I'm just about to have a set of 29nr wheels built up
Bike is a hardtail and i'm using rigid carbon forks at the front
using bike for bikepacking type stuff
My mate has suggested using a stans crest at the front but putting a heavier duty Arch Ex at the rear.
Can anyone explain what benefit i'll get from this ?
Or should i stick to crests all round
Cheers
There's an argument (a pretty solid one) that given the back wheel takes most of your weight, if your wheels are the same, the front is overbuilt or the back is underbuilt.
People don't like things not matching (bad ju-ju/ general tartiness) so it's quite rare to have different builds.
Some people prefer a wider profile on the front tyre, so would prefer the wider (usually stronger) rim on the front, rather than the back.
If you're bikepacking (rather than fully laden touring) you're probably not taking massive weights, and any incerase in weight is probably going to be offset by a smoother/calmer/more cautious riding style? You're probably OK with crests both ends?
If it would please the engineer in you, you could always go for more spokes on the back than the front, if the rims and hubs allow the option. eg 28f/32r or 32f/36r
I use a heavier rear rim on my tourer. The majority of spoke failures are on the rear so having a stronger wheel at the back where most of the weight is makes sense.
From Sheldon Brown:
[url= http://sheldonbrown.com/wheelbuild.html ]How Many Spokes?[/url]
Up until the early 1980s, virtually all adult bikes had 72 spokes.
32 front/40 rear was the standard for British bikes, 36 front and rear for other countries. The exception was super-fancy special purpose racing wheels, which might have 32 spokes front and rear.
The Great Spoke Scam: In the early '80s a clever marketeer hit upon the idea of using only 32 spokes in wheels for production bikes. Because of the association of 32 spoke wheels with exotic, high-performance bikes, the manufacturers were able to cut corners and save money while presenting it as an "upgrade!" The resulting wheels were noticeably weaker than comparable 36 spoke wheels, but held up well enough for most customers.
Since then, this practice has been carried to an extreme, with 28-, 24-, even 16-spoke wheels being offered, and presented as it they were somehow an "upgrade."
Actually, such wheels normally are not an upgrade in practice. When the spokes are farther apart on the rim, it is necessary to use a heavier rim to compensate, so there isn't usually even a weight benefit from these newer wheels!
This type of wheel requires unusually high spoke tension, since the load is carried by fewer spokes. If a spoke does break, the wheel generally becomes instantly unridable. The hub may break too; see John Allen's article.
If you want highest performance, it is generally best to have more spokes in the rear wheel than the front. For instance, 28/36 is better than 32/32. People very rarely have trouble with front wheels:
?Front wheels are symmetrically dished.
?Front wheels carry less weight.
?Front wheels don't have to deal with torsional loads (unless there's a hub brake).
If you have the same number of spokes front and rear, either the front wheel is heavier than it needs to be, or the rear wheel is weaker than it should be.
Sheldon does not take into account disk brake forces...