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Q's running a shorter i2i shock on Moment

2K views 12 replies 3 participants last post by  bpnic 
#1 ·
I am going to buy a 7.5" x 2.0" Rp23 for my V1 Moment in hopes to "fix" the Geometry.
By that I mean slacken the HA, lower the BB, and shorten the wheelbase. I realize this will lessen rear travel. Has anyone done this mod, and what will travel be, 5"?
 
#3 ·
The wheel base will get longer if you slacken it and lower the bb this could be a good thing though if you are trying to improve elsworths lacking geo. Go for it you may loose some tuneibility of the shock but you will get a more desirable geo a rear shock is cheaper then a new frame or bike you will how every void any warranty but they don't have to know you put a shorter shock on it if something goes wrong, not that it will but you get the drift
 
#4 · (Edited)
PTP said:
The wheel base will get longer if you slacken it and lower the bb this could be a good thing though if you are trying to improve elsworths lacking geo. Go for it you may loose some tuneibility of the shock but you will get a more desirable geo a rear shock is cheaper then a new frame or bike you will how every void any warranty but they don't have to know you put a shorter shock on it if something goes wrong, not that it will but you get the drift
thanks ptp! You're right, the wheelbase did grow a mm or two. I really like the slacker HA, and lower BB. Standover is better too. I have no Ells warranty, I purchased the frame second hand, and was just looking to improve the very XC'ish geometry.
I'll post pictures soon.

Notes: The carbon brace does not come close to the seat tube under full compression and I haven't measured yet, but travel looks like 5 or 5.25 (approx) inches.
 
#5 ·
you can do the math yourself. If you start with the 2.25 stroke being 152mm or 6 inches (its actually a little more apparently) divide 152 or 6 inch by 2.25 (57mm) and times x 2.0 (51mm)

bb comes down approx 3/4 inch head angle slackens 1.5 degrees.

If I get time I will put one in mine and post it (have a feeling I have done this before on MTBR so have a look).

To throw another option in, how about a 7.5 x 2.25, (190 x 57) you can buy them from fox as a coil, same travel but the slacker geometry. You would need to check the cross brace does not contact the seat stay and your warranty may be voided.
 
#6 ·
Nsynk said:
you can do the math yourself. If you start with the 2.25 stroke being 152mm or 6 inches (its actually a little more apparently) divide 152 or 6 inch by 2.25 (57mm) and times x 2.0 (51mm)

bb comes down approx 3/4 inch head angle slackens 1.5 degrees.

If I get time I will put one in mine and post it (have a feeling I have done this before on MTBR so have a look).

To throw another option in, how about a 7.5 x 2.25, (190 x 57) you can buy them from fox as a coil, same travel but the slacker geometry. You would need to check the cross brace does not contact the seat stay and your warranty may be voided.
Thanks Nsynk. I still have no warranty, so no worries there.

I searched for a previous thread, but had no luck....so I posted here.
i also searched ebay for a 7.5" x 2.25 shock, but found nothing.
I was confused by your math, (i confuse easily)....what will my travel be?
 
#9 · (Edited)
ok, I finally took some measurements:
HA is 66 degrees with the Lyrik at the full 160mm travel setting. 67* at 140mm, and 68.5* for climbing in the 115mm setting.
ST is 71 degrees at 160mm and travel is 5.25" regardless.
Wheelbase is 45" and BB height at 160mm is 13.75"
I'm running a 50mm stem and a 30" bar with 10mm rise.

Overall, every measurement looks like an improvement, without a huge sacrifice in travel.
 

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#10 ·
nice. That static geometry is spot on.
Don't forget though that it is the dynamic geometry that determins how a bike handles.
that is the geometry with you riding the bike,
Now you have a shorter eye to eye, you will use less of the stroke in sag than you would have with the longer stroke, lessening the difference in dynamic geometry.

You could have achieved the same dynamic geometry by allowing the difference in eye to eye as more sag. of course this would rsult in a lowere spring rate and hence a softer ride.
 
#11 ·
Nsynk said:
nice. That static geometry is spot on.
Don't forget though that it is the dynamic geometry that determins how a bike handles.
that is the geometry with you riding the bike,
Now you have a shorter eye to eye, you will use less of the stroke in sag than you would have with the longer stroke, lessening the difference in dynamic geometry.

You could have achieved the same dynamic geometry by allowing the difference in eye to eye as more sag. of course this would rsult in a lowere spring rate and hence a softer ride.
I agree with you 100% Nsynk.

Every geometry chart for every frame made lists static geometry numbers. So my listing the numbers of an unsprung bike are just for comparison sake. Plenty of factors determine dynamic geo's, but I agree with your point.
These numbers are spot on, but sure, once you sit on the bike, they're gone.

I had a 7.5 x 2.0 rp23 on hand, but I'd surely prefer an 7.5 x 2.25".
 
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