2011 Sag Adjustment Question
Posted 14 May 2012 - 05:21 AM
The bike did seem to be hitting a little hard on landings, especially the front, and the rider complained of arm pump from vibration and shock thorugh the handlebars. Keep in mind, this rider is almost hopeless at describing what he likes or doesn't like about suspension settings.
First order of business was to check the sag. Book says 105mm, but his was around 70mm. The stock purple spring is installed.So we adjusted it for 105mm. It was way too soft. It appeared too soft, rear ride height was way too low, and rider complained he wasn't getting the air he wanted over jumps. So more adjustments were in order and he eventually felt comfortable with it set to about 85mm.
1/ My question is if this 85mm sag is common, or is he just so used to the old 70mm of sag, so he can't get his head wrapped around the recommended setting of 105mm?
And since I'm posting, I'll add that no changes have been made ot the rear shock, but we did play around with the front fork settings. Compression started stock at 11 clicks, trying 13 proved too soft, but he liked 12. (Personally I wonder if he can tell, but i have to go with his feedback regardless). Rebound, which is stock at 11, he seemed to prefer 10. He seems to like a little kick up of the front and doesn't like the mushy feeling of when the front wheel stays planted on the track (which seems confusing ot me, but i don't race).
2/ Bascially, I'm open to suggestions and would like to hear opinions and any recommendations on all suspension settings. Please include your weight though, so I have an idea of how to compare things.
Posted 14 May 2012 - 06:13 AM
Posted 14 May 2012 - 09:03 AM
Posted 14 May 2012 - 12:14 PM
Posted 14 May 2012 - 05:14 PM
I do agree that the rider needs to give the full 105mm sag a chance, but on the other hand, when he's on the bike, it does give it a nose up attitude. He was out today with it at 85mm, and came back happy. So he's getting used to it in the right direction anyway.
It really seems I'd have to do somehting to shorten the front forks with the rear spring set to 100mm of sag. Not sure what to do there... if anything.
As far as the spring colour goes, it actually appears more red than purple. If I had to call it a name, I'd say burgandy. But in the page below, you can see the stock spring is labelled as purple, and there is no red spring.
I am setting the sag as shown on the page below. Rider has some weight on pegs, and is sitting forward, almost to the gas tank. Maybe that is the trouble and he ought to sit back a bit.
Thanks for all the replies. Gives me lots to consider.
Edited by Eggbert, 14 May 2012 - 05:15 PM.
Posted 15 May 2012 - 12:56 AM
Posted 15 May 2012 - 05:01 AM
I recently set the sag for one of his friends who's light weight and rides a Honda 125 2-stroke. That worked out great, and from what i remember, the young lad did sit more in a trail riding poistion.
I'll have to check the static sag. It was pretty neglible when the spring was factory set and yielded only 70mm of race sag. There's undoubtedly more now.
I'll check static sag and re-positioned seat sag this evening and get back with the results.
He only started racing a few years ago, and last year switched from a RMZ250 to the 450 for the Fall season. That's MX Junior for 450 4-strokes and 250 2-strokes.
For just starting a few years ago, he's not bad, but he performs much better during practise than during a race. There's an intimidation factor as most of the other riders have many more years of experience. Anyway, the following video gives an idea of the type of tracks and his abilities, although as I mentioned, he's much more impressive when he's relaxed on a practise track (which is likely the reason for his arm pump).
He's number 427, and this must be on his 250, as it's from 2010:
Edited by Eggbert, 15 May 2012 - 05:15 AM.
Posted 15 May 2012 - 01:02 PM
back to the suspension, gear will add about 15 to 20lbs to the rider weight (so about 205lbs for spencer) which may indicate the need for stiffer springs. regardless, getting him to sit in a more neutral position (much like in the video) should yield a good sag measurment.
Posted 16 May 2012 - 01:50 PM
He likes the 450 as he does a lot of fun woods running and gravel pit stuff with his friends and likes the extra torque and power of the 450. Based on MX racing, he likely does better with the 250. I like to see him in the 450 class as he's usually racing against only 15 riders or so. When he was racing 250's, there was usually about 36 to 38 riders, and I never liked watching the start. After about a 1/2 lap or so, things start to thin out and I'm comfortable watching.
We checked tonight and when he sits around the middle of the seat, (a typical trail riding position), I get 90mm sag, which is closer to the recommended 105mm. From this, I know the adjustment for 105mm sag will not be nearly as soft as when I adjusted it before (rider sitting near fuel tank). So that seems to be most of the problem. The rest is likely him not being used to it.
The static sag surprised me. 35mm static. The 90mm we are presently adjusted for, is made up of this 35mm plus another 55mm once the rider climbs on board.
Thanks for all the replies. I appreciate them.
Edited by Eggbert, 16 May 2012 - 01:52 PM.
Posted 17 May 2012 - 12:33 AM
i can relate to the 250 class, my last race had 36 riders on the gate in my class alone (250B), 450B had 19. its not too bad on the track, the starts also intimidate me and i always let them go since i cant afford to get hurt and miss work. however the 250 will teach you to keep your momentum going. i am going to consider moving to the 450 class myself either next year or a the year after.