180mm Fork on Trek Rail

[rsutton1223]

I have made some upgrades to my 9.8 and now I am thinking about going with a Zeb. Has anyone ran a 180mm fork on their Rail? I found one YouTube video in Spanish where a guy did but that is all I have been able to find.

 

[Supernils]

No, but I have a 170mm Lyrik. Wouldn't go futher if you have technical climbing. Actually I'm thinking of going back to 160mm to make it to climb better, or trying to set the mino link in the high position.

That being said, it's cheap and easy to reduce the travel if you want.

 

[Doomanic]

180mm takes you outside the frame's warranty conditions, but there's ways round that...

I have to ask "Why"? What are you hoping to achieve by extending the travel that much?

 

[rsutton1223]

In the past I have typically slacked out bikes a little bit more than most. I am willing to give up some climbing performance for descending. That said...I probably will just get the ZEB in a 170mm to start. It is a cheap upgrade to 180mm if I decide I want to go that route. They were supposed to make a "e-bike" specific one that had a 2 step function to it to lower the suspension for climbs. I haven't seen one yet though.

 

[Supernils]

What about changing the rear stroke to 60mm if you want the bike a slacker....? Or 62.5 if it's possible. I'm thinking of getting a DHX2 2021 62.5mm and putting the bike in the high position

 

[R120]

In the past I have typically slacked out bikes a little bit more than most. I am willing to give up some climbing performance for descending. That said...I probably will just get the ZEB in a 170mm to start. It is a cheap upgrade to 180mm if I decide I want to go that route. They were supposed to make a "e-bike" specific one that had a 2 step function to it to lower the suspension for climbs. I haven't seen one yet though.

This is what I would do. I think going to a Zeb would be more noticeable in terms of descending performance due to the chassis stiffness, than going up to 180. Having tried a 160mm fox 38 recently, it definitely tracked better than my 170mm Lyric, and I was more confident in it when going through sketchy terrain at speed despite it having less travel.

On my bike (not a trek) that was designed around a 170, I went to 180, but went back to 170 after bout 6 months as the extra travel made no difference but it lowed the handling down and made climbing anything steep and technical lees easy.

 

[rsutton1223]

What about changing the rear stroke to 60mm if you want the bike a slacker....? Or 62.5 if it's possible. I'm thinking of getting a DHX2 2021 62.5mm and putting the bike in the high position

Going coil in the near future is a real possibility. I tend to like the small bump and midstroke performance out of coil shocks on heavier bikes.

 

[Doomanic]

Changing the stroke will not slacken the bike unless you plan to run more sag.

 

[Supernils]

Are you sure? 30% of 150 is 45. 30% of 160 is 48.

 

[Doomanic]

60mm stroke is 156.5mm travel. How much difference will less than 3mm extra sag make to the head angle?

 

[Supernils]

Well... Not very much. According to Treks geo-chart, if you raise the BB with 0,5mm, you also steepen the head angle with 0,4.

 

[Bike Gorilla]

180mm takes you outside the frame's warranty conditions, but there's ways round that...

I have to ask "Why"? What are you hoping to achieve by extending the travel that much?

Interested in where this info is from? Tracey Mosely was running 180mm fork for the EWSe recently

 

[Doomanic]

Interested in where this info is from? Tracey Mosely was running 180mm fork for the EWSe recently

The bike specs on Trek's website specify 170mm as max travel. I've posted a screenshot of it previously. However, it seems to been removed from the current spec sheet and I have no idea why.
I doubt TM is overly worried about potential warranty issues...

 

[LexC]

Reviving this old thread as I have decided to upgrade my Yari to a ZEB. I could only find a ZEB in 180mm, so took it knowing I could adjust the travel down if it's just too slack by swapping the air spring.

I was concerned about the Trek website mentioning 170mm as the max travel on a Rail. It's not the warranty I'm concerned about as much as potentially damaging the frame with a hard flat landing considering the slacker angles. So with the help of a geometry calculator, I came up with the following:

- The stock head angle on 160mm suspension and the Mino Link on LOW = 64.5 degrees
- The stock head angle on 160mm suspension and the Mino Link on HIGH = ~ 65 degrees

- Head angle on 170mm suspension and the Mino Link on LOW = ~ 64.1 degrees
- Head angle on 170mm suspension and the Mino Link on HIGH = ~ 64.59 degrees

So we can see that with the Mino Link in LOW and 170mm upfront the head angle is 64.1 degrees - This is pretty slack and would place the most stress on the headtube in the event of a flat landing. And this is still warrantied by Trek.

So if we bring the 180mm fork into the equation, our results are as follows:

- Head angle on 180mm suspension and the Mino Link on LOW = ~ 63.7 degrees
- Head angle on 180mm suspension and the Mino Link on HIGH= ~ 64.19 degrees

So my assumption is that if you are going to run 180mm the Mino Link should always be in the HIGH position and the angles still fall within spec of 170mm forks and the Mino Link in LOW. I.e, angles warrantied by Trek - kind of

Running the Mino Link in LOW with 180mm forks might be pushing things a bit far at 63.7 degrees ?

The bike in question is a Rail 9.7 in XL. I am quite tall so am not too worried about the taller BB or stack heights though - at least in theory lol.

This is simply considering the headtube geometry and not the actual rideability of the setup though, it just gives my mind ease that the 180mm fork won't throw the geometries out terribly on paper, but yet to see if the bike will still be rideable uphill.

Anyone else running a 180 up front and care to share their experience?

 

[Bike Gorilla]

Are you still running the rear at 150mm? If I went to 180mm it would be for the slacker of the two HA. I would also be confident that the Rail could handle it too?

 

[bluewater87]

I run 170 zeb and like it.
FYI the zeb a2c is actually 5-8 longer than the equivalent Length lyrik/yari.

*edited

 

[Hob Nob]

Reviving this old thread as I have decided to upgrade my Yari to a ZEB. I could only find a ZEB in 180mm, so took it knowing I could adjust the travel down if it's just too slack by swapping the air spring.

I was concerned about the Trek website mentioning 170mm as the max travel on a Rail. It's not the warranty I'm concerned about as much as potentially damaging the frame with a hard flat landing considering the slacker angles. So with the help of a geometry calculator, I came up with the following:

- The stock head angle on 160mm suspension and the Mino Link on LOW = 64.5 degrees
- The stock head angle on 160mm suspension and the Mino Link on HIGH = ~ 65 degrees

- Head angle on 170mm suspension and the Mino Link on LOW = ~ 64.1 degrees
- Head angle on 170mm suspension and the Mino Link on HIGH = ~ 64.59 degrees

So we can see that with the Mino Link in LOW and 170mm upfront the head angle is 64.1 degrees - This is pretty slack and would place the most stress on the headtube in the event of a flat landing. And this is still warrantied by Trek.

So if we bring the 180mm fork into the equation, our results are as follows:

- Head angle on 180mm suspension and the Mino Link on LOW = ~ 63.7 degrees
- Head angle on 180mm suspension and the Mino Link on HIGH= ~ 64.19 degrees

So my assumption is that if you are going to run 180mm the Mino Link should always be in the HIGH position and the angles still fall within spec of 170mm forks and the Mino Link in LOW. I.e, angles warrantied by Trek - kind of

Running the Mino Link in LOW with 180mm forks might be pushing things a bit far at 63.7 degrees ?

The bike in question is a Rail 9.7 in XL. I am quite tall so am not too worried about the taller BB or stack heights though - at least in theory lol.

This is simply considering the headtube geometry and not the actual rideability of the setup though, it just gives my mind ease that the 180mm fork won't throw the geometries out terribly on paper, but yet to see if the bike will still be rideable uphill.

Anyone else running a 180 up front and care to share their experience?

Worth considering they are slacker than 'official' geometry anyway (and a bit longer & lower), so your measurements are likely to be even further out. I run a 170 fork on mine & it's ~63.5 degrees. There is a lot of material around the HT, so that wouldn't overly concern me.

I would be more concerned about the big mismatch of suspension travel. I run a longer stroke shock on the back to make the bike 160mm rear travel to go with 170mm front, but 180/150 would be a bit odd.

Can look at the higher BB one of two ways, you will lose stability, but the bike will react quicker when tipping it over between corners. Pick your poison.

Personally, I would just get a 170 air shaft & just run that

 

[Gyre]

So my assumption is that if you are going to run 180mm the Mino Link should always be in the HIGH position and the angles still fall within spec of 170mm forks and the Mino Link in LOW. I.e, angles warrantied by Trek - kind of

I'd keep a 170 spring handy and swap it out if the frame breaks. Yes, Mosley runs a 180 in EWS. Yes, it's effectively the same angles. Still, you don't want to try to use logic to argue against a corporate bureaucrat, especially when it comes to insurance and warranties.

 

[Bike Gorilla]

If it snaps, put the old spring back in the fork! Then send it back

 

[Bike Gorilla]

If it snaps, put the old spring back in the fork! Then send it back

Just read you said the same thing ?

 

[coregrind]

FYI the zeb a2c is actually 15-18mm longer than the equivalent Length lyrik/yari.

Where did you get this info? I ask since the RockShox Technical Specifications show the difference for Axle to Crown, at same travel and wheel size, with ZEB being (only) 5mm longer than Yari/Lyrik.

 

[Gyre]

Where did you get this info? I ask since the RockShox Technical Specifications show the difference for Axle to Crown, at same travel and wheel size, with ZEB being (only) 5mm longer than Yari/Lyrik.

Yeah, can't be that much. I switched from Lyrik to Zeb on my Wreckoning. It feels like 5mm but absolutely no way for 15-18mm.

 

[R120]

Yup I just switch out a 180mm Lyric to a 180mm Zeb and its not that much

 

[LexC]

Woah thanks for all the responses

I am still running 150 in the back - how are you guys getting 160? Retrofitting a 230x60? Instead of the stock 230x57


So I just finished fitting up the fork and damn it looks burly. Just riding around my yard it feels pretty similar to before (before = Mino Link LOW, 160mm up front), haven’t noticed the front part of the saddle violating me more than usual so guessing the Geo’s are not toooo far off. I have had to drop the seat about 4mm though as it’s definitely higher now.

hitting my local trail park in the AM and will report back on the experience ?

 

[bluewater87]

I run 170 zeb and like it.
FYI the zeb a2c is actually 15-18mm longer than the equivalent Length lyrik/yari.

Sorry meant 5-8mm.
I increased travel by 10 hence the 15-18 I had in my head.

 

[LexC]

Reporting back from a morning on the trails

Wow, it’s better than I could have expected.

I started with the settings that came out of the trek suspension calculator for a 2021 Rail 9.8 which comes with a 160 ZEB Ultimate. I’ve got about 24mm sag or about 15% sag as per the markings on the stanchion.

The geometry feels very similar to the stock forks with Mino Link in LOW.

It’s definitely riding higher though as not one pedal strike on the rocky climbs where id usually pick up a couple pedal strikes if I’m not careful.

In the berms I felt I had to push the bike down a tad more to keep the front wheel from wanting to climb out, the whole bike seemed a bit more resistant to wanting to lean over at speed. Likely to do with the higher center of gravity, but this is not a problem though and i quickly got used to it.

As far as the fork goes though; over small bumps like a cobbled road for example it feels basically the same as the Yari. As soon as those bumps start to become slightly bigger it starts to shine and it properly eats them up. Rock gardens are a whole different experience to the Yari, I feel like this is where this fork really shines - you can be so lazy with the line choice as it just irons out everything. It exceeded my expectations. Like seriously SERIOUSLY.

on the jump lines I can’t really comment, if you’re not landing flat it’s all pretty smooth on both forks, however I did notice that when preloading for the jump face I didn’t get the same pop as the Yari, it was far more soft and progressive. I think it’s probably just down the the pressure I’m running /volume spacers - the fork is pretty linear stock.

I could definitely feel the rear shock behaves a bit like a pogo vs the ZEB which is like a cloud, so will probably look at changing that out next.

All of this being said, Strava agreed that the ZEB is faster - not to bore you with my segment data, but lately my times have been extremely consistent (last 3 runs are exactly the same, to the second.) and today I smashed all of them by 3-5 seconds, including bringing home a new KOM. I mean what better reason to change to a ZEB, right ?.

 

[Bike Gorilla]

Thanks for the update. You going to try it in Low? Out of interest, where in the world are your trails? Cheers

 

[Stray cat]

Reporting back from a morning on the trails

Wow, it’s better than I could have expected.

I started with the settings that came out of the trek suspension calculator for a 2021 Rail 9.8 which comes with a 160 ZEB Ultimate. I’ve got about 24mm sag or about 15% sag as per the markings on the stanchion.

The geometry feels very similar to the stock forks with Mino Link in LOW.

It’s definitely riding higher though as not one pedal strike on the rocky climbs where id usually pick up a couple pedal strikes if I’m not careful.

In the berms I felt I had to push the bike down a tad more to keep the front wheel from wanting to climb out, the whole bike seemed a bit more resistant to wanting to lean over at speed. Likely to do with the higher center of gravity, but this is not a problem though and i quickly got used to it.

As far as the fork goes though; over small bumps like a cobbled road for example it feels basically the same as the Yari. As soon as those bumps start to become slightly bigger it starts to shine and it properly eats them up. Rock gardens are a whole different experience to the Yari, I feel like this is where this fork really shines - you can be so lazy with the line choice as it just irons out everything. It exceeded my expectations. Like seriously SERIOUSLY.

on the jump lines I can’t really comment, if you’re not landing flat it’s all pretty smooth on both forks, however I did notice that when preloading for the jump face I didn’t get the same pop as the Yari, it was far more soft and progressive. I think it’s probably just down the the pressure I’m running /volume spacers - the fork is pretty linear stock.

I could definitely feel the rear shock behaves a bit like a pogo vs the ZEB which is like a cloud, so will probably look at changing that out next.

All of this being said, Strava agreed that the ZEB is faster - not to bore you with my segment data, but lately my times have been extremely consistent (last 3 runs are exactly the same, to the second.) and today I smashed all of them by 3-5 seconds, including bringing home a new KOM. I mean what better reason to change to a ZEB, right .

Is this one a Zeb Ultimate? Where did you get it? Thanks

 

[LexC]

Thanks for the update. You going to try it in Low? Out of interest, where in the world are your trails? Cheers

I didn’t plan to, but maybe just to experiment I will do it and report back.

I am in Cape Town, here is a nice POV showing my local trail: . Same route I tested this new set up on this morning, rock gardens galore

 

[LexC]

Is this one a Zeb Ultimate? Where did you get it? Thanks

Yup, ZEB Ultimate 180mm. I’m based in Cape Town, and its from a bike shop just a little out of town, finding it hard to get bike parts online lately - everyone is out of stock #rona.