# What rigid fork to replace 100mm suspension fork?



## empre (Aug 28, 2012)

Bike will be this: RADON BikesZR Race 8.0

Fork is this: SID RL | SRAM

Axle to crown length of that fork is 473mm and spring travel is 100mm. I've been told rigid fork's a-c should be 445mm, is that correct?

It seems that the brakes are PS mounted so I need a fork with PS mount or can I use IS mount fork if I'll use an PS -> IS adapter?

445mm PS mount Carbon fork option examples:

DT Swiss - XRR 445 - 240€ / 585g
eXotic Carbon - 130€ / 780g
eXotic Carbon Tapered  - 170€ / 860g

445mm IS mount Carbon fork option examples:

eXotic Carbo - 130€ / 760g
eXotic Carbon - 190€ / 740g

445mm IS mount Alu fork option example:

eXotic Alu - 100€ / 900g

It seems that all Carbon forks have around 95kg limit for rider weight and Alu forks have no limits. For some reason Alu forks feel stronger and safer. The eXotic Alu fork also looks better than the Carbon forks since Alu version is matte black. Not big difference in weights expect the DT Swiss which is almost half the weight of the eXotic Alu, but then again it's also over twice the price and has that 95kg rider limit.

So as for now I would prefer Alu forks. The eXotic Alu would need a IS to PS adapter though. Don't know if that setup would give any problems.

What would be the way to go?


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## empre (Aug 28, 2012)

Any suggestions?


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## Glide the Clyde (Nov 12, 2009)

If you're concerned about the rider weight limit with carbon, then it seems your choices are alloy or steel.


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## perttime (Aug 26, 2005)

440 to 450 mm should be about right.
Most frames and forks used to come with IS brake mounts. My bikes have that and there's been no problems with the adapters.

I'd take a steel fork over an aluminum one.Aluminum does not like flexing, so structures made out of it are designed to be very rigid. Sometimes uncomfortably so.


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## JonathanGennick (Sep 15, 2006)

For 9mm dropouts, I like Surly's Instigator fork. I also run an Identi Rebate 20mm thru-axle rigid fork on one of my bikes, that I'm pretty happy with too. The Instigator's on the bike I've been riding most this season.


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## empre (Aug 28, 2012)

Malibu412 said:


> If you're concerned about the rider weight limit with carbon, then it seems your choices are alloy or steel.


I'm not concerned about the weight since I'm only 75kg, but the weight limit is one reason aluminium fork feels stronger and safer.


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## NYrr496 (Sep 10, 2008)

Maybe a little longer than you want...

Rigid Fork 470mm - Licorice


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## perttime (Aug 26, 2005)

NYrr496 said:


> Maybe a little longer than you want...
> 
> Rigid Fork 470mm - Licorice


Too tall for a 26er XC bike.


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## NYrr496 (Sep 10, 2008)

perttime said:


> Too tall for a 26er XC bike.


Oops.


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## NicoleB (Jul 21, 2011)

i second whoever said steel. it feels better. i've never had a steel fork, but i've had a steel rigid bike vs aluminum rigid, and at least steel has some spring to it. Alum feels harsh


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## JonathanGennick (Sep 15, 2006)

I like steel forks because they are bomb proof, but there is no spring of any sort to them.


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## empre (Aug 28, 2012)

I can consider steel fork too if I can find one that weights around 1kg.

I've used rigid aluminium fork so far and I have no bad things to say about it. My riding is usually on urban areas and easy trails so I guess it's different in the harder trails where suspension fork would be optimal.


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## empre (Aug 28, 2012)

Found this "cromoly" (some kind of steel I guess) fork:

Madison.co.uk : Rigid MTB Fork 115€ / 800g


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## JonathanGennick (Sep 15, 2006)

empre said:


> Found this "cromoly" (some kind of steel I guess) fork:
> 
> Madison.co.uk : Rigid MTB Fork 115€ / 800g


I don't know anything about that brand and model fork, but chromoly steel is the good stuff.

Linky: 41xx steel - Wikipedia, the free encyclopedia

If it is steel and it doesnt say chromoly, then stay away.

If you see the words "hi-ten" or "hi-tensile", then run away screaming.


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## Glide the Clyde (Nov 12, 2009)

empre said:


> I'm not concerned about the weight since I'm only 75kg, but the weight limit is one reason aluminium fork feels stronger and safer.


At your weight, I'd go with the carbon fiber fork. Lighter, less harsh than steel or alum, plenty strong for your weight and riding style.


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