Teboner92

Why couldn't i put a fork with 140mm of travel of my hardrock when a specialized enduro has the same head tube angle?

paul emick

*hypothesis mode on* Because, though the head tube angles measure the same, when you increase the fork length on your bike, you will alter the effective rake angle, which could negatively affect your steering, and put undue force on the headtube welds, some things which were engineering considerations on the Enduro. *hypothesis mode off*

Personally, I'd try it.

norco_rider77

ya, it could be a handling risk and your frame could break at the headtube (from what ive heard)

mcoine

First, it doesn't have the same headtube angle.

Second, The headtube angle of the enduro is measured with a 150mm fork on it already.. the hardrock is measured with a 100mm fork. Putting a 140mm fork on the hardrock is going to change the headtube angle.

Third, the enduro frame is made to handle the added stress from a fork that size, the hardrock is not.

Cyclist30907654

Very true. However, the Hardrock is marketed as a do-it-all bike, and is built pretty beefy for that description. Other people have done it with success. I know Mtnbiker66 had a hardrock with a Fox 140mm or something like that on it.

OP: I would try it. and then you can let me know if your frame snaps in half.

mtnbiker66

I had a HRSS with a 125mm fork on it. Girlscout(my son) had a HR with a 125 Vanilla so I'm no help at all.

junkyard

This is great advice. Take a picture of where the broken frame impales you too.

Teboner92

lol

Cyclist30907654

lol.

Anyhow, I don't think the frame would end in catastrophic snap. Wouldn't it just crack the frame? I can't see putting on a 140 mm fork snapping the frame.

But then, this is all me speculating. Anybody with real experience?

Dannihilator

The frames have a different headtube angle, the fact that the enduro is running a longer travel fork than the hardrock, it looks to the eye that they have similar head angles. Put the fork from the enduro and put it on a hardrock, it's going to have the frame all raked out.

If you want to put a long travel fork on a bike that is not designed for it, go ahead, just don't cry when the fork shears the headtube off and specialized won't honor the warranty due to abuse of the frame.

scrublover

That was a steel frame, built around a 100mm travel RS Duke. Fork in the pic is a 130mm Z-1. About the same difference in a2c as the OP is considering... Not a super light frame either; about 4.5# for the frame. Granted, it was also being ridden much harder than when I originally bought it...

Cyclist30907654

Wow, that is an impressive break. So if we have aluminum frames, is that where its likly to break? Also, did you ride it with a crack or did it just snap all of a sudden? Lastly, how do you know that the extra 30mm was the culprit.

I'm not saying I don't believe that a longer travel fork will snap the frame, just curious...

scrublover

Likely closer to the headtube; that frame had a very small gusset on the underside of the frame, but not enough... Broke just past the reinforcement. I don't know, but it was a factor. Taller fork + riding uglier terrain + riding harder/bigger than the bike was intended for... Doesn't take a rocket surgeon to figure out what's a possibility.

Second run of the day at Keystone three years back. Something felt off the last half of the run, like something loos, or a rear flat. Stopped several times to try and figure it out, never found anything. I think the frame had started to crack on the underside of the downtube first, and I just couldn't see it. Wasn't making any noise. Very bottom of the mountain, heading back to the lifts, lofted the front wheel up to clear over a drainage ditch. The front end parted ways from the back mid-air. Full face helmet and full pads on , and I still have some small scars on my chest where one of the tube ends managed to nail me... Obviously, I'm not a rocket surgeon.

It may not. Some folks aren't riding hard enough that they'll stress things enough, and if that is the case, then they are probably on too much bike anyhow. Some bikes are likely tough enough, some aren't. I'm sure the terrain and type of riding plays a big factor. Had I only been riding on smooth, buff singletrack rather than small drops and rock gardens maybe my Curtlo frame would still be around.

All that said, I found true love with my much beefier Peyto after that experience. A bike intended for the fork travel and riding I wanted, and it's working much better. Here, with my old Z-150 on the front, at Keystone.

The builder cleared this frame for up to 7" up front. With a Pike up front, it's tits!

FreeRidin'

Here's my old hardrock with 150mm up front.

The lower right chainstay snapped by the BB after many years of abuse. The headtube was also slightly ovalized.

Teboner92

thats what i've always invisioned. Did you build it yourself and how long did it last