Suspension Fork on a Trek 520
 

Is it possible, AND safe to do so? The 520 has 700's , what if I put a 26 up front?

Purpose: Intending to do a tour to the Arctic Circle, and I don't want to buy a new bike. Of course the 520 is durable enough for the trip, but the ride will not be as nice as my aluminum mountain bike with front suspension. Just a thought.

A suspension fork on a 520? You could do that. My question would be why? Or rather, why not just tour on the mountain bike that already has the suspension...you kind of answered your own question there, actually.

As far as a 26" fork, don't do it...it will change the geometry of the bike drastically, and end up making it uncomfortable.

Just the humble opinion of a 520 rider who has never considered suspension necessary.

If you were to use a suspension fork, I would figure a 29er fork would be best since 29er rim is the same as a 700c which is what you have now.

I saw a 520 with 42mm tires on it. Not sure if you could go wider, but if you could, that might be a possibility. 42mm or wider tire in the rear and a fat 29er up front on your suspension fork. Itll put some tilt back to your position since the 29er tire is taller than the 42.

Another option would be a large 27.5" tire and wheel up front. That would give you about the same overall size as your rear wheel and tire.


But this is all funky since it would be a suspension fork up front wonking up the geometry. Is your hardtail MTB something you could set up for touring?

You will raise the head tube and Lower the head tube angle , Screwing up the Trail/steering specification A Lot..

Dual Sport?

Better still A Tout Terrain Silk Road [R'off or derailleur versions offered)

http://www.peterwhitecycles.com/imag...es/TTBERF1.jpg

Note the gap over the mudguard, That is a Suspension corrected fork , (could fit a 29er wheel in there)
http://www.en.tout-terrain.de/bicycles/tanami/tanami/

Thorn, UK , is another One ..



;)

Another https://s-media-cache-ak0.pinimg.com...7b36b915fc.jpg

My mountain bike is a great riding bike, and would be fine for the trip. However, I would not be comfortable with the flat handlebars, would have to buy mud guards, rack, probably a generator, and so on.
I really like the 520, and I bought it for touring purposes, so maybe I'll just have to suck up the ride on the Dempster Highway. Quit complaining. I should remember that I am lucky to be able to go touring, and not have a job that I have to go to! Count my blessings. Thanks for the contributions guys!

You should check out this guys writeup. He started out a circumnavigation of the Americas by riding up the Dempster Highway to Inuvik. He rode a custom touring bike similar to a 520. Kept very good records of equipment and replacements:
https://www.crazyguyonabike.com/doc/..._id=377064&v=6

I'm posting this again because anytime I put in a link it must be approved by moderator and sometimes it takes forever.

You should google Jeff Kruys crazyguyonabike. He started out a circumnavigation of the Americas by riding up the Dempster Highway to Inuvik. He rode a custom touring bike very similar to a 520. Also kept very good records of places, services, equipment and replacements. Its a very good read as well.

you could put a 26 up front, might even like the geometry change.
but then you need to carry double the spare tires.

they do make 700 suspension forks....

Yeaaah no. What it would certainly do would screw up the geometry completely and the bike would likely handle like absolute crap
The worst case is that the change in head tube angle would cause too great a prolonged stress to the frame and would eventually rip the head tube right out of the down tube. Modern mtb's are built with these stresses in mind and the steel frames have gussets in critical high stress areas created by the slacker head tube angles.

Even the 26" forks are 490mm axle to crown whereas the 520 fork is 400mm maximum (Surly touring forks are 390mm). For reference MTB frame manufacturers specify a window of 40mm of acceptable travel change so +/- 20mm from the intended travel for the frame before you lose the warranty. This is with machines designed for the increased stresses of slack headtube angles.
In the case of the 520 you would be increasing the fork length with 90-100mm. That is HUGE! It is RIDICULOUS! Don't do it man.

This is of course with the level of suspension forks that are worth even considering (RockShox Reba and above). There are of course those clinky hybrid forks but... Well let's just say they are an abomination and a pestilence upon the cycling world. Don't go that way.

People seem to be missing the forest for the trees here. While you might be able to put a 29er fork on a 520, the frame isn't built to take the stresses that a suspension fork puts on it. About the shortest travel 29er fork you can find is a 100mm travel fork. That puts a lot of stress on the head tube/top tube/down tube junction. Mountain bikes have been designed to take the stress without breaking apart. Road bikes...even steel ones...aren't built to take those kinds of stresses.

Another thing to think about, you don't want to buy a cheap 29er fork...or cheap suspension fork of any kind...you want something that at least has a lock out so that you don't have to deal with the bike inchworming down the road when you don't need it. You also want a durable fork. None of that is cheap.

It would probably be cheaper to just add drop bars to your mountain bike and ride it. It would certainly be more up to the job if you feel you need suspension.

2 guys from Sweden rode south from Anchorage , on step thru Commuter bikes with 622-42 Tires..

Leave the 520 as is.. just bring some spare tires.. and tubes obviously..

Perhaps some butterfly/trekking bars for the MTB? That would give you a lot of good hand positions.

Now here is the big question - if your travel will be so rough that you want a suspension fork, do you really think a 700c rear tire that is small enough to fit in your frame with fenders will be adequate on back for your trip?

My expedition bike was sold specifically with a frame that was designed to use a 100mm suspension fork or with the solid fork that came with it. It uses 26 inch wheels. I have used both types of forks on that bike. In the photo, my expedition bike had the solid fork installed. I found that 2.25 inch width (26 inch) tires were good enough for this road without having a suspension fork. It rode a bit rough, but I was really glad I had a heavy duty frame with wide tires. If it was rough enough that I felt that I needed the suspension fork, I really would not have wanted to have a 700c pavement touring machine.

When you said you could use 26 inch wheels, were you trying to ask if a 26 inch suspension fork would work on your 700c frame without messing up the geometry? Interesting question. And if you did that, would that mean a 700c on back and 26 inch up front? I do not know enough about frame geometry to have a clue, so I will not offer an opinion.

If you try a suspension fork, you might want to also order the lower headset bearing race to install on the other fork so you do not have to remove the race from one fork to install on the other. I did that when I bought my suspension fork, when I switch forks I am happy that I do not have to mess with the lower headset race since both forks have the race installed and are ready to swap in and out.

I was thinking of something like this. It has only 30mm of travel, the axel center to crown measurement is 409, and mine is 405. The price is steep though, and I would have to put a disc in the front, which means I then loose my SON 28, and of course would have to build up a new wheel. Thanks for all the input. I will leave things the way that they are. When I built up my 520, it was meant to be taken everywhere, and that included the Dempster as that was on my mind at that time. Thanks again for your thoughts.

Lauf Grit | Lauf Forks - The lightest suspension forks on the market

And, something seems to have changed on the Forum, maybe I've just been away too long on my last trip, but how do I add a picture instead of a link? It keeps asking for a URL when I want to upload a picture.

Photos, took me a while to figure it out.

Below the text box, click on "Go Advanced".

Then above the text box you get a bunch of icons, one of which is a paper clip. Click that.

That opens up a pop up window. YOu can click Browse to find your photo. It can't be too big, I am not sure the limit. And it will make your small photo even smaller.

And click on Upload to load your photos before you click submit reply, or before you click preview if you want to preview first.

suspension fork on a Trek 520
 

Thanks Tourist. I did it a slightly different way....I think it worked

Interesting but...Damn! $900 for a springer fork!

And I'm not so sure about the effectiveness of the fork if the video is any indication. Look at about the 40 second mark where the rider makes the transition from gravel to pavement. The front tire almost bottoms out with the fork to about the same degree as the rear tire. The front tire deflection should be less, especially if you are going to spend $900 on a fork.

Is something gonna break when you don't want it to? More parts usually means more stuff to break.

Think long and hard before attempting the Dempster Highway. I have not done it because it is reputed to turn to mud in the summer and be miserable with mosquitoes. During winter it is seriously cold. If you find out otherwise, please post.

OK, you got me, but since this thread is 3 years old, I wonder how the ride went.

This is something that I think about every spring when I take my 520 out for the first few rides of the season, so I understand the temptation to want to do this, but as others have pointed out, the 520 just isn't built for it. The reason I experience this is that I ride a Haro 29er through the winter months and get very used to having front suspension. When I get back on the 520 in the spring, the first thing I notice is how harsh the ride is on my shoulders etc with the rigid fork. Yes, you can lower the front tire pressure, but the trade off is that you increase rolling resistance by doing so. I suggest you consider starting out with a 29er that is designed for front suspension and put road friendly wheels and tires on it (for lower rolling resistance). That's what I did with my Haro 29er, originally intending it to be a winter beater, but over the years I've overhauled it & upgraded components so now it's not really a "beater" anymore. Last summer, when my 520 was in the LBS, I took the 29er on some longer rides ( 75-90 miles through hilly terrain) and found it was surprisingly capable and comfortable compared to the 520. I think I would still prefer the 520 for longer tours, (it's lighter and rolls better) but the Haro 29er acquitted itself surprisingly well in that role. Call me old school ,but I've never been a huge fan of compact frames, so I do wish someone would sell a steel touring frame with a horizontal top tube that is designed for an appropriate short travel suspension fork, but so far, I haven't found one.

I always run my front tires about 75 to 80 percent of the pressure that I have in the rear tire. A couple years ago I did a week long trip in West Texas that was on some really rough chip seal. I ran my front tires at about half the pressure that I had in the rear, it did not slow me down noticeably.

Not sure what the importance of the horizontal top tube is, but there have been a few bikes that worked well with drop bars that could take a suspension fork.

I think that some years the Surly Troll could take a suspension fork, but I have never considered buying one so maybe my memory is wrong on that.

My Thorn Nomad Mk II was not intended for drop bar setups, but I have drop bars on mine. It was designed for either the solid fork that came with it or a 100mm suspension fork. It however is designed for only a Rohloff, so if you wanted derailleur gearing you are out of luck. I did have trouble finding a suspension fork for my Nomad, it had a headtube longer than many mountain bikes so some forks had too short of a steerer tube. The new Thorn Nomad Mk III does not take a suspension fork, once current inventory of the remaining Mk II versions are all sold, that option will be harder to get.

And lots of people have converted older hard tail mountain bikes to drop bars for touring.

Given how much rolling resistance one experiences on (G.D.) chipseal, it doesn't surprise me that you didn't notice the much smaller increase in rolling resistance from lower tire pressure. On the roads I ride on, my tires are usually inflated to around 72 lbs. If I forget to check, and they've gotten down to around 60lbs, I notice right away, and usually do a U-Turn and go straight home to top them off (with the compressor).

It's just my personal preference. I've read many studies comparing the two and they're usually along the lines of "on one hand blah blah blah, but on the other hand blah blah blah", are generally inconclusive, and end up leaving it to personal preference. For example, one such study concluded that the compact frames were more aerodynamic, but when you put a rider on it, its "advantage" disappears.

I feel the same way but it's strictly for aesthetic reasons. Top tube should be horizontal, stem should parallel the top tube, rear racks should be horizontal as well. Probably a minority opinion. (Yeah, I know, you have to make the bike fit and you can only buy what the market offers...)