Technology Improve Of Light-Bicycle Carbon MTB 650B Rims

The team at Light Bicycle is committed to producing a better carbon 650b rims & 650b wheels. Therefore, after months of testing and rider feedback on the newly released 27.5 carbon rim, Light Bicycle has moved to completely overhaul the manufacturing process greatly improving the strength and reliability of the 650b bikes rims.


During the redesign, we focused on five main improvements, carbon length/layup, carbon base ring removal, air bladder removal, internal uniformity improvement, and enhance testing protocols.


1.The standard carbon layup procedure involves forming the rim out of three pieces, this simplifies and accelerates production however there are a few drawbacks in comparison to using a single piece in forming. Swapping over to single piece construction took a good amount of work but the benefits are worth it. Based on the single point of overlap the new rims are both stronger and lighter.


carbon 650B process

2. Another standard trend that we decided to change is that of using a pre-cured carbon ring as a base to build the wheel from. Again this simplifies and accelerates production, increasing uniformity during the old way of manufacturing. However there are a few notable drawbacks, chief among them performance loss with weight and ruggedness. When using a pre-cured ring in forming, the ring has to be heated again when going through final curing. This can impact the strength of the rim, so normally the ring is made extra thick to preserve strength at the cost of weight.


With our new process we completely changed the layup schedule and manufacturing, forgoing the standard pre-cured ring. This takes a little longer and more effort but we have found the results to be excellent. In spoke tension testing the new rim could maintain twice the resistance while still shaving weight overall.


650B rim carbon ring


curing carbon ring carbon fiber ring

Curing carbon ring



3. A third major difference in the manufacturing process is centered on air bladder removal. In the past due to the type/thickness of bag, a square hole was used in removal. This square notch was a weak point even after a carbon patch was installed and main rim structure was not as strong as it could be. With a change to the bag material we were able to use a smaller round hole for removal. At the end of the curing process the hole is then used as a standard spoke hole eliminating any excess loss of material or inherent weakness.


carbon rim square hole


4. One of the major goals of the redesign was to improve internal uniformity of each rim. If a rim is not uniform it’s inevitable that there will be weak points that result. After the layup rescheduling, removal of the pre-cured carbon ring from the process, and change in the air bag removal the resulting rim is a huge step forward in strength and uniformity.


650B carbon rim cross section

650B carbon rim cross section


5. Finally to top off the new 650b rims design we needed to be able to get true insight into the changes that were being made therefore we expanded the quality assurance testing. Several new tests as well as expansion on existing tests took place. List of current testing regiment is below.


Test item Standard Remarks
Lateral stiffness 5mm↓ Testing weight: 4.72kg
Tire pressure 0.5mm↓ rim width formation Tire pressure 60psi
Spoke tension 300KG↑ No visible crack
Breaking test 300KG↑ No visible crack
Impact test 600mm/22.5KG No visible crack


Inspection item Standard
Inner width 23+/-0.15mm
Spoke hole diameter 4.5+/-0.15mm
Valve hole diameter 6.4+/-0.15mm
Appearance clean, even, no stain
abnormal noise Shaking, nothing left in the rim
Number of holes 24, 28, 32, 36…
Weight standard +/-15g
Flatness 0.3mm↓
Roundness apex – nadir ≦ 0.6mm


650b rim lateral stiffness test

650b rim lateral stiffness test


27.5er rim lateral stiffness test

27.5er rim lateral stiffness test


650b rims width check after tire pressure

650b rims width check after tire pressure


650b rim spoke tension test

650b rim spoke tension test


650b rims impact test

650b rims impact test


New Update : All wide 29er all mountain rim, 27.5er rim and New 26er DH rim(33mm wide&30mm deep rim) are now all used new process. And For new process rims, only can be available for Light-bicycle. We haven't sold to any other local trade companies.
Learn more about: How to distinguish rims with new & old manufacture process

COMMENTS

R

Robert 2017/03/12

What manufacturing process do the 700c U-shaped rims use?


LightBicycle 2017/03/14

Hi Robert, For U shaped road rims, they are with the same manufacturing process as mtb new technology now. But for road rims, there will be one process different due to high TG resin, to make rims resist high temperature during long-time braking. Thanks, Lightbicycle


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chris 2016/04/02

I do not know how to calculate spoke length for offset holes. Do you have a chart or some help to choose spoke length for offset drilling?


Light-Bicycle 2016/04/05

Hello Chris, Sorry for the late reply. We were on vacation last 3 days. Please check below link and attached pictures for helping you how to get the spoke lenth for offset drilling. It is just for your reference. You can let us know if there is any questions. http://www.kstoerz.com/freespoke/fullcalc Thanks, Lightbicycle


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C

Chris 2016/02/22

Hello have the new process been added for the 26" dh wheels?


Light-Bicycle 2016/02/23

Hello Chris, Thanks for your inquiry. Yes, our 33mm width or 38mm width 26er DH rims are manufactured by new manufacturing process with one-piece-layer, to make carbon fiber layer continuous and rims strongest. We can build the wheels with Novatec/ Hope/ DT Swiss hubs. Most of our customers choose Hope or DT Swiss which are with better quality. Thanks, Lightbicycle


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S

Simon 2016/01/31

Hello. What is the recommendation for enduro and DH rim? I am 100kg. Riding 165mm travel frame. Is the asymmetrical frame as strong with spoke hole offset as 38mm rim. I'm not needing 38mm rim if asymmetrical rim provides same strength. Thanks Simon


Light-Bicycle 2016/02/01

Hello Simon, Thanks for your inquiry. The hookless "lips" on the 38mm rim are 3.2mm wide vs. 3mm on the asymmetrical rim. Both are the same depth and are quite strong. Technically the 38mm yields a slightly higher impact resistance, but it's quite close. You will get more even spoke tension with the asymmetrical rim which makes for a more durable wheel build, so the 34mm has the advantage there. I would go by width in this case as the strength is so similar. If you prefer a slightly more round and more natural tire profile with medium stiffness, go with the asymmetrical rims. If you prefer a wider more squared off profile with more volume, then go with the 38's. Go with the heavier version of either rim in your case as you are heavier and riding more aggressively. The additional reinforcement will handle g-outs more effectively. RM650BC13 (38mm width HD): 505 /-15g, $188/pcs RM650BC17 (34mm width EN): 460 /-15g, $269/pcs Thanks, Lightbicycle


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M

Mike 2016/01/02

Would it be better to drill the spoke holes slightly off the center line so the spokes pull More directly towards the hub?


Light-Bicycle 2016/01/04

Hello Mike, Thanks for your inquiry. For rim with offset drilling, it gives a much better bracing angle than classic rims and equalizes the spokes tension. And their stiffness and durability are improved also. Currently, the new 34mm wide 650B asymmetric rim is available. It is 410g /-15, USD200/pcs. Please find attached rim profile. 3k/12k/UD are the 3 choices for cosmetic appearance. The rim strength & weight is virtually identical. UD Matte is the most popular. Which do you prefer? Thanks, Light-bicycle


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G

Guus 2014/03/01

Hello, Could you please send me the cross-section with erd of 35mm 29er rim, as well as delivery time and total cost incl. shipping to the Netherlands? I prefer ud matte, 32h, internal nipples. Thanks!


Light-Bicycle 2014/03/03

Hello Guus, Thanks for your inquiry. Please find the attached cross-section drawing of the 35mm wide 29er hookless clincher rim. It’s OK to have the rims with UD matte and 32H for internal nipples. The price is USD180/pcs(AM version: 420 /-15g) and the shipping cost is USD68.1 for 2pcs rims to Netherlands by TNT. Thanks, Light-bicycle


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erik 2013/10/13

Hello, are you using the new process on the wide 29 rims? also, is there a beadlock or "shelf" for the better tubeless set up?


Light-Bicycle 2013/10/14

Hello Erik, Thanks for your inquiry. Please find the attached cross-section drawing for the wide 29er rim. For the rims, do you prefer UD, 3k or 12k? Matte or glossy? 32H? http://www.flickr.com/photos/light-bicycle/sets/72157631717562968/detail/ Currently, we manufacture the all wide 29er rims with new process. For the beadlock/"shelf", do you mean the rim bead hook? For tubeless, most customers use a kind of yellow tape, sealant and tubeless tire. Then it works perfect. Thanks, Light-bicycle


P

Peter 2013/11/17

Hello, The cross section drawings above still show a bead-hook profile. Are the Wide 29er with the new manufacture process being made without the bead-hook (just like the latest Specialized/Roval wheels are?) Are your rims as good as Roval? Finally - how do you order rims with the custom decals? and can the decal say whatever you like or are there copyright restrictions? Thanks


Light-Bicycle 2013/11/18

Hello Peter, Thanks for your inquiry. There are two kinds of 29er hookless rims(27mm outer width and 35mm outer width). 1)27mm outer width https://www.lightbicycle.com/bead-hook-less-rims-carbon-29er-light-bike-rim-tubeless-compatible.html#.UomNJfnDdy0 2) 35mm outer width The rim mold is just started. We will start to sell it around at the end of this month. They are both manufactured with new process and also tubeless-compatible. Our carbon rims are all with good quality. Please find the attached cross-section drawings of rims. Which one do you prefer? You can let us know what kind of graphic you like for rims. Then we can make graphic file for your reference. It will need extra cost for custom graphic. But there are copyright restrictions. If the graphic you provided is a brand. It's easy to be detained by custom, so we don't recommend you to have this kind of decals on the rims.You make your own graphic design, then we can manufacture accordingly for you. Thanks, Light-bicycle


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Remy 2013/09/16

Jump bikes are mentioned on the 26 wide rim. Is it safe to use 50-80psi when using tires rated to that pressure? I run pressures 20psi over recommended for my current rims without problem. Is it critical to be ≦40 psi?


Light-Bicycle 2013/09/17

Hello Remy, For mtb rims, it is better to ride less than 75psi. Why you ride 80psi for mtb bike? And we have new 26er 33mm wide rims for jump bikes and downhill bikes, please find attached rim cross-section drawing & pictures. There are two weight version for this rim. All mountain: 375g /-15 downhill: 460g /-15 Thanks, Light-bicycle


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T

Tom 2013/03/25

I've recently built up a set of 29er wheels using I9 hubs and your 29er wide rims and very happy with them. I'd like to convert my 26" DH wheels with your wide carbon rims too, but I'd like to keep it around 400gr. I am also waiting to see if this new manufacturing process will be added to your 26" rims. Also let me know if I can help with the preliminary testing (pre-production rims). I will compare them to industry nine DH rims. Thanks


Light-Bicycle 2013/03/26

Hello Tom, Thanks for your support. We are happy to hear that you like our rims. And currently, we do not have plan for 26er wide new process. Because the current process for 26er wide rim stable and the failuare rate is much less than 29er wide rims. Is it DH rims with current process ok for you? http://www.flickr.com/photos/light-bicycle/sets/72157631704846817/detail/ Thanks, Light-bicycle


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Gee 2013/03/15

Hi There I'm just about to order a pair of26er wide rims and wondering if the new manufacturing process to be used on the 26er wider rims is any closer to happening and when?. I'm particularly interested to now if the new process will mean that you may sell the wide 26er rims with less weight or will you keep the weight the same and offer a rim with better strength? Kind Regards G


Light-Bicycle 2013/03/16

Hello Gee, Thanks for your inquiry. Currently, we just start to use new process on 29er wide rims, it is still being tested. So, we still haven't got a plan to start on 26er wide rims. Also, the current 26er wide rims are stable. We will check whether to use new manufacture process until the testing on 29er wide rims is finished. It will take quite a few months for the ride testing. The weight is quite similar for new process & current process. The current strength for 26er wide rims are pretty good and stable. We will let mail you once we have a plan for 26er wide rims with new process. Thanks, Light-bicycle


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