[Closed] 140/150mm fork on a bike that came with 100mm.....will it be ok??

For a time, yes.

Go for it. We await stories.

Just fit a 24" front wheel instead of a 26" and it'll be fine! 😉

Seriously though, it may well be strong enough, but it'll handle quite badly I reckon. On some frames you can get away with running 20mm more travel than recommended in my experience, but any more and you're really pushing the boat out... Literally!

the frame is very robust and was well underforked to begin with.

I see several problems with this.

1) knackers up the geometry a bit
2) tears the headtube off necessitating a trip to dentist and reconstructive plastic surgery

on the other hand it might be fine.

What frame?

frame is a kona hoss

You'll ride it for...2 weeks? Go for it.

Everyone says it'll knacker the geometry, nobody bats an eyelid at 456s, or at Souls with 100mm and BFes with 160mm.

The bottom bracket will also get jacked up and it'll be like riding a horse.

A 140/150mm fork is going to run with a good bit of sag anyway. I ran a 80mm designed RockLobster with 125mm Psylo & it was a bit slow/slothfull in the steering dept, but still rideable.

[i]nobody bats an eyelid at 456s, or at Souls with 100mm[/i]

mainly because they were designed to use forks that length I suspect?

Northwind - Member
Everyone says it'll knacker the geometry, nobody bats an eyelid at 456s, or at Souls with 100mm and BFes with 160mm.

Those are pretty lazy designs though. Every bike I have put a longer than advised fork on has royally ****ed up the handling, other than straight line rock garden stuff. That'd be Kona Pahahoe, Planet X Armadillo, Orange Patriot, SC Bullit off the top of my head. I have been vaguely tempted to stick a Lyrik on my PA but I've learned from my mistakes over the years.

head angle is 68.5 degrees......if that helps

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If its not steel I wouldn't risk it, could snap or crack the tube or break while going fast and goodbye 'teesh' and dose.

Don't do it, maybe 120 max.

Besides the handling will be messed up.

i rode it round the carpark at work...it feels like that walleater... 😆

cheers fellas.....ideas for a frame of the robust kind to run 140/180 adjustable forks.

"nobody bats an eyelid at 456s, or at Souls with 100mm

mainly because they were designed to use forks that length I suspect? "

Soul/BFe certainly wasn't, it was a long-travel XC bike that then had a stronger version built which just happens to ride brilliantly with long forks.

Then you have your Inbreds and Scandals, which allegedly were designed for up to 130mm but actually don't ride all that well at all at full length, and your Idrive 5s that ride better with 140mm than the recommended 130mm.

I thought Cy did design the Soul to take 100mm - his ones always have 100mm forks on them from what I've seen?

ideas for a frame of the robust kind to run 140/180 adjustable forks

you know the answer

[b]Cotic BFe.[/b]

nuff said

besides surely 20 stone has a greater effect on the fact that the thing might break rather than the fork length 😆

oh and have you dried off after your 'swim' yesterday? looked hot, the weather, not you BTW

vortex, where did you buy yours from.

BFe, 2nd hand off here.

the Soul was direct form Cy at Cotic

Its my understanding that the 456 is designed to be spot on with 5" but will run ok with 4 or 5. Geometry of the scandal is slightly different and whilst it may be strong enough to take a 5" fork feels better with 4". I thought the BFe was designed to take a longer fork than the Soul. I think the key is that some/most bikes are built to cope with the stresses created by a certain lenght of fork ie 100-150mm but handle best with a specific length ie 120-130mm. Orange certainly used to have a guide to this for their bikes on the website.

I thought the BFe has the same geometry as the Soul but is stronger so can take longer forks.

Orange certainly used to have a guide to this for their bikes on the website.

They still do under the geometry section, gives max, min and optimum travel.

wwaswas, yes it was- what I'm saying here is that the exact same geometry of the Soul is used on the BFe, which is fine for up to 160mm. Now, if someone on here said "What'll happen if I fit a 30mm longer fork to this bike that was designed for a shorter fork" The Internet will say it'll handle badly. But if Cy says "Lets fit a 30mm longer fork to this bike that was designed for a shorter fork", and obviously beefs it up, then that's fine. See what I'm getting at? The Soul/BFe geometry was never designed with 160mm in mind, but it works.

Obviously none of that helps if he rips the headstock off but it doesn't mean it won't handle 😉

Have you people seen how thick the head tube is on a Hoss? If any frame will stand a longer fork that will.
Ton, have a 140mm Fox 32 Van on my Hoss, and I love it, keeping the front down on steep slow climbs is a trick, but it's nailed on the downs.

It might want to fold over turning into corners & the seat angle will also be effected putting more weight over the back & on the seat post & seat tube. But that might be OK if your not so heavy.
I thought the unwritten rule was +20mm over designed travel & no more for most frames.

What make of forks are you planning to run? I had a Hoss for a little while and ran it with 04 Marzocchi Z1 freerides which were 130mm travel, but a pretty tall fork. A set of pikes would have had a lower axle to crown measurement and probably ride ok, but 150mm zocchi's will be awful.

I ran a "classic" Blur (not LT) with RC41F's for ~2 years including trips to wales and the alps (and I'm on the hefty side).

Was great, drifted a bit on the climbs but I'm shit on them anyways and was ace on the level/downwards. Eventually sold the frame on because I was tired of replacing bearings and the miniscule tyre clearence and stuck the fork onto a 456. BB clearence was massive too.

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What about a Duncon Cock? BFe's are awesome, mine at 160mm was ace, ran Wotans, but never felt the need to reduce them to 120mm.

Dialled Alpine?

Then you have your Inbreds and Scandals, which allegedly were designed for up to 130mm but actually don't ride all that well at all at full length

Scandals are a racy frame designed for a racy 100mm-ish fork. Inbreds are more of an all rounder and designed for 100-130mm. I'm now running a 140mm Vanilla on mine having tried a Reba at 115mm and a Recon at 130mm. The Vanilla is only 2-3mm longer than a 130mm Recon and it's fine for me although a tad wandery on steeper climbs.

It's not just head angle and strength that matters when putting a longer fork on, it's the length of fork the frame is designed for. A shorter travel frame will (In general) have a longer head tube, and a too long fork will raise the whole bike, slackening the seat angle and raising the BB. So you end up with sloppy settering, a high centre of gravity, and your weight too far back. I've tried it on and older frame and it makes for one horrible ride: It will feel sloppy and slow, like it's falling over on any corner, it'll understeer and you'd better forget climbing.

Just don't bother. Believe me.

Bike building is all about 'balance' - Match the frame to the fork to the wheels to the brakes to the tyres and it'll be good to ride no matter what it is. Mess with this balance at your peril. 🙂

"Scandals are a racy frame designed for a racy 100mm-ish fork. Inbreds are more of an all rounder and designed for 100-130mm. "

The geometry of the vertical dropout Scandal and Inbred is absolutely identical, according to On One... This is exactly what I'm getting at, you think it's fine for a longer fork on a Bred but not a Scandal, the only actual difference is your perception of the bike not the actual frame.

boght a new frame to take the forks today.......... 😆

Ton, until recently I ran a Kona Kikapu deluxe with Fox Talas 140mm forks (original forks were Marzocchi 105mm & then Reba's) only took it apart as I was having a bike cull.