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Not really that big!
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Discussion Starter · #1 · (Edited)
I have recently purchased a new G2 Reba that was taken off of a Fisher HiFi. I am waiting for it to be delivered but in the meantime, I figured out the trail numbers for different scenarios. Just a good way to think bikes while I am watching bowl games! I was considering a Fox F29 with 46mm offset for the Sultan until I found the G2 Reba(51mm offset) so I thought I would try it. I used the trail calculator from GTed's blog http://g-tedproductions.blogspot.com/search?q=trail+calculator for my calculation. I have ridden the HiFi Pro 29 and really liked the handling. I really like the way my Sultan rides and it does not feel slow as the old Fisher geometry did but I want to make my Sultan ride a little bit more like the HiFi. I really like how quickly my Dos handles in the twisty Midwest singletrack as a race bike, so if I can make the Sultan just a little lighter steering without taking away the bike's ability to DH like a kamikaze, I should have the best of both worlds right?? :thumbsup: The Fisher website says that the HiFi has a trail figure of 71.7mm. Just for fun, I thought I would do some comparisons between the different frames. While figuring the HTA/Trail figures, I assumed the correct travel spec for the appropriate frame (i.e. 80mm travel for Dos and Paragon and 100mm for Sultan and HiFi) Here is what I found.

Information entered into the calculator:

Wheel Size: 29 inches

Sultan HTA: 71 Degrees
HiFi 29 HTA: 71 Degrees
Dos Niner HTA: 72 Degrees
Fisher Paragon 05 HTA: 71.5 Degrees

Fork Offset:

G2 Reba: 2.0 inches (51mm)
Reba: 1.5 inches (38mm)
F29 (non G2): 1.8 inches (46mm)

G2 Reba Trail Calculations for:

HiFi 29: 73.66mm
Sultan: 73.66mm
Dos Niner: 66.04mm
Paragon: 68.6mm

F29 Trail Calculations (44mm non-G2 offset) for:

Sultan:76.2mm
Dos Niner: 71.12mm
Paragon: 73.66mm

Reba (38mm offset) calculations for:

Sultan: 86.3mm
Dos Niner: 78.7mm
Paragon: 83.8mm

When I compare the specs of the HiFi and the specs of the Sultan, they are surprisingly close with a G2 Reba on both of them. The only glaring difference is the bottom bracket height. I also factored the added wheelbase of the G2 fork on the Sultan in these measurements.

HiFi Sultan
Wheelbase(mm) 1146.7 1148.38
Chain Stay(mm) 462.1 462.3
BB Height(mm) 320.0 337.82
Trail(mm) 73.6 73.6

Should be a fun comparison in handling with the G2 offset to try out on these three bikes. Now I just need the foot of snow to melt so I can make a fair comparison on dry ground! Here is the bike I plan to run the fork on:
 

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Expert Crasher
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Interesting.

I thought the non-G2 F29 was 44mm offset. I seem to remember some bru-ha-ha over the 46/44 number.

Any difference in the AtoC of the Reba and Fox? That would muck up HTA wouldn't it?

What number did you use for the external dimension of the tire?
 

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Let's ride
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Yeah, after all the back and forth, the final number is 44mm.

BG, you're figuring the change in HTA for the 10mm AC diff for F29 and the Reba right?

I'm railin a G2 F29 on my Small One9, and it is quite a nice thing.
 

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Not really that big!
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Discussion Starter · #4 ·
I was factoring the F29 as 46mm offset. I have recalculated it with 44mm offset and edited the original post to reflect the correct numbers. I still don't know how Fisher is getting 71.7 for their number, but I'm sure they are doing a measurement instead of an online calculator.

GLG- I used 29" just to keep it simple. I thought I factored in the difference in the AtoC difference of .5 degrees for the Fox. I think that is about right for the head angle change isn't it??? I was thinking a 20mm difference in AtoC made a 1 degree difference in HA. Someone please correct me if this is wrong.

Rensho- Glad to hear youre lovin the fork swap. I'm just trying not to shell out the cash for the Fox. Won't match my bike either!!!

Thanks guys!
 

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Expert Crasher
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Here's one more to consider

WB Magic or Fluid 110 w/ the thru-axle, 42mm offset and a 510mm AtoC, that would be a good compliment to the Sultan (nice color BTW).
 

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Not really that big!
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Discussion Starter · #6 ·
Maybe someday...

Yeah I've thought about that one too. I would like to try the thru-axle sometime too. I would like to try it with a WB Fluid 135. I'm sure the that would compliment the stiffness of the frame nicely. I think I'm going to try the DT ratcheting skewers to see if they make a difference. I don't have a convertible hub to go 20mm thru. Thanks for the compliment. The bike has more black bits on it now than it did in the picture. Here's an updated one.
 

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:confused: I didn't know there was such a thing as a G2(51 mm offset) Reba yet. I was under the impression that only the G2 Fox and the Manitou Minute were the only 51mm offset forks available at this time.:confused: :shocked: :shocked:
 

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rensho said:
Yeah, after all the back and forth, the final number is 44mm.

BG, you're figuring the change in HTA for the 10mm AC diff for F29 and the Reba right?

I'm railin a G2 F29 on my Small One9, and it is quite a nice thing.
Hey Rensho, where'd you score the G2 F29?
 

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Just Wanna Ride!
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I'm riding a G2 Reba on my Stumpjumper FSR. The FSR has a pretty slack heat tube angle by modern 29er standards. Their 26" bikes use a pretty slack head tube for XC bikes so they set the 29er 1 degree steeper than that 26. Have ridden it both ways with a standard Reba and with the G2 fork and prefer the G2 for the local trails.

The standard Reba didn't feel bad, but the quickened handling G2 fork is better for the trails I ride most of the time. Our trails are typically tight and twisty singletrack and the G2 gives the bike the feeling of steeper headtube without much loss in high speed handling. The FSR handles very well - a bit slower handling than my KM (which has a much steeper HT angle - 72 - when mounted with the standard Reba) and it absolutely flies when the trail opens up a bit and holds a line like it no other bike I've ridden. On rolling flowy singletrack it's like the bike is on rails with the slacker geometry. Over rough technical trails the slack angle really keeps the bike in line - rarely being thrown off line by rocks/roots. Stable.

I'm loving the FSR! Had a HiFi that had a few issues I wasn't happy with. The FSR has none of the flex of the HiFi, though the FSR probably weighs 3/4 to 1 pound more with the same parts. The HiFi was light, but the frame just wasn't robust enough for me. Give me that extra weight and the stable ride anyday!
 

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Not really that big!
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Discussion Starter · #10 ·
I believe it is coming off a GF HiFi Plus, size XL so it has a nice long steer tube.
 

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Not really that big!
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Discussion Starter · #11 ·
sthrnfat- good to get your feedback about the handling of the G2 on the Specy. I look forward to the comparison on the Sultan. How much do you weigh? I weigh 210+ in riding gear and I didn't really notice the HiFi to be flexy. Sure is nice n light. My Sultan frame weighed exactly 6.5 lbs. What does your FSR weigh?
 

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Big29 said:
I still don't know how Fisher is getting 71.7 for their number, but I'm sure they are doing a measurement instead of an online calculator.
They may be measuring the trail with the suspension sagged. Did you try plugging in the sagged head tube angle into the calculations?
 

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Not really that big!
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Discussion Starter · #14 ·
Thanks

Titus Maximus said:
Actually, if you plug in a wheel radius of 365 mm (7.3 cm. diameter) to the Hi-Fi numbers of 71˚ head angle (unsagged) and 51mm. rake, you get a trail of 71.7 mm. I used a different calculator. This one: http://www.anvilbikes.com/images/1064634020.xls Using the one from GTed, you get a result of 7.2 cm. Pretty close.
Thanks for working thru the numbers. I tried the sagged number in the one on GTed's blog too but it made the trail figure come out even higher. I figured it must have been in the way the spreadsheet data was calculated differently. I appreciate your help.:cool:
 

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The DT RWS

Big29 said:
Yeah I've thought about that one too. I would like to try the thru-axle sometime too. I would like to try it with a WB Fluid 135. I'm sure the that would compliment the stiffness of the frame nicely. I think I'm going to try the DT ratcheting skewers to see if they make a difference. I don't have a convertible hub to go 20mm thru. Thanks for the compliment. The bike has more black bits on it now than it did in the picture. Here's an updated one.
system does reduce the overall flex of the reba using the 9mm QR.
 

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rensho said:
Jeffh loaned it to me off his 08 Rig. He's going to have a very tough time getting it back. :)
That's what I assumed. To bad you can't keep it!

I would really like an 80mm sussy fork with higher offset for my JW... :madmax:
 
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