Geometry change with 170mm and DHX2 65 fit

[ribtek]

It seems that adding 10mm of fork travel change the slack angle 0.5 degrees. So does that mean that running 160mm front + low position for the mino link is the same geometry as running 170mm with high position?
I am debating between a Fox Factory 36 160 or a 38 170. I am unhappy with the Yari, harsh feeling especially on rapid small bumps.

Also, with the new 2021 DHX2, will the 230x65 fit? I know the 230x60 is ok, but wondering for the 65 which would be great travel. Also, what mounting hardware to order?

 

[Supernils]

It might preserve the angles for the fork and seat tube angle. But it makes the BB higher.

Remember that if you don't like it, it's easy to convert the forks to 160mm again. That's possible with the Fox 38 also. And you can always put a 2,5mm spacer on the shock to make it 62,5mm if you don't like it at 65.

I'm planning on 170f/62,5 rear. I have probably tested it in a weeks time.

It seems like you can just use the same mounting hardware as the stock shock, if you have the 7 or 5, that is. The upper "bolt" (or whatever you cal it) is 54mm wide, 10mm thick. The lower is 40mm wide and 10mm thick. The bushing eyelet is standard inner diameter 12,7mm and outer dia 15mm. And then there is the "spacers" that keep the shock from moving sideways, which I dont know the size or name of. They slide easily of, so I'll just use the stock ones.

Someone else can probably answer better than me, but at least it's something.

 

[bluewater87]

I've decided to go with a 170 Zeb ultimate and adding a meg neg and 60mm stroke on the stock deluxe (non thru shaft) on my 2021 9.7

 

[ribtek]

What’s the mounting difference between a 7 and 9.7?
I still don’t understand what mounting hardware I need to get for a 9.7 XL.
Also if anybody can confirm a 230x62.5mm DHX2 will fit that would be great.

 

[Supernils]

What’s the mounting difference between a 7 and 9.7?
I still don’t understand what mounting hardware I need to get for a 9.7 XL.
Also if anybody can confirm a 230x62.5mm DHX2 will fit that would be great.

Seems to be the same shock, same mounts. Which means you can just use the same. Can´t answer the second question, but if a DHX2 2020 fits in 230x60, the 2021 should probably fit with the 62,5 because of the smaller piggyback.

 

[ribtek]

I've decided to go with a 170 Zeb ultimate and adding a meg neg and 60mm stroke on the stock deluxe (non thru shaft) on my 2021 9.7

Be careful with the Zeb. Not only 170mm makes the bike already slacker (which you can counter with the Mino Link) but the Zeb 170mm is also 8mm taller than a 170mm Lyric giving you again more slack per this site: RockShox Zeb: first ride on 38mm stanchion 160-190mm suspension fork - MBR

The rail is known to be a bit light in the front in steep climbing. I think a ZEB 170 will make it too unbalanced.

EDIT: I did some research and here you have everything: https://www.sram.com/globalassets/d...a-2021-fs-oil-air-coil-token-spec-english.pdf

I can confirm that a 160mm ZEB is longer than an 160mm Lyrik or Yari and will make the bike slacker. So Going 170mm ZEB is a no-go for me. That would be equivalent to put a 180mm Lyrik in term of geometry change.
I also checked on FOX website and here is the recap:

160mm fork length for Lyrik, Yari and 2021 Fox 36 = 571mm (I also measured the Yari on my Trek and it's matching).
170mm same forks = 581mm
Fox 38 adds in both case 2.7mm at 573.7mm and 583.7 respectively.
Rockshox ZEB adds 5mm officially at 576mm and 586mm respectively, but measured at 8mm by MBR magazine.

 

[bluewater87]

Be careful with the Zeb. Not only 170mm makes the bike already slacker (which you can counter with the Mino Link) but the Zeb 170mm is also 8mm taller than a 170mm Lyric giving you again more slack per this site: RockShox Zeb: first ride on 38mm stanchion 160-190mm suspension fork - MBR

The rail is known to be a bit light in the front in steep climbing. I think a ZEB 170 will make it too unbalanced.

EDIT: I did some research and here you have everything: https://www.sram.com/globalassets/d...a-2021-fs-oil-air-coil-token-spec-english.pdf

I can confirm that a 160mm ZEB is longer than an 160mm Lyrik or Yari and will make the bike slacker. So Going 170mm ZEB is a no-go for me. That would be equivalent to put a 180mm Lyrik in term of geometry change.
I also checked on FOX website and here is the recap:

160mm fork length for Lyrik, Yari and 2021 Fox 36 = 571mm (I also measured the Yari on my Trek and it's matching).
170mm same forks = 581mm
Fox 38 adds in both case 2.7mm at 573.7mm and 583.7 respectively.
Rockshox ZEB adds 5mm officially at 576mm and 586mm respectively, but measured at 8mm by MBR magazine.

Im ok with a little longer a2c, as I’m using maxxis 2.5 tires and could use some additional bb clearance.
Also, the 2021 rail comes with the zeb 170

 

[ribtek]

Im ok with a little longer a2c, as I’m using maxxis 2.5 tires and could use some additional bb clearance.
Also, the 2021 rail comes with the zeb 170

The problem is not the bb, But the bike will be way slacker than stock even with the Mino in high. Also, the 2021 comes with Zeb 170 but they changed other specs too because the slack angle is the exact same as the 2020 with Yari 160mm.
As I explained going with the Zeb 170mm would be equivalent to go with a Yari 180mm in term of how it changes your angles.

Also, yesterday I tried the bike for the first time on a very steep climb and it was barely manageable with the front wheel going up all the time. Note that I have an XL with dropper seat all the way up and due to how the bike is If you are tall it makes this issue worst as pointed in most reviews.

But to each his own of course. I am looking forward to get your feedback once you have it.

 

[Supernils]

The problem is not the bb, But the bike will be way slacker than stock even with the Mino in high. Also, the 2021 comes with Zeb 170 but they changed other specs too because the slack angle is the exact same as the 2020 with Yari 160mm.
As I explained going with the Zeb 170mm would be equivalent to go with a Yari 180mm in term of how it changes your angles.

Also, yesterday I tried the bike for the first time on a very steep climb and it was barely manageable with the front wheel going up all the time. Note that I have an XL with dropper seat all the way up and due to how the bike is If you are tall it makes this issue worst as pointed in most reviews.

But to each his own of course. I am looking forward to get your feedback once you have it.

Are you basing on the geo sheet? Because it seems to me that they are not really accurate. See mbr latest article on the slash, where they actually measured the angles, and found it to be off by some margin. I haven't checked the charts pn the rail with 160mm and 170 mm forks, but
I wouldn.t be surprised to see they would be the exact same, even though the frame is the same.

 

[Hob Nob]

I'm currently switching between a 170mm Ohlins RFX M2 & Lyrik Ultimate, which have an almost identical a2c measurement. Trek are usually a bit slacker standard than they advertise, so when measuring, it wasn't really a surprise to see my bike has a 63.8 degree HA now. The Zeb is definitely a longer fork than the others I have used.

The shock mount issue, is just the difference between the the thru-shaft shocks & bikes without. All the bikes with it are trunnion mount, all the bikes without, arn't. It does mean you can either run a trunnion mount or a traditional eyeletted shock, you just need the relevant hardware to make it work. All you need to do is ask your local Trek dealer to order you the relevant mounting kit for the type of shock you want to run.

For reference, I use a Push 11-6 on mine with a 64mm stroke. 65mm makes the seatstay bridge very close to the back of the ST on full bottom out, so I chose to reduce the stroke a touch more to give me a 5mm gap. 64mm stroke gives 167mm travel, which is a big difference to stock.

 

[Supernils]

I'm currently switching between a 170mm Ohlins RFX M2 & Lyrik Ultimate, which have an almost identical a2c measurement. Trek are usually a bit slacker standard than they advertise, so when measuring, it wasn't really a surprise to see my bike has a 63.8 degree HA now. The Zeb is definitely a longer fork than the others I have used.

The shock mount issue, is just the difference between the the thru-shaft shocks & bikes without. All the bikes with it are trunnion mount, all the bikes without, arn't. It does mean you can either run a trunnion mount or a traditional eyeletted shock, you just need the relevant hardware to make it work. All you need to do is ask your local Trek dealer to order you the relevant mounting kit for the type of shock you want to run.

For reference, I use a Push 11-6 on mine with a 64mm stroke. 65mm makes the seatstay bridge very close to the back of the ST on full bottom out, so I chose to reduce the stroke a touch more to give me a 5mm gap. 64mm stroke gives 167mm travel, which is a big difference to stock.

Do you find that the extra length does something to the progression and the end of the travel?

 

[Hob Nob]

I haven't mapped the leverage ratio out, to be honest its a non issue for me anyway as the 11-6 has a hydraulic bottom out. The curve to that point is pretty progressive & works well with a coil anyway, so I see no reason why the extra bit of travel does anything weird.

It rides fine, just a bit of extra in the bag for when it gets rowdy. It makes no difference to how the bike rides the rest of the time

 

[Supernils]

I haven't mapped the leverage ratio out, to be honest its a non issue for me anyway as the 11-6 has a hydraulic bottom out. The curve to that point is pretty progressive & works well with a coil anyway, so I see no reason why the extra bit of travel does anything weird.

It rides fine, just a bit of extra in the bag for when it gets rowdy. It makes no difference to how the bike rides the rest of the time

Thanks. I just innstalled the DHX2 with the 450 spring myself. I´m 80kg plus equipment. The spring was cleary too light for me. I felt several bottom out´s, and it felt like the shock didn´t have to much reserves when it got rowdy. Gonna try 475 and 500.

 

[Doomanic]

I'm 85KG plus equipment and I'm running a 550.

 

[Forever Wild]

I've decided to go with a 170 Zeb ultimate and adding a meg neg and 60mm stroke on the stock deluxe (non thru shaft) on my 2021 9.7

How do you like this setup. I have a Super Deluxe ultimate with Meg neg on order. Someone is trying to sell me the 170mm Zeb ultimate.

Thoughts on fork geometry change? Thoughts on harshness improvement over the 160mm Yari ? I’m sure it improved, but was it a huge improvement ?

 

[bluewater87]

How do you like this setup. I have a Super Deluxe ultimate with Meg neg on order. Someone is trying to sell me the 170mm Zeb ultimate.

Thoughts on fork geometry change? Thoughts on harshness improvement over the 160mm Yari ? I’m sure it improved, but was it a huge improvement ?

i wasn’t able to get around to installing the Meg neg, as I’m having other issues with the bike still. The time I did get on it was with the zeb 170 installed.
The zeb is stiff! It’s more like a 40 than a 36/lyrik/yari. I definitely made the right choice buying the zeb vs upgrading the yari.