ceelint

Stock wheels... Bontrager TLR

sumdum gai

Anyone upgraded to 100mm forks? If so, what model, and how's the ride change? I see lots of mention of the Paragon, but that's still ~65mm.

I'm on a '13 8.6. I just switched up my riding last year, found some nearby mountain/forest (new england) trail network so it's *lots* of hills, rocks, & roots. I'd love to upgrade to a XC or down country bike for this kind of riding, but with the supply chain being wiped out this past year, thinking of trying to get a couple more years out of my DS and maybe upgrade it a bit to better handle my terrain. I feel like the stock ~60mm fork it gets rough and/or bottoms out a lot on the roots or rocky descents. I've been thinking of switching to a 100mm fork.

I've seen all the posts about the Paragon, but wondering if there might be options with more travel. Anyone riding the Judy or Reba?

jondi77

Hi,

This is my first post here :-)

I recently got a DS3 (2021) and i would like to get wider tires, 700x45c or 700x50c.
Which size would you reccomend and what tires ?
I mostly ride on pavement in my city, but i donīt feel 100% confident (safe) on the stock tires, iīm more used to wider tires on my old mountain bike so therefore i would like to replace the 700x40c ones.

Jon

Junker84

Recently after 2years of owning my 2018 DS2 I am now replacing the tyres. I have read countless posts on fitting 29er Mtb tyres, some people fitting widths of 2.0" and 2.1". I thought I'd put my pennies worth in on this theory. Today I fitted a schwalbe 2.1 ( not nobbly on the edge) a tyre I had off another bike to the rear of the bike to see what the clearance was like..... There was no clearance.. and it was rubbing the frame at the chain stays. To me it's crazy going beyond treks recommended 1.9". Running tight to the chain stays and getting a wheel out of alignment over a bump then it's game over... Frames rubbed, your in the dirt and your carrying your bike home.

Also my ds2 has the standard 700 x 16mm rims (16mm inside width where the bead sits) so the 2.1 tyre and wheel just looked unsafe and stupid as I suspected. You can grab the tyre and twist it with your hand and almost fold it off with 50psi in it because the rim is too narrow!!! "mountain bike" wheels are 20mm+ inside width of rim which the 29" mtb tyre is designed for. Also forget using the hybrid tubes as they are only good for 32-45 ( 1.7") anything over a 42/45mm tube is massively over inflated and thin. A 29mtb tube is also useless as when inflated it fills the 2.1 tyre above the bead as it doesn't seat in the tiny 16mm inside rim (less than 16 actually as the tyre beads take up 6mm..) I know people that fancy making a mtb out a hybrid don't want to hear buy a mountain bike but....

​​​​​​I'm really surprised that on here nobody has mentioned the rim width and how that effects a wide tyre seating and stability. All you see is yeh 28,29 and 700 are the same the tyre will fit.

I don't want unsuspecting owners to overlook this.

jondi77

Has anyone put a 700c x 47 on their Trek DS 3 ?

subgrade

Didn't want to make a seperate thread, and since this one seems to be a fairly active one and contains talk on replacement suspension forks, I thought I'll ask here: has anyone tried using a 100mm travel 27.5 inch fork on a hybrid?

I'm asking since the choice in hybrid specific forks is scarce, and the RS Paragon and Suntour NCX-E and NRX-E are pretty much the only available air forks for hybrids. At a similar price, there's also Manitou Markhor which is a 100mm MTB fork, but the 29' version is 40mm taller than the 63mm travel fork my frame is designed for. However, the 27.5' is just 10-20mm taller which might be alright, and in theory it should fit a tire up to 730mm in diameter (that's around 28/29x2.0') - so that sounds as if it should work on a 28' hybrid too. The Markhor is a bit lighter and has more adjustability, which probably is not necessary but still a plus.

I would consider also a rigid fork, but it seems that the choice is no better there - you have some (stiff) Al forks which doesn't sound like a good idea to me, some steel MTB forks (Salsa CroMoto Grande would fit, but I'm not sure about how the huge 90mm tire width clearance would look on a hybrid, and they're out of stock everywhere I've looked anyway), and then you have carbon forks twice the price of the aforementioned suspension forks - not a reasonable investment in a hybrid in my opinion, and most are tapered anyway.

hokiefyd 

Yes, a 27.5" MTB fork should work just fine. An 80mm travel fork has about exactly the same axle-to-crown distance that your 63mm fork currently does, and a 100mm travel fork would sit about 20mm higher, as you noted. It'll still be a change, but it won't be a huge change.

You should also be able to go shorter within some reasonable range and still have a nice-riding bike, too. So don't feel limited to a fork with exactly the same axle-to-crown distance. To test, you can remove the spring from your NEX fork and go ride around...gently. You don't want to be going off jumps or anything, but riding around normally should be just fine. I tried this with a Giant Roam I once owned and I actually liked how the bike rode with the compressed fork. I think the axle-to-crown distance was something like 425mm -- much shorter than stock.

In the pictures below, the first picture is at stock height and the second picture is fully compressed (no coil spring). Sure, the front end sits lower this way, but the bike actually felt pretty nice! Based on that, I think any rigid fork with an axle-to-crown distance in the 430-460mm range would have worked out just fine. I sold the bike before I spent any money on a fork, but it rode very nicely fully compressed. You can very easily try the same for yourself and see if you like it.

DorkDisk

This is your major issue. A larger wheel + tire might rub the crown when bottomed out, or rub the brace. This will stop the bike and launch you over the bars. 730mm wheel diameter for a 27.5" fork sounds a bit off to me. You have to see if your wheel clears the fork while bottomed out.

Markhor's specs say its travel is adjustable from 80-120mm, so 80mm might be a better option. Also, running more sag will allow one to minimize the A-C delta; air forks can differentiate between spring rate and sag.

Carbon forks are not a bad idea, these are not bad and not too expensive.

subgrade

Of course, I would measure if I could, but it's not possible when buying online.
Yes, I guess I would be able adjust the sag and thus also the A-C. However, the main question is if the wheel clears the fork brace, everything else is secondary. I reckon the clearance for 730mm could be for 27.5+ tires.

DorkDisk

Fork brace clearance is one thing to check. The other one is to see if the tire rubs the bottom of the crown (where the steerer tube is) when bottomed out. This requires letting all the air out and compressing the fork, also not that difficult - in person.

hokiefyd 

The inexpensive Suntour fork on my MTB has a 370mm dimension from the axle to the brace, which supports up to a nominal 740mm diameter tire. Of course, actual clearance wouldn't be that much, but a 720mm diameter tire would likely work (which is a 50-622 tire, or 29x2). The brace is, by far, the closest point of contact. Even under full compression, the brace is lower than the crown. But this would be a good thing to verify before purchase, if possible.

DorkDisk

From this page, I found this:



Another slight difference between 27.5 and 29 forks is in the amount of fork offset

subgrade

That was my line of thinking too. However, since Manitou has the reverse arch, it could in theory be possible for the wheel to contact the crown before contacting the arch, so DorkDisk has a fair point. I suspect that is also the reason Manitou specifies the minimum clearance to the brace and the maximum tire diameter - I haven't seen other mfr's doing this.

I guess as long as the specs are true, it should be fine with 50-622 tires, which are also about the maximum most dual sport hybrid frames can fit.

hokiefyd 

If your primary goal is to rid yourself of the NEX fork for anything else (like a nicer air fork or a rigid fork), then a rigid fork will be the option with the fewest variables and almost guaranteed satisfaction. You can look at the geometry of the rigid fork options out there (Salsa and Surly are good sources for forks with specs available) and you can do a spreadsheet of how changing the fork will change your bike's geometry (such as head tube angle, seat tube angle, trail, etc.). A rigid fork with the exact same A-to-C distance of your unlocked NEX fork will be the safest bet (but you'll have the huge gap that you mentioned). Alternatively, you can go with a shorter rigid fork...something like a Surly ECR fork. It comes in two models, one with a 447mm A-to-C and one with a 468mm A-to-C. The offset of your NEX fork is probably in the neighborhood of 42-45mm (Suntour's website should say for sure). If you went with the 29+ ECR fork, you'd have a very slightly smaller A-to-C and a very slightly increased offset, but it'd probably ride pretty close to how your bike rides today. The 27.5+ version would lower the front end of your bike about an inch and a half or so compared with what it is now. It has a similar offset to your NEX fork, so you'd be able to find out today how that fork would ride. Just take the spring out of your NEX fork. If you need to, you can cut a small dowel rod to just the right length to get your NEX fork to have the same A-to-C length as that 27.5+ ECR fork.

DorkDisk

Performance parts don't have extra material. Especially when it comes to stack height, there is a concerted effort to keep the front ends of MTBs low. I cannot say I have worked on or ridden every fork out there but I do know that back in the day, it was something to keep an eye on, especially when one intends to run a larger diameter wheel than intended.

hokiefyd 

It's a great point to be sure. I wonder why the brace is so tall in the case of that Magnum fork. If you couldn't run a tire that tall because it'd hit the crown anyway, I wonder why they used such a tall brace. Maybe they used the same lower assembly for forks of different heights, and it was necessary for such a tall brace on similar models?

DorkDisk

The brace is not larger than any brake system that the fork can run. Rim brakes had larger clearance requirements. I don't know if that makes sense, I'm not great with words.

One can see on a disk brake fork, there is less clearance. 2.1 tire for 2.3 max clearance

100mm sid xx w 2.1" tire

coffeesnob

what kind of seat is on that?

minder02

Hello, I'm a newbie. Just arrived.
I'm getting a Trek DS 1 (2021). The plan is to travel with some friends in the Patagonia (I'm from Argentina). Nothing fancy and almost no dirt.
Just getting along the route.
The DS 1 is what I can buy here (U$ 700/900 financed). Yes it is far expensive than in the US or Europe.
Anyway my concern is with the factory installed Suntour fork. Just read that there's no posibility to lock it and I think that that will be a problem traveling.
One possibility is to replace it with a fixed fork or a better Suntour model but that seems expensive.
Look for the DS 2 but it is out of reach (U$ 800/ 1000 financed)
So the question will be if I can cycle in route (asphalt) with the installed Suntour. What are your recommendations or advice?
Thanks

DorkDisk

One runs the risk of breaking the frame at the downtube/headtube junction as the longer forks place more stress on frames. Aside from the obvious geometry challenges.

Karmajack

That was a Terry Liberator Y. I don't recommend it. I've since gone with a Brooks C17, which I'm getting along good with.

Durde_cecof

Brooks is such a great saddle. I got a B17 last summer and fell completely in love with it!

subgrade

My current fork is a NCX, not a NEX (that one got destroyed in a crash two years ago and I replaced it with what was readily available). It's not a big step up, but still noticeable: it's about a pound lighter, has some sort of damping and has so far held up better than the stock NEX, which had a lot of stiction and play in the lowers (presumably the plastic bushings were worn, didn't care to check before throwing it out after replacing). So I'm no dire need, but I'm toying with the idea, as the moment will come sooner or later.

The current A-C is 465mm (around 450mm with me on the bike). Of course, it's impractical to aim for the exact A-C, so after messing around in CAD a little I've come to a conclusion that 450-480mm should be close enough (or 15m m less for a rigid fork).

The problem with the rigid forks is that there are virtually no CroMo steel forks available in the European webshops right now. - it's either aluminum or carbon. Since weight is not my main concern, I can't justify bying a $400 carbon fork for this bike.

subgrade

As long as you don't load the front end heavily with cargo, there should be no problem riding as it is. There is no reason why one couldn't ride an unlocked suspension fork on asphalt, it just lowers the pedalling efficiency a bit due to the front end bouncing when pushing hard, like when going up hills.

minder02

Thank you but I cancelled the DS1 and bought a Venzo Traveler (an almost identical copy of the Trek 920)