Woo? A package for Marc? Well this looks quite nice...

[Marc]

Maybe in Engineer geek talk. But in MT Bike terms It is actually a single pivot linkage

In MTB terms its a 4 bar Horst linkage.

 

[MR. evil]

In MTB terms its a 4 bar Horst linkage.

How is it a four bar? there is only one pivot point at the BB. A four bar would have another pivot on the chain stay or seat stay. The is not a pivot at the top of the seat tube, it is a brace. Horst link simply refers to the placement of the pivot

edit: is there a 2nd pivot at the rear wheel drop out? It is very hard to tell from the pics

 

[bvibert]

edit: is there a 2nd pivot at the rear wheel drop out? It is very hard to tell from the pics

Yes. It's definitely not a single pivot design.

 

[Marc]

How is it a four bar? there is only one pivot point at the BB. A four bar would have another pivot on the chain stay or seat stay. The is not a pivot at the top of the seat tube, it is a brace. Horst link simply refers to the placement of the pivot

edit: is there a 2nd pivot at the rear wheel drop out? It is very hard to tell from the pics

There are pivots on the chain stay. The Horst link design is any that puts the rear dropout behind and above that pivot.

 

[severine]

This discussion again???? :roll:

 

[Marc]

This discussion again???? :roll:

No silly, we're having a barely distinguishably different technical discussion about rear suspension design. All that matters though is it feels squishy when you sit on it.





/Giggity.

 

[severine]

I meant the "how is it 4 bar" part of the discussion. Geez.

I'll admit that while having donated part of my brain to having kids normally makes me feel a little less sharp than I used to be, reading the stuff you post, Marc, and your dissection of the minutiae often makes my head spin.

Then again, I have a cousin who is an engineer so I'm somewhat used to it.

 

[Greg]

Marc is an alien. That is all.

 

[cbcbd]

I really want to try my hand at building a set of wheels some day, but that would probably go much smoother with some sort of truing stand.

...and a dishing tool, and a spoke tension measuring tool...

Although I didn't rebuilt my entire wheel I did kinda mess with all the spoke tensions to try to get it as balanced and true as I could... it was a lot of fun and very interesting what I learned in the process - it's all a give and take between equal spoke tension and the different trues. You can't have it all with everything usually so you have to find a happy equilibrium.

Park tool used to have this nifty excel spreadsheet on their site that made adjusting a wheel much easier to picture. I can't find the copy I thought I had on my pc... its not on their site anymore... bummer.

 

[severine]

Marc is an alien. That is all.

I think that's a very astute (and accurate) observation.

 

[bvibert]

...and a dishing tool, and a spoke tension measuring tool...

Yeah, that stuff would help as well. Like I said someday I'll collect the tools and do it myself. I don't care how much of a PITA it is, I want to do it. I may never build another wheel again, but at least I'll know that I can.

 

[Marc]

...and a dishing tool, and a spoke tension measuring tool...

Although I didn't rebuilt my entire wheel I did kinda mess with all the spoke tensions to try to get it as balanced and true as I could... it was a lot of fun and very interesting what I learned in the process - it's all a give and take between equal spoke tension and the different trues. You can't have it all with everything usually so you have to find a happy equilibrium.

Park tool used to have this nifty excel spreadsheet on their site that made adjusting a wheel much easier to picture. I can't find the copy I thought I had on my pc... its not on their site anymore... bummer.

Although helpful, you don't need either of those tools. Spoke tension you can check by hand if you know what a properly tensioned spoke feels like and you can get away without a dishing gage or truing stand by mounting the wheel on the bike and using the brake pads if you have rim brakes or a screw driver (or other handy stick shaped object) and a c clamp or a spring clip clamp.

I watched my friend build a rear wheel for someone by eye, drunk, and he still rides on it. And he's not easy on it either. 205 lbs, and has no respect for his bike...

 

[cbcbd]

Although helpful, you don't need either of those tools. Spoke tension you can check by hand if you know what a properly tensioned spoke feels like and you can get away without a dishing gage or truing stand by mounting the wheel on the bike and using the brake pads if you have rim brakes or a screw driver (or other handy stick shaped object) and a c clamp or a spring clip clamp.

I watched my friend build a rear wheel for someone by eye, drunk, and he still rides on it. And he's not easy on it either. 205 lbs, and has no respect for his bike...

I know, I know, I just used the tools because I had access to them. Now that I don't I'll be doing the ghetto truing stand with it on the bike. And spoke tension you can feel and hear when plucking the spoke... gives a good idea of where you are and doesn't take a scientist to figure out if you're way off. But it was nice going through the process the right way just to see what it entails... then after you know you can fudge it up wherever you want.

 

[cbcbd]

Park tool used to have this nifty excel spreadsheet on their site that made adjusting a wheel much easier to picture. I can't find the copy I thought I had on my pc... its not on their site anymore... bummer.

Found it:
www.parktool.com/repair/howtos/TCC_version10.xls

I used that once and messed around with my mtb wheels trying to get the tensions, dishing, radial truing, and lateral truing as perfect as I could. It was fun, good to know, but I haven't gone through the full extent ever since... just kept doing the occasional, as needed, lateral and radial truings and tried to have my spokes' tension tight enough to not come off the hub on hard landings.

The only thing is that you pretty much need to have is a park tool spoke tension tool to use this... unless Marcguiver can figure out a way to manufacture one out of paper clips and rubber bands.

 

[Marc]

I know, I know, I just used the tools because I had access to them. Now that I don't I'll be doing the ghetto truing stand with it on the bike. And spoke tension you can feel and hear when plucking the spoke... gives a good idea of where you are and doesn't take a scientist to figure out if you're way off. But it was nice going through the process the right way just to see what it entails... then after you know you can fudge it up wherever you want.

Yeah, I'm used to fudging... almost everything :dunce:

I usually squeeze two adjacent spokes together to feel for tension.

Sucks you had to move to the west coast. We coulda used another guy on our Killington trip... the more that go the cheaper the room is.

 

[bvibert]

Yeah, I'm used to fudging... almost everything :dunce:

I usually squeeze two adjacent spokes together to feel for tension.

When truing my wheels using the brake pad method that's what I do as well.

 

[MR. evil]

When truing my wheels using the brake pad method that's what I do as well.

The method I do it to attach a zip tie on each side of the fork (at the same height) perpendicular to the wheel. Find a spot of the wheel that looks to be true and trim each zip tie so they just touch the rim at that true spot. Then slowly turn your wheel using the ends of the zip tie as a guage. When you come to a spot that is way off tighten or loosen the spoke cloesest to the zip ties.

 

[bvibert]

The method I do it to attach a zip tie on each side of the fork (at the same height) perpendicular to the wheel. Find a spot of the wheel that looks to be true and trim each zip tie so they just touch the rim at that true spot. Then slowly turn your wheel using the ends of the zip tie as a guage. When you come to a spot that is way off tighten or loosen the spoke cloesest to the zip ties.

Yeah, I've heard of that method as well. Since I have V brakes the brake pad method works well. I can adjust the brake pads in towards the rim using the barrel adjuster on the levers to get them close enough to the rim that they'll start to rub on the out of true spots. I keep moving the pads in and truing trouble spots until the whole rim rubs about equally.

 

[cbcbd]

Yeah, I'm used to fudging... almost everything :dunce:

I usually squeeze two adjacent spokes together to feel for tension.

Sucks you had to move to the west coast. We coulda used another guy on our Killington trip... the more that go the cheaper the room is.

Yeah, sucks, you guys will have to spend more money, and it is all my fault.
How about a trip to Whistler? I'll provide free board.

 

[Trekchick]

Is it possible to get on with the project?
Marc, we wanna see progress!!!