Replacement 1 inch fork for Gary Fisher Mamba

[DukeSilver79]

The title says it. My old fork is pretty worn. Looking for 1 inch threaded possibly with suspension with U/mount and v brakes. Some have told me its better to look for a rigid fork, rather than a cheaper suspension one. It's a 26inch bike. It's rather old, but in good shape. I will mostly do city park trails, camping trails, but nothing too intense as my wife won't be as into that.

I've looked a bit on ebay and amazon, but not with great results. Any suggestions? I know 1 inch forks are getting harder to find.

[xerxes]

They are out there: http://www.ebay.co.uk/itm/RIGID-MTB-MOUNTAIN-BIKE-FORK-1-inch-26-22-2-THREADED-/290669857175?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26​otn%3D21%26pmod%3D140710546303%26ps%3D54

http://www.ebay.co.uk/itm/Dimension-26-Mountain-Fork-1-Threaded-140x50mm-Black-/260979748089?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26​otn%3D21%26pmod%3D140710546303%26ps%3D54

If you want something really nice, perhaps made with good quality Reynolds or Columbus tubing and with high quality drop outs, you could probably have some custom made by a frame builder.

[DukeSilver79]

I'll probably get one of those if they fit U mount with v brakes. Thanks.

[xerxes]

I'm not sure what you mean by U mount?

[DukeSilver79]

(06-01-2012, 08:08 AM)xerxes Wrote:  I'm not sure what you mean by U mount?

The "u" shaped... Actually upside down u shaped bar that fits behind the brakes on my fork. I'm on my phone, but later I'll post a pic. Can that bar be attached onto a new fork?

[Joe_W]

So, is it a real U-brake or is this just the brake power.. uhm... "increaser" (forgot the real name), which is a piece of metal that stiffens the whole brake setup so that there is less flex?

(U-brake mounting bolts sit above the rim)

[DukeSilver79]

Uploaded is what I mean as the "u mount." Do I need that part on a new fork? Is that just part of the old fork?

[xerxes]

That's a brake booster, they were popular a while back but have largely gone out of fashion now. The idea was to stop the frame and forks flexing out, away from the wheels as you applied the brake and giving more braking power. I'm not sure they actually did much, a well made frame or fork should be stiff enough to handle the force of the brakes anyway.

You should be able to fit it to your new forks if you want, but I probably wouldn't bother, I think it looks neater without them.

[DukeSilver79]

(06-04-2012, 09:22 AM)xerxes Wrote:  That's a brake booster, they were popular a while back but have largely gone out of fashion now. The idea was to stop the frame and forks flexing out, away from the wheels as you applied the brake and giving more braking power. I'm not sure they actually did much, a well made frame or fork should be stiff enough to handle the force of the brakes anyway.

You should be able to fit it to your new forks if you want, but I probably wouldn't bother, I think it looks neater without them.

Ok, thanks. Now that I know I don't have to worry about it, I'll start searching for a fork.

[Joe_W]

Right. That's what they were called... *slaps forehead*

[DukeSilver79]

(06-04-2012, 10:08 AM)Joe_W Wrote:  Right. That's what they were called... *slaps forehead*

I'm just glad the pic finally cleared things up. I've been looking at forks, and none of them had that thing. It was really getting frustrating.

[xerxes]

Actually, thinking about it, on your original suspension fork, it probably is necessary because there isn't an integral cross brace between the two lowers as there is on many suspension forks:



So the brakes would push out on the lowers against the seals inside the forks.

However, on a pair of rigid forks, you'll have no problems and you won't need it.

[DukeSilver79]

Ok, thanks for that. I'm probably going rigid anyway.

[DukeSilver79]

Thoughts on something like this rigid fork for about $40, or the suspension for $100? What tools do I need to have or buy to do this project? I'm just learning do it yourself repair. I guess I could read the big ebook I have one it, but I'll just ask here.

[xerxes]

Unless you're going to be doing some fairly serious off-road rides I'd probably go with a rigid fork. A rigid steel fork requires no maintanance, is lighter and will pretty much last forever provided it's not allowed to go rusty.

I still ride a rigid frame and forked MTB on and off road regularly and I like the direct, lively feel compared to my hardtail. It does get more "hairy" on fast, bumpy decents, but you can counter that to some extent by riding with softer tyres, or simply by taking it slower.

To maintain the geometry of the bike, and a similar feel, you will need to take some measurements into account:



You will need a steerer tube at least as long as the one on your existing forks. Too long and you can cut it down, but too short and it will never reach the top headset cup and locknut.

A similar axle to crown length to your existing fork would be preferable. Take into account the fact that the suspension will sag a bit, when you're on the bike and shorten the axle to crown length by 10 or 15mm, possibly more.

Some more info on fork length and geometry: http://www.sheldonbrown.com/rinard/forklengths.htm

Because your frame originally had suspension, it probably had a fairly safe/slow head angle and you could put slightly shorter, rigid forks on it without upsetting the handling.

Incidentally, the suspension forks in your picture above will not be suitable; there's no bosses for V-brakes, they are only suitable for disc brakes.

Of the forks I linked to earlier, I think these are slightly nicer: http://www.ebay.com/itm/Dimension-26-Mountain-Fork-1-Threaded-200x50mm-Black-/260979737823?pt=Cycling_Parts_Accessories&hash=item3cc39ac4df

Here are some more with different length steerer tubes: http://www.ebay.com/sch/i.html?_from=R40&_nkw=Dimension%2026%22%20Mountain%20Fork%201%22&_sop=15

They are chromoly, which is a higher grade steel than high-tensile, slightly lighter and have forged drop-outs, which are stronger and better quality than stamped.