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Messages - olao

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29er / Re: Dengfu M06
« on: April 25, 2018, 04:20:02 PM »
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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29er / Re: Dengfu M06
« on: April 24, 2018, 04:04:27 PM »
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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Thanks :)

Ok, nice to hear that. Perhaps I might wait a bit with shortening the fork then. I'm all for feeling safe, but also think I want a longer reach. An additional 20 mm fork gives me a degree less in head angle, 15 or so mm less reach, a degree less in seat tube angle and the saddle 15-20 mm further back from the bottom bracket. But the bracket should be 10 mm or so higher.

Oh well, it's not all numbers... I'll try.

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And the photo of the build. Sorry for this mess (how do you do to post your photos?)

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All right, I am a rookie when it comes to posting images here. Trying again...

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Ok, so after having been a proud alloy builder, I found that the m06 appears to have all I desire in terms of geometry and weight. I must say the exterior of the frame is better than I hoped - it is a beauty. My build is not quite ready yet, so have only been sitting on it in the living room, but it looks and feels fast :)

While making up my mind, I was playing with Linkage, and drew the frame there. Once the frame arrived I double checked all measurements and just now uploaded the drawing to the web library, for anyone to play with.



As you can probably see from the photo of the bike below, the fork (Manitou Minute Pro) has 120 mm travel. My plan is to shorten it, but I will need to rebuild it to do that (cutting the air piston, and a bit more), so just trying to gather all the info first. [you can also see that the rear brake and some other cables are still in a rat nest on the bar, but that is not the point now]



In another post adbl, and perhaps others, had run the frame with 120 mm, but were not happy with that in the end, as far as I recall. Recently I saw that Dengfu wrote that the m06 was for 110 mm travel. Has anyone tried 110?

I'd be happy to hear what people are thinking and their experiences regarding 120 or 110 vs 100 mm. My inclination is definitely to go 100 mm, as I want a fast xc bike and believe that the 68.5 degree head angle is slack enough. But I am happy to take advise before cutting my piston...

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29er / Re: Dengfu M06
« on: October 26, 2017, 02:24:43 PM »
Some of the theory behind is explained on youtube in videos such as this, which I have found quite useful:

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29er / Re: Dengfu M06
« on: October 24, 2017, 03:25:23 PM »
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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29er / Re: Dengfu M06
« on: October 23, 2017, 03:39:22 PM »
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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