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Messages - adbl

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1
29er / Re: Carbonda fm936 Thoughts
« on: July 10, 2020, 09:41:39 PM »

I have a hard time of trusting any of the Chiner geometry drawings. Not because they are trying to deceive or are just getting it wrong. These open mold frames go through so many iterations that the one we see posted might not be the final iteration or at least the drawing is not updated to the most current geo numbers.

Having said that, you need to at least have a starting point to begin with. Without having a frame here in front of me to measure I have no choice but to reference the drawing. If I were to assume the drawing as listed on their site is accurate at 100mm travel, then according to my calculations shock travels would be as follows:

40mm shock = 101mm travel
42.5mm shock = 105mm travel
45mm shock = 112mm travel

My calculations come from a CAD program that has been used in Motorsports for years to model suspension kinematics and is dead nuts on!

Could you model the NS frame dimensions as well?  Curious how it stacks up b/c the rear triangle measurements look the same to me, just visually different.


I've modeled the NS frame. Their rear triangle is different than the 936. You can tell straight away from looking at the interface at the seatstay rocker link. The results are as follows:

37.5mm = 100mm travel
42.5mm = 112mm travel
45mm = 120mm travel

The frame has an average leverage ration of 2.66, a little higher than the 936. That accounts some for the travel differences. I feel the 936 has a more progressive ratio, should work well with this style of frame.

2
29er / Re: Carbonda fm936 Thoughts
« on: July 10, 2020, 10:02:45 AM »

I have a hard time of trusting any of the Chiner geometry drawings. Not because they are trying to deceive or are just getting it wrong. These open mold frames go through so many iterations that the one we see posted might not be the final iteration or at least the drawing is not updated to the most current geo numbers.

Having said that, you need to at least have a starting point to begin with. Without having a frame here in front of me to measure I have no choice but to reference the drawing. If I were to assume the drawing as listed on their site is accurate at 100mm travel, then according to my calculations shock travels would be as follows:

40mm shock = 101mm travel
42.5mm shock = 105mm travel
45mm shock = 112mm travel

My calculations come from a CAD program that has been used in Motorsports for years to model suspension kinematics and is dead nuts on!


3
29er / Re: Carbonda fm936 Thoughts
« on: July 07, 2020, 07:34:16 AM »
is to model the frame in a CAD program.

One day im going to do that.... But dont hold your breath :D



4
29er / Re: Carbonda fm936 Thoughts
« on: July 06, 2020, 11:00:00 AM »
165x42.5 should give around 120mm of rear travel.



How did you calculate this?
The average suspension ratio should be 2.5 for this frame (100mm wheel travel with 40mm shock as stated by Carbonda)
So with a with 165x42.5 it would be 106.25 mm travel...? Am I missing something?


I believe that calculation was based on linear thinking. When you look at the travel of the rear triangle it is dependent upon the shock stroke, leverage ratio, and the rear axle path. Depending on the suspension design, the initial rearward axle path will have a great effect on final travel. The only way to get an accurate travel number is to model the frame in a CAD program. And that measurement is a vertical wheel travel number. That's why the axle path is so important.

5
29+ & 27+ / 29+ wheels on a 27.5+ Frame
« on: June 19, 2020, 04:23:32 PM »

Quick question. Has anyone tried 29+ wheels/tires on a frame designed for 27.5+? I'm looking at a frame that is a 27.5+ design with 430mm chainstays and looks to have plenty of room around the 27.5 x 3.0 tire. Other than raising the bottom bracket (which I would like) seems like it would fit. I'd like to use a 29 x 3.0 but would settle for a 29 x 2.8 if I had to. Any one tried it?

6
29er / Re: Pro-mance M7007 II Build (9000 g/19.84 lb)
« on: April 01, 2020, 01:49:26 PM »
Very nice, but let me ask you why are you riding a medium frame being 182cm tall? No wonder you are using a 100mm stem  ???

7
Road Bike Frames, Wheels & Components / Re: Avenger Fm109
« on: September 18, 2018, 02:05:34 PM »
I can't speak to this particular bike but I have a recent experience I can share. I own three Chiner bikes. Two mountain bikes and one road bike. I mostly ride mountain bike but lately I have been training for a Gran Fondo so I've been riding my road bike exclusively. My road bike is a very well made frame from DengFu. It's basically a copy of the Specialized Venge. It has a very beefy bottom bracket area and I've always thought it to be an efficient bike. Because I have been riding it so much lately I have come to realize the geometry of the frame doesn't fit me very well and I've been struggling with longer rides. That prompted me to look for another frame and swap my parts over. Because of the geometry I wound up buying a Focus Paralane. It's a bike that's more upright and built for longer rides. I just finished putting the bike together and took it for a few mile ride last night. WOW, what a difference!!! This bike totally blows my DengFu frame away. It's light at 17.8lbs but not feather light. The acceleration and energy transfer is amazing!!! It is the best handling road bike I've ever been on. I am extremely happy with my purchase.

The moral of the story is, there is a damn good reason why some (not all) name brand frames cost thousands of dollars. The engineering and quality of the build really results in performance. Don't get me wrong, I'm a big fan of Chiner bikes. They have a legitimate place in the market. You just can't beat all the engineering and effort that goes into a high quality frame. So if you're looking for top performance and you can somehow afford a well designed brand name frame, don't hesitate! You too well be happy with you purchase

8
29er / Re: Buyer BEWARE: Hongfu bikes
« on: August 21, 2018, 04:25:38 PM »
One more thing worth speculating: What if they hadn't performed any production or labour before I said "refund"? Is there any way of knowing?  They expected me to pay their arbitrary costs based on no evidence. I could go on and on but you get the idea.

You are absolutely correct here! Hongfu did a horrible job of communicating with you (probably because they were trying to rip you off). And because of their actions their name is being dragged in the mud, which they deserve!!

9
29er / Re: BB30 or BSA....
« on: August 21, 2018, 04:18:47 PM »
My M06 has a BB92 bottom bracket. I've been riding it for 1.5 years now with no issues or creeks. I think a lot has to do with the installation. You really should buy the proper tools to press the bearings in straight and firm. Other than that make sure the frame you are buying has enough strength in the bottom bracket area. Press-in bearings need more support there than threaded bottom brackets. No doubt BSA bottom brackets are much stronger (in my opinion). The threading of the bearing cup into the frame creates it's own anchoring point. Plus it's easier to remove the bearing for a thorough cleaning and greasing! I'm not sure how a press-in frame would tolerate frequent installation and removal of the bearing cups.

10
29er / Re: Buyer BEWARE: Hongfu bikes
« on: August 21, 2018, 03:55:11 PM »
He probably works for Hongfu. That or he felt compelled just to join and post that?   :o

Hey, i'm not trying to be a dick, but in all fairness when dealing with these Chiner companies you do need to know how these transactions work. Now, i'm not sticking up for anyone or any company specifically. It's difficult to know exactly where these open mold frames are physically made. I'm sure Peter from Carbon Speed doesn't manufacture all the frames he sells. Hongfu, Dengfu, Workswell, Ican or whomever never makes all the frames they sell. These companies do deals with each other and give permission to sell each others frames. Hell, some of the places don't produce products at all, they are just re-sellers.

In this case here, the buyer was not happy waiting for as long as he did to receive his frame. So, he decided to purchase it from another seller who had it in stock. Through the buyers own words he mentioned he "assumed" the frame was in stock from Hongfu. The first mistake Hongfu made was to tell him to purchase it through Aliexpress. That to me right there throws up a red flag. I have only dealt with the selling companies directly. It's possible they were trying to get the sale straight away knowing they did not have the frame in stock. Bad business practices for sure! In the early discussions it appears Honfu told the buyer the frame was in production and then would need to be painted. If that is true then the buyer should expect to pay some recovery fee for a project that had been started, even though it's supposed to be an item that would usually be stocked (or maybe they had to order it from another company and the frame was in production). The buyer requested the order be canceled even though it had been started. Hongfu then decided to force the frame down the buyers throat, which in my opinion, has done nothing but cause bad blood and horrible reviews. Well deserved by them. Hopefully the credit card company can get this sorted and funds returned.

Moral of the story, either verify for sure the seller has the frame in their hands, or search around for someone trustworthy that does. If neither of these situations  can be verified, then be prepared to wait a long time to receive your frame. Do not be in a hurry!

Just my $.02 worth  :-\

11
29er / Re: The girls Chiner
« on: August 20, 2018, 09:22:25 AM »
Oh wait, then again you're using a RWC bearing kit so if the play is between the bolt and the bearing, there's nothing you can do there. Can't get a custom bearing with a custom inside diameter. You would be stuck trying to make a custom diameter bolt like what I need to fit tighter.

12
29er / Re: The girls Chiner
« on: August 20, 2018, 09:13:28 AM »
Very difficult to see but it appears the play is in the hole of the shock itself? It looks as though the rocker is one with the bolt. That's different from what I am experiencing. The only solution I see is to install a bronze bushing in the shock eyelet then hone it out to proper size. If your shock is not machined for a bushing then you would have to perform that. Not the easiest thing in the world to do. You need the right tools. It's totally doable though  ???

13
29er / Re: The girls Chiner
« on: August 18, 2018, 10:10:02 AM »
Play in which direction? I have a little play on my M06 but it's in the aluminum rocker for the rear shock. The bolt holes are just a tad too big so the thru bolt has a touch of play. Doesn't effect the performance at all. Not much i can do to correct it other than custom make a proper diameter bolt to match the rocker then hone out the shock to accept the larger diameter bolt. Way too much work work for no gain.

14
29er / Re: Mickes Dengfu M06 build
« on: August 18, 2018, 10:03:45 AM »
It seems it was the rear axel that wasn't tight enough!
I had a (small) crash and the handle on the rear axel took a hit (and so did my elbow and knee :) ) and got more tension / tighter.
Anyway, I think that may have solve the problem, because now: silent!  ;D

I went to a DT Swiss RWS axle and it really stabilized the entire rear triangle of the bike! I can get the wheel mounting as tight as I need to and still remove the wheel on the trail if needed. Yes, it's a couple of grams heavier but well worth the weight!!!

15
29er / Re: Thru axle help
« on: August 08, 2018, 11:33:57 AM »
I found one article that said Shimano and SRAM parts are interchangeable except for 11 speed chains.  I don't know.   I have ordered a Shimano chain to try.

I have had all kinds of chain issues in my riding past. The ONLY chain i will use now is the KMC X series chain. Not any of the lightweight ones either. All the lightweight chains give up too soon. Yes the standard X series chain is a little heavier but if you're counting that many grams then you should switch to road biking  :P And the KMC chains work well with all manufacturers. I've been pounding on mine for over a year now with no measurable stretch or shifting issues. I even use an oval chainring with narrow wide teeth.

FYI: Out of all the chains i have used the Shimano ones were by far the worst  :-\

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