What length rigid fork for Kona?

[jupiter]

After snapping my Marzocchi's in half I'm thinking of going rigid. Now, I probably should go for Kona Project 2's, but I'm thinking either Salsa Cro-moto's, On-One carbon or Element/Nukeproof/Whitebros/Superstar/Axima carbon. They must have v-brake mounts, but what length? The frame is a 2001 Kona Pahoehoe which had 80mm Marzocchi z3's on it giving a head angle of 71 and a seat angle of 74. So, Salsa's are 425mm, On-Ones are 440mm and the rest are 445mm except the WhiteBros which also come in 425mm. Any help or experience most appreciated.

 

[hamster]

I run a 2000 Cindercone. I bought a set of P2s (new) which I assumed were the right length. To cut a long story, they are shorter versions, looking as though they are for older bikes and don't have the jacked-up front you would expect.

I run it as a singlespeed on bash roads (pretty much all there is round here).

The bike handles fine, even at low speeds. I only discovered all this after putting it next to the wife's older Fire Mountain and seeing how the tubes all seemed steep.

 

[tintin40]

vintage rigid forks are 390 long - Ritchey logic.

But more mobern forks like Pace carbons seem to be 420 and 440 long.

I fitted Pace and the length through the front end out to much. so I always look for vintage forks.

 

[hamster]

I suspect that going slacker in angle is worse than going steeper. So fitting shorter forks onto a newer bike is less drastic than fitting longer ones onto an old one.

 

[MikeD]

420mm is the traditional "80mm suspension equivalent" length. Most current carbon jobs are around 440 (to replace 100mm sus forks). P2s have come in all sorts of lengths over the years.

 

[Kona Paul]

Agreed. 420mm would be the rough equivalent. However, the Pahoehoe is an alu ("freeride") hardtail, so the ride might be a bit harsh with rigids...even steel ones. Not saying it can't be done, just something to keep in mind.

 

[MikeD]

Since when does alu=freeride?

 

[Anthony]

After snapping my Marzocchi's in half I'm thinking of going rigid. Now, I probably should go for Kona Project 2's, but I'm thinking either Salsa Cro-moto's, On-One carbon or Element/Nukeproof/Whitebros/Superstar/Axima carbon. They must have v-brake mounts, but what length? The frame is a 2001 Kona Pahoehoe which had 80mm Marzocchi z3's on it giving a head angle of 71 and a seat angle of 74. So, Salsa's are 425mm, On-Ones are 440mm and the rest are 445mm except the WhiteBros which also come in 425mm. Any help or experience most appreciated.

A 2001 Pahoehoe has the same geometry as Konas have had since 1994, so the quoted head angle of 71 deg is taken with a P2 fork of 41cm a-c.

If you think that sounds as though it can't be right considering the length of the Z3s, I agree with you, but the source is tech@konaworld.com so I think it must be right. When challenged as to why Kona used a head angle that was in effect so slack with the suspension forks they actually fitted, Tech said 'it works'. When challenged further, he said something along the lines of 'look, the race team use it, the test team like it, thousands of customers like it, that's good enough for us. If you don't like it, there are plenty of other brands.' So I think we can take it he was being quite serious.

So of the forks you quote, the Salsa is 1.5cm too long and will give a head angle of 70, the On-One is 3cm too long and will give a head angle of 69. I think what tech was saying was that a slack head angle is fine with a suspension fork, as the angle will get quite steep when the fork compresses, as it will when ridden properly. However this obviously doesn't apply to rigid forks. Personally I would advise you to use a P2 and stick to 71 deg, but of those you quote only the Salsa is worth considering IMPO.

 

[MikeD]

I ran 80mm Z2s on my 1995 Kilauea for years, it was great. It's also great with 420mm RC31s. I've got some 410mm P2s for it as well, but I'm not sure my reactions are up to it these days ;-)

 

[Kona Paul]

Since when does alu=freeride?

Who said alu=freeride?