[Defenestrated]

Hey I just got my new Large VP Free built up from parts off my old Bullit, I put a new chain on it for good measure and I've noticed right off the bat that it doesn't seem to pedal any better than my single pivot Bullit, now I am aware the VPP linkage's secret has somthing to do with chain tension and I haven't taken any links out of the new chain, is this my problem?

If so how would you guys recommend determining how many links to take out?

Thanks,
D

 

[_*sTiTcHeS*_]

the tension is caused by you as the pedaller.

 

[Defenestrated]

So chain length is no issue with the vpps?

 

[joelsman]

what size chainring are you using, the bullit(single pivots in general) pedal pretty good when the top of a chain ring is about the same height above the BB or a little bit below.
the vpp is supposed to be better over the bumps while pedaling and be active under braking.

 

[Defenestrated]

38 tooth single sprocket up front on both bikes

 

[Fly]

We need to know

Your weight
Shock you're using
Air pressure in the reservoir of that shock
Amount of low speed compression you're running
Spring rate

Mine pedals really well. No bike will completely eliminate pedal bob, its also up to the rider to learn to pedal in a more circular, less up and down fashion (not meaning to imply that you don't already have a good pedal stroke.)

 

[Defenestrated]

Fox DHX 5.0
185 lbs (rider weight)
Pro Pedal is 5 clicks from all the way firm (15 total clicks)
spring rate is 500
150 psi in reservoir I believe

I know you cant eliminate all bob, however it dosent pedal any better than my olf bullit (5th element), it may be even worse. I have never owned a DHX before so it could just be they are less of a platform, however I'm liking the plush feel they have a lot.

 

[ChrisKring]

My VP Free suspension doesn't move when sprinting in a parking lot with the Fifth on it. Sounds like shock set up needs adjusting if you want zero movement. If your just riding DH with it, I would suggest allowing the suspension to move a little under pedaling. Otherwise, the small bump compliance will suffer.

 

[Defenestrated]

I have no problems with a little movement, but it bobs a lot, and you notice it when you need to pick up some speed.

 

[AirAddict]

You could not be running enough spring preload. If you set up too much sag on those bikes then they're past the platform that the linkage can provide. With the proper amount of sag, it should pedal better than your bullit. I had a bullit before my vp-free too.

I've played with this by running more sag than usual to try to make it sit lower/corner better on the downhill runs.... and it does do that, but it makes the bike pedal pretty bad.

hope this helps.

 

[Defenestrated]

Ahh okay that makes sense, now to reduce sag should I turn the spring retention nut counter clockwise a turn or two? (compressing the spring further)

 

[ChrisKring]

Yes, turn the preload up. No more that 8-10mm of total preload. Anymore and the spring might bind. Try 2" of sag. Measure from the seat to the rear axle.

 

[davep]

You have two things going on.

1 You went from a shock with a LOT of platform in the fifth to a shock with much less platform in the fox. Even with the propedal, the fox is much more active. Any input from you will be more noticable with the fox shock.

2 the VPP bikes are, as mentioned above, sensitive to sag. If you have too much sag, the chain tension will tend to extend the suspension, and with too little sag, chain tension will compress the suspension. If you dont get this correct, any pedal stroke, and thus chain tension will cause suspension movement.

dial in the recomended sag as per Santa Cruz's recomendations and crank the pro pedal if you are pedaling a lot.

 

[Defenestrated]

Thanks

 

[Killerbarbies]

to quote the VP Free FAQ:
How long should my chain be?
This will depend on the size gearing you are using.
To check correct chain length, take the spring out of the shock and compress the suspension all the way. Then install the chain as you normally would.
The VP-Free’s VPP system uses chain growth to pedal efficiently, so it is important to take this extra step. While you have the spring out, check to make sure the tire won’t hit the saddle under bottom out.

 

[OGRipper]

It's definitely true that a DHX feels more active than a 5th, so part of it may just be getting used to it. Also, you might be running too much spring and too much pressure in your boost valve. I'm 200 or so and run a 450 on my free, with around 80-90 psi. You should also confirm that you have a DHX from Santa Cruz and that the air chamber volume is correct. (SCB has a set-up guide on their site, check it out.)

Correct sag is really important on a vpp bike. The axle moves in a slight "s" curve and you get the most pedaling efficiency at the proper sag point, which is about a third into the travel. The first third will be a little less efficient for pedaling, and with a 500 lb spring and too much psi, you may be riding high in that first third. Also, the heavier spring will also give you stronger rebounding action, so unless you're taming it with lots of rebound damping it will seem like lots of "pogo."

It may seem counter-intuitive to say you should soften the suspension a bit to assist pedaling performance, but you might be surprised. With the right spring and shock setttings your free should be more plush AND a better pedaler than your bullit.

That said, both bikes rely on chain tension to limit "bob" and with a 38t the bullit isn't such a slouch. The vpp efficiency would probably be more noticeable to you if you used smaller gears.

 

[frorider]

fwiw, my uzzi vpx is currently set up with 35% sag (DHX 5 shock), and i pretty much leave the propedal off for most riding. pedals efficiently. for long uphills i go about 5 clicks in on the PP.

 

[Defenestrated]

Ok OG I dropped the psi in to about 105-100 and added some preload as well. I will try it out as soon as I can get a new rear hub sorted