Hi,

I am suffering a deep dilemma here. This is my current touring bike:


It's really great and has taken me on one tour thus far. My future tours include trips much longer than my previous 4 night trip. The fork I put on it is a Surly Troll fork and as you may be able to tell from the picture, it has messed up the handling quite a bit. The fork is corrected for 100mm suspension forks with 40mm rake and 453mm axel to crown length. My question is, what fork options are there to straighten out the handling?

The 80mm corrected Surly 1X1 fork looks nice on paper, with 45mm rake and 413mm axel-to-crown, but it doesn't have any front rack eyelets. Second option would be the Surly Big Dummy fork with 43mm rake and 425mm axel-to-crown. I've looked through the 1993 vintage Fisher catalogues but can't find any geometry charts to sway my decision. Also I was wondering if anyone has any other suggestions besides Surly's offerings. I'm a pretty light packer and would appreciate lighter steel than 4130, especially paired with the Tange Prestige on the Fisher frame.

Thanks,

Max

What about the 26 inch Long Haul Trucker fork.
Very nice for touring and has mid fork rack mounts.
Disc or No Disc.
Got mine for $53 on sale.

I'll be honest, I don't really know that much about fork geometry etc so looking at your photo doesnt tell me anything. What do you mean by "messing up the handling", and "straightening" it out. Describe the handling changes that started with the new fork.
I cant offer help but am curious about what negative effects happened, and at the same time to figure out fork stuff more.

I take it the wheelbase is longer because of the new fork? Did it slow down the handling a great deal?

so what exactly is the handling issue ? I cannot guess .. You dont say.

can you measure and report back on what the TRAIL is ?

[hint: its the distance laid out on the ground, between the head-tube axis line, and the plumb line thru the hub axle.]

shorter blades steepen the head angle.., then you need less off-set to maintain the same trail

combine the steeper steering angle and more off-set maybe shortens the trail ,
but how much IDK, you have to do the math to figure that out.

your present axle to crown is obviously too long, the 26" surly LHT is 376 so measure that against your present fork and see if you like the way the bike sits. Dropping it 7.7 cm is quite a bunch but maybe? Is that a 1 or 1 1/8" steerer?


Here's almost 40 to choose from

https://www.bikeparts.com/categories/...1&f%5B%5D=1389

The Surly forks are the only (new) forks that I've come across for rigid 26" wheeled bikes. If you don't like those, you will need to go with a custom fork but those will cost way more.

Thorn sells some forks that might work for you, e.g.

https://www.sjscycles.co.uk/26-thorn-...ack-prod30197/

Put an OMM Sherpa front rack and you won't need any eyelets.

I would suggest something like this:

https://www.universalcycles.com/shopp...1&category=703

~400mm long, 1-1/8" threadless, and eyelets. Cheap, too. Don't bother trying to find something in a nicer steel than plain 4130, the market for 26" forks is just too small these days. And, most upgraders probably want carbon, anyway.

I think it would be helpful to know dimensions and angles of the frame first. I find with my 26" MTB frames the head angle is in the area of 70 degrees. With that and a descent length fork, I like a little more offset to reduce the trail to around 47mm. It works well for me with a front load. That typically means a fork offset of 60 to 62mm. I have had a few forks bent to get that offset. It is pretty easy for a descent frame builder.

I think you might have a hard time finding a fork in the geometry you need, with mid-fork braze-ons, for a decent price, or not custom made. IIRC you are looking for either a 440mm or a 425mm fork. 413mm is likely to be squirrelly unless your original fork was a 60mm travel one. Possibly even then. Do you know what model fork was originally on it? Assuming it was a shock fork, we should be able to determine what size replacement rigid fork you need from what it originally had.

If you are willing to forego the mid-fork braze-ons, there are some options out there in the sizes you need. I replaced the Rockshox Judy 21R on my girlfriends 1996 GT Pantera with an IRD 440mm fork and it worked perfectly. Handles great, she uses it around town (10, 20 and 35 mile rides) and for unloaded touring to bed and breakfasts. She loves that bike now. At the time (two years ago?) IIRC, I shelled out $115 (shipped) for it. I'm having a hard time finding them online, but one search redirects to Soma's 440mm "rigid fork for cantilevers" which appears to be exactly it. Same black glossy color and yellow Tange steel logo. Looks like these are going for $125 plus shipping now, although a LBS might be able to get it in for less, or at least spare you the shipping expense.
https://store.somafab.com/socrmtbfoca.html

I'd second the vote for either going with Old Man Mountain racks so you don't need to use mid-fork braze-ons or using P-clamps to make other racks work. I've used both very successfully. The only downside of OMM racks I can see, is your bike won't fit in a roof top bike rack that requires the front fork to fit into it (the attachment at the fork bulks it up so it won't fit). OMM racks otherwise have a great reputation, deservedly so, as they are bombproof. I've taken mine far beyond what it was designed for and it handled it like a champ.

I was leery of P-clamps at first, but I attached my Nitto Big Front Rack to an MTB fork with them and have had zero issues in the nearly three years since I mounted it. That's with running heavy asymmetrical loads regularly, very regularly having a heavy load on the top of the rack, riding daily over rough roads, and having loaded it pretty heavily for a couple of short tours, including one with a fairly lengthy very rough gravel segment. I once filled a full sized Ortlieb pannier to overflowing with donated books, hung it on one side of the rack and hauled it the ~8 miles home over quite rough roads, and still it didn't show any signs of slipping or the clamp failing.

The P-clamps that came with the Nitto Big Front Rack were actually too small to wrap around my fat MTB forks (another old GT) and so I used them as a model, bought a scrap of aluminum sheet stock from a hardware store and used tin snips to fashion my own. IIRC, the rubber cushions that came with it to put between the clamp and the fork ended up being too short as well and I simply fashioned similar replacements out of an old inner tube. Still going strong, with no signs of slipping or fracturing nearly three hard years over rough roads later.


FWIW, at the time I replaced my girlfriends shock fork, I did some research and came up with:
(quoting myself from my notes at the time)

Kona Project 2: 60-70$, ugly?, eyelets, crown hole, 440mm, 1040g/813g (disc vs canti weight, triple butted)
disc tabbed https://www.cycle-solutions.com/Project-2-26-P4797.aspx
https://www.cambriabike.com/shopexd.asp?ID=87429
https://www.bikeman.com/KON-P2MTN440.html

96$ IRD 440, 40mm rake, black, unicrown, 907g, eyelets,
https://www.speedgoat.com/Catalog.asp...116&Prod=22806

$103 for Soma, canti, 40mm rake, 440mm length,
https://www.niagaracycle.com/product_...ucts_id=802955
https://store.somafab.com/socrmtbfoca.html

One One Inbred fork is 440mm.
Van Nicholas VNT TRX Alloy MTB Fork is only 420mm
IndyFab no-Travel fork is 430mm for 80mm fork replacement.

Vicious Cycles (custom) forks are very expensive i.e. $275 + $15 for fender tabs + $60 for low rider rack mounts. Straight blade.


At the end of my notes is also this unattributed quote I snatched from somewhere on the web: "Kona and Surly forks are too short at 410mm, unless you want crazy twitchy handling. Vicious and Salsa are the only two currently available that (I know of that) are the correct length 425mm (or so)." I believe this was from a thread somewhere (MTBR forums maybe, if not, likely here at Bikeforums) specifically addressing Rockshox Judy 21R replacement, or 80mm travel fork replacement.

That's the extent of my notes from then, although I did come across several other places online that do custom forks, I just neglected to jot any info down, as they were rather pricey and had decided to forego mid-fork mounts at that point. If you have the dough, there are a number of places out there that will custom make forks for you, but you'll have to come up with some measurements for them to work from or make an educated guess from some options they might have.


FWIW, at first I was afraid that what I really needed was a closer to a 425mm fork from the measurements I had taken. I went ahead and went with a 440 because the bike was a little sporty to begin with and a figured if it was just a touch high that would tame it just a bit. I don't know if my inexpert measurements were off, or my rationale was dead on, but the bike handles fantastically for her, she really loves it.


Hope that helps!

What length would it take for a frame made for a 80mm OR 100mm travel fork? Would it be 440mm?

I might as well put this down Medic, thanks a lot for taking the time to put down your experiences and notes about replacing a fork. At some point my late 90s Rockhopper will probably need a replacement fork for its Manitou suspension one, and so your notes helped to understanding a bit more about the various ins and outs of fork lengths etc.
I will probably only do more reading to understand all this stuff when and if I get to the fork replacement point, but it does help having someones personal experience as a start to read up on the whole procedure (and frankly, to be more informed so as not to make a mistake like this fellow did. Its good to have more info to hopefully not go that route, or at least understand the diff parameters better when getting opinions from store people or whatever)

cheers

ps, re P clamps, I too agree that it seems that the key is making rubber bits from old tubes that make a big difference stopping slipping etc, thats been my experience as well with them in any case.

Why I asked about trail has to do with how you will change the HTA, as you shorten the
fork tip to crown race distance, with a shorter fork ..

then with a shorter fork and so a steeper HTA, you need a longer fork offset
to hope to keep the trail the same .


Just offering a brand of fork doesnt really offer much in that regard. good luck with your homework..

you might be able to lay out a full sized drawing using the bike box cardboard to draw it out on.