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Tree Spline Drive Sprocket...

cornfed

cornfed

Monkey
Jul 30, 2007
199
0
Do any of you use it?

I like the idea; I am concerned with durability. I think it addresses a problem inherent to profile cranks, but I do not like the idea that the splines have to withstand driving force. I would like to use the Tree spline sprocket in conjunction with a drive bolt for increased durability. If there is any type of impact to a conventional sprocket, the Profile spindle splines (and all the clones of Profile cranks) press into the bushing or ring and the sprocket hole ovalizes. This causes loose/tight spots in the chain and is the primary source of that dreaded Profile creakiness. I guess I am just wondering how well the spline drive holds up to chainring bashing. The consequences for an ovalized spindle hole when it shares the drive duties could be nasty if the spline drive gives out while I am applying torque to the pedals. O.T.B...no thank you...

If you use it, do you like it?
 
dexter

dexter

Turbo Monkey
Sep 23, 2001
3,053
99
Boise, Idaho
deity has sprockets that have both the splines and the bolt if you want it like that.

anyways i have no idea about tree durability i want one tho
 
Evil4bc

Evil4bc

Turbo Monkey
Jun 17, 2005
1,080
1
Nor-Cal
cornfed said:
Do any of you use it?

I like the idea; I am concerned with durability. I think it addresses a problem inherent to profile cranks, but I do not like the idea that the splines have to withstand driving force. I would like to use the Tree spline sprocket in conjunction with a drive bolt for increased durability. If there is any type of impact to a conventional sprocket, the Profile spindle splines (and all the clones of Profile cranks) press into the bushing or ring and the sprocket hole ovalizes. This causes loose/tight spots in the chain and is the primary source of that dreaded Profile creakiness. I guess I am just wondering how well the spline drive holds up to chainring bashing. The consequences for an ovalized spindle hole when it shares the drive duties could be nasty if the spline drive gives out while I am applying torque to the pedals. O.T.B...no thank you...

If you use it, do you like it?
Click to expand...
The tree light sprockets are either OR , so it's spline drive or crank bolt .

I have both set up here un demo bikes and they hold up very well , I'm almost willing to say the spline drive feels stiffer and smoother !
Sam had them tourque tested at some lab so there proven to hold up.

Dexter the Deity spline drive is NOTHING close to the tree , and I'd be willing to say if you ran one of the Deity spline drive sprockets without the bolt that it woulnt last more than a block or two .
 
don

don

Turbo Monkey
Nov 8, 2001
1,319
0
Rumson, NJ
I would guess the torque on a 175mm crank arm would be a bunch greater than the torque on the chainwheel. If the cranks are tight, the spline chainwheel should be putting all the force in the right spot. Some of the bigger gearheads might know a bunch more, but some car axles the same configuation - splined shafts. Here's a link to a Dana44 setup: http://www.4x4wire.com/jeep/tech/axle/superior02/ I know the axles are a bit bigger 1.3" vs. 0.75" but so if the force of a 35" tire vs. a 33T chainwheel.

Adding to what Brad said, Sam/Tree make some great parts - and they seem to test the hell out of them. I have Props w/ a Tree Roadtrip and those boys ride hard.

I bought a Tree chainwheel before the splined ones came out and have been very happy with it. Not too mention it's really smooth. Over the winter bike rebuild I'll be getting the Tree spline Chainwheel to make it that much smoother but in looks and spinning.
 
F

Fish777

Chimp
Aug 26, 2007
32
0
I've been running a tree splined ring for about 3 weeks and it's been fine. I bashed it pretty hard once and it didn't grenade so all is great so far.
 
chuffer

chuffer

Turbo Monkey
Sep 2, 2004
1,547
888
McMinnville, OR
don said:
I would guess the torque on a 175mm crank arm would be a bunch greater than the torque on the chainwheel. If the cranks are tight, the spline chainwheel should be putting all the force in the right spot. Some of the bigger gearheads might know a bunch more, but some car axles the same configuation - splined shafts. Here's a link to a Dana44 setup: http://www.4x4wire.com/jeep/tech/axle/superior02/ I know the axles are a bit bigger 1.3" vs. 0.75" but so if the force of a 35" tire vs. a 33T chainwheel.

Adding to what Brad said, Sam/Tree make some great parts - and they seem to test the hell out of them. I have Props w/ a Tree Roadtrip and those boys ride hard.

I bought a Tree chainwheel before the splined ones came out and have been very happy with it. Not too mention it's really smooth. Over the winter bike rebuild I'll be getting the Tree spline Chainwheel to make it that much smoother but in looks and spinning.
Click to expand...
actually the torque is very nearly the same on the crank arm and the sprocket. before you argue that the crank arm is longer thus must apply more torque, write down the balance of moments equation for a crank arm spindle. If you dont know how to do that, dont argue.

that said, i have never heard of anyone actually slipping the spines on a properly tightened pair of profiles.
 
BikeSATORI

BikeSATORI

Monkey
Apr 13, 2007
720
0
one world...
chuffer said:
actually the torque is very nearly the same on the crank arm and the sprocket. before you argue that the crank arm is longer thus must apply more torque, write down the balance of moments equation for a crank arm spindle. If you dont know how to do that, dont argue.

that said, i have never heard of anyone actually slipping the spines on a properly tightened pair of profiles.
Click to expand...
chuffer, your math makes me ride better. haha, no seriously though, I had to say it. I want my tree spline drive bad... been waiting for a long time for a custom 9spd one...
 
Stoked

Stoked

Turbo Monkey
Nov 28, 2004
1,809
1
LI, NY
my spline drive has been smooth as fvck since ive been on it. it's really think in the center where the i-beams are. just simple
 
prana.ferox

prana.ferox

Chimp
Aug 24, 2006
31
0
Seattle, WA
chuffer said:
actually the torque is very nearly the same on the crank arm and the sprocket. before you argue that the crank arm is longer thus must apply more torque, write down the balance of moments equation for a crank arm spindle. If you dont know how to do that, dont argue.

that said, i have never heard of anyone actually slipping the spines on a properly tightened pair of profiles.
Click to expand...
Balancing your moments only works in statics problems, which this is definitely not. If you want to be able to accelerate your bike (which I do), you better be able to apply more torque with your crank arm than is applied by the sprocket.

Any way you slice it, I really wouldn't worry about the sprocket interface with the spindle. I think the critical area to look at is where the insert is splined into the rest of the sprocket.
 
chuffer

chuffer

Turbo Monkey
Sep 2, 2004
1,547
888
McMinnville, OR
prana.ferox said:
Balancing your moments only works in statics problems, which this is definitely not. If you want to be able to accelerate your bike (which I do), you better be able to apply more torque with your crank arm than is applied by the sprocket.

Any way you slice it, I really wouldn't worry about the sprocket interface with the spindle. I think the critical area to look at is where the insert is splined into the rest of the sprocket.
Click to expand...
Actually the angular acceleration that comes into play in the dynamics part of this issue is only that of the spindle, crank arms, pedal and maybe your shoes if you really want to stretch things... The acceleration of the bike and the rider is directly related to the torque being transferred (minus frictional losses) to the rear sprocket by the front sprocket. This torque in turn is identical to that of the torque being applied to crank arms minus the mass of the spindle, crank arms and pedals multiplied by their respective angular accelerations. This difference is second order at best in real life. If you don't believe me do the math and see how fast a small difference in torque will make your cranks spin. (Think applying torque to your cranks with no chain on the front sprocket...)

Again, I really wouldn't worry about it....it really is academic.
 
cornfed

cornfed

Monkey
Jul 30, 2007
199
0
Thank you for responding.

*Geek check-in*

I actually had a similar idea to this sprocket; I think the Tree design is much better than my idea. Something else to consider: I bet this ring is designed to be used primarily w/ 20" wheels w/ 2.75:1 (or so) ratio. Bigger wheels, like 26ers, require a reduced ratio. I'm running 2:1. The lower ratio produces higher drivetrain torque...

Mathematically, I think the stresses that are applied to a crankset are much more dynamic. There are torsional stresses to consider outside of just the linear torque. This could possibly play a factor in the fatigue life. For example, I have noticed when pedaling @ the bottom of my pedal stroke, certain instances when I land off a hip, etc, can cause torsional stresses to the drive boss point. I confirmed this when I noticed an indentation in the tree chainring @ the drive boss contact point. My cranks had a slight "creak" to them too. I disassembled everything and reinstalled the chainring on the splines and added the drive bolt. The shoulder contacts one of the aluminum "spokes" of the ring to secure it to the drive arm. No more creak..creak...

I think this ring would work better w/ a locater hole for an optional drive bolt to secure lateral force, or use a drive arm w/ no drive boss so there is no contact @ the drive boss location during crankarm deflection...

So far, I think the spline drive is a better way...

*Geek check-out* :biggrin:
 
BikeSATORI

BikeSATORI

Monkey
Apr 13, 2007
720
0
one world...
Leethal said:
The key is to not lube it, therefore it doesn't get dirty...
Click to expand...
haha, yeah... I've got the same chain as stoked, but mine isn't that bad at all (although I hardly ride dirt with it, 99% street/commuting so far). Lubed it once with some road lube over the summer when I was a road mechanic, but nothing since and it's spotless, even after riding in several rain storms and commuting everyday...
then again, you don't always realize how dirty shift is until you bust out the camera with flash....


btw, never noticed you scored some of those profie ti kit bolts... pretty trick, but a shame to waste the nice hollow chromo ones that come with the Medials... looking to get rid of them? or the ti crank bolt??? may have a use for them with my WTP royals... :lighten:
 
Stoked

Stoked

Turbo Monkey
Nov 28, 2004
1,809
1
LI, NY
BikeSATORI said:
btw, never noticed you scored some of those profie ti kit bolts... pretty trick, but a shame to waste the nice hollow chromo ones that come with the Medials... looking to get rid of them? or the ti crank bolt??? may have a use for them with my WTP royals... :lighten:
Click to expand...
the bolts are knight ti. ive had them for a couple years. the demo bolts are nice, ill prob hang onto them
 
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