Mountain Bike Reviews Forum banner
1 - 13 of 13 Posts

·
Living the Dream
Joined
·
1,793 Posts
Discussion Starter · #1 ·
I was wondering if you did the geo measurements for your 5 Pack. I've been running my AM1 on SPot in the 130mm & I am digging the bike feel. I should get 6 Pack front triangle within a week, so I'll be running a 5 Pack full time. Just curios about what your head angle was? Thanks
 

·
Registered
Joined
·
1,644 Posts
what about your BB height?

Alpenglow said:
I was wondering if you did the geo measurements for your 5 Pack. I've been running my AM1 on SPot in the 130mm & I am digging the bike feel. I should get 6 Pack front triangle within a week, so I'll be running a 5 Pack full time. Just curios about what your head angle was? Thanks
Hey guys,
I am running spot rockers on my 6pack. SS is that what you are doing?
I'm not sure if there is much benefit. I thought the BB would be lower than it is. Its only
.25 inches lower than with the 6" rockers. I was hoping the BB would be more in the 13.5 range (like running 5" rockers on the RFX).

I do like the slightly firmer feel for general trail riding. Excelerates a bit better. The 6 pack is just such a sweet and plush ride it is hard to beat.

Alpen - that fork should be pretty sweet with your new set u.....SS what fork are you going to run. I noticed your ZAM is in the classifides.

Thanks for any additional info.
 

·
Alaska Turner Mafia
Joined
·
1,119 Posts
G-AIR said:
Hey guys,
I am running spot rockers on my 6pack.

I thought the BB would be lower than it is. Its only .25 inches lower than with the 6" rockers. I was hoping the BB would be more in the 13.5 range (like running 5" rockers on the RFX).
G-AIR, I just took delivery of a 6 Pack, and ordered it with an additional set of 5" Spot rockers. I was curious as well as to the differences in each configuration, so I taped the Spot rocker on top of the Pack rocker....see pic.

It appears that the compression strut moves in an arc radiused around the Horst pivot as you move from one rocker to the other, so has no effect on BB height. The only way to reduce the height would be from the reduction in fork A-C height, which you suspected isn't very much. Maybe someone else will chime in that's put 5" RFX rockers on a Pack, that might have a BB height reducing effect.

Rando
 

Attachments

·
Natl. Champ DH Poser/Hack
Joined
·
12,942 Posts
i think it might. i have the '02 frx with pack and what i think are rfx "a" rockers. i thought they were spot rockers but recent threads tell me otherwise. anyway, the reason i pipe in here is with both installed i seem to recall a pretty big diff in b/bkt height. i dont have the numbers handy but maybe ill get some tomorrow. till then, look for yerselfs. i think youll see the lower chainstay angle in the second pic of the 5" rockers. im thinkin this might be relevent to the question. you tell me.
 

Attachments

·
Registered
Joined
·
1,644 Posts
more thought

cactuscorn said:
i think it might. i have the '02 frx with pack and what i think are rfx "a" rockers. i thought they were spot rockers but recent threads tell me otherwise. anyway, the reason i pipe in here is with both installed i seem to recall a pretty big diff in b/bkt height. i dont have the numbers handy but maybe ill get some tomorrow. till then, look for yerselfs. i think youll see the lower chainstay angle in the second pic of the 5" rockers. im thinkin this might be relevent to the question. you tell me.
cactus,
I would have to agree with you.
By the looks of it you have the 6 pack rockers and the old 5" RFX rockers.
On my old RFX the 5" plates dropped the BB substancially. The rear triangle gets "pulled up" to the shorter rockers, pushing the BB down. This creates a slacker HA if you keep the same fork.

I thought this would be the case with the 6 pack and 5" rockers, but not so. I do not no why????
 

·
Natl. Champ DH Poser/Hack
Joined
·
12,942 Posts
hey g. seems it might have somethin to do with the profile, or triangulation if thats a better term, of the rockers in question. i think endo addressed this issue pretty well up above. from what ive read here recently theres a pretty substantial diff between all the generations of turners bigger rockers, at last count theres 4 since 2000 not counting the custom ones like lucky has or the protos such as the lucky 7. im guessin you havent parrused this thread yet. http://forums.mtbr.com/showthread.php?t=149811 check it out man. its given me a ton of knowlage about this subject and part of why i decided to offer up a possible answer to alpens question. im sure theres alot more to learn here than what i have now. all of a sudden this is cool to me. must be the new bike, dont ya think? if at all possible, ill rebuild the SPaaNB to the 5" spec and get us some real numbers on both tomorrow. unless i go skiin instead.

speakin of endo, hows it goin man? feelin any better yet?
 

·
Natl. Champ DH Poser/Hack
Joined
·
12,942 Posts
some numbers for ya

i just finished swappin 5" and 6" bits and i sure as hell hope you guys appriciate the time this is takin me. i expect a krismiss card from each of ya and a 6 of good beer wouldnt be a bad idea either.

all this was done on flat, hard tile usin the same tools on the same '02 rfx front end and '05 pack rear end, 7 1/2" eye to eye shock with fully inflated tires. i relied on a old school craftsman bubble type surface level/protractor and a general tools #17 stailess steel angle finder to come up with my head tube and seat tube angles so dont kill me if im off a bit but i promise you i tryed very hard to be as accurate as i could be. heres what i got:

6" mode w/ 2.5" kenda blue groove / nevegal tires, '05 66 rc fork:

ground to axle centerline = 13 3/8"
ground to b/bkt centerline = 14 9/16"
axle center line to crown = 22 1/2"
wheelbase on centerline = 45 9/16"
head tube angle = 67 1/2 deg
seat tube angle = 74 1/2 deg
axle centerline to main rocker pivot centerline = 18 13/16"
horst link centerline to main rocker pivot centerline = 16 5/8"

5" mode w/ 2.35 maxxis minion dhf tires, '01 z - 1 mcr ecc fork:

ground to axle centerline = 13 1/4"
ground to b/bkt centerline = 13 1/4"
axle center line to crown = 19 1/2"
wheelbase on centerline = 44 1/4"
head tube angle = 72 deg
seat tube angle = 76 deg
axle centerline to main rocker pivot centerline = 17 11/16"
horst link centerline to main rocker pivot centerline = 16 3/4"

----------------------------------------------------------------------------------------------------------------------------------

i thought while i was at it, it might be cool to get some numbers on the rockers. im too pooped tonight to work out the triangulation.

'05 pack rockers w/ 7 1/2" eye to eye shock:

Main rocker pivot to shock stay pivot on center line = 7 1/2"
Main rocker pivot to shock mount pivot on center line = 3 1/16"
shock stay pivot to shock mount pivot on center line = 9 15/16"

'02(?) rfx type "A" rockers w/ 7 1/2" eye to eye shock:

main rocker pivot to shock stay pivot on center line = 5 13/16"
main rocker pivot to shock mount pivot on center line = 3"
shock stay pivot to shock mount pivot on center line = 8 3/8"

----------------------------------------------------------------------------------------------------------------------------------

so heres the diff between the 2 rocker set ups:

ground to axle centerline = 1/8"
ground to b/bkt centerline = 1 5/16""
axle center line to crown = 3"
wheelbase on centerline = 1 5/16"
head tube angle = 4 1/2 deg
seat tube angle = 1 1/2 deg
axle centerline to main rocker pivot centerline = 1 1/8"
horst link centerline to main rocker pivot centerline = 1/8"

main rocker pivot to shock stay pivot on center line = 1 11/16"
main rocker pivot to shock mount pivot on center line = 1/16"
shock stay pivot to shock mount pivot on center line = 1 9/16"

make of this what ya will.
 

·
Alaska Turner Mafia
Joined
·
1,119 Posts
Hey cc, appreciate all the work, but man are you sure about your angle finder? In 5" mode those seem like some seriously steep angles, even the seat tube angle in 6" mode sounds steep. Did you use the method of taking a reading, reverse the bike end to end 180, measure again, and average? Sometimes unlevel floors can require that.

PM me your real name and address and I might have a little sumthin' for krismas for ya.

Rando

P.S. Thanks for askin' about my condition. Improving both physically and mentally each week. Physical therapy is making me stronger, and being able to turn some wrenches in the garage mahal is saving my sanity.
 

·
Natl. Champ DH Poser/Hack
Joined
·
12,942 Posts
EndoRando said:
Hey cc, appreciate all the work, but man are you sure about your angle finder? In 5" mode those seem like some seriously steep angles, even the seat tube angle in 6" mode sounds steep. Did you use the method of taking a reading, reverse the bike end to end 180, measure again, and average? Sometimes unlevel floors can require that.

PM me your real name and address and I might have a little sumthin' for krismas for ya.

Rando

P.S. Thanks for askin' about my condition. Improving both physically and mentally each week. Physical therapy is making me stronger, and being able to turn some wrenches in the garage mahal is saving my sanity.
most importantly im glad yer doin better. ive been down that road more times than i like to recall. take it slow and keep movin to yer goal my friend.

i did dbl check the numbers as they kinda freaked me out too. i didnt do the reverse and average thing but thats a fine idea. this bike has a seriously steep seat tube, so much so its easy to see when ya stop and look. then ya put it next to say, a flux and damn! shes like a friggin shuttle launch! ill go back and try it yer way tomorrow night. my brain is full for now.

pm on the way. wonder what ya got up yer sleave?
 

·
not so super...
Joined
·
11,466 Posts
Alpenglow said:
I was wondering if you did the geo measurements for your 5 Pack. I've been running my AM1 on SPot in the 130mm & I am digging the bike feel. I should get 6 Pack front triangle within a week, so I'll be running a 5 Pack full time. Just curios about what your head angle was? Thanks
I did take some of the measurements but I forgot to bring them with me this morning - sorry for the delay.

I think this is what I ended up with but I will verify with what I wrote down tonight:

HA was Approx 70 degrees
Seat tube was approx 72.5 degrees
BB at 13.75" (ground to center of BB - unsagged).

The measurements were based on the following set-up :
5" RFX rockers w/ Spot (TNT) rear, ZAM1 set at 130mm, 2.5 Blue Groove (f) and 2.35 Nevegal (r)
 

·
Natl. Champ DH Poser/Hack
Joined
·
12,942 Posts
i scrounged up the geo chart for a '02 RFX and it confirms my numbers or damn close to it. like i said, i didnt have optimal tools for that part. ill see if i can borrow a real digi angle finder somewhere and get back to ya.
 

Attachments

·
Living the Dream
Joined
·
1,793 Posts
Discussion Starter · #12 ·
So it would seem that the 5Pack runs a degree steeper

than the 5 Spot. Mine will probably be a little slacker due to the fact that I run 2.5 Nev up front with a 2.25 Mutano in the back. Thanks a lot.

SSINGA said:
I did take some of the measurements but I forgot to bring them with me this morning - sorry for the delay.

If I remember correctly the HA was Approx 70 degrees and the seat tube was approx 72 degrees with the BB at 13.75" (ground to center of BB - unsagged).

The measurements were based on the following set-up :

5" RFX rockers w/ Spot (TNT) rear, ZAM1 set at 130mm, 2.5 Blue Groove (f) and 2.35 Nevegal (r)
 

·
not so super...
Joined
·
11,466 Posts
Alpenglow said:
than the 5 Spot. Mine will probably be a little slacker due to the fact that I run 2.5 Nev up front with a 2.25 Mutano in the back. Thanks a lot.
I took the measurements with the fork in 150mm mode too but I don't recall the numbers. I think it slacked the HA to 69 and raised the BB to 14.25".
 
1 - 13 of 13 Posts
Top