View Full Version : C.O.G. Spec on new chair
I'm filling in an order form for a ZR for myself before I meet with a DME next week. My numbers look pretty normal until the COG. My current setup is about an inch. I read about some orders and the COG is often 3". Am I out to lunch?
I'm 6'2", 180 lbs, C6/7 Inc. and have been rolling around in a Quickie XTR for 6 years. I can easily hold a balanced wheelie and in 6 years have never gone over backwards. I don't have wheelie bars.
Thanks in advance for your perspective.
Pat
www.gofreewheel.com
Jeff B
08-21-2009, 02:48 PM
A quick look at your pictures looks to me like you have a long torso and sit well back in your chair, so you have more weight rearward than someone with a slouched forward posture or heavy legs that would put more of their weight forward. This would probably be why you only need 1” COG in your current chair. You just have to find what works for your own bodies balance.
Have you demoed a ZR or ZRA to see how your balance works in that setup? The XTR and a ZR are going to balance way different. You can’t realistically just pick a number for COG and assume that it will work, especially in a ZR, which has only a little bit of adjustability. The number of the COG is meaningless to compare between different chairs and especially different people.
SCI_OTR
08-21-2009, 09:25 PM
COG really depends of front/rear STF and seat depth among other things. Can you post what you can about your specs?
Yes,
My cushion is 18" x 18"
Front seat height 19.5"
Rear seat height 17"
STF 17.5"
Front angle 85 degree
I heard that for TiLite that I should add a little to the seat depth, but I don't know.
Thanks,
Pat
www.gofreewheel.com
SCI_OTR
08-23-2009, 11:58 PM
You'll get 1.25" either way on a ZR. At 18" deep, a 19.5 STF, and based on looking at your function in the YouTube videos for that product you sell (What's it called again?), even 4" wouldn't be outside the realm of possibilities.
Another way to look at a ZR's COG, is you are talking about the distance from the large bolt at the back of the frame for the backrest latches, and the midline of the vertical "stalk" connecting the frame to the camber tube.
The ZR and XTR are totally different animals, so having the opportunity to demo would be wise indeed.
Thanks, I'll look to demo tommorrow with the DME.
My XTR setup is about 1.5 cog.
Pat
www.gofreewheel.com
fuentejps
08-24-2009, 07:21 AM
im 6'2 bout 190-95 i run 3.5 cog[specd], then adj forward another hole. on 17x16 85 deg frt.
Thanks guys,
I think I'm leaning toward the ZRa for the adjustability. Also, mounting my disc brakes will be easier! The DME didn't know squat. Oh, life in Boise, Idaho!
Pat
www.gofreewheel.com