Thursday, July 28, 2011

Doug's 2008 YZ250 suspension lowering link question

From Doug: just installed on my 2008 YZ250. Nice product, easy to install. On the subject of the SAG - I weigh 135 lbs without gear and am not in the habit of riding punishing tracks with high jumps (I do not race). My question is: would it be OK to have the SAG at closer to 5 inches than the recommended 3.9 which would give me a slighter lower seat height (fork tubes have been raised) and softer suspension? Any info would be appreciated. Thanks, Doug.

Our reply: Putting in 5 inches of sag is a BAD idea. Why? You will ride too far into the shock's progression and it will actually ride harsher on the smaller items because the shock will "think" you are much heavier and/or going much faster through a larger bump than you truly are, and it will ramp up to prepare for the big hit.

You will also lose an extra inch of overall net travel. You start with about 12 inches. Then do the approx 4 inches of sag. That leaves you 8 inches of usable travel. When you put an extra inch of sag you now have, in theory, 7 inches of net travel.

At your weight and the YamaLink the sag setting of around 100mm, give or take, should be spot on. Maybe play with your high and low speed compression, and make sure the rebound is set so it's not packing up and making the ride feel more harsh.

Try up to 105mm of sag from the 100mm we recommend. Any more than that and the rear will squat too much in relation to the front even if you slide the fork tubes all the way up.

David's KTM 350 lowering link

David had a question about the Kouba Link KTM lowering link he purchased from us:

I purchased an link from you guys a few months back - the KTM 2 link. I have dropped the front forks down as much as possible but I still have "Chopper feel to the bike". Should I crank up the preload a bit as the back feels a bit soft and I suffer a bit of understeer in the corners. I weight 68Kg's in my jocks so not heavy at all.

Any advice - must say love the bike, the link make riding a pleasure. For the first time i can touch the ground.

Our reply:

I ride a 2010 KTM 400 XCW (PDS, linkless of course) and have spent quite a bit of time on the KTM 350XC and SXF.

The PDS 400 bike likes about 105mm of sag best. The linkage 350 like to be set up more like a Japanese linkage bike. But the spring rate or shock valving on the 350 feels more linear or soft in stock form. When I set the 350 up with 100mm sag BEFORE a Kouba link it feels like it is sitting low in the rear. So I put in 95mm and eventually about 92mm of race sag STOCK.

Then you throw on a Kouba Link and its extra leverage. I would NOT reset sag at 100mm. I'd try setting sag at 92-95mm race and see if you can still get at least 1/4 inch free sag. The free sag numbers on a bike with aftermarket link are totally different than a stock linkage bike. You want a little bit, at least, to prevent the bike from having a very rigid "riding on ice" feeling over the fast chatter and ruts.

2006 WR450 lowering link require heavier spring?

Darryl rides a WR450F (2006) and asks "I weigh 72 KG (approximately 80 KG with all my gear on) I am 5 foot 8 inches tall (171 cm). What spring tension should I set my bike to? Do I need to replace the spring?"

Our reply: You may be able to set race sag at approx 94mm and still have enough free sag with the stock spring, but to get perfect handling I recommend a 5.5 kg/mm rear spring or closest rate. Then you have the option to set sag from 94 to 100mm.