CR/XR50 Frequently Asked Questions
Note: Some of the items discussed in this FAQ are no longer available. This
information has been left online for historical reasons and to assist current owners of these now
discontinued items. If any of these parts are still available (new, used, or otherwise), they will
be listed on our product pages. To see all product listings for the this model click
Our BBR Product Identification section has more information about older products from our past.
Is the BBR pipe louder than stock?
Yes. Unfortunately, power and sound go hand-in-hand. Don't let anybody tell you
different. We have neighbors and ride in our backyard's too. So we have designed
the BBR CRF/XR50 pipe to accept the stock endcap from the CRF/XR50 exhaust. This
lets you achieve the same noise level as stock. When you are riding in your
backyard, you pop on the stock endcap (3 bolts). When you're at the track,
trying to beat the local heroes, you pop on the BBR endcap. Or you can order the
BBR quiet core ( 220-BBR-1004 $39.95 ) and run the trick fluted end cap.
What is the difference between BBR's pipe and the other guy's pipes?
Compare the details and you'll understand. The BBR pipe is 100% designed and
built in our Auburn, WA production facility. We have our own in-house dyno and
ride mini 4-strokes more than all the other companies combined. We've won every
major mini 4-stroke race in the country and we sell the same pipes we race with
to the public. Our designs are painstakingly developed to achieve the best
possible performance. Most models use multi-stepped headers and all our headers
are ceramic coated or stainless steel. The muffler can is anodized to protect it and keep it
looking great for a long time. Because we're concerned with noise restrictions,
many of our exhaust systems will fit the OEM endcap (for stock noise level). For
full race mode, we include our super trick billet aluminum endcap and US Forest
Service approved spark arrester. We regularly test our competitors pipes and are
confident that ours are the best exhaust systems made. We have the results to
back up our testing.
How fast will the CRF/XR50 (or BBR XR50) go?
Not very fast. That�s why it�s so stinkin� fun to ride. We do not measure top
MPH of any motorcycles. In motocross, it isn't how fast it goes, but how quickly
you get there.
Can BBR sell me cables so that I can use one of the other available triple clamps?
Sure. We are selling our cables and accessories as a kit. Check out our CRF/XR50
product pages for more details.
Why does BBR always use aluminum for its frames?
When used correctly, aluminum is the strongest, lightest material
available for use in motorcycle frame construction. Few companies use it
because of the difficulty in machining, welding, and heat-treating. The BBR
crew has worked closely with major motorcycle manufacturers perfecting the
art of frame building
What fork does BBR recommend for the CRF/XR50s?
Our SP-5 forks are a great all-around fork for the CRF/XR50. The damping and
spring rates are designed for adult riders and hold up well for most abuse. They
are the best forks available for backyard play riding and the best bang for your
buck. I you're going big and for the ultimate performance and durability we
recommend the BBR E-6 or Marzocchi Shiver Works fork kit.
Does BBR sell a disc brake setup for the CRF/XR50?
Sure. Check it out on our products pages.
How much does the Pastrana / McGrath / Carmichael / Gosselaar / Windham / Reed / Lange etc... bike cost?
BBR can hand build your works CRF/XR50 machining and massaging every part for
approximately $2000 to $15000. BBR offers all different levels of bikes to fit
everyone's budget (starting at $3000 for a full aluminum-framed bike).
Can you help me jet my XR50?
There are not two CRF/XR50s that are raced or ridden in the same climate. The
quickest jetting test is to play with the choke. If your bike has an off-idle
stumble, that gets better by pulling the choke on slightly, then you know that
the bike is to lean. The quick fix is to move the clip on the needle down, or go
up 5 sizes on the main jet. This is usually the case with any aftermarket pipe
(BBR included). You are flowing more air which means you need more gas. The
stock CRF/XR50 main jet is a 58. Other sizes are available from BBR or your
Is the XR50 legal to race in the 2-stroke 50 class?
Every track and racing organization is different. Our local tracks run a
separate class for the CRF/XR50 (it happens to be the biggest class). Check with
your track officials.
Are the BBR CRF/XR50 springs too stiff for my 9 year old?
Probably. These we're designed for adults, but we have lots of fast kids that
absolutely love them. You'll have to make the decision. They are about 60%
stiffer than the stock springs. Really fast kids will probably prefer our SP-5
fork kit with stock XR50 springs (or the way we run them, one stock and one stiff
Does BBR make a big-bore kit for the CRF/XR50?
Yes. BBR sells several different big bore kits ranging from 82cc to the wild
dual overhead cam 124cc kit. For backyard riding we recommend the 82-88cc kits.
These kits are our own aluminum cylinder with iron liner, 82-88cc piston, rings,
pin, clips, gaskets, and a high performance camshaft. No exchanges are required.
This piston is 9.75:1 compression (with the CRF/XR50 head) and will run great on
pump gas. We prefer this setup over the bigger bore kits as it lasts longer, is
easier on the oil, and doesn't overheat as easily. This due to the thicker
cylinder sleeve. This kit is the quickest way to double the horsepower on the
CRF/XR50 without reducing reliability. We also have an 88cc kit for use with the
stock head, an 88cc kit with a big valve head, and we have high end engine kits
available. If you're going big, trying to make money, or just need to have the
coolest bike in your neighborhood garage, the Kitaco 124SE kit or Daytona
4-valve kit is the way to go. Engine kits for the XR/CRF50 change daily. So feel
free to give one of our expert sales techs a call for all the latest info.
Will the Super Pro frame kit swingarm fit my stock frame?
No, the Super Pro frame uses an entirely different upper shock mount. In
addition, the shock is not the same as other CRF/XR50 shocks. We have a custom
wound spring that handles that super high leverage ratio of the rear suspension.
We only sell this frame as a set that includes the frame, subframe, shock, and
swingarm ($1899.95). You will need your stock CRF/XR50 swingarm bolt, axle bolt,
and chain adjusters (plus all the other parts).