Tandem Cycling - how low can you go

Yes, another spoke count thread...

Hi all.

I am about to build a new set of wheels and I'm not quite sure I'm being reasonable.

1° Like many, I found White Ind. MI6 and H2 to be the best weight/strength/durability/price value. That's the easy part.

2° C-4's V-22 (24 / 22mm profile) rim -- according to its manufacturer -- can endure a spoke tension of 140kgf (that's a lot). It only weights 465gr, can be built tight and stiff and will perfectly accommodate a 28c tire.

3° I am thinking of building 28 2x front and 32 3x rear with DT double butted Competition @140kgf tension, tied and soldered.

This would make for sub $700, sub 1900gr wheel set.

We are a 310lbs team riding somewhat rough Québec roads.

Now, doctor, am I going crazy?

Not familiar with those rims. I have had good luck with Velocity Fusion rims which weigh about the same.
White Industries hubs are really nice.
140kgf is a lot and not sure you need it. 100kgf is more typical.
I have had problems with spoke breakage on wheels I built 28 hole 2X. I think it had to do where the spoke crossing was relative to the butting in the spoke.
It seems a popular configuration so not saying you will have problems with it.
You could do 28 3X or Radial, I believe the hubs are designed for it.
IMHO and from what I have read tying and soldering does not do much of anything.

IMHO and from what I have read tying and soldering does not do much of anything.+1
waste of time

I recently tried to lace a wheel 28-hole, 3x and discovered that it is not possible with some hubs - it depends on the hub flange diameter whether the spoke can make the angle required to do 3x, should be no problem with 2x. But I'm more conservative when it comes to tandem wheels and would use 32 hole 3x on the front as well as the rear because the front wheel is still bearing a lot of weight.

Everything I've read has also said that tying and soldering is a waste of time.

I recently tried to lace a wheel 28-hole, 3x and discovered that it is not possible with some hubs - it depends on the hub flange diameter whether the spoke can make the angle required to do 3x, should be no problem with 2x. But I'm more conservative when it comes to tandem wheels and would use 32 hole 3x on the front as well as the rear because the front wheel is still bearing a lot of weight.

Everything I've read has also said that tying and soldering is a waste of time.

You are correct about 28 3X might not work on some hubs because the angle is too great.
I was using Ultegra hubs which have a small diameter.
I found with 2X that there was a very small angle and the spokes crossed closer to the hub at the thick portion of the spoke butt.
This was causing the spokes to leverage against each other and creating a force was which enough to over stress and break the spokes which happened as soon as I rode the wheel. This may or maynot be a problem depending the particular hub and spokes being used.
I agree That 32 hole 3X is a better configuration and is what I use on front and back.
If you want to save some weight and make the wheels more aero, consider using Sapim CX Ray or similar bladed spokes. It will cost you about $2 more per spoke.

There is no point in tying and soldering spokes from a functional point of view save for keeping broken spokes from getting wound in other things.

I have little use for lower spoke count wheels... with these you always need a heavier rim which negates the grams you save, increases spoke tensions to very high levels, and when you do frag a spoke the wheel will probably not be ride-able.

Somewhere people got convinced that lower spoke counts equaled better / lighter wheels and this just isn't so... one can build with 32 or 36 spokes and still get a light and strong wheel and reduce the weight at the rim which is very important from a performance standpoint.

Now, doctor, am I going crazy?

No, you just have a mild case of Gramitus: a slighly irrational desire to reduce weight from inanimate, two-wheeled machines.

Unless these wheels will be reserved for competitive events, what are you looking to gain long-term by going to something less than a pair of wheels with 36 spokes laced 3x? That you plan to run 28mm tires on these wheels makes even less sense since any weight and aero reductions you make are offset by the added girth and weight of the tire.

You should be able to build a 1900gr - 2000gr wheelset with 36h front & rear for your target price that should, long-term, give you wheels that are a bit more durable and a better match for the tire size you plan to run as well as the road conditions you describe.

Just my .02.

28mm makes sense : I don't want to start a debate on that subject, but for what I understand, you have to ride crazy high tire pressure not to increase rolling resistance in going down to 25mm tires because of tire deformation. I will not go to 140-150psi because of the bad pavement over here (porous, cracked). I stick with 28.

32 spokes : I do agree with all of you here thinking 36 spokes would be more reasonable. The thing is that I found only 3 rims of a proper width to accommodate the 28s : Velocity Dyad, C-4 v-22 and HED Belgium. The latest seems out of production and is/was expensive*, the first is heavier than the V-22 and does not seem as well made (in regard of the spoke tension it can endure and the junction type). So I wish to go with C-4's V-22 that is not available in more than 32 holes drilling. This is why I decided for 32 spokes.

28 - x2 front wheel : it's almost certain I will chicken out and build a more conventional 32 spokes front wheel. Still, I wonder...

TG, IMHO, we don't care much if the wheels are for "competitive events" or going to the market to buy a crate of eggs. One may have an every-day wheelset to preserve an expensive race wheelset -- that does not mean that the latest can/should only ride races. If I want my tandem to handle like a race bike, so be it -- as long as I am willing to cope with the downsides of it.
Of course, my tandem will not handle like a race bike : it's too soft, too heavy and my stoker doesn't like to hammer until it hurts too much. BUT, if I invest time and money in a set of wheels, I want the most of it : light, fast, and reliable in a way that will benefit to both the bike and the team. Not bombproof, that, I already have.

Everything discussed in this forum is not a matter of needs; it's all about fun. Even racing, except for pros, is about fun. Nobody here is affected by Gramitus for anything close to a serious reason -- and there is nothing wrong with it. I get from my readings on the forum that you will understand this as well as anybody else ;-)

Back to the question : is this setup going to hold or should I drop the C-4 rims and go Dyad for 4 more spokes and bring the tension down to 110kg?
And : knowing that the lesser the tension, the more spokes you need, is 36s@110kfg a gain over 32s @ 140kgf?


*Expensive for me, that is.

TG, IMHO, we don't care much if the wheels are for "competitive events" or going to the market to buy a crate of eggs. Everything discussed in this forum is not a matter of needs; it's all about fun. Even racing, except for pros, is about fun. Nobody here is affected by Gramitus for anything close to a really good reason -- and there is nothing wrong with this. I get from my readings on the forum that you will understand this as well as anybody ;-) If I want my tandem to handle like a race bike, so be it -- as long as I am willing to cope with the downsides of it.

So, if I might summarize: You're not looking to gain anything. This is just for kicks and you understand the pros and cons.

Thanks.

That's all I was looking to ascertain. :thumb:

TG

You really did a bad job at summarizing.

I am looking to gain something : livelier, lighter wheels.
I do understand pros and cons : livelier and lighter wheels always means more fragile. More fragile does not mean too fragile.There are some compromises I am willing to make , others not.

All this, yes, just the kicks of enjoying riding my bike.

I am not quite sure how you came to be under the impression I was looking for no gain: you didn't bother asking what is my actual set of wheels. How can you evaluate the gain (or lack of it)?

This was intended to be a technical discussion, not a cock fight. You may want to stick to the actual subject please. :thumb:

(I had to edit my previous post for it's hard for me to express myself properly in English.)

I am not quite sure how you came to be under the impression I was looking for no gain: you didn't bother asking what is my actual set of wheels. How can you evaluate the gain (or lack of it)?

Because I wasn't comparing your proposed ~1900gr 28h / 32h configuration to what you are riding. I was comparing it to a ~1900gr - 2000gr 36h / 36h configuration.

I think the latter mated to a set of 28mm tires sounds just fine for what you propose.

What I was struggling with was the willingness to remove more spokes than necessary to meet your objectives for no apparent net increase in performance.

Then, saying there is no gain, have you considered this:


knowing that the lesser the tension, the more spokes you need, is 36spokes @110kfg a gain over 32spokes @140kgf?

I insist because we do not usually consider spoke tension as a variable. In this case, it is : a 30kgf difference is as much a difference as 4 more spokes.

And again : sadly, the rim I want is not offered in 36 holes drilling.

Then, saying there is no gain, have you considered this:

Yes. At best it is a wash.