Tight BEAD REMOVAL TECHNIQUE?

Some deflated tires are difficult to remove over the bead retention ridge without using the following technique:

Lay a short section of the rim with deflated tire over a log or arm of a couch, or any platform surface,

Hold up the majority of the wheel behind the platform edge level with one hand,

Grab the tire hanging over the platform edge tightly with the other hand, and quickly push down with your palm on the sidewall near the rim.

The bead should pop down into the deep center channel pretty easily, and the rest of the bead can be peeled over the retention ridge into the center channel after the initial section pops over.

​IS TIRE PROFILE CHANGED WITH WIDER RIMS?

I always recommend using the same tires your are most familiar, even if used and swapped form another wheel set, and ride on familiar trail, as a baseline, to feel the difference with wide Derby Rims. I've found that old worn out tires work better on Derby Rims than the same tires when new on narrow 30mm rims.

The tread profile is really not changed as much as is hyped by some riders without experience, or very little experience and have not tuned tire pressures to be optimized lower than they had on narrow rims. The sidewall becomes wider mostly near the rim, and no wider near the edge knobs. More square profile tire edge knobs rise about 1 mm or so, less so with rounder profile tires, the center cannot rise because it is constrained like a belt around the wheel. The casing is constrained in diameter and profile, so the casing stiffens under the edge knobs and gives a feeling of a harder edge and more stable tire.

Wider rims enable much lower tire pressures, from 5 to 10 psi lower, heavier riders able to lower air pressure more than lighter riders who already can ride much lower pressures on narrow rims. With lower tire pressures the edge knobs and casing comply more to the ground surface during cornering, increasing tire patch size when weighted in a corner. And cornering is more forgiving with the same tires on wider rims, they do not wash out as easily or as quickly as the same tire on narrower rims. There are some who have no experience who say that the profile becomes much more square with wider rims, and then the tire suddenly looses traction, which is not true, the tire whether rounder or more square in profile design slides with more predictability when set up with optimized lower pressure for the wider rim.

If you like round profile tires now, they will remain just about the same round profile, with more traction and more edge bite. If you like more square tires, they will square up slightly more and become more forgiving and slide at the limit more predictably using lower pressures enabled by the wider rims.

TIRE RECOMMENDATION?

I always recommend using the same tires your are most familiar, even if used and swapped from another wheel set, and ride on familiar trail, as a baseline, to feel the difference with wide Derby Rims.

I don't think there is an optimum tire size. Smaller tires have a greater rate of improvement. There is more tire profile change compared to larger higher volume tires.

Derby Rim riders are riding on 38C and 40C (road), and 2.0 to 2.4 (trail), even 2.8 (27+ and 29+)

A smaller tire with wide Derby Rims works better with more handling stability and cornering traction than large volume tires with similar tread on narrow 30mm rims. I like 2.2 sized tires for most trail conditions from gravely hardpack to slower technical rocky riding, and larger volume 2.3 to 2.4 and more aggressive knobs on AM rims for more and taller tire space before casing the rims in faster rocky conditions such as very rocky high mountain and desert riding. And I have reports that 27+ riders are using 2.8 and 3.0 tires in 29r frames and forks. And 29+ riders are using 3.0 tires on 29+ frames.

​TUBELESS READY (TR)?:

Derby rims are so deep at 31mm that normal mountain bike tubeless Presta valves are too short to get an air pump chuck to lock on. So 40m or longer is required. I like the Stan's 44mm, having a removable valve core so that sealant is easy to add with Stan's sealant syringe.

A tube with normal 35mm stem is OK without the lock nut, to get an air pump to lock on. But I try to carry a long stem tube for flats that won't seal with sealant, it just easier with a longer valve stem.

Orange Seal 48mm tubeless stem is what I use. These have a removable core for easy access to add sealant with a Sealant Injector. They can be mail ordered from Stan's web site, and shipped quickly.

The best most effective tape I've found is Orange Seal 18mm wide tape. It can be found for $10 to $12 (MSRP) on-line. One roll is enough for 4 rims, one round.

Another option is  using one round of Stan's 12mm wide tape and adding another round of  3/4 inch (18mm) wide plastic tape over the narrow Stans, such as electricians black tape.

Using tape wall to wall is not needed, this can be too tight, and not seal as well with good quality tires. Only the spoke holes need to be sealed with good sticky tape, 3/4 inch or 18mm wide in the center channel. Derby Rims don't burp with tape only in the center channel, using every tire I've heard of. No one has ever complained about burps.

​HOOKLESS RIM WALLS:

Derby Rims has an industry leading original tubeless ready (TR) thick hookless rim walls and a bead seat design with bead retention ridges, tightly centering and locking the tire in the Derby Rim bead seat, introduced in 2013. Now in 2016 most other rim companies making new model carbon and aluminum rims have closely copied the Derby Rim bead seat patent-pending design. A rim wall bead hook is useless for all quality mountain bike tires available and TR cyclocross and TR road tires, all having a strong safe tire beads that do not stretch more than a millimeter or two during their useful life. Road clincher tires maintain old 1970's technology, thin tire beads, that stretch easily from higher air pressure to become 7 millimeters or more oversize with more than about 65 psi, requiring rim wall bead hooks and tubes to restrain the weak and soon to become obsolete clincher bead road tires from blowing off the rim. Motorcycles don't have bead hooks, cars don't. The side hooks or "clincher" bead hooks, first became used in the early '70s when high pressure inner tubed road tires had trouble centering on the rim when airing up to 65+ psi and would blow off the rim sooner or later. Road tires will evolve to join the advances lead by mountain bike tires and rims, the weaker hooked rim walls required to restrain the thin and stretchy clincher road tire beads will soon become obsolete.

BEAD SEAT RETENTION, tire BEAD LOCKS:

Derby Rims have a bead seat retention ridge next to the deep channel around both tire-centering, tubeless ready bead seats. Much like UST bead seat design, the raised bead seat ridges prevents a tubeless tire bead from sliding into the deep center channel and burping while hard cornering. Also the bead retention ridges secure the bead on the bead seat when the tire goes flat, so the flat tire can protect the rim from rock damage while rolling to a stop after flatting. The hookless bead wall with bead seat retention has been used in motorcycle and car tires for decades, but never produced in bicycle rims design before Derby Rims. The Derby Rims innovative more durable and safer optimized thicker hookless rim wall with bead seat retention ridges is patent-pending.

Spokes, and nipples, and nipple corrosion:

I'm 200+ lbs ride weight, 6'1". I like using DT Swiss Competition DB 2.0/1.8 spokes. I have always built 3 cross lace up, and sometimes 2 cross on the non-drive/ non-front-rotor sides of some wheels with Derby Rims to lower weight without risk of weakness or much flex, because Derby Rims rims are very stiff. I like to use 16 mm alloy nipples because I like the bigger size look, more "moto". Because of the very thick spoke bed of Derby Rims, 14 mm nipples appear exposed how a 12 mm nipple appears exposed in a more thin aluminum rim. 12 mm nipples do work fine, but appear stubby, shorter than nipples are commonly exposed.

I have used alloy nipples with Derby Rims for nearly 2 years with no corrosion problem at all, riding often in the winter in rain and muddy conditions, commuting every day to work rain or shine, and washing my bike and wheels often with a garden hose. There has been no rapid corrosion problem reported with alloy nipples and Derby Rims in nearly 3 years.

Your wheel builder could offer spoke suggestions for you , better knowing your weight and riding style.

​​​

Frequent Questions


Why Derby Rims vs. other carbon fiber RIMS?

Ray AKA 'derby', the designer and producer of Derby Rims, has been asked, "Why Derby Rims vs. other carbon fiber rims?" Here are many great reasons to ride Derby rims vs. any other carbon fiber rim option.

- Mountain biking guru Keith Bontrager once came up with the moto: 'Cheap, light, durable - pick two.' ...However, with Derby Rims, pick all three!

Click here: To see many more reasons why to ride Derby rims vs. other carbon rims, listed near the bottom of the WIDE RIMS page!

Bicycle INDUSTRY PRICE DISCOUNTS:

Dealers, OE, professional wheel builders, and bicycle industry full-time employees ...

Derby Rims promotional bicycle industry wholesale and employee pricing is now available for your shop's customer wheel builds, resale, or if you are employed in the bicycle industry full time. Please email ray@derbyrims.com, and include your shop name or bicycle business, and your management title or your manager's name and contact in the email for verification.

SHIPPING COst:

Shipping cost within the mainland USA is normally $20 to $25 for 2 rims. Shipping by USPS Priority to Hawaii, Alaska, and Puerto Rico is normally $50.

Shipping cost to deliver 2 to 4 rims outside the US is usually $65 to $70 USD. 

Shipping in the USA mainland is by UPS Ground Signature-Required for commercial addresses, or UPS Ground No-Signature Required to residential addresses except Signature-Required to apartment building addresses. Shipping is from northern California, and delivery is 1 to 5 days in the USA.  

International shipping, and to Hawaii, Alaska, and Puerto Rico is by United States Post Office (USPS) Priority, usually 4 to 6 days to your nation's customs station, political import fees may apply, and a signature is always required for international deliveries.

For US shipments, if you do want “signature-required for delivery”, or any comment you would like to add, please put this request in the “Special Instructions box in the Derby Rims shopping cart's shipping page, before confirming your order. ( www.shop.derbyrims.com )

X-CoUntry, ALL-Mountain, or DOWNHILL LAYUP?

The AM Derby Rims are about the same weight as 24mm wide major brand's "light weight" aluminum rims.

The external design and all dimensions of the rims are the same for either XC layup, AM layup, or DH layup, for each wheel size. Only the additional  carbon-fiber layering inside the hollow “double wall” rims is thicker in the AM and DH options. The AM is about 20 to 25 grams heavier in carbon-fiber layering than the XC layup, and the DH is about 30 to 40 grams heavier in carbon-fiber than the AM.

Riding fast though rocks is the most harsh and damaging condition for a bike and wheels, more harsh and hard on equipment than landing 10 foot drops. If you ride fast through rocks or roots or like to leave the ground to land jumps or drops, the All-Mountain rims will endure these heavier duty conditions better. If you like to keep the wheels on the ground and riding 80% hardpack, gravel, sandy, loamy.... mostly smoother conditions, the X-Country layup is fine for most riders. The Downhill layup is for maximum durability under the hardest riding conditions for any weight rider of extremely rocky trails, and is recommended for DH bikes, and very heavy weight riders over about 220 lbs on any bike.

If you are a very light body weight rider who is fast over rocks, order the AM rims for trail riding.

Derby Rims are not for weight weenies. These very wide trail rims are for high performance bike handling, improving the performance of nearly any trail tire. These AM rims are about 0.75 lb, about 300 grams lighter per set than an equivalent width aluminum rim. This is a huge weight improvement in rolling weight. With wide Derby Rims there are additional effective ways to reduce weight. Some examples: Wide rims with smaller tires have more traction and cornering grip than a high volume tire with bigger knobs on narrow 30mm rims. And Sapim CX-Ray spokes drop about 100 grams compared to common double-butted spokes.

PROCORE EVALUATION

March 2016
Schwalbe has only tested ProCore with aluminum rims, made by Syntace. Schwalbe ProCore published documentation for outer tire pressures is only valid for aluminum rims.

ProCore is experimental with any brand of carbon rims. Aluminum rims can flex and spring back much more than carbon rims can flex without cracking. When using Derby Rims with ProCore installed, NEVER USE LOWER TIRE PRESSURE in the outside threaded tire compared to the same tire without ProCore installed.

Derby Rims have a deeper rim than recommended by Schwalbe for ProCore use. But the valve lock nut does barely screw in about 2 turns, and is possible to install ProCore in Derby Rims.

Derby Rims recommends a maximum of 4 bar (65 psi) ProCore pressure no matter how heavy the rider weight. Because if the ProCore is compressed by a hard hit with any higher pressure, then ProCore is very hard and transfers all impact to flex the rim. And carbon rims will crack from too much flex.

Experienced Downhill lighter body weight racers never go below 2 bar (or 28 psi) pressure in 2.3 or 2.4 size tires. Any use of lower pressures than 28 to 35 (maximum) psi in Derby DH rims reduce knob edge traction at DH speeds. 

The Derby Rims warranty is published on the Warranty page of www.DerbyRims.com, and the warranty will be honored if ProCore is used and rims are damaged. No refund is possible for used rims, after the rim is built into a wheel. 

​NIPPLE WASHERS?

No nipple washers are required for rim strength and durability, unless the nipples are undersized in rim surface flange size compared the normal 6mm flange width, such as when using internal tower nipples. Smaller internal nipple rim spoke holes can be special ordered, so that no washers would be required for internal nipples.

​SPOKE LENGTH?

Building wheels is very satisfying. It does take a long time at first. My first full wheel build took me about 6 hours. Now I can build wheels in about 2 hours each, and that is slow. The pros are less than 1 hour each wheel. Use a professionally build wheel with the same spoke count next to you to reference for the lacing pattern. It's pro style to align the hub label center with the rim's valve hole (kind of tricky to do at first).

A spoke tension gauge is REQUIRED to build durable wheels.

Here is a link to the DT Swiss spoke calculator. It has their DT Swiss hubs in their drop down list, otherwise you need to get the hub specs or measure the hubs for the spoke hole center and flange width numbers needed for the calculator.

http://spokes-calculator.dtswiss.com/Calculator.aspx

You will need the ERD (Effective Rim Diameter). The ERD measurement is listed above in the rim specifications.

Use the "rounded" (stretched by tensioned) spoke length measurement calculated, and round up or down to a whole mm number get the length of spokes to order.

I use the average "Rounded" measurement of all four sides (if the flanges are all the same diameter), and round up to the next mm to get one spoke length that works well for both sides of both hubs. I have never had a problem using the average of all the "Rounded" numbers when all four flanges are the same size.

Professional wheel builders tend to be very exact and want perfect measurement for each side, each flange. The DT Swiss spoke calculator can provide the precise lengths if you want exact length for each side to evenly fill the nipples to the maximum without being too long.

I like using 14mm or 16mm nipples for a better appearance in my eyes. Standard 12mm nipples also work fine, but look very short in carbon rims.

Here's a place I've found to get spokes and nipples for less than anywhere I've ordered from before. "Dan's Comp". https://www.danscomp.com/

There are many videos on U-Tube and guides on line for wheel building if you search with google.

​IS TIRE PROFILE CHANGED WITH WIDER RIMS?

I always recommend using the same tires your are most familiar, even if used and swapped form another wheel set, and ride on familiar trail, as a baseline, to feel the difference with wide Derby Rims. I've found that old worn out tires work better on Derby Rims than the same tires when new on narrow 30mm rims.

The tread profile is really not changed as much as is hyped by some riders without experience, or very little experience and have not tuned tire pressures to be optimized lower than they had on narrow rims. The sidewall becomes wider mostly near the rim, and no wider near the edge knobs. More square profile tire edge knobs rise about 1 mm or so, less so with rounder profile tires, the center cannot rise because it is constrained like a belt around the wheel. The casing is constrained in diameter and profile, so the casing stiffens under the edge knobs and gives a feeling of a harder edge and more stable tire.

Wider rims enable much lower tire pressures, from 5 to 10 psi lower, heavier riders able to lower air pressure more than lighter riders who already can ride much lower pressures on narrow rims. With lower tire pressures the edge knobs and casing comply more to the ground surface during cornering, increasing tire patch size when weighted in a corner. And cornering is more forgiving with the same tires on wider rims, they do not wash out as easily or as quickly as the same tire on narrower rims. There are some who have no experience who say that the profile becomes much more square with wider rims, and then the tire suddenly looses traction, which is not true, the tire whether rounder or more square in profile design slides with more predictability when set up with optimized lower pressure for the wider rim.

If you like round profile tires now, they will remain just about the same round profile, with more traction and more edge bite. If you like more square tires, they will square up slightly more and become more forgiving and slide at the limit more predictably using lower pressures enabled by the wider rims.

WIDE RIMS CHANGE TO TIRE SIZE:

Going to wider rims, the tire's circumference doesn't grow taller, except very slightly in diameter increase if the 35 mm to 50 mm wide Derby Rim is more than about 20 mm wider than the previous rim with the same tire. I've closely measured roll-out circumference which calculates to tire height, and measured knob width too. Using the same 2.3 Pacenti neo-moto tire on a 650b x 40mm Derby Rims compared to a 28mm Blunt, the tire doesn't grow taller, the tire is no higher at the center knobs, and the edge knobs are actually a very small measurement narrower, about 0.0225 inch  or 0.6 mm narrower. But the edge knobs do "stand up" a little higher making a more "square" tread profile, and these edge knobs do come closer to the arch of a fork or yoke of a chain-stay by about 1 to 1.5 mm, so it is slightly closer clearance above the edge knobs.

Tire sidewalls increase in width with increased rim width. The tire beads widen the same amount as the rim width increase. But because the tread cannot grow wider unless wrapping far down the sidewalls, the sidewall is constrained and with widest section of sidewall increases in width 50% of the increased rim width. For example the same tire going from a 25mm wide rim to a 35mm wide rim will increase in sidewall width by 50% or 5mm, and become 2.5mm closer to the fork legs or rear stays, and the tire is no taller except the edge knobs stand up a very small amount. If the tread remains the widest cross section of the tire after mounting on a wider rim, there will be no increase in tire width because the tread (that can contact the ground during cornering) cannot increase in width going to a wider rim.

"27.5" (650b)  x 40mm '35i'

AM, DH layup options - for 2.2 to 3.0 tires

Weight +/-10: 485g [All-Mountain], 545g [Downhill, e-Bike]

BSD: 584mm

Outer width: 40mm, Inner width: 34.5mm

​Depth: 31mm

ERD: 542mm (DH add 1mm) – Always  measure to confirm

AM Rim impact force test: 267KgF (588lbs, cracks at valve hole, 90' from force)

AM Spoke pull force test: 352KgF (775lbs, spoke broke, no rim damage)

​​"29" x 35mm '30i'

XC, AM, DH layup options - for 2.0 to 2.8 tires

Weight +/-10: 460g [XC], 485g [All-Mountain], 525g [Downhill, e-Bike]

BSD: 622mm

Outer width: 35mm, Inner width: 29.5mm

​Depth: 31mm

ERD: 582mm (DH add 1mm) – Always measure to confirm

29r AM Rim impact force test: 224KgF (494lbs, cracks at valve hole, 90' from force)

29r AM Spoke pull force test: 326KgF (719lbs, spoke broke, no rim damage)



"27.5" x 50mm '45i' - for Plus tires

AM, Enduro-DH layup options - for 2.8 to 3.8 tires

Weight +/-10: 530g [All-Mountain], 560 [Enduro-DH, e-Bike]

BSD: 584mm

Outer width: 50mm, Inner width: 44.5mm

Depth: 34mm

ERD: 538mm – Always measure to confirm

Spokes off-set from rim center: 5mm



"29" x 45mm '40i' - for Plus tires

AM, Enduro-DH layup options - for 2.5 to 3.5 tires

Weight +/-10: 520g [All-Mountain], 565 [Enduro-DH, e-Bike]

BSD: 622mm

Outer width: 45mm, Inner width: 39.5mm

​Depth: 31mm

ERD: 582mm – Always measure to confirm

Spokes off-set from rim center: 5mm

29rx45 XC Rim impact force test: 436KgF (961lbs, cracks at valve hole, 90' from force)

29rx45 XC Spoke pull force test: 325KgF (717lbs, spoke broke, no rim damage)



TECHNICAL SPECS, RECOMMENDATIONS, & FAQ's


Photo above is courtesy from Mike Curiak, of Big Wheels, Grand Junction, COwww.lacemine29.com

"26"  x 40mm '35i'

AM, DH layup options - for 2.2 to 3.0 tires

 Weight +/-10: 440g [All-Mountain], 465g [Downhill, e-Bike]

BSD: 559mm

Outer width: 40mm, Inner width: 34.5mm

Depth: 31mm

ERD: 518 mm (DH add 1mm) – Always measure to confirm

AM Rim impact force test: 373KgF (822lbs, cracks at valve hole, 90' from force)

AM Spoke pull force test: 427KgF (941lbs, spoke broke, no rim damage)

700c x 32mm deep x 23i mm CX / Gravel Road

One light weight layup option - for 25mm to 48mm tires

Disc-brake, tubeless-ready tires only, 95 psi max.

Weight +/-10: 430g 

BSD: 622mm

Outer width: 29mm, Inner width: 23mm

​Depth: 32mm

ERD: 578mm – Always measure to confirm

CX Rim impact force test: 272.7KgF (601lbs)

CX Rim Spoke pull force test: 410.4KgF (905lbs, spoke broke, no rim damage)

​​​All Rims
  • Material: UD carbon-fiber
  • Spoke holes - Mountain: 32, 28.
  • Spoke holes - Road: 20, 24, 28, 32. CX/Gravel: 24, 28, 32.
  • Spoke hole size: 4.5mm (for external nipples)
  • Spoke hole alignment, for all rims (except 27.5: x 50mm and 29" x 45mm): Rim centered, All rims have spoke holes angled towards hub flanges. Key/First spoke: Stand up the rim vertical as if ready to roll forward, with valve hole at the ground. Looking down at the valve hole, the 1st spoke hole forward of the valve hole angles to the right-side hub flange, next spoke hole forward angles to the left side hub flange, etc.
  • Presta valve hole, required length: 40mm minimum (48mm Orange Seal valves are recommended)
  • Recommended max spoke tension: 125KgF
  • Recommended rider weight limit: 200 lbs / 90kg  for XC rims, 220 lbs 100Kg  for AM, 245 lbs 120Kg for DH, RC,RD, CX rims
  • Max tire pressure (mountain): 35 psi (for road use), 25 psi for 2.6 and larger tires. Max for DH race/park/shuttle: 32 psi, ProCore max pressure: 70 psi, 4.5-bar
  • Max tire pressure (CX/Gravel tubeless-ready tires only): 95 psi (for paved road use)
  • Max tire pressure (RC/Road Clincher tubed or TR tires): 125 psi
  • Minimum tire pressure (35mm and 40mm rims):                      XC hard-pack/gravely: psi = ( 10% x [rider+bike in lbs] );                  AM (rocky and fast trail): psi =  XC psi calculated + 2 - 4 psi          DH park and DH race and eBike: psi = XC psi calculated + 8 psi
  • Tire pressure to seat beads of most new tires, with soapy water or bead seating lubricant: 35 to 40 psi for mountain rims, or 60-90 psi for CX gravel road rims and RC or RD road rims.
  • Tubeless rim tape maximum width: 18mm or ¾ inch; 25mm or 1 inch only for 29x45mm rims; 12mm only for CX, RC, or RD rims. Only tape within the center channel, not taping over the bead seats, for best results.
  • Recommended rim tape : Orange Seal rim tape 18mm or 25mm wide (two rounds), Stan's 12mm wide for CX (two rounds).
700c x 32mm deep x 22i mm Road - RC & RD

One light weight layup option - for 25mm to 48mm tires

RC - Road Cantilever (w/ rim-brake surface), RD - Road Disc

Both tubed clincher or tubeless-ready tire compatible, 125 psi max.

Weight +/-10: 440g

BSD: 622mm

Outer width: 29mm, Inner width: 22mm

​Depth: 32mm

ERD: 578mm – Always measure to confirm