Chinertown
Chinese Carbon MTB => 29er => Topic started by: adbl on October 18, 2016, 09:44:56 AM
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Hey,
Does anyone know anything about this new frame on Dengfu's site M06? Looks to be of modern geometry specs and i like the integrated rear triangle. Also, do we have anyone on here that can model the suspension characteristics?
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So, looking at this frame more closely it seems it's based off the new Yeti ASRc. Understanding it is a single pivot design i'm wondering if that's a step backwards as most "modern" designs are of the floating type suspensions. The redesigned Yeti has received good reviews and looking the frame up on Linkage Design, it has good antisquat numbers as well as pedal kickback and braking squat. I wonder how similar this frame would feel ::)
Anyone..........anyone..........hello, Mcfly???
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Intriguing frame. It looks like an improved CS-036. Significantly slacker head angle, shorter stays, less stack, and a one-piece rear triangle that might improve the stay flex in the CS-036. And it's lighter, probably from the absence of a bushing set and thinner shaping on the main tubes.
I'm a little concerned by the seatstay. They flattened it for comfort, but I find that nonsensical in an FS bike. It's not clear what effect that'll have on the shock's performance.
A significant missing piece, relative to current name frames, is Boost spacing. It's clear that's where the industry is going; it's an awkward time to build a nice set of wheels for a frame with the older standard. Still, if I were on the market for a 29" FS Chinese frame, this one would be my first choice.
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Intriguing frame. It looks like an improved CS-036. Significantly slacker head angle, shorter stays, less stack, and a one-piece rear triangle that might improve the stay flex in the CS-036. And it's lighter, probably from the absence of a bushing set and thinner shaping on the main tubes.
I'm a little concerned by the seatstay. They flattened it for comfort, but I find that nonsensical in an FS bike. It's not clear what effect that'll have on the shock's performance.
A significant missing piece, relative to current name frames, is Boost spacing. It's clear that's where the industry is going; it's an awkward time to build a nice set of wheels for a frame with the older standard. Still, if I were on the market for a 29" FS Chinese frame, this one would be my first choice.
I think the flat seat stays are there now because they removed the pivots, allowing the frame to flex vertically but not laterally. I like the slacker HT angle as well. It does appear to be a more updated version of the CS-036, but like you said, Boost spacing and room to comfortably run a 27.5" x 2.8"-3.0" plus tire would be much more appealing.
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A significant missing piece, relative to current name frames, is Boost spacing. It's clear that's where the industry is going; it's an awkward time to build a nice set of wheels for a frame with the older standard
Double that. In the same time I have a 142x12 hardtail frame, so theoretically I'll be able to switch wheelsets between two bikes. This frame looks very interesting, I have a plans for it in 2017 8)
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> Do you know if there are any full-suspension 29er Boost frames in the works?
From Peter at XMCS:
> We are working on it
:D
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Given 68.5° head tube angle, how do you guys think the handling will change compared to 36?
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Given 68.5° head tube angle, how do you guys think the handling will change compared to 36?
Compared to 036 it will be a rocket on descent but slower to turn on flat and a bit more difficult to climb too. That's why you'll probably need to get handlebar low to put weight on front axle or putting a 51mm offset fork but i never tested this option.
On the frame itself i find the main pivot seems low to achieve a good antisquat with big chainrings and i would like to know how will the carbonflex pivot affect the suspension.
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Given 68.5° head tube angle, how do you guys think the handling will change compared to 36?
Compared to 036 it will be a rocket on descent but slower to turn on flat and a bit more difficult to climb too. That's why you'll probably need to get handlebar low to put weight on front axle or putting a 51mm offset fork but i never tested this option.
On the frame itself i find the main pivot seems low to achieve a good antisquat with big chainrings and i would like to know how will the carbonflex pivot affect the suspension.
Given that we know how little testing or engineering goes into Chiner designs (or at least we perceive little testing/engineering) it does concern me as well how the flex will effect the rear suspension. I guess the only way to know is to actually build one and perform our own scrutineering. If it doesn't work as desired one would be out $700 - $800 bucks on the experiment???
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Found another 29er that looks interesting! I was searching on Yishun Bike's site looking for carbon rims and found this: LCFS902. It's similar to the Dengfu M06 but has the pivot point near the rear axle. Might be a little more conventional than having a fixed triangle? Just a thought. Take a look at the specs and comments are requested ;D
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Dengfu just posted a 27+ frame design based on the M06, except with Boost spacing in the rear. The geometry is identical to the current Scott Spark down to the millimeter. (The M06 has an ETT 1.3cm shorter.) Which means, save for Trek's Top Fuel, it's about as aggressive as a modern XC bike can be.
My only concern is that a 51mm BB drop may be a bridge too far with a 27.5+ tire. Typical XC 29ers are around 40mm (the CS-036 is 43mm), with 27+ bikes nearer to 30mm. Makes me wonder about pedal strikes. If you're after Nino's ride, the sensible course would be to buy the 27+ frame and equip 29" wheels.
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Hey Alex, you should post some info in the 29+/27.5+ bike forum. I see DengFu has a 27.5+ boost frame and the 29er M06 Frame on their website. They show 50.5mm BB drop for the M06 29er (which I am wondering if that's correct) but no info on the 27.5+ boost frame that I can see. My Spec SJ CC 6Fattie (27.5+) has a BB drop of 33mm and pedal strikes are a bit of an issue so 50.5mm would be not something I would want.
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I'm also really interested in this frame, but there's not much to read about it, apart from the info at Dengfus site.
Now I have an "IP-106" HT frame (from XMIPlay.com) right now, very pleased with it, but would like to build a FS for XC/trail.
Anyone seen more info or a M06 build somewhere?
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I was planning to order it since Octorber and now finally did it. Expect photos/weight in about month, build list can be found here (https://docs.google.com/spreadsheets/d/1VSs4fpCMdeyprIfcxefqJzcgb2gh3znI4IERou-u_PU/edit?usp=sharing).
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It's a new frame so time will tell how it works! By the way the single pivot is nothing new, C'dale Habit or Scalpel, Yeti as someone said before...I own a Salsa Spearfish with this system and works great; you'll not have the very small bumps sensitivity as a 4 link but will give you a great power transfer when kick on pedals.
This frame have very good geo numbers, slack HA, short chainstay, ST near 74° ...51mm offset fork for sure and 90/100mm stroke.
Can't find any number about rear stroke but I think 80 mmas mine Salsa, so an XC race machine.
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I was planning to order it since Octorber and now finally did it. Expect photos/weight in about month, build list can be found here (https://docs.google.com/spreadsheets/d/1VSs4fpCMdeyprIfcxefqJzcgb2gh3znI4IERou-u_PU/edit?usp=sharing).
Same here. Just ordered! Exciting times ahead... ;)
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More info in the dedicated thread (http://chinertown.com/index.php/topic,1156.0.html). tldr: 2057g with stock shock bolts in size 19.5", about 8cm of rear travel.
(http://i.imgur.com/kl3ZYqc.jpg) (http://i.imgur.com/kl3ZYqc.jpg)(http://i.imgur.com/HOM7Aeh.jpg) (http://i.imgur.com/HOM7Aeh.jpg)(http://i.imgur.com/tb490Av.jpg) (http://i.imgur.com/tb490Av.jpg)(http://i.imgur.com/uJdDQBX.jpg) (http://i.imgur.com/uJdDQBX.jpg)(http://i.imgur.com/2S3p4Fc.jpg) (http://i.imgur.com/2S3p4Fc.jpg)(http://i.imgur.com/dEUlFB9.jpg) (http://i.imgur.com/dEUlFB9.jpg)(http://i.imgur.com/NN2y5KS.jpg) (http://i.imgur.com/NN2y5KS.jpg)(http://i.imgur.com/fcGeoSM.jpg) (http://"http://i.imgur.com/fcGeoSM.jpg")
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So, looking at this frame more closely it seems it's based off the new Yeti ASRc. Understanding it is a single pivot design i'm wondering if that's a step backwards as most "modern" designs are of the floating type suspensions. The redesigned Yeti has received good reviews and looking the frame up on Linkage Design, it has good antisquat numbers as well as pedal kickback and braking squat. I wonder how similar this frame would feel ::)
Anyone..........anyone..........hello, Mcfly???
Did you draw the bike in Linkage ? Wondering about the anti-squat numbers.
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No i did not. I haven't had time yet as this is the busy season for work. I went off geometry specs but i do believe the pivot point compared to the Yeti is a little lower so i'm sure the anti-squat numbers aren't as good.
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No i did not. I haven't had time yet as this is the busy season for work. I went off geometry specs but i do believe the pivot point compared to the Yeti is a little lower so i'm sure the anti-squat numbers aren't as good.
Yep, you're right. Rainy day, so I drew it on Linkage and the anti-squat was not that great, neither the progression. I added it to Linkage library if you're curious to check.
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Awesome, thank you! How did you come up with the pivot point location? Did you estimate it or use a virtual measurement?
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Just used the cad drawings.
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How much torque did you guys use for shock binding posts? My M06 does not have any required values printed anywhere.
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How much torque did you guys use for shock binding posts? My M06 does not have any required values printed anywhere.
Not sure what a shock binding post is, but if it is the rear shock sex bolts, I had to grind them because they were a tad too long. I just tightened them as much as I could without stripping them.
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Not sure what a shock binding post is, but if it is the rear shock sex bolts, I had to grind them because they were a tad too long. I just tightened them as much as I could without stripping them.
Yeah, those. I did the same but want to be extra sure, even if it's only in my head.
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Somebody plans to sell it (https://www.bikerumor.com/2017/09/26/ib17-rotec-returns-revert-5-0-revo-trail-bike-27-529-nine-dh-bike-way) (the 27.5 version) as a "brand" bike.
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Yep, you're right. Rainy day, so I drew it on Linkage and the anti-squat was not that great, neither the progression. I added it to Linkage library if you're curious to check.
I'm a complete novice to Linkage, but took a look your drawing of the M06. It seems you defined it as a 4-bar swingarm, and not a MonoPivot. Is there a reason for that, or does that actually not affect the calculations?
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I believe it does make a difference. When i drew it on my program i used mono pivot and my numbers came up much better than what is in the library. That was a concern as to how low the anti-squat values were but after i drew it a few times just to be sure i was more confident the frame would work well.
My experience riding the bike is that it climbs very well and bob is almost non-existent. I have been very happy with the return of performance based on the energy put in.
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Thanks. I thought it should matter. I'll keep playing with Linkage and try to learn some of that theory. Still, your empirical test and experience counts more, so really reassuring to hear that.
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When i drew it on my program i used mono pivot and my numbers came up much better than what is in the library. That was a concern as to how low the anti-squat values were but after i drew it a few times just to be sure i was more confident the frame would work well.
Would you mind to share some theory behind this, or good web sites where I could educate myself ?
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I use Linkage Design software. It's a program you can draw bike frames and then analyze the geometry. You can trace a frame, put in specs from a known frame or design one of your own. The link to the site is here: http://linkagedesign.blogspot.com/
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Thanks a lot! Very interesting.
What a chance, I understand Spanish :)
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Google Translator works well for me ;)
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Some of the theory behind is explained on youtube in videos such as this, which I have found quite useful:
https://www.youtube.com/watch?v=D0bAVTiFyy4
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Thank you for these links full of material !
There is much more on bike theory than I thought.
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Hello
I read that in case of tailgating of the damper, the rear axle can come to touch the frame.
What do you think ?
Is there something to modify ?
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(https://images.empreintesduweb.com/1487878999.jpg.html)
https://images.empreintesduweb.com/1487878999.jpg.html
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I have read about that as well. I don't know if DengFu made a change but with my bike when the shock is completely bottomed out there is plenty of clearance for just about any size tire. I don't know why that owner had that issue.
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Will try to resurrect this old thread, just in case anyone cares to continue the discussion on the linkage and suspension of the frame.
I just decided to measure the leverage ratio on my M06 - which is the awesomest bike I have owned btw - because I still have some trimming of the rear shock to do.
When I drew it in Linkage the leverage ratio is very progressive, but that has not really been my feeling riding it. The measurements tell me that it is a completely constant leverage ratio of about 2.75. I trust the measurements (23 measurements of shock compression and wheel travel, regression line completely linear, with an R2=0.999, line through the origin), but not my linkage drawing. In Linkage I was not able to draw the little swing arm between the seat stay /rear triangle and shock, and I guess that swing arm actually bends the seat stay during compression. And that might linearize the shock - wheel travel relation.
Any thoughts on this?
What shocks are you using? I am using a Manitou McLeod, which is probably a great shock, but I have a hard time finding a single rebound setting that makes me happy on every trail. I will probably change the shim stack eventually, but decided to measure the leverage ratio to help me think about if I would be helped by a larger can on it.
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Will try to resurrect this old thread, just in case anyone cares to continue the discussion on the linkage and suspension of the frame.
I just decided to measure the leverage ratio on my M06 - which is the awesomest bike I have owned btw - because I still have some trimming of the rear shock to do.
When I drew it in Linkage the leverage ratio is very progressive, but that has not really been my feeling riding it. The measurements tell me that it is a completely constant leverage ratio of about 2.75. I trust the measurements (23 measurements of shock compression and wheel travel, regression line completely linear, with an R2=0.999, line through the origin), but not my linkage drawing. In Linkage I was not able to draw the little swing arm between the seat stay /rear triangle and shock, and I guess that swing arm actually bends the seat stay during compression. And that might linearize the shock - wheel travel relation.
Any thoughts on this?
What shocks are you using? I am using a Manitou McLeod, which is probably a great shock, but I have a hard time finding a single rebound setting that makes me happy on every trail. I will probably change the shim stack eventually, but decided to measure the leverage ratio to help me think about if I would be helped by a larger can on it.
I also tried to draw it in Linkage but could not finish it to spec because of the seatstay flexing instead of pivot. I'm thinking about pointing a gopro to the suspension and see how it behaves.
I also have a sussmybike that I'm waiting for years from kickstarter, that should help suspension setup.
So far on the same page, love the bike, but when I look at the bobbing while pedaling it does not seem optimal.
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A couple of things about my bike. I have been riding it for about a year now. Best mtb bike i have ever owned! I am using an X-Fusion O2 RLR shock and in the beginning i wasn't sure the tune was correct for the bike. I sent the shock out to MAD Racing in Reno NV. They have been great to deal with, can't say enough good things about them!!! Gave Mike all my information, sent him drawings of the bike and i have to say, other than pressure, i haven't touched anything on the shock since. Feels great and i am using the whole amount of travel without ever bottoming out. I will say on the bigger drops and hits i can feel the seatstays flex. They're supposed to do that, it's part of the suspension package. I'm sure you are feeling it too. Might be why you feel the ratio is more linear than the drawings suggests.
I must have drawn the frame at least 10 times before i felt i had it right. Now, i'm using an oval chainring so it always feels like the suspension is bobbing but when i set the oring position at where i'm pedaling (on a flat road) the oring doesn't move at all. Maybe using a GoPro will help to visualize what's going on back there. I think a lot is made of suspension bobbing and how detrimental it is to performance and efficiency. I used to be a big believer of that but now i concentrate more on how it puts the power to the rear wheel. On a mtb you are constantly flexing, moving, changing your seat position front and aft and i don't feel any of these conditions are effected by bobb. If you ride out west where you have long flat climbs straight pedaling might be effected but on single track where the riding surface is constantly changing i don't feel bobb comes into play at all. My M06 accelerates really well, puts the power to the rear tire extremely well and climbs technical climbs like a goat. Yes, other frames might show better specs but to me it's more about how the bike feels underneath you that counts :)
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I have sort of given up Linkage, since the numbers there do not necessarily reflect the true numbers on the bike. The problem, I suppose, is that Linkage does not have this kind of design as an option. Or i have not realized how to do it. At any rate, the numbers are less important the the bike's actual behavior anyway. But of course, the numbers and measurements can still guide you in the right direction when you want to adjust stuff. From measuring the leverage ratio (or leverage curve) I feel quite confident that I should not need a larger air can.
I tend to use most of the travel, without bottoming out hard. However, the rear is a little harsh on small bumps while still nearly too soft on larger bumps, and there I sometimes get a somewhat too strong rebound. Still need to play with pressure and rebound, and if that is not enough I will adjust the shim stack.
Regarding bob, I do not experience much of that. However, I do use a remote with three steps, and in the most locked position the shock and fork are very firm, even if not completely locked. That's what I use on the flat for going fast or up on smooth hills. In the open position there would be a little bob if I push hard in a high gear on the flat, but on the typical trail you do not notice any of that. Rather it tracks the trail nicely. On technical climbs I typically use the middle position and sometimes also on smooth trail.
And, yeah, I agree, this bike accelerates nicely and feels really fast. I have not yet contested it against my old hard tail on my favorite gravel roads, but on some of the more technical trails it is certainly faster than both the hard tail and my previous full suspension.
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I use Linkage Design software. It's a program you can draw bike frames and then analyze the geometry. You can trace a frame, put in specs from a known frame or design one of your own. The link to the site is here: http://linkagedesign.blogspot.com/
adbl, may I use some of your pictures on the frame wiki ?
http://www.bikebuilderinfo.com/bin/view/FrameList/
I'm trying to put together structured info from forums so it's easier for new builders to find.
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Sure, you can use whatever you need.