john
On my tandem, combined weight, ~ 400+ lb, I built some Hplus son sl-42.
main reason, pretty good mass (600 grams each) with lots of convective
surface area, for braking. No problem coming down from skyline to hwy 30
on newberry, germantown, with these wheels. 20 spokes front. 24 back
2to1 pattern for even spoke tension on 130 old hub.(yes so I can use these
on my road bike as well) Equal or nearly equal spoke tension is important
(as everyone know, but few seem to do) . [for an asymmetric wheel, I always
try to use the 2to1 or offset rim for this reason.]
Rear hub I used 32h M629, inexpensive, with 10 mm steel axle, 1/4" balls,
great seals, just can't beat these sort shimano hubs and I really like the
quick freewheel engagement.) And no i am not using the disc. I personally
think discs are scary on a tandem, unless you like a lot of mass. Thus
imho, unnecessary, you already have the mass to make a strong wheel, Might
as well use it for the brake heat as well. See Santana website for what
they think.
Disclaimer, 20 and 24 spokes on tandem wheel with thin wall rim bed. this
requires MORE than just a good wheel builder, but really smart rim bed
washers (that I had to make; what you really need is not avail..) . I
had to put in some serious effort, but then again I fully expect the spokes
and wheels to be fine 20 years from now, or until the brake track wears
out.
Anyway. CXP30 - 32 spoke. will be fine IMHO. They also have decent rim
bed washer that spreads the spoke load out nicely, for less chance of rim
cracking. Problem is how to do the rear wheel for even tension? If you
can find a 36 hole cxp30. and a 48 hole rear hub, you could build a 2to1
wheel, that, since the spokes have even tension, it would be
indestructible. But actually at only 275 lbs total.. I personally would
go ahead and chance a 24 hole CXP30 for the rear (with 32h hub) and do the
2to1 spoking. The even tension is WAY better than a 32 hole with half the
spokes nearly slack. Up front 24 CXP30 would be fine also, but wouldn't
hurt to go to 28 or 32. With a 32 could then go with lighter gauge spokes.
Also if the rear wheel snaps a spoke or two , you'll still be able to
stop safely. (and then you'll also know that wheel was inadequate :)
This assumes good initial spoke "stress relieving" which is actually
"over-stressing" and really good tension (you'll want ~ 250 lbf into each
spoke if 14g elbows) . High quality spokes of course. Brass nipples.
On Wed, Jun 17, 2015 at 2:18 PM, via OBRA wrote:
> I am looking for a set of wheels for training/spares and for both my
> road bike as well as my tandem that I use with my son. We are currently
> around 275 pounds total with bike so I don't think I need a full set of 40+
> spoke tandem wheels and will just use them for TTs and short rides on the
> tandem. With our weight I could likely go with almost any wheels, but I
> am thinking safer is better.
>
> I think the ideal is a set of 32 spoke Mavic cxp30s, if someone has a set
> they would like to get rid of. There are plenty on ebay, but thought I
> would check here first and to double check if 32 spokes with a medium depth
> rim is a good choice for a sub 300 pound load. I really don't like the
> idea of a 48 hole box rim.
>
> Any thoughts on experience of using medium built wheels on a tandem vs
> heavy built would be awesome as well. Last thing I want to do is take out
> my front wheel because I chose poorly.
>
> Thanks
>
> Jamie
>
>
>
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