Light Bicycle Carbon Rims/Wheels (Review Included on 1st Post))

[JONO WADE]

Depends on the type of damage, but there is a lot where the hook is where the damage is - without the hook they are also able to make the edge of the rim slightly thicker and therefore stronger.

More likely however, is wider carbon rims have a widespread belief that you can magically run lower pressures without a downside. What this gives is more rim strikes on a brittle material. Don't succumb to the hype, run the same pressures that you always have - rim strikes on carbon are bad.

Yes but regardless of whether the rim is hookless, the problem described is as a result of the knob profile on specific tyres, which would mean either way, hookless or not, you'll see the same amount of rim strikes.

I just figured if a company as well established as syntace are recommending it, then there must be some substance behind it. That being said, i'll probably continue using minion DHR II's because they're so damn good.

 

[pharmaboy]

Yes but regardless of whether the rim is hookless, the problem described is as a result of the knob profile on specific tyres, which would mean either way, hookless or not, you'll see the same amount of rim strikes.

I just figured if a company as well established as syntace are recommending it, then there must be some substance behind it. That being said, i'll probably continue using minion DHR II's because they're so damn good.

There are whole threads on these topics on mtbr and I don't think I've heard that the actual tyre has a roll to play in rim strikes.

The rim strikes are a function of tyre pressure and tyre size. The various problems associated with some tyres from maxxis are that they are designed for a 25mm internal rim width as a maximum. This means as people are sticking them on 30mm and up widths, the grip changes as they square off.

This seems to be they go from gradual loss of grip to more on off.

The model of the tyre effects grip on wide rims, but not rim strikes

Ps - I don't use maxxis or super wide rims, but the above is a synopsis of posts by the guy who designed those tyres for maxxis on mtbr (Bholwell)

 

[link1896]

This seems to be they go from gradual loss of grip to more on off

A new generation of rider needs to experience the Tioga psycho feeling, lean too far and you'd pucker up

 

[teK--]

How would hookless make a difference to the problem described?

Hookless sidewall is made thicker and without the bead poking out is a more consistent shape easier to form into carbon. Hence stronger and less likely to be damaged.

 

[Minlak]

I don't know the relevance here but I have syntace w30 rims and was told to not ride at all if the tyre goes flat that the rims would suffer damage. I got an instant flat when I tore a sidewall on a Maxxis Ardent Race on a sharp larger rock and the rim faired well suffering no damage at all.

 

[B Rabbit]

Ordered mine on the weekend for a Pivot Mach 6.

Rims: 38mm 650b 12k weave matte, 28H, 450+/-15g, no decals
Hubs: Black, DT Swiss350 J-bend center lock front 15mm/ rear 12*142mm for Sram xx1
Spokes: Black, Sapim cx-ray spokes
Nipples: Black, Sapim nipples

$1077 aud, wussed out of using DT Swiss 240 hubs, they were $300 more.


Can't wait.

 

[CharlieDontSurf]

Ordered mine on the weekend for a Pivot Mach 6.

Rims: 38mm 650b 12k weave matte, 28H, 450+/-15g, no decals
Hubs: Black, DT Swiss350 J-bend center lock front 15mm/ rear 12*142mm for Sram xx1
Spokes: Black, Sapim cx-ray spokes
Nipples: Black, Sapim nipples

$1077 aud, wussed out of using DT Swiss 240 hubs, they were $300 more.


Can't wait.

Are you building up the wheels or is LB?

Are they stocking DT hubs and spokes other than DT and Pillar now? They haven't got that on their ordering page yet

 

[B Rabbit]

Are you building up the wheels or is LB?

Are they stocking DT hubs and spokes other than DT and Pillar now? They haven't got that on their ordering page yet

Yep, they are building them, ain't nobody got time for that!
I emailed them directly because I wanted a hub that was for centrelock rotors but with sram XD 11speed driver, DT was the only company I found that made this combination but it wasn't on the online form. I saw a build on another forum with DT 240 hubs so I guess they stock them. My guess is they could do them all along but 99% of people are happy with novatec or hope hubs so they don't bother confusing people with more choice.

 

[teK--]

It may be of interest that after I had my LB wheels re-built locally with brass nipples, that they felt much nicer, smoother and not as harsh. I went back to the wheelbuilder (Astro Boy Racer) and he said that in his opinion LB put too much tension in the spokes.

So in essence he built my wheels to be slightly less stiff, and in my case I found it was much more comfortable and I did not notice any more flex than previous. In fact it was easier to hold a line on the trail since you aren't getting bounced around as much. I don't know if he would have built more tension in, if I was a chubbier fellow

Your mileage may vary, depending on the bike and rider weight, terrain. I suspect though that LB build them as tight as they can so everyone gets the maximum OMG NEW STIFF CARBON WHEELS!!! effect.

 

[whodesigns]

It is a myth that increasing spoke tension will change the built wheel stiffness. The type of spoke and lacing pattern do however have an effect.

 

[pharmaboy]

It is a myth that increasing spoke tension will change the built wheel stiffness. The type of spoke and lacing pattern do however have an effect.

Agree - tightness doesn't effect stiffness. Tightness does effect whether it goes out of true though, as long as it's equal tightness.

The biggest doubt I'd have with LB wheels, is they use aluminium nipples on the ones I've seen ( which are a shit choice for longevity), and they are built by someone who doesn't have to deal with any customer returns and likely has no experience at all with mountain bikes, nor likely even road bikes - so de tensioning during build process, prevention of twists, lubing of threads etc would be unlikely. Ie built in 30minutes, not carefully built over a couple of hours.

 

[MTB Wanabe]

Agree - tightness doesn't effect stiffness. Tightness does effect whether it goes out of true though, as long as it's equal tightness.

The biggest doubt I'd have with LB wheels, is they use aluminium nipples on the ones I've seen ( which are a shit choice for longevity), and they are built by someone who doesn't have to deal with any customer returns and likely has no experience at all with mountain bikes, nor likely even road bikes - so de tensioning during build process, prevention of twists, lubing of threads etc would be unlikely. Ie built in 30minutes, not carefully built over a couple of hours.

BS, tightness does effect stiffness. Test, build a wheel with 50kgf and one to 125kgf using the same components, the lesser tensioned wheel will flex more than the higher tensioned wheel as more of the spokes' natural elasticity has has been taken out of the higher tensioned wheel compared to the lower tensioned wheel.

120kgf is the recommended spoke tension for most rims and adequate for all applications. IMO, anything higher is excessive. Lightweight rims such as the Stans Crest have a tension limit of 95kgf but I build these to 110kgf as the tension reduces when the tyre is fitted and longevity of the build.

Stiffness is a combination of spoke tension, spoke count and inherent rim stiffness. Lower any of these three and you will have a more flexible wheel than if you used higher values.

As far as build quality from LB goes, I don't have an opinion as I haven't had them build a wheel for me. I have rebuilt a set of LB built wheels for a RB member and they were fine. He had cracked the front rim and got a replacement but decided to change the hubs so I changed the rear hub and rebuilt the front. I agree that brass is more durable than ally nipples but some people want that 20g per wheel saving.

 

[pharmaboy]

Mtbwannabe, the comments above weren't referring to a ridiculous 50kgf wheel. There have been tests done and for normal wheel builds, eg 100 versus 120 - there is no change in stiffness.

It still stands as a point, taking a wheel built to 105 then tightening it to 120 will not make the wheel stiffer

I doubt a 50kgf wheel would survive a full lap round a XC course???

http://sheldonbrown.com/rinard/wheel/index.htm
http://www.reynoldscycling.com/reynolds/news/Understanding-Wheel-Dynamics-Wheel-Stiffness

Who designs, is on the money though - it's a myth, it's been tested by plenty of mags - once you get to a half reasonable tension it make SFA difference.

 

[The Duckmeister]

The biggest doubt I'd have with LB wheels, is they use aluminium nipples on the ones I've seen ( which are a shit choice for longevity)..

The use of aluminium nipples is not limited to LB; virtually all builders of carbon wheels use them, because saving those few extra grams at the (ignored) expense of structural integrity is paramount to the sales dudes' minds. To hell with the fact that it is the most inappropriate stuff to use in contact with carbon, because it will fall apart.....

 

[pharmaboy]

The use of aluminium nipples is not limited to LB; virtually all builders of carbon wheels use them, because saving those few extra grams at the (ignored) expense of structural integrity is paramount to the sales dudes' minds. To hell with the fact that it is the most inappropriate stuff to use in contact with carbon, because it will fall apart.....

Fair call. Not just carbon either, most factory wheels seem to go alu - even my hope hoops had aluminium nips, but your right it's even a dumber idea on carbon

 

[MTB Wanabe]

Mtbwannabe, the comments above weren't referring to a ridiculous 50kgf wheel. There have been tests done and for normal wheel builds, eg 100 versus 120 - there is no change in stiffness.

It still stands as a point, taking a wheel built to 105 then tightening it to 120 will not make the wheel stiffer

I doubt a 50kgf wheel would survive a full lap round a XC course???

http://sheldonbrown.com/rinard/wheel/index.htm
http://www.reynoldscycling.com/reynolds/news/Understanding-Wheel-Dynamics-Wheel-Stiffness

Who designs, is on the money though - it's a myth, it's been tested by plenty of mags - once you get to a half reasonable tension it make SFA difference.

Quite good reading, however, those tests Sheldon under took were with a static load and doesn't take into account the flattening effect the rim under goes when being ridden. My conclusions to the analysis are that the higher tension wheels will still perform better than those of lesser tension. When a wheel rotates, the rim flattens (the amount will vary depending on rim strength/integrity and rider/bike etc weight) at the bottom thereby reducing the local spoke tension and the more it flattens the more tension is lost in the local spokes.

Now, Sheldon doesn't state at what tension the wheels under test start at but it only takes 2 turns of the spoke nipple to start to produce an increase in deflection. Approximately, the difference between 105kgf and 120kgf is about 1/2-3/4 of a nipple turn around an entire wheel, depending on the spoke. Each nipple turn equates to roughly 1mm. So going by Sheldons data, a rim only needs to flex 2mm before the spokes go slack. Therefore increasing the spoke tension increases the load the wheel can take prior to the spokes becoming "slack". The limit of spoke tension is governed in a wheel build by what the rim can take or the manufacturer recommends.

 

[whodesigns]

Since I built my wheel lateral stiffness test rig and have tested over 180 wheels, I have found that many wheel building myths are in fact just myths or marketing and the data shows some very interesting results.


Higher spoke tension can also lead to the wheel failing at a lower load due to buckling, as well as a lower fatigue limit.

Another thing of interest is that stiffness can affect the traction and control and that stiffer is not always better.

Also with alu nipples I have not had a problem myself with my builds, although I have seen a number of other people's wheels that have had problems. I was curious so I did what I normally do and did a test. I cut open a carbon rim and put a range of different nipples attached to spokes in it, as a build, then poured stans over it and placed in a large container. After 9 months and several re applications of stans, the results are also surprising.



Remember one test is worth a thousand opinions.

And if anyone wants to have their wheels tested let me know.

 

[pharmaboy]

Since I built my wheel lateral stiffness test rig and have tested over 180 wheels, I have found that many wheel building myths are in fact just myths or marketing and the data shows some very interesting results.


Higher spoke tension can also lead to the wheel failing at a lower load due to buckling, as well as a lower fatigue limit.

Another thing of interest is that stiffness can affect the traction and control and that stiffer is not always better.

Also with alu nipples I have not had a problem myself with my builds, although I have seen a number of other people's wheels that have had problems. I was curious so I did what I normally do and did a test. I cut open a carbon rim and put a range of different nipples attached to spokes in it, as a build, then poured stans over it and placed in a large container. After 9 months and several re applications of stans, the results are also surprising.



Remember one test is worth a thousand opinions.

And if anyone wants to have their wheels tested let me know.

No one picture is worth a thousand words ! So what happened in the the stans test!?

Suspect also that where you are and ride makes a difference to alu nipples - I'm 2km from a surf beach and regularly ride within metres of salt water and occasionally through it - alu nipples have been problematic for me on occasion, not helped by using multi tools to tighten nipples O:

 

[whodesigns]

No one picture is worth a thousand words ! So what happened in the the stans test!?

Suspect also that where you are and ride makes a difference to alu nipples - I'm 2km from a surf beach and regularly ride within metres of salt water and occasionally through it - alu nipples have been problematic for me on occasion, not helped by using multi tools to tighten nipples O:

Of course, different environments have an influence, with salt spray being one of the worst. Stainless steel rusts along the coast also. There are treatments and coatings available that will help with this. Also the nipples that I have seen corrode badly were not-anodised, 7075 alloy will dissolve in front of your eyes if it is not treated properly, as what happened with many internal nipples used.

The stans test showed that a quality aluminium nipple was no worse than brass, different liquids, or salt spray etc would require a different test.

 

[creaky]

different liquids, or salt spray etc would require a different test.

So more than one test is worth a thousand opinions ????

:behindsofa: