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Discussion Starter · #1 ·
I upgraded the 100 mm MX COMP fork on my 05 Kona Deluxe to a 100mm Reba and bought a 110mm deus stem to replace the ultra short 90mm stock stem.
Since the stem was so short i was running it in the negative 5 degree rise above two spacers so the front tire didnt bike lift that much.
Now after several rides with the new fork/stem in the positive degree and without any spacers i feel that the bike drifts A LOT at turns, and the steering feels very slow.
I feel as if the bike`s center of gravity had been raised a lot both front and back.
I ride maily xc trails but race and train against hardtails with very aggressive geometries. And i feel way slower in tight twitchy singletracks but way faster than them in straight lines.
Is this the way the bike was supposed to feel because of the higher bottom bracket and longer wheelbase than the one of a hardtail?
Or is there a way i can give it a more XC feel to the bike running the stem in the negative rise and messing around with both the shock and the fork sag?
I have run out of the road at turns several times in fireroads and singletracks due to this, would the tires have something to do with this? Im running maxxis Larsen`s at 35 psi, i have a pair of tubeless Geax Mezcal but `they have a minimalistic racing thread that i`m afraid they might make the problem worse than it already is.
Thanks for any comments that might help.
 

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Have u measured the axle to crown height on ur old MX fork and compared it to the new REBA's? might have a taller A to C which has raised the bike slightly and also slackened your head angle a bit. Try the stem how u had it b4 and c if that corrects the problem. If the tires r the same as u were using then there should be no effects caused there.
 

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Discussion Starter · #3 ·
The a/c lenght is the same that on my previous fork as is the trvel 100mm.
the only differnce might be in the ride as the fork seems to ride higher than the marzocchi ( less dive and bob) which made me put a slighter higher air preassure on the shock to level the bike... With the shock at 120 psi and the fork with 90 + and 60 - its hard for me to bottom out and i use the same % of front and rear suspension with my 156 pounds.
 

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90 mm is not ultra short, it should not cause the problems you describe unless it has a huge rise to it.
 

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Discussion Starter · #5 ·
eobf said:
90 mm is not ultra short, it should not cause the problems you describe unless it has a huge rise to it.
The stock stem was 90 mm with a 5 degree rise.... i changed it because my front tire always lifted while climbing. i had to turn it around to its negative degree rise and even that way there was a tendency for the tire to wonder... i had to put myself in an uncomfortable position all hunched and i didnt feel streched out enough to breath well.
All of this changed after swaping to a 110mm 6 degree deus stem.
My kikapu has a top tube on the short side 23.1 long besides i`m 5`10" with long arms.
 

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pornstar said:
The a/c lenght is the same that on my previous fork as is the trvel 100mm.
the only differnce might be in the ride as the fork seems to ride higher than the marzocchi ( less dive and bob) which made me put a slighter higher air preassure on the shock to level the bike... With the shock at 120 psi and the fork with 90 + and 60 - its hard for me to bottom out and i use the same % of front and rear suspension with my 156 pounds.
You are messing up the balance of the suspension by increasing the shock pressure.

Did you set the sag of the Reba to be about the same as your old fork?
 

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Discussion Starter · #7 ·
shiggy said:
You are messing up the balance of the suspension by increasing the shock pressure.

Did you set the sag of the Reba to be about the same as your old fork?
Thanks for your help Shiggy.
The reba fork doesnt sag more than 1cm when i sit on my bike.
I dont know if the 68 degree steep head angle has to do with it.
I didnt even get enough sag while sitting on it at 50 psi.
So i ran it as recomended by RS with 100+psi and it was too harsh, then i tried 80 psi and it was too soft and i bottomed out frequently.
That`s why i ended up with 90 psi.
After different sections of different trails i use the same porcentage of the travel on both the fork and the shock and when i bottom out, which is rare, it happens on both ends.

The rear shock gives me 25% sag at 110 psi, and around 15% at 120 psi; eventhough the recomendation of Kona and Fox is 125psi.
Is the way im setting it up ok?
 

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pornstar said:
The a/c lenght is the same that on my previous fork as is the trvel 100mm.
the only differnce might be in the ride as the fork seems to ride higher than the marzocchi ( less dive and bob) which made me put a slighter higher air preassure on the shock to level the bike... With the shock at 120 psi and the fork with 90 + and 60 - its hard for me to bottom out and i use the same % of front and rear suspension with my 156 pounds.
I think u had posted about pressures for the REBA but can't remember. Thos pressures are way high for your body weight on a REBA, I'm 175-180 w/out gear 185-190 w/ gear and I only use around 90-100POS in my REBA SL. Try lowering your pressures.
 
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