Mountain Bike Reviews Forum banner

Pedal bob when standing? Set up issue?

4K views 11 replies 11 participants last post by  JACKL 
#1 · (Edited)
I'm three rides into the full suspension AND 29er world. I bought a Scalpel Carbon 1 last week and love it! Rode it once, then raced it and it already feels completely comfortable. But... today, on a moderate climb, I stood and hammered. I felt like I was on one of those old kid's toys - the horse suspended by 4 springs. It felt like 25% of my power was being lost in the bounce. Is this a setup issue?

I weigh 185 lbs. The rear is set at 190 lbs. The Lefty is at 140lbs. I've been monitoring the ring on the rear - it goes down all but about 1/2"

I'm riding with ProPedal "Open". Is that my "mistake"? I guess next time out, I'll play with that. But, am I missing anything here?

Thanks.
 
#2 ·
some of the rear suspension designs want you to sit and spin rather than hammer. There are also design tradeoffs for example the tallboy ltc is designed to minimize pedal bob on the middle ring, but in the small ring there is a lot. If you are going to stand up and hammer, you should do it in the middle ring.

Closing propedal will definitely help.
 
#3 ·
I don't think you're missing anything, OldZaskar. I would keep the rear completely locked out on climbs. You can certainly experiment with the suspension settings over the next few rides to see what works best for you to reduce some of the bob. However, since you've been riding ht's for 20 years and now have gone to a fs- a certain amount of that movement comes with the territory. This is especially true if you're standing up and hammering.

Once you get the suspension dialed in, then as goodmojo mentioned, it may be a matter of getting used to a different riding style as well. Try staying seated, leaning your upper body forward with your chest down towards the bars and utilizing power from different muscle groups.
 
#5 ·
You aren't going to drop 185 pounds on the pedals of a bike and not get suspension bob if it's a FS bike. You can change your technique when standing and hammering and get less bob, but if you stand and pedal, don't expect any FS bike to act like a hard tail. It's ok to stand, I do it on my FS bike in short intense bursts of pedaling (very hard to clear sections of trail for instance) but nothing that resembles sustained where effort being wasted is going to hurt. Mostly I sit and spin though.
 
#6 ·
Okay. All makes sense. The middle ring thing made me laugh though... I should've mentioned it's a 2x10. I'm still getting used to that. With the triple, I spend 90% of the time in the middle ring. With the 2x10, it's about 30/70 small/big. And that may change as I get used to the setup - I've noticed that I'm often in the smallest 2 cogs and small ring.

I'll try standing in the big ring and see if that feels any different. And, I'm going to have to get familiar with those 36 settings (Closed, 3 Open, 12 rebound) with that rear shock.
 
#7 ·
Okay. All makes sense. The middle ring thing made me laugh though... I should've mentioned it's a 2x10. I'm still getting used to that. With the triple, I spend 90% of the time in the middle ring. With the 2x10, it's about 30/70 small/big. And that may change as I get used to the setup - I've noticed that I'm often in the smallest 2 cogs and small ring.

I'll try standing in the big ring and see if that feels any different. And, I'm going to have to get familiar with those 36 settings (Closed, 3 Open, 12 rebound) with that rear shock.
The other thing to try is to increase the damping in the shock, in general, with the rebound. I believe that also indirectly affects compression but could very well be wrong. One of the trade-offs I am accustomed to for simpler suspensions designs such as your Scalpel is that at the cost of small bump compliance you can get a better overall ride with a stiffer damped suspension. This would decrease pedal-induced activity, particularly with the extra platform-damping engaged. I'd think that the D mode on the CTD shock on a Scalpel would only be useful on long downhills (where the time to switch the shock in and out of mode was worth while).

Since it's a race targeted bike I'd speculate it's more honestly tuned for a stiff and less forgiving suspension setup.
 
#8 ·
I'm three rides into the full suspension AND 29er world. I bought a Scalpel Carbon 1 last week and love it! Rode it once, then raced it and it already feels completely comfortable. But... today, on a moderate climb, I stood and hammered. I felt like I was on one of those old kid's toys - the horse suspended by 4 springs. It felt like 25% of my power was being lost in the bounce. Is this a setup issue?

I weigh 185 lbs. The rear is set at 190 lbs. The Lefty is at 140lbs. I've been monitoring the ring on the rear - it goes down all but about 1/2"

I'm riding with ProPedal "Open". Is that my "mistake"? I guess next time out, I'll play with that. But, am I missing anything here?

Thanks.
Lots of threads on FS and "bob". Here's one...

http://forums.mtbr.com/29er-bikes/how-much-pedal-bob-you-get-when-seated-your-fs-bike-773277.html

Spend some time reading about and getting used to your rear shock and fork to find the settings that get the most out of the bike and your riding style.

Here's another read...

http://forums.mtbr.com/shocks-suspension/rear-shocks-pedal-bob-individual-manufacturers-606862.html
 
#9 ·
The Scalpel should be a decent out-of-the-seat-hammer fs if the rear is set up correctly with your weight and ride style. It is, after all, an XC race design. Even with platform, though, you'll get some bob. Part of the game.

Try bumping the pressure up in the suspension and ride in the pro-pedal setting and see how it feels. Also, a more calm mashing technique can help -- think more circular in your pedaling rather than up and down.

You mention the o-ring covers all but about 1/2" of the travel and I'm assuming that's after a complete ride, not just a climb? Too much travel if just a climb, about normal for a complete ride.
 
#12 ·
I've got a GT Sensor 9r with I-drive, and minimal pedal bob was one of the main things that sold me on the bike. After running a few different Fox shocks, I'm currently running an X-fusion 02 shock which seems to have very little compression damping. As long as I lock out the fork, I can stand and hammer it and it just shoots forward. It feels like there is no bob, but if I watch the shock I can see it moving a bit. I don't even bother locking out the shock on the street.

A friend of mine had a Motobecane 120 travel bike with a cheap coil shock. It bobbed pretty bad even when seated. There is no way I could tolerate that - I'd just get a hardtail.
 
You have insufficient privileges to reply here.
Top