Doubletrack to 729?

[milkman]

Anyone have any real world experience with both? My doubletracks are in great shape (even after 3 years) and I love how tough they are. I might be looking for a lighter (but still tough) rim, but I'm not sure if switiching to 729's or MTX's will make a noticable weight difference. 175g doesn't seem like a whole lot and I think I should probably just save my cash. Anyone care to comment?

[trouble]

I've had both, both are strong obviously. the 729 felt somewhat lighter to me, but it could be all in my head.

unless you have money burning a hole in your pocket I'd say stick with the doubletracks if they are still going strong. no sense messing with something thats working for you

[coverider18]

729 hands down... but if are not that heavy go for the 721

[DaveM]

729 hands down... but if are not that heavy go for the 721

how much time do you have on the Doubletrack, 729 and 721?

[milkman]

729 hands down... but if are not that heavy go for the 721

Not what I was asking. Looking to see if there is a noticeable weight difference (enough to justify buying new rims) from people who have ridden both....

DaveM beat me to it....

[thedude]

729's are the way to go.

You will notice the weight difference.

[DaveM]

I ran Doubletracks for 3 years, they were still in good shape except for a few stress cracks when I took them off. I changed to 729's and have been running them for the past year. The rear has a couple of dings, but that was from poor setup causing me to bottom out harshly.

I did notice the weight difference, weight reductions are quite noticeable in rotating mass. The bike just felt like it rolled faster.

Doubletracks do seem bombproof though.

[milkman]

729's are the way to go.

You will notice the weight difference.

So your doubletracks were that much heavier when riding? I know rotational weight is huge, but $300ish seems like a lot to spend on a few hundred grams. I'll do it if I can really notice the diff....Thanks to everyone who's responded so far....

[DaveM]

I wouldn't say it's like riding a different bike, but I would say it was a definitely noticeable improvement.

Put it another way, after 3 years of beating on your Doubletracks it's probably time to think about replacing them anyways. Rims fatigue, they will fail one day, hopefully not when you're in the middle of nowhere, or somewhere where you're paying to ride (like Whistler) or even worse, when landing something big. Might as well upgrade while you're at it.

Although I can pretty much find a way to justify buying anything if it catches my fancy. :lol:

[coverider18]

i rode for a couple months on a double track on my old vps... and 729s on my peeler
but if you're worrying about weight i would take a look at the 721 i have one in my rear and there is a notible difference. they do get flat spots easy but they are strong

[Jeff M]

I've ridden both and while you can notice a difference in weight I don't think the difference is enough to, by itself, justify shelling out the money for new rims.

I'd spend the money on a whistler season's pass instead.

DaveM, I've never seen a doubletrack fail catastrophically. Actually 729s are the only rims that I've seen break into pieces (but not under normal riding conditions to say the least).

milkman, If this is a DH/freeride bike then I'd just keep riding the doubletracks and check them periodically for cracks, just like you should check your frame and fork. When they finally do need replacing maybe go for something lighter.
If you do much climbing then I'd ditch the doubletracks, but I would pick up something lighter than the 729s to make the swap really worthwhile.

[milkman]

Thanks for the insight. I just swapped all the parts from my Stiffee to my new G-Spot. The doubletracks were nice on the hardtail (didn't have to worry about the rear rim), but seem to be overkill for the dually. I'm only 175lbs, so can get away with a lighter rim. I do climb a lot, so perhaps a 721/729 front/rear combo, or even dual 721's may be the way to go....

[sdwkubed]

I havent ridden the the Doubletrack, but I do switch between the 729's and the 721's, the weight difference between those two rims is even closer then the difference between the DT and 729... and I really notice how much heavier the 729 is, to the point that I only run the 729's when I plan on riding very hard, and aint planning on pedalling too much, or want the larger footprint from my tires ie. mud (though the 729's did make me stronger when they were my only rim).

Even though the weight difference seems small on the scale, there is a multiplication factor when comparing non-rotating mass to rotating mass, as I recall it is something like 4 or 5 :1 (maybe someone else can help me out with that one) so a 175g difference even at 4:1 works out to a weight savings of 700grams off somewhere else on your bike... times both wheels, that's 1400 grams, or over 3 pounds. That' s why the small difference becomes noticeable.

Have Fun
T

[milkman]

^ Thanks. Very informative post. The 721's seem like the way to go. I don't go huge, so as long as I find a good builder they should hold up fine. My only concern would be Whistler, but again if the build is decent I shouldn't have any probs....

[coverider18]

my 721s lasted me all last season... now there are sooo many flat spots... so i am getting a new 721

[milkman]

On another note, can anyone compare the 721 to the Syncros DS28? The syncros looks a little more appealing because of it's increaed width, but strength is my major concern...

[Air Supplier]

ya 729 rims are amazing! I had mine for 2 years and they never warped or went out of true!