what are good training wheels

[Willehond]

Thanks Johan, luckilly my eyebrows are fully trimmed, it's my hairy legs I am worried about! 

 

Your answers are more than adequate for me and answered questions I had not even considered.  I always wondered why Shimano stuck to their design, but it seems that other manufacturers try to (and succeed!) in getting people to buy into buzz words that sound better. Like sealed bearings MUST be better than unsealed bearings, right 'cause they are sealed?  Hype sells

[jeremyd]

budget definitely blown!

[Willehond]

Firsly my surname is Wheeler - history means I may have been part of the design of the 1st square wheels.

More seriously current profession is to make Carbon wheels for PRO - yes 12 teams in the TDF next years will be using disc wheels and 4 spoked wheels made in Cape Town under licence for PRO.

Unfortunately The best wheels for training for a 98kg (I am 96kg - with 3 x sub 2h30 cycle tours under my belt) person would have to be Spinergy. They have really floppy spokes - you can even knot them' date=' But the PBO fibre is 8 times stronger than steel.

So how can these wheels work if you can knot the spokes - beleive it or not a wheel hangs - so any thing that works well under tension is great for material for building wheels. The added advantage with non ridged spokes is that they absorb a hell of a lot of road vibrations giving a far more comfortable ride, without sacraficing any performance of the wheel.

Now the down side - that out of the budget! Starting at R4900.00 for a new set.

[/quote']

 

OK, now you guys are confusing me.  So the wheel hangs and that I can deal with, but what about lateral stiffness?  Just another misunderstood concept?  How do these concepts gel?

[jeremyd]

Willehond there's a new salon in JHB called wax in the city that'll sort out the legs

[Troi Sport]

 (I am 96kg - with 3 x sub 2h30 cycle tours under my belt) 

 

that weight at that speed would definately test the wheel strength

 

 

howzit Peter?

 

didn't you also do the ACT wheels and bikes.

I saw some FRED riding one in Centurion last week, they still look fast even when going slow

[Icycling]

Lateral stiffness is caused by the tension in the spokes. When you built a wheel - you start with all the spokes been lose - their is no Lateral stiffness - the hub or the rim can more left to right relative to each other. Only once you apply tention to the spokes does the wheel become laterally stiff.

 

 

 

The stongest steal spoke a sapin race spoke can with stand 220n of tension before the bend, at the head, elongates at about 227n is brakes.

 

 

 

So even with a floppy material like fish nilon - because it can take a high load before it brakes you could use it to make a super lateraly stiff wheels. The only problem is how do you put it in tension while making a round and true wheel?

[Icycling]

Thanks Shamus, no the Lotus bikes which still holds the world 1hrs record at 56.375km/h in 1996 by Chris Boardman

[Johan Bornman]

Firsly my surname is Wheeler - history means I may have been part of the design of the 1st square wheels.

More seriously current profession is to make Carbon wheels for PRO - yes 12 teams in the TDF next years will be using disc wheels and 4 spoked wheels made in Cape Town under licence for PRO.

Unfortunately The best wheels for training for a 98kg (I am 96kg - with 3 x sub 2h30 cycle tours under my belt) person would have to be Spinergy. They have really floppy spokes - you can even knot them' date=' But the PBO fibre is 8 times stronger than steel.

So how can these wheels work if you can knot the spokes - beleive it or not a wheel hangs - so any thing that works well under tension is great for material for building wheels. The added advantage with non ridged spokes is that they absorb a hell of a lot of road vibrations giving a far more comfortable ride, without sacraficing any performance of the wheel.
[/quote']

 

Firsly my surname is Wheeler - history means I may have been part of the design of the 1st square wheels.

More seriously current profession is to make Carbon wheels for PRO - yes 12 teams in the TDF next years will be using disc wheels and 4 spoked wheels made in Cape Town under licence for PRO.

Unfortunately The best wheels for training for a 98kg (I am 96kg - with 3 x sub 2h30 cycle tours under my belt) person would have to be Spinergy. They have really floppy spokes - you can even knot them' date=' But the PBO fibre is 8 times stronger than steel.

So how can these wheels work if you can knot the spokes - beleive it or not a wheel hangs - so any thing that works well under tension is great for material for building wheels. The added advantage with non ridged spokes is that they absorb a hell of a lot of road vibrations giving a far more comfortable ride, without sacraficing any performance of the wheel.

Now the down side - that out of the budget! Starting at R4900.00 for a new set.

[/quote'] <?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

Whoa there "Icycling". You present your credentials instead of physics. It just doesn't gel.

 

Floppy spokes? Steel spokes are floppy. The fact that they can support their own weight doesn't mean that is how they support the bicycle.

 

A tensioned bicycle wheel is a prestressed structure that doesn't conform to conventional wisdom. Pre-stressed concrete can take tension (just have a look at a lintel above a window) and a prestressed spoke can take compression. A wheel "stands" on its spokes and doesn't hang from its top spokes like you make out. That is to say, you can apply a compressive force to a spoke up to the point where the compressive force equals the tension in the wheel. At that point it will buckle.

 

A spoke is therefore just a piece of string with tension in it. The fact that an untensioned string cannot take a compressive force doesn't mean a wheel does not "stand" on its bottom spokes.

 

As for your PRO stuff, whatever that is (but I bet it is just a fibre of sorts) is X times stronger than steel is neither here nor there. Steel is strong enough and strong enough is strong enough. Spokes don't break in tension, they break because of fatigue. Even the strongest steel can be broken quite easily by repeatedly bending it and that is how spokes break.

 

A tension break creates a typical cup-and-cone interface whereas a broken spoke shows clear fatigue break characteristics.

 

Here's a piece of wire broken in tension:

 

 

The other side of the wire will fit nicely into this cup.

 

 

Here's a broken spoke:

 

 

Note the difference in fracture. The bottom one is a typical fatigue break like a spoke. Both these photos were taken with metallurgists' microscopes.

 

Here's a photo I took from a customer's wheel.

 

Have a good look at that break. It is a fatigue break.

 

I have no idea what a non-ridged spoke is. But I have no doubt that you can tell us in layman's terms, how this spoke absorbs vibrations.  And whilst you are at it, please explain what properties a material "that works well under tension" has.  Or are you perhaps referring to tensile strength?

 

JB

 

 

 

 

[Johan Bornman]

Lateral stiffness is caused by the tension in the spokes. When you built a wheel - you start with all the spokes been lose - their is no Lateral stiffness - the hub or the rim can more left to right relative to each other. Only once you apply tention to the spokes does the wheel become laterally stiff.

The stongest steal spoke a sapin race spoke can with stand 220n of tension before the bend' date=' at the head, elongates at about 227n is brakes.

So even with a floppy material like fish nilon - because it can take a high load before it brakes you could use it to make a super lateraly stiff wheels. The only problem is how do you put it in tension while making a round and true wheel?[/quote']

 

Lateral stiffness is not caused by anything. It is not a disease.

 

It is a function of the bracing angle of the spokes, the stiffness of the rim and the thickness of the spokes. The Bracing angle on a modern 9/10 speed wheel is very, very small, in the region of 7 degrees and hence these wheels are not very stiff. However, they are stiff enough.

 

Stiff enough is stiff enough.

 

Please don't steal spokes. Steel spokes on the other hand are alloyed from nickel, steel, vanadium and chrome. All the different alloys are all equally strong (give or take a few degrees of latitude) but have vastly different fatigue (durability) properties.

 

A Sapim Race spokes is just a standard double-butted spoke with 2mm head and thread dimensions and a shank of 1.8mm. An equally thick or thin spoke from other manufacturers has a similar tensile strength but as I explained different fatigue properties. Unfortunately most of the spoke companies brag that their spokes are cold-formed or cold-forged. They refer to the process making the shank thinner than the rest of the spoke and that's not where the strength (aka durability) is required.

 

The rest of your claims as to the strength of a particular spoke is nonsensical.

 

As for "super lateraly stiff wheels" - you also miss the mark. If they are laterally stiff they'll be radially stiff as well, so no need to use the word lateral or radial, stiff is stiff.

 

You claim the only problem bla bla bla with making a fishline wheel is making it round and true. There are other problems such as vastly inadequate strength I'll worry about long before I'll concern myself with how to increase or decrease the tension in them. Nylon does not have enough tensile strengh to create a spoked bicycle wheel. 

 

Also, note the difference between break and brake and Sapim and Sapin and many others.

 

JB

 

 

Johan Bornman2007-09-06 15:17:55

[Johan Bornman]

Thanks Johan' date=' luckilly my eyebrows are fully trimmed, it's my hairy legs I am worried about! 

 

Your answers are more than adequate for me and answered questions I had not even considered.  I always wondered why Shimano stuck to their design, but it seems that other manufacturers try to (and succeed!) in getting people to buy into buzz words that sound better. Like sealed bearings MUST be better than unsealed bearings, right 'cause they are sealed?  Hype sells

[/quote']

 

But wait, there's more.....

 

Sealed bearing hubs are far, far cheaper to manufacture than cup-and-cone bearing hubs. The latter is generally forged whereas the sealed bearing hubs are mostly made on CNC machines. The two production methods don't produce similar products. The forged product is far stronger and more resistant to fatigue than the CNC hub.

 

Hype indeed sells.

 

Usually, the cup-and-cone hubs have several seals. On the Shimano MTB hubs for instance, they have two rubber seals and one labyrinth seal. Rubber seals most people can visualise, but a labyrinth seal is like its says, a labyrinth that traps any splashed water. It cannot be submerged but it is very effective at keeping the alien liquid away from the rubber seal that is effectively weeping grease to keep itself lubricated. As soon as water is to get onto this seal whilst the wheel is working, it would form an emulsion that escapes back under the seal and contaminates the grease inside and rusts the bearings inside their apparent safe grease layer.

 

This is quite evident from grease-port hubs. Ride them in the rain and then eject the old grease  and you'll see how contaminated it is close to the seals. It takes quite a bit of fresh greast to get rid of all the dirty grease inside.

 

What is a labyrinth seal you ask?

 

Visualise it as two C-shaped rings the one slightly smaller than the other. They're turned face-to face .i.e. hollow sides facing each other like two Cs formed by your fingers of both hands and then interleaved. You'll see that water that splashed inside the ring runs down the bottm and out.

 

 

Most Shimano hubs I've seen have labyrinth seals, which incidentally are non-contact seals since they just divert the water. On Shimano it is recognised as the shiny cap just behind the drop-out locknut.

 

JB

Johan Bornman2007-09-06 15:31:49

[Icycling]

Johan Bornman - you choose to defend yourself, WHY?

 

 

 

Nylon - that is why we choose a far stonger material like PBO frber - which has a tensile streght 8 x higher than steel. It was an example how material used in diffrent applications can still do the job. Hopefully something that a person without an egineering education can understand and relate too!

[buckstopper]

Johan,  you have your work cut out for you on this forum if correcting spelling, typo and grammatical faux pas is your thing.

 

My previous post contained an ambiguity referring to spokes and Ksyriums and stiffness. You could and should (as I intended) to have read that I was making the point that they are stiff wheels, and not referring to the spokes.

 

If, however my bad English contributed to your inputs on wheel stiffeness, I am grateful and have learned. Thank you.

[Johan Bornman]

Johan' date='  you have your work cut out for you on this forum if correcting spelling, typo and grammatical faux pas is your thing.

 

My previous post contained an ambiguity referring to spokes and Ksyriums and stiffness. You could and should (as I intended) to have read that I was making the point that they are stiff wheels, and not referring to the spokes.

 

If, however my bad English contributed to your inputs on wheel stiffeness, I am grateful and have learned. Thank you.

[/quote']

 

Dear Buckstopper. I have no intention in playing sub-editor and correcting spelling and typos for the sake of doing it. After all, every literary flame contains at least one error. I am sorry if I misread your comment on Ksyriums, I'll go back and see what happened there.

 

However, when it comes to issues of clarity and where people are trying to understand a concept, it doesn't help if people use sloppy language and confusing spelling. I think it is important to distinguish between brake and break when talking about spokes failing or frast bends coming up. Also, when brand names are introduced that are not all that familiar to the average Joe, correct spelling and capitalisation of the first letter is important. Writing sapin instead of Sapim wont help someone find out by, for instance googling (should that be Googling?) that Sapim is a brand of spoke.

 

Typos are neither here nor there but if you are going to bother answering a question, at least make yourself legibile.

 

Yours in the odd typo.

 

JB

 

 

 

 

Johan Bornman2007-09-07 00:50:30

[Johan Bornman]

Johan Bornman - you choose to defend yourself' date=' WHY?

Nylon - that is why we choose a far stonger material like PBO frber - which has a tensile streght 8 x higher than steel. It was an example how material used in diffrent applications can still do the job. Hopefully something that a person without an egineering education can understand and relate too![/quote']

 

Peter, I find you difficult to understand. We're in a technical discussion here so perhaps a bit more care with your wording will go a long way to solve this Babelish confusion.

 

I don't get your point about the strength of PBO fibre. So what? Anything that is strong enough is strong enough. For instance, the paper we print and write on each and every day is strong enough for the job. Why reinforce it with glass fibre or as is the fashion nowadays, carbon fibre? Apart from turning the paper black, there's no point to it. Same for any other bicycling material.

 

There are usuaually more than one appropriate material for a particular application. I'd say steel, aluminium and carbon are appropriate materials for bike frames. Titanium, plutonium and unobtainium is not.

 

Is PBO fibre an appropriate spoke material? I don't know the stuff but what I do know is that strength alone doesnt come into play. There is also the problem of attaching it to the hub and rim, durability, susceptibility to cuts and more.

 

JB

 

 

[Marius]

Johan...slow day at work? 

[jeremyd]

Ooops don't get into the titanium is not an appropriate material for bike frames here on the wheel issue, you'll just divert the topic. How much is that unobtainium per g?