Question about suspension/feel on my HT

[RobynE]

Hoping folks can explain some stuff for me. 

So I have new wheels on my bike, this includes different tyres to what I am used to and significantly wider, stiffer rims. 

Bike: circa 2013 Giant XTC Advanced SL carbon, 1x12 (Shimano SLX RD, Deckas 32t NW oval ring, Shimano Deore Chain, Sunrace 10-52 cassette - chain and cassette are brand new) - in case there is drivetrain relevance

Old front setup: American Classic Tubeless Race 29 with Maxxis Forekaster 2.4 up front, AMC hub, non-boost, QR

New front setup: Spank 345 Trail with Vittoria Barzo 2.25, Hope Pro 2 Evo hub, QR

Fork: Rockshox SiD WC XX, no change there - serviced by Jaco a couple of months ago and not many rides since

Rear setup: was AMC as above with Ikon 2.25, now Spank as above with Vittoria Saguaro 2.2

Pressure: running same tyre pressures as I was with the old setup, can't tell you exactly what it is as it's more of a feel thing - tubeless

Type of riding I do - Northern Farm Red route; Trailseeker type stuff; my local is the bottom section of Steyn City (Porcupine Park) if anyone knows it. Nothing hectic. I am no racing snake but I give it what I've got on all the terrain I ride. 

So what I'm finding is that I am much more planted in the corners and faster on the descents (which I LOVE), but, I am really feeling the bumps a lot more, even chatter, and it feels that the front end of the bike is coming back at me faster and harder. Like I'm getting bumped off the bars a bit. It's knocking my confidence on the tech sections and I'm losing my rhythm easier than before.

I am fully aware that the rims themselves are apples and pears. The bike is quite a bit heavier than it was which I expected and I'm adapting to. 

My questions: 

1. Do I need to change settings in the fork to damp the stiffness of the new rims? The AMC were definitely more flexy and the Spanks are super stiff in comparison

2. Since fitting the new wheels I feel like my saddle needs to be set back a bit further - on the flats my butt is over the end of the saddle. Nothing is loose and nothing was changed in this regard. Is this a figment of my imagination? I don't feel that I'm compensating for my decreased confidence on the flats by sitting further back, but maybe I am. I don't think so, though. 

3. When do I use the fork lockout? I have only ever used it on tarmac before but today felt a bit more confident locking it over the little bits of techy climbs and not having the bike hit back at me so hard

4. Would changing back to the Maxxis make any difference? I still have them and they're good for a long while yet. 

Any suggestions appreciated! 

[Super Sywurm]

Get a steel hardtail.🤪

[DieselnDust]

28 minutes ago, RobynE said:

Hoping folks can explain some stuff for me. 

So I have new wheels on my bike, this includes different tyres to what I am used to and significantly wider, stiffer rims. 

Bike: circa 2013 Giant XTC Advanced SL carbon, 1x12 (Shimano SLX RD, Deckas 32t NW oval ring, Shimano Deore Chain, Sunrace 10-52 cassette - chain and cassette are brand new) - in case there is drivetrain relevance

Old front setup: American Classic Tubeless Race 29 with Maxxis Forekaster 2.4 up front, AMC hub, non-boost, QR

New front setup: Spank 345 Trail with Vittoria Barzo 2.25, Hope Pro 2 Evo hub, QR

Fork: Rockshox SiD WC XX, no change there - serviced by Jaco a couple of months ago and not many rides since

Rear setup: was AMC as above with Ikon 2.25, now Spank as above with Vittoria Saguaro 2.2

Pressure: running same tyre pressures as I was with the old setup, can't tell you exactly what it is as it's more of a feel thing - tubeless

Type of riding I do - Northern Farm Red route; Trailseeker type stuff; my local is the bottom section of Steyn City (Porcupine Park) if anyone knows it. Nothing hectic. I am no racing snake but I give it what I've got on all the terrain I ride. 

So what I'm finding is that I am much more planted in the corners and faster on the descents (which I LOVE), but, I am really feeling the bumps a lot more, even chatter, and it feels that the front end of the bike is coming back at me faster and harder. Like I'm getting bumped off the bars a bit. It's knocking my confidence on the tech sections and I'm losing my rhythm easier than before.

I am fully aware that the rims themselves are apples and pears. The bike is quite a bit heavier than it was which I expected and I'm adapting to. 

My questions: 

1. Do I need to change settings in the fork to damp the stiffness of the new rims? The AMC were definitely more flexy and the Spanks are super stiff in comparison

yes if the fork is coming back at you then something between you and the contact patch has changed. A stiffer rim shouldn't be the problem unless it is also more "springy". It could e that the spoke tensions are higher in your new wheels while the older wheels had spokes that were a little more loose either due to fatigue or build intent. Just 1 click toward slow (clockwise) at a time. You don't want it too slow and have the fork stack down. Stack down = very bad

28 minutes ago, RobynE said:

2. Since fitting the new wheels I feel like my saddle needs to be set back a bit further - on the flats my butt is over the end of the saddle. Nothing is loose and nothing was changed in this regard. Is this a figment of my imagination? I don't feel that I'm compensating for my decreased confidence on the flats by sitting further back, but maybe I am. I don't think so, though. 

Seems to further suggest the wheels are stiffer than the units being replaced but this is mostly your imagination  When you go a bit faster people tend to want to slide a bit further back. You might want to consider a bike fit as well (standard BH recommendation so lets get it ou of the way :))

28 minutes ago, RobynE said:

3. When do I use the fork lockout? I have only ever used it on tarmac before but today felt a bit more confident locking it over the little bits of techy climbs and not having the bike hit back at me so hard

Generally the idea behind a lock out is about efficiency of energy transfer. It allows a racer to run the fork a bit softer for the bumps but have a solid platform to push against when pedalling hard. Its a gofaster tool

28 minutes ago, RobynE said:

4. Would changing back to the Maxxis make any difference? I still have them and they're good for a long while yet. 

Any suggestions appreciated! 

The forekaster is a heavier and more damped tyre. Switching back to it means you likely won;t make a change to your rebound setting but that's actually just a band aid. you should get the rebound setting right where the fastest setting you can handle without it hurting your hands is ideal.

[RobynE]

DD! 💡 I reckon you’re absolutely bang on the money about the spokes… I didn’t think about that at all and 💯 YES that my old setup did not have stiff spokes mostly because of fatigue. These wheels are super super stiff and tight. 

Seating: yes, perhaps I am going faster. Let me ride it a bit more and see as I don’t feel the usual fallout of bad fit. A bit of numb hands but I think it’s from gripping too hard because of the front end bounce. Not the same as the fit-related numb hands from leaning on them. 

Lockout: thank you for that explanation - I get it. I think this moment of feeling ill at ease will actually improve my riding going forward. 

Tyres: noted, and thank you. I will stick to the Vittorias and start with the damping first. 

[droo]

3 hours ago, RobynE said:

Pressure: running same tyre pressures as I was with the old setup, can't tell you exactly what it is as it's more of a feel thing - tubeless

Here's your issue (IMO).

Wider rims can get away with much lower pressures. The AC MTB 29 are 21mm internal, the Spanks will be closer to 30.

Get a decent pressure gauge and experiment. Doesn't need to be digital, just needs to be consistent. Or if you don't have a decent floor pump, Ryder do a great one with a digital gauge.

[RobynE]

Thanks gents! 

I adjusted the rebound and found a happier place (it was 2 clicks, 3 became a little too compliant) - not quite perfect but I reckon with adjusting tyre pressure as droo suggests I’ll find the sweet spot. I have not heard or felt a single ping over rocks where I used to have a fair amount on the old rims with the same pressure. 

Took my kiddo for an ice cream ride afterwards and she took off like a bat out of hell on a looooong paved downhill covered in dry cut grass (and with questionable paving maintenance on any given day) - and actually allowed myself to match her speed instead of feeling overly cautious. I wouldn’t have felt comfortable going that speed this morning in that section while trying to keep an eye on kiddo with the chances of hitting rocks/bottles/loose/missing paving. 

[DieselnDust]

2 minutes ago, RobynE said:

Thanks gents! 

I adjusted the rebound and found a happier place (it was 2 clicks, 3 became a little too compliant) - not quite perfect but I reckon with adjusting tyre pressure as droo suggests I’ll find the sweet spot. I have not heard or felt a single ping over rocks where I used to have a fair amount on the old rims with the same pressure. 

Took my kiddo for an ice cream ride afterwards and she took off like a bat out of hell on a looooong paved downhill covered in dry cut grass (and with questionable paving maintenance on any given day) - and actually allowed myself to match her speed instead of feeling overly cautious. I wouldn’t have felt comfortable going that speed this morning in that section while trying to keep an eye on kiddo with the chances of hitting rocks/bottles/loose/missing paving. 

Now if you get the Sid Xx World Cup serviced it will be even more compliant. If you’re in Cape Town speak to the Droo.

if outside , RBC might be easier to access but I think Stoke does courier in’s too

[RobynE]

20 minutes ago, DieselnDust said:

Now if you get the Sid Xx World Cup serviced it will be even more compliant. If you’re in Cape Town speak to the Droo.

if outside , RBC might be easier to access but I think Stoke does courier in’s too

Thanks DD - up here we have Jakes from Shockingly Good Bicycle Service Centre (gets a lot of 👍 on the hub) and he’s awesome. He serviced the fork in Feb I think and it was like night and day! So I think it’s good from a mechanical perspective, I am just so used to it on a wheel with spokes like wet spaghetti and I do think tyre pressure a little too high still. 

[MORNE]

2 hours ago, droo said:

Here's your issue (IMO).

Wider rims can get away with much lower pressures. The AC MTB 29 are 21mm internal, the Spanks will be closer to 30.

Came here looking for this comment…

Edit: not to mention that 2.2 tyres on 30mm ish rims will inflate pretty square and probably feel weird. Also, If you are going by feel…you’re likely running the narrower tyres harder…

Edited April 14 by MORNE

[RobynE]

Ok gents so I’ve done some fiddling and I think I’ve found the sweet spot. Felt my usual level of confidence on the same trail as mentioned the other day. TP is like 1.0 at the back and 0.8 at the front. No pings, sits nicely, rebound feels good and as far as I can tell no burping. I’ll check the pressure again this evening and see if it’s dropped since this morning. Obvs on tarmac I’ll be pumping them right up but this felt good for sandy/rocky single track.