Half radial rear wheels: why rare

[abradleyInf]

Half radial rear wheels (I read about them in SHeldon site), seem a good idea for strong rear wheel: so why are they rare?

[hamster]

Radial spokes are not good at taking up twist between the hub and rim - which is what the drive does. Secondly, while radial spokes use lower tension, fitting them onto the lightly loaded non-drive side makes the inequality in spoke tension (from wheel dish) even greater.

I had a set of such wheels and the rear was always needing re-truing. A swap to good old 3-cross solved it and they get a little true-up tweak roughly ever 1-2000 miles now. I have to ride over lots of cattle grids, so they take a beating.

[stoobs]

Secondly, while radial spokes use lower tension, fitting them onto the lightly loaded non-drive side makes the inequality in spoke tension (from wheel dish) even greater.

I'm not arguing with you, but is inequality in tension necessarily a bad thing?

For info, I have a 16-spoke rear-wheel, radially-spoked on the non-drive side, whiich I use exclusively off-road, where cattle-grids are the least of my worries. 2000 miles and straight as the day it was born.

Compare and contrast....

[robinlh]

You can get away with radial spoking on any wheel where no very significant torque is involved.This means the idler wheel on a one -wheel drive trike.
In any other application radial spoking is technically stupid,and it does'nt even offer any advantages even where you can get away with it.
I've struggled for years to understand why anyone would want any spokes radial on any wheel on any bicycle.
Except,I suppose for fashion reasons.
I dismiss this with the scant regard that all fashion victims richly deserve,I don't tolerate airheads kindly.
Robin

[pherron]

I've struggled for years to understand why anyone would want any spokes radial on any wheel on any bicycle.
Except,I suppose for fashion reasons.

I don't really know enough to argue with you but the front wheel of my Brompton is radially spoked and never gave any problems in 17 years. I replaced the wheel after 16 years simply because the hub & rim were both worn out. The new wheel is also radial. I've never had a problem. I think I'll stick to 3 cross on my tourer though!

[andrew_s]

Radial is good on small front wheels, where the hub is large in proportion to the rim. It's probably obligatory if you use a dynohub with a wheel smaller than 20".

Crossed spokes lead to the spoke meeting the rim at an angle, and this gets bigger the more crosses, the fewer the spokes and the bigger the hub relative to the rim. Nipple seats will only accommodate a limited angle, and if this is exceeded you tend to get problems with spokes breaking at the nipple. This can be avoided by putting a bend in the spokes where they meet the nipple (as Thorn do with Rohloff wheels)

[mark a.]

The OP was asking about half-radial wheels, not wholly radial. According to Sheldon it's precisely because the radial spokes can't withstand the twist between hub and rim that they're a good idea.

half radial rear wheels can be substantially more durable than conventional ones, in cases where the wheel is highly dished.

http://sheldonbrown.com/wheelbuild.html#spoke_patterns

Do the people on here still dismiss half-radial as stupid?

[hubgearfreak]

Do the people on here still dismiss half-radial as stupid?

i do

[mark a.]

Do the people on here still dismiss half-radial as stupid?

i do

Ah, but you're cheating with your dishless hub-geared rear wheels!

[Freddie]

Perhaps it's dish that's stupid (along with 9+ sprockets on the rear end).

[PW]

With the majority of hubs a radial layout is risking pulling the top off the flange above the spoke hole. There simply isn't enough metal if the hub is aluminium. Shimano ban radial spoking on most of their hubs for that reason - look at the instruction leaflet in the box if you don't believe me.

[stoobs]

A good point, although it does depend on the design of the hub

[Cranks]

They are rare cuz they don't work.

[mark a.]

They are rare cuz they don't work.

Or that they look strange and hence manufacturers wouldn't dare use anything so unfashionable?

You're all probably right, but I haven't heard anything on here yet that shows that half-radial doesn't work other than "because it's just the way it is", which isn't very instructive. Granted the flange-breaking aspect is a potential show-stopper, but that may be only for fully-radial wheels, not half.

[SA_SA_SA]

Is there a magic phrase that will cause Chris Juden to adjudicate.