120mm FOX 34SC & SID Ultimate for lightweight riders

Discuss light weight issues concerning mountain bikes & parts.

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jcrr
Posts: 212
Joined: Wed Nov 30, 2011 4:36 am
Location: Seattle, WA

by jcrr

There are several topics on both, but I didn't find opinions on performance related to rider's weight.

I have a 120 32 FOX fit4 non-SC performance fork with remote that I would like to upgrade to one of these. The bushings issue on the SID are a concern. The damper setup issues on the SC are a concern. I am just wondering if other details become an issue/a feature that shines for smaller humans. I absolutely agree a big part of the equation are a) the fork setup, b) the type of terrain that is ridden, and c) the rider skills.

In general/specific terms, I would like to hear from sub 60kg riders who use these forks on 'advanced' XC trails. The terrain rating I'm familiar with is North America Pacific NW, blue-to-black (in Canada), black (in US). How do they perform? What do you like/dislike? Any/all input appreciated.
:beerchug:
"If it ain't broken, it could be lighter"

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Hexsense
Posts: 2640
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

I'm in, as I had RS and now own Fox and I'm 62kg.

Back story:
I originally bought RS Sid Ultimate for my bike. It works. No bushing issue but there is an issue when I try to service mine. RS overtight the damper side shaft from the factory. The crush washer deform way too much and it's super hard to drop the lower leg out. And the thread on that side is damaged once I finally got it out. Sram denied that it's not warranty issue and charge me $170 to fix it which make me not wanting to use RS anymore and bought 2022 34 SC. Regardless, I'm not going to bias against it while describing how it feels.

How it feel:
0) I feel like RS has low compression damping. The bottom out resist almost entirely come from spring side, which is very progressive. Fox has opposite problem, HSC set too high on Fit4 and thus I don't need much spring progression on the spring side. In a nutshell, if you prefer spring dominant system with compression damping set to all the way open then bias toward RS. If you like the mix of compression damping and spring working together then Fox.
1) my RS has a bit tighter bushing. The small bump compliance is better on Fox.
2) Drop compliance is also better on Fox. RS without any volume spacer is more progressive than Fox with 1 volume spacer (stock setting on 34 SC). I struggle to use more than 85% of travel on RS. On flat-ish XC course, set sag at 20% you might end up using 70% of the available travel on RS. While you can run Fox with 0 volume spacer and use 85% travel on the same course. For me, optimal spring rate set using Shockwiz result in RS sag 24%, and Fox sag 20%.
3) However, Fox is harsher on repeated medium size bumps. That Fit4 is better than years before. But HSC is still preloaded heavily for stiff lockout mode and there is no way to reduce it for lighter rider.
This is likely non permanent issue though. Unlike that dinky Race day charger damper on RS that no one is going to modify. There were plenty of mod for earlier versions of Fit4. So, it's just the matter of time until someone offer to revalve or do more extensive mod to Fit4 to make it suite light rider better.
Also, Since HSC is set high, as a light rider, I can drop the spring progression rate down (remove volume spacer) and it's still not easy to bottom out. I suggest this route over the stock 1 volume spacer unless you bottom out 0 spacer on 34SC 2022.
4) If you are on budget. 34 SC Performance with grip damper can actually be a better option than the 34 SC Factory with Fit4 damper. Grip is more plush than Fit4 with slight weight penalty.

By any chance you consider Manitou R7 Pro instead of these 2?
https://www.mtbr.com/threads/2020-manit ... t-15359250

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jcrr
Posts: 212
Joined: Wed Nov 30, 2011 4:36 am
Location: Seattle, WA

by jcrr

@Hexsense- thank you so very much for taking the time to provide such detailed insight. You are not the first person's experience I've read with own maintenance of the RS as less-than-good. One additional question for you: do you use a remote lockout on either? If so, did that affect/help in any way with the HSC on the 34 SC? I remember another WW member commenting elsewhere on damping setup difficulties of the 34 SC. I think it was @LeDuke, maybe?

Before my post, I had started to read and got lost in the 9pages of the mtbr forum topic on the manitou. I confess to being ignorant of that alternative up until a few days ago, and after reading through some of the mtbr discussion, it would seem to me the R7pro is competitive with RS and Fox at the expense of more complexities with setup. Also, it weighs slightly more (and that remote lockout lever looks to be far less polished). Anybody here using an R7 Pro fork?
"If it ain't broken, it could be lighter"

Hexsense
Posts: 2640
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

I didn't use remote lockout on any of these two new forks. 2019 generation RS Sid on Scott Spark was the last remote fork and shock I had.
However, I read that one is push to lock another is push to unlock. And Fox has 3 position, RS is either open or lock. So, make sure it sync well with your rear shock if you lock both with the same lever.
On both fork, HSC aren't user adjustable so LSC setting using remote lockout would not help with that. Sure there are some cross talk that HSC open based on build up pressure in the damper and LSC setting can alter the pressure that HSC circuit experience but I think it's not going to make a big difference.

On the HSC and lock out thing. Well, it's just how the damper work on Fit4 damper. In open mode, both LSC and HSC circuits are parallelly working together. In middle mode, LSC flow is restricted but still flow. In lock out mode, LSC is completely shut off but HSC is still there to take big hits. That means, to provide stiff lock-out, HSC must be preloaded heavily such that there is no movement at all from pedaling motion of average rider. It can only move by taking a bit hit. As a light rider, HSC can be revalved lighter while still stiff enough that it doesn't move from sprinting. Mods like Vorsprung Fractive makes it ride better with HSC setting way down for good ride quality but the stiff lock out is gone. Manitou R7 Pro doesn't use this design. The main damper in R7 is tuned for good ride in open mode, and then the lock-out mode use entirely separated circuit dedicated for lockout mode. I believe Fox DPS rear shock also has this separated circuit for lock-out mode just like Manitou R7 fork.

I doubt anywhere other than MTBR even know Manitou/Hayes exists and kick asses. It's always either Rockshox or Fox. Despite the awesomeness of Hayes Dominion A4 brakes and Manitou front and rear suspensions.

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jcrr
Posts: 212
Joined: Wed Nov 30, 2011 4:36 am
Location: Seattle, WA

by jcrr

Hexsense wrote:
Fri Jan 28, 2022 10:48 pm
I doubt anywhere other than MTBR even know Manitou/Hayes exists and kick asses. It's always either Rockshox or Fox. Despite the awesomeness of Hayes Dominion A4 brakes and Manitou front and rear suspensions.
@Hexsense -once again, I very much appreciate you taking the time to provide good intel and useful opinions. I am sure not everyone here is 90kg when kitted, so hopefully other smaller humans benefit from the info :D

I went thourgh the mtbr forum chat https://www.mtbr.com/threads/2020-manit ... 851/page-3 on the PR7 Pro. The amount of info shared there is somewhat overwhelming for the average garage mech, IMHO. Which is fine, it may just be more tuning than a lot of people are wanting to do to a fork on their own. The Manitou appears to be a -should we say- more complex(?) initial investment for the uneducated end-user than Fox or RS would be. I can admit I don't know enough about suspension tuning to have an opinion on whether that is a good/bad thing, or if it really makes a difference for the rider. In this case, for the smaller humans :mrgreen:
"If it ain't broken, it could be lighter"

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