . . .
Your comments are great food-for-thought. I'm still "learning" this bike with the power mods and handling changes with the fork mods (especially since I keep changing things). Right now I'm finding that if I can get the kind of traction that keeps me from spinning the rear tire, then my weight on the outside footpeg with my arse on the outside edge of the seat and my bike leaning over considerably gets me 'round the curves plenty quick! The CEK needle, however, gives me the ability to get some pretty good wheel spin if I try.

Having stated all of this, make no mistake: I'm a total novice at this stuff! With a bike with very good but reasonably controlled power and a decent suspension, though, I have what I need to try to get good.

It's a beautiful thing!

>|<>QBB<
UFS207 wrote: Off-topic: how do you like your YZ forks? You may not remember me but I recently did a CR fork swap on my '00 220 and I really like them other than the fact that my steering radius is severely reduced. Going to have to come up with something different. I noticed you did something similar to what I did to fix the stop problem, is your turning radius noticeably narrowed? Mine has probably lost a good 8-10 degrees stop to stop which is all the difference in the world on tight stuff. Was looking at your gallery and your stops on the clamp seem much further apart.
I DO remember you and your CR fork swap, happened very close to the time I swapped mine. As things worked out for me, my turning radius is great. In fact, once I started to really push things I noticed that the steering with my initial USD setup felt weird, almost too sharp like it wanted to fold up. I made some changes that put me closer to the original KDX geometry - I ended up adding another spacer underneath the top triple clamp. By spacing the distance between clamps it allowed me to raise the forks in the clamps about 6-8mm roughly and still have plenty of clearance for the bars, rebound adjustments, etc. BIG difference for the better. The turning feels more solid, and with that I have more confidence when I round tighter curves. With some quality tires, good geometry, great forks, good traction, and the power to pull me out of the curves I have a bike that is MUCH better than I am, so it's time for me become a better rider!!

One thing I want to do is improve the fork action in the stutter-type bumps and the small stuff in general. When I hit a series of small bumps it can be unnerving. I still need to really put the clickers through the paces and see what I can come up with (rebound adjustments will probably help), but chances are I'm going to spring for a RaceTech Gold Valve kit and revalve. I'll try one of the GNCC-type shim configurations for the active valve stacks when I put in the Gold Valves so I'm figuring that the result should be quite a difference . . .

I'm already saving money!!

If you need more specific pictures/measurements or anything feel free to holler. If you end up changing the forks altogether, the YZs DO work and I'm seeing 'em on Ebay when I poke around from time-to-time.

**** EDIT ****

BTW - the extra spacer under the clamp is not my creation. When I was in the process of installing the USDs I noticed others had added spacers and at the time it didn't make sense to me. NOW it does!!
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Post by Colorado Mike »

Jeb,

Bbefore you go running off into the Racetech camp, You might want to check out MX Tech. Bradf, who knows a thing ot two about suspension says that Jeremy out there has an awesome GNCC type setup. I actually have gold valves in my '03 Kx forks, and intend to get Jeremy to offer some ideas.
Mike

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Jeb
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Post by Jeb »

I "found" a copy of bradf's stacks for the rebound and compression circuits and was seriously contemplating using those configurations (very well written) . . .

MX-Tech also sells valves & such, I wonder how they compare to the gold valves? Maybe if I purchase the valves/shims from MX-Tech they'll offer that advice your talking about . . .
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

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Jeb
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Post by Jeb »

Got the chance to put in a few hours on the "farm", more open with some small woodlots and some rough field edges. Great place for more high-speed testing. I just gained a little more respect for this bike today. As much as the 220 is touted for low end, and it certainly has it, a well-modified 220 is no slouch on the upper end (relatively speaking). The shorter gearing amplifies that!

Keep in mind what I'm working with - RB modded head, RB modded carb in the SSS zone, no airbox lid, FMF rev w/ PC spark arrestor, power reeds, premium pump gas w/ 32:1 Amsoil Interceptor . . . and now a 12t Renthal C/S (but with a bigger 110/100 Pirelli MT16).

Some highlights:
  • *I'm in 4th and even 5th much more. I can easily get the front wheel up in the first three gears. The bike revs up quicker - I sound like I'm jamming on a 250 when I've got her opened up running down a fenceline!

    *More wheelspin, no doubt about it, and I can dial it in even in places where I hookup pretty good. My impression is the 110/100 does allow for controllable wheelspin with these mods. I've not tried other needles since the RB mod but understand that the CEK needle contributes to this.

    *I find myself needing to pay more attention when I'm in the upper end of the powerband. As I'm jamming through the rough field edges I'm finding the front wheel wanting to rise up as I get traction/no-traction on the rear wheel with the throttle opened up (kept having to back off of WOT - YEAH BABY!!!!). There's a couple of places where I shoot out of a dried up, overgrown pond (it's analogous to the face of a jump or the top of a steep hill) and was surprised - almost unpleasantly - to find that this mutha' wants to jettison over the rim!! MORE BOOM, I LOVE IT!!

    *I was wrong about the spooge decrease, it's still there (remember I thought taking the airbox lid might have decreased spooging). Kind of drools down the underside of the PC S/A . . . . . OH FREAKIN' WELL!!
I know I tend to ramble when I'm excited, fellas, but the gearing change is a hit . . .

oh, and I seemingly sweetened things up on the forks with rebound 11 clicks out and compression 2 clicks from being all the way out, seemed plusher (I still want more). Or maybe an illusion was created with that front end being so light all the time :lol:

This is getting to be WAY too much fun!!

**** EDIT ****

I almost forgot - I should be able to till the garden in 1st gear now :supz:
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

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Post by Jeb »

Just one more comment - rode at Saddleback as a guest this afternoon, some slow, gnarly trails . . .

ridin' around in the slow stuff (the stuff that makes ME slow anyway) today and the jetting felt fat - raised the clip back up to #3 slot when I got home, seems better. #4 clip position worked in the colder weather . . . in my estimation.

The 12t sprocket gives me PLENTY of snap . . .

must be careful on rooty uphills . . .
must be careful on rooty uphills . . .
must be careful on rooty uphills . . .
must be careful on rooty uphills . . .
must be careful on rooty uphills . . .
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

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