Chinese Carbon MTB > 29er
Pro-Mance M9007 FS 29er 21lb build
Jerry:
--- Quote from: sclyde2 on August 24, 2018, 11:30:23 PM ---
--- Quote from: Jerry on August 24, 2018, 04:29:44 AM ---
Thank for the extra (technical) feedback.
My shock is a 168x38 RS Monarch RL. I can not specifically set the compression damping as far as I know. I can only choose between two fixed compression damping settings: 'open' and 'full lock'. Plus tune the rebound via a red rotary knob. That's it.
What shock do you recommend if I want to upgrade?
--- End quote ---
Don't worry about upgrading the shock. Just get a bigger chainring. Your "reverse" Bob (extreme anti squat) will be reduced if you get a bigger chainring.
I assume you mean 165x38.
I am running a cheapie manitou mcleod and I'm very happy with it. But my 32t setup is more neutral than yours (though maybe slightly high on anti squat still).
--- End quote ---
Sorry for the late response.
There is a 32t chainring on the way to me. Am very curious if this solves the extreme anti squat or at least reduce it in full lock mode.
Still, I still find this problem a bit strange. It can almost not believe that Pro-Mance designed the M7007 frame specially for a chainring bigger than 32t. But maybe it did.
About the Manitou McLeod. That was also my number one choice, but I bumped to the 165x38 Monarch RL for a very attractive price ::). And it just works fine in open fashion.
gohloum:
OK, maybe I missed something, but did you post pics of the bike built? I didn't see any in the thread, but would really like to.
Also, regarding carbon components on AliExpress:
Your handlebar - looks good by the seller's pic. Can you tell me how thick the walls are?
Seatpost - This reminds me of he ASIACOM stuff. NEVER BUY ASIACOM BRANDED COMPONENTS! That stuff is junk and very dangerous! I broke a seat post by them in 1 day. So, I got wise and when I check the handlebar, I found stress cracks.
What I have found that worked for me is Tideace brand bars and seat post which have held up for the past year. I've had a few nasty crashes, and thinking I may replace the bar, so that's why I am curious about yours. Rather replace and have piece of mind.
My Seat post: https://www.aliexpress.com/item/Tideace-carbon-bicycle-seatpost-MTB-road-mountain-bike-seat-post-seat-tube-glossy-matte-carbon-bicycle/32800640505.html?spm=a2g0s.9042311.0.0.27424c4dik4raZ
Saddle - Let me know how this turns out. I have bought a few from AliExpress. Anything I've bought with carbon rails seems to fail fairly quickly. I have usually been able to find the Selle SMP style saddle with titanium rails for a few dollars more. I just broke on of those (the rail) this week, but it's been on my bike for 5100 miles and I ride a hard tail where I should be on a long travel FS. So sometimes I've hit the saddle pretty hard.
Good thing, I had a spare saddle. But when I looked on Aliexpress, I couldn't find the SMP style anymore. Maybe there was a trademark crack down. I ordered something similar, but doesn't have the bent down nose... Kinda worried I might get a beak up the but if I'm not careful. This is the one I ordered. I've found that cradle shaped work good for me and I don't need any padding on the seat itself.
https://www.aliexpress.com/item/New-Arrival-No-Logo-3K-Gloss-Full-Carbon-Fiber-Bike-Riser-Saddle-Titanium-Alloy-Rail-Carbon/32858297872.html?spm=a2g0s.9042311.0.0.6e704c4dOqPKjz
sclyde2:
--- Quote from: Jerry on August 30, 2018, 07:17:39 AM ---
Sorry for the late response.
There is a 32t chainring on the way to me. Am very curious if this solves the extreme anti squat or at least reduce it in full lock mode.
Still, I still find this problem a bit strange. It can almost not believe that Pro-Mance designed the M7007 frame specially for a chainring bigger than 32t. But maybe it did.
About the Manitou McLeod. That was also my number one choice, but I bumped to the 165x38 Monarch RL for a very attractive price ::). And it just works fine in open fashion.
--- End quote ---
I am no expert on kinematics, but I have picked up that gear choice will have an impact on anti squat on any suspension system, some systems more than others. There will always be compromises, some gear combos that are more optimal for a given pivot placement. This frame is modelled off a Scott spark RC, a bike made for XC racing. It came out around the same time as SRAM eagle did, with the 50t cog. A 34t chainring with a 50t cog is a very low gear, probably lower than what a competitive racer would use in a typical xc event. It does not surprise me that they've put such a high main pivot on that bike, to suit a bigger chainring.
It doesn't mean that the bike won't work with a smaller chainring, it just won't be optimal. I use a 32t myself, and i notice no Bob (either pedal induced reverse bob, or stomp induced bob). And I run my rear shock with the compression full open.
The setup you have is no big deal, the sensation you are getting when you lockout the suspension should not bother you much. If it does bother you, you have a choice: either stop locking out the rear shock, or get a bigger chainring. It sounds like you are going the latter route. Let us know how it goes - it might still have it when locked out, but I reckon it'll be reduced.
Jerry:
--- Quote from: sclyde2 on August 31, 2018, 02:24:25 AM ---
--- Quote from: Jerry on August 30, 2018, 07:17:39 AM ---
Sorry for the late response.
There is a 32t chainring on the way to me. Am very curious if this solves the extreme anti squat or at least reduce it in full lock mode.
Still, I still find this problem a bit strange. It can almost not believe that Pro-Mance designed the M7007 frame specially for a chainring bigger than 32t. But maybe it did.
About the Manitou McLeod. That was also my number one choice, but I bumped to the 165x38 Monarch RL for a very attractive price ::). And it just works fine in open fashion.
--- End quote ---
I am no expert on kinematics, but I have picked up that gear choice will have an impact on anti squat on any suspension system, some systems more than others. There will always be compromises, some gear combos that are more optimal for a given pivot placement. This frame is modelled off a Scott spark RC, a bike made for XC racing. It came out around the same time as SRAM eagle did, with the 50t cog. A 34t chainring with a 50t cog is a very low gear, probably lower than what a competitive racer would use in a typical xc event. It does not surprise me that they've put such a high main pivot on that bike, to suit a bigger chainring.
It doesn't mean that the bike won't work with a smaller chainring, it just won't be optimal. I use a 32t myself, and i notice no Bob (either pedal induced reverse bob, or stomp induced bob). And I run my rear shock with the compression full open.
The setup you have is no big deal, the sensation you are getting when you lockout the suspension should not bother you much. If it does bother you, you have a choice: either stop locking out the rear shock, or get a bigger chainring. It sounds like you are going the latter route. Let us know how it goes - it might still have it when locked out, but I reckon it'll be reduced.
--- End quote ---
Thanks for the extra clarification. It helps me to gain more insight into the possible cause of the extreme pedal bob in lock mode.
At the same time it is as you said: in itself it is not a big problem. I will use the lock function only sporadically, on the fire roads to and from the tracks. Usually the shock is in the full open setting.
It was just a nice extra that my Pro-Mance M7007 would behave as a hardtail in lock mode (with a 30t chainring).
Anyway, a 32t chainring is underway and as soon as I have the chance to assemble and test it, I'll let you know what effect that has.
Jerry:
***update***
Well, as advised I have mounted a larger chainring (32t) and the extreme pedal bob / aniti-squat is indeed reduced. However, only from the top half of the cassette. On the smallest toothing in the rear, there is still a noticeable amount of anti-squat ::)
Anyway, because 90% of the time I have the rear shock in full open mode, I can live with the current level of anti-squat. Nonetheless, I continue to find it a strange design choice of the Pro-Mance M7007 frame (and thus Scott, because the M7007 is a resemblance to their Spark).
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