# 100mm vs 120mm Fork



## mtber13 (Oct 16, 2011)

Howdy MTBers. I've been riding some very technical trails lately on my 2011 Specialized Epic Comp and have been wishing at points that i had some more travel. In the Epic Manual, it says that you can put up to a 120mm fork on it without harming the frame or voiding warranty. So here are the questions; A. Do you guys think that upgrading my fork from a 100mm RS Reba to a Fox F120 with Kashima coat will make a BIG difference in feel? B. Will a 120mm fork make the bike feel awkward and weird for climbing?

Thanks :thumbsup:


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## arkon11 (Jul 26, 2009)

Put a 140mm on it. It won't make a large difference in climbing ability, but it'll make the bike a heck of alot more fun.


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## mtber13 (Oct 16, 2011)

arkon11 said:


> Put a 140mm on it. It won't make a large difference in climbing ability, but it'll make the bike a heck of alot more fun.


I like the idea but I do not want to void the frame warranty and i really don't want to cause too much stress on the frame. I was thinking about getting 110-140mm Talas and mainly have it in 110mm until the downhill.


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## shenny88 (Sep 24, 2009)

i went from a 100mm Marz 44 on my hardtail to a 120mm RS SID and i dont think i could go back now, nor would i want to. The 120 resulted in a slacker head angle and slightly higher bottom bracket, both of which were way more fun on the trail, especially at high speed slalom/downhill legs of the trail. I dont miss the twitchy-ness of the 100.


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## mtber13 (Oct 16, 2011)

shenny88 said:


> i went from a 100mm Marz 44 on my hardtail to a 120mm RS SID and i dont think i could go back now, nor would i want to. The 120 resulted in a slacker head angle and slightly higher bottom bracket, both of which were way more fun on the trail, especially at high speed slalom/downhill legs of the trail. I dont miss the twitchy-ness of the 100.


Wow, I wouldn't expect it to make that much of a difference.

Thanks so much for the advice. :thumbsup:


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## shenny88 (Sep 24, 2009)

mtber13 said:


> Wow, I wouldn't expect it to make that much of a difference.
> 
> Thanks so much for the advice. :thumbsup:


Just a heads up, it does feel very strange at first, especially when you first test it out in the street or parking lot. You get so used to the bike you have that its often easier to adjust to a totally different bike opposed to modified version of your own. Just give it a few rides to decide if you like it.


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## bclagge (Aug 31, 2009)

YMMV, I went from a 100mm Tora 318 to a 120mm Recon Gold and it hasn't notably impacted the handling of the bike.


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## Ace5high (Jan 4, 2011)

Check this out http://forums.mtbr.com/29er-bikes/100mm-vs-120mm-fork-735875.html#post8413987


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## Turveyd (Sep 30, 2007)

I'm 235lb's and I've ran 100mm 29er fork + 29" wheel which gives me the length of a 180mm fork ( less sag ) on a 100mm XC Frame without an issue.

So do it, my ownly issue is I'd say a RS 100mm fork likely out rides a 120mm fox fork, but thats just me.


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## DiRt DeViL (Dec 24, 2003)

I'm doing the opposite, my bike came with a 100mm (Suntour Radion 29) fork and replaced it with a 120mm (Zocchi 44 TST2 Air). The bike creaks a lot and became twitchy/nervous when climbing but forgiving on the rough stuff, left it at the LBS to reduce the travel to 100mm and have the nice handling bike that it was before but with a better fork.


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## bing! (Jul 8, 2010)

I think the RS Sektor RL U-turn is a great deal. 110-150 and anywhere in between.


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## amd (Oct 14, 2011)

arkon11 said:


> Put a 140mm on it. It won't make a large difference in climbing ability, but it'll make the bike a heck of alot more fun.


At what weight point, does it make a difference? Ie: do you need to weigh a certain amount for the extra travel to help?


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## William_Cannon (May 5, 2009)

Why not have the shop install a smaller shim on the Reba to make it go to 120? I'm having the same argument with myself. My HT angle is 71 with a 100mm fork and it is twitchy on the downhills, but excellent on switchbacks and quite responsive on narrow trails.

At the end of the season, I will likely have the shop swap out the shims. My only reservation is the affect on standover. Anyone know how I can hypothetically calculate this?


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