Best rim width for DH

[Freeo]

Hi all,
I am looking at getting new rims for DH. I would like to know the pros and cons with different widths.
I am looking at mavic ex823, mavic ex729 and spank spike race evo28al.

 

[sim70n]

i cant comment on the widths but i run the ex823 and nudging the 100kg mark kitted up and a fair hack and the 823 are near bombproof. they're a very worthy rim

 

[driftking]

I believe the external widths are

Spank 28 (obviously)
823 is 30mm
829 is 36mm

Generally a wider rim is better, you get less tire roll and are much less likely to roll off a tire. Tubeless really needs a wider rim to help reduce burping and rolling.
A wider rim gives a bigger contact patch for more grip and squares off the tire, it results in less squirming of the tire, you don't want to go to wide however most rims these days don't have the issue of too wide. (A wider tire will obviously want a wider rim)

You are comparing very different weight rims though.

Ex823 655g
Ex829 675g
Evo 28 500g (is is very much a race rim)

 

[brendonj]

If it wasn't for weight, we would all be using wider rims because of the above noted benefits. Usually the spank spike / mavic 721 type rims are the thinnest you want to go on a DH bike (21 inside / 28 outside). Some heavy duty trail rims have similar widths although may not be as deep to cut down further on weight.
I personally like rims about 25 mm on the inside (about 32 mm on the outside) but have used wider and narrower rims. I wish Mavic would make a high end version of their 325 rim, like a 725.

Also I didn't think the 823 was that heavy. I thought it was under 600 grams.

 

[driftking]

If it wasn't for weight, we would all be using wider rims because of the above noted benefits. Usually the spank spike / mavic 721 type rims are the thinnest you want to go on a DH bike (21 inside / 28 outside). Some heavy duty trail rims have similar widths although may not be as deep to cut down further on weight.
I personally like rims about 25 mm on the inside (about 32 mm on the outside) but have used wider and narrower rims. I wish Mavic would make a high end version of their 325 rim, like a 725.

Also I didn't think the 823 was that heavy. I thought it was under 600 grams.

They have been weighed at 716g with inserts. The mavic website lists the rim at 655.
If you were wanting tubeless they are pretty decent, the spank 35 is 599g but its not UST ready.

I really want to find a 32width UST ready rim that comes in at 600grams for myself.
I'm not a fan of super light weight race rims, I'm too abusing on rims for that.

 

[No Skid Marks]

They have been weighed at 716g with inserts. The mavic website lists the rim at 655.
If you were wanting tubeless they are pretty decent, the spank 35 is 599g but its not UST ready.

I really want to find a 32width UST ready rim that comes in at 600grams for myself.
I'm not a fan of super light weight race rims, I'm too abusing on rims for that.

Atomlab Pimp lites are about as strong as 823s and about same weight set up ghetto tubeless.

 

[driftking]

Atomlab Pimp lites are about as strong as 823s and about same weight set up ghetto tubeless.

If they workout the same weight whey wouldn't you just buy proper tubeless rims and get 823's?
Also pimplites are 28mm wide where 823 are 30mm.

Unless I am missing something, I cant see any reason why you would get pimplites over 823's in that case. Same weight, 823 stronger or equivalent, 823 wider and 823 UST ready.

Id actually go to the DHR rims first, weight wise they are only 10gram heavier than the pimplites but they are 34mm wide.

How much difference does rim height make I did notice the DHR are 21mm high where pimplites are 27mm what advantages does this give, im assuming strength.

 

[indica]

Wiiiide.
Gaping wide.
Bigger is always better.
29er wheels, 12" travel forks.


900mm bars.

 

[No Skid Marks]

If they workout the same weight whey wouldn't you just buy proper tubeless rims and get 823's? Atom Lab set up ghetto burp a touch less.
Also pimplites are 28mm wide where 823 are 30mm. Pretty sure Pimplites are wider internally. The newer version would be for sure.

Unless I am missing something, I cant see any reason why you would get pimplites over 823's in that case. Same weight, 823 stronger or equivalent, 823 wider and 823 UST ready. Pimp Ghetto will seal better dented, no screwing nipples in. Less cracking at nipples maybe. A touch lighter maybe too.

Id actually go to the DHR rims first, weight wise they are only 10gram heavier than the pimplites but they are 34mm wide.Is that the newer AtomLab? i though it was just a pimp lite.

How much difference does rim height make I did notice the DHR are 21mm high where pimplites are 27mm what advantages does this give, im assuming strength.Lots of things determin strength, and also it depends how you define strength. MTX are a strong wheel that dent easy, 721s are possible a weeker wheel that don't dent as easy. What one is stronger?

There's no clear cut answer as to what to choose, they all have their pros and cons.

 

[brendonj]

I do like these. About 32 mm wide outside and 25 mm inside. Around 610 or 620 grams.
I have used them in a wheelset and they seemed pretty stiff and strong, but I only did limited riding on them before I sold that bike.
Not sure if you can get a welded version and obviously not UST up front.

http://www.velogear.com.au/bike-parts/bike-parts/wheels-rims/26-mtb-wheels-rims/fsa-gravity-dh-300-rim.html

 

[driftking]

There's no clear cut answer as to what to choose, they all have their pros and cons.

I wasn't really asking what makes a rim strong more alluding to what role does the rim height tend to play in a general sense.
Burp less? really, thats interesting I always was under the assumption that ghetto burped more regardless.
By time you add in goo and the extra tape would it really save that much weight?

Not sure if they are the new ones, here the link
http://www.atomlab.com/rims.html

they are a little heavier but seem to be a better rim in terms of dimensions. (they have a much lower profile thought so that was why i was curious about the general consensus with higher vs lower walled rims.

The pimplites on the site are 21 ID and 28 OD the 823 are 23 ID and 30 OD.
Are they the new ones on the site though?

Maybe the DHR is the new one? its 26 ID and 34 OD which is brilliant. and only 10 grams heavier than pimplites (but as i mentioned much lower profile)

 

[No Skid Marks]

I wasn't really asking what makes a rim strong more alluding to what role does the rim height tend to play in a general sense.
Burp less? really The Atom Lab has a larger overall diameter than the Mavic, then add the width of the BMX tube, makes the tyre tighter. then the tyre also sticks to the BMX tube better than the 823 rim. If this isn't the case as Mavic bead lock is brilliant, it is the case when there's rim dents. But there's sweet F A difference. and not enough reason if any not to choose one over the other., thats interesting I always was under the assumption that ghetto burped more regardless.
By time you add in goo and the extra tape would it really save that much weight?I run sealant("goo") in either set up. Atom Lab is lighter than 823, and about the same with BMX tube. Atom Lab has oversize aluminum nipples, that don't round crack as easy as normal sized ally ones if you ran them on the 823 to save weight.

Not sure if they are the new ones, here the link
http://www.atomlab.com/rims.html Not sure sorry. I'm not sure of the width of the old PimpLites. I'll measure one of mine later. Good link though. I'm sussing out the super lites for my 27" AM build. Although I have Stans Flow EXs to start with.
they are a little heavier but seem to be a better rim in terms of dimensions. (they have a much lower profile thought so that was why i was curious about the general consensus with higher vs lower walled rims. Yeah, hard to say. I guess you would need to consider tyre profile and it's protection of rim also. Narrower rim would give more protection with same tyre. Again, sweet F A difference though I guess. I'd have thought the taller Pimp Lite would be stronger for flat spots, the wider rim stronger if the spoke offset is different for stiffness. I dunno.

The pimplites on the site are 21 ID and 28 OD the 823 are 23 ID and 30 OD.
Are they the new ones on the site though? No idea. I'd say so judging by the new graffix, but maybe the "new one" is the wider one. I'll measure an old one tomorrow.

Maybe the DHR is the new one? its 26 ID and 34 OD which is brilliant. and only 10 grams heavier than pimplites (but as i mentioned much lower profile)

Thanks for the link, made me look, LOL.