Critical Cycles - Beaumont 7-Speed Diamond City Bike Charcoal / 50cm / s, Critical Cycles - 5

Beaumont 7-Speed Diamond City Bike

$ 299.99 $ 219.99
Suggested Height:
5'2" - 5'9"
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Our latest offering in city-dwelling transportation has something for every type of rider, riding on any type of urban terrain. Combat Bay Area inclines, flat Chicagoland bureaus, and all else in between with a classic retro style and ease of a top-notch hybrid city bike ride. Combined with front and rear alloy brakes, the Shimano 7-speed drivetrain and RevoShift grip shifters ensure the utmost control and precision.

The Frame

We stuck to the classic tried-and-true diamond shape in this lightweight, hand-built, high-tensile strength steel frame with rack & fender braze-ons. Unlike the heavier materials found in other bikes, a steel frame means you get an absorbent, softer ride, ideal for your daily commute.

The Parts

Between the seven-speed Shimano Rear derailleur and the RevoShift grip shifter, you can do just about anything on this sublime commuting machine. The Shimano drivetrain is one of great prestige. Shift gears with precision and speed. The shifter is integrated into the grips on the handlebars, which means you never have to compromise control of your bike or ride. Simply twist your wrist to switch gears. The Beaumont-7 city bike also has front and rear alloy brakes for responsive stopping and safer rider. 

The bottom bracket is sealed, protecting the fragile pieces of the bike from getting damaged or dirty. This sealed mechanism keeps out dirt, water, and muck and also reduces the amount of necessary maintenance over the bike’s lifetime.

The Pieces

Beaumont 7-Speed Diamond City Bike has extra robust 700x35C Wanda tires for reliable gripping and improved shock absorption. 

These tires are resilient against potholes and uneven ground. Plus Wandas have unique water dispersion tread, which evenly distributes water, resulting in a better grip in damp conditions.

*All of our bikes have a weight limit of 220 lbs.

Included Accessories
Chain guard, Center Mount Kickstand, Classic Bell, Fenders, & Tools
Extra-Soft Brown Rubber
Synthetic Leather
Lightweight Hand-Built Diamond High-Tensile Strength Steel Frame with Rack & Fender Braze-Ons
Lightweight Hand-Built Classic Urban Fork
Bottom Bracket
Neco Sealed Cartridge Bearing 110.5mm
Neco 1-1/8” Steel
Alloy Riser City Bars 620mm, 60mm rise, 15° sweep, 25.4 Center
Alloy 30° Rise, 220mm, 25.4 Clamp
Shimano 7-Speed Revoshift Grip-Twist Shifter
Brake & Lever
Alloy Dual Caliper Brake & Alloy Four Finger Lever
700c Stars Deep-V Double-Wall Alloy Rim 30mm 32H with machined sidewall
Front Hub
KT 100mm spacing, 32H
Rear Hub
KT 135mm spacing, 32H
Shimano TX35
Kenda Kwest 700 x 32c
Kenda 700 x 32c, Schrader Valve
Protek Alloy 170mm, 44T Chainring
KMC Z410, 1/2" 1/8"
Seat Post
Alloy 25.4 x 300mm
Seat Clamp
Alloy 28.6
Urban Pedal Alloy 1/2"


What we give you: 2 Allen wrenches (5mm & 6mm), a 10-function multi-tool

What you need: scissors or diagonal cutters, Phillips screwdriver, 15mm open end wrench or adjustable wrench


Unpack Your Bike

1 – Cut the white shipping straps on the outside of the box.

2 – Remove the box staples as these are sharp and can cut you as you access the bike. Open up the cardboard flaps and lift the bike out of its box.

3 – Rotate the fork so that it is facing forward of the bike. Place the bike on the ground, so it’s standing upright on the fork dropouts and rear tire.

4 – Cut all of the zip ties.

5 – Separate the loose front wheel from the bike by carefully slipping it away from the crank arm, which is resting within the spokes.

6 – Remove the accessory box and set it aside.

7 – Examine your new bike for any visible damage that may have occurred during shipping and make sure you have all of its bits and pieces.

NOTE: For tightening all fasteners, please refer to Appendix D in the back of your owner’s manual for all fastener torque specifications.



1 – Remove the plastic shipping plug from the top of the seat tube.

2 – Use the included Allen wrench to loosen the seat clamp at the top of the frame.

RECOMMENDED: Apply a thin layer of grease to either the end of the seat post or inside the seat tube.

3 – Insert the seat with the seat post into the seat tube of the frame to at least the minimum insertion line on the shaft of the seat post.

WARNING! The minimum insertion line must NOT show above the seat tube.

4 – Using the Allen wrench, tighten the seat clamp once it is at the correct height.

NOTE: This is how you will adjust the height of the seat as needed in the future.


WARNING! Using the bike with the minimum insertion line on the lower portion of the seat post showing above the frame could result in a failure of the seat post and/or the frame causing a loss of control with potential injury to rider. Such failures are not covered by warranty as it is improper use of the product.



1 – Loosen the stem bolt at the top of the stem, remove the plastic packing cap from the bottom of the stem.

RECOMMENDED: Apply a thin layer of grease to the end of the stem shaft by the wedge.

2 – Untwist the handlebars and control cables and insert the quill end of the stem into the fork steer tube. You may have to loosen the bolt and wedge a small amount to allow the quill to fit into the steer tube.

3 – Make sure that the fork is facing forward and the handlebars are lined up with the fork dropouts.

4 – Adjust the height of the stem to your desired level and tighten the stem bolt using a 6mm wrench.

NOTE: Be sure that the minimum insertion mark on the shaft of the stem is inside the frame—it must not be visible outside of the frame.



Installing the stem with the minimum insertion mark showing outside of the frame could create a dangerous condition allowing the stem to break causing the rider to lose control resulting in serious injuries to the rider.


Front Wheel

1 – Flip the bike over so it’s resting on the saddle and handlebars.

2 – Remove the small black plastic protector from the fork dropouts.

3 – Loosen the axle nuts on the unattached front wheel.

4 – Place the front wheel into the fork dropouts and insert the safety washers into the small holes on either side of the wheel on the outside of the fork.

5 – Begin tightening the axle nuts on each side of the wheel by hand.

6 – Inspect the wheel to make sure it is centered in the fork. To do this, stand the bike up on its wheels and check to see that the axle is fully in the drop out. Then tighten each axle nut with the wrench, alternating between sides, until each axle nut is properly tightened.



1 – Locate the pedal labeled “R” (you’ll find this identifier on the end of the spindle). This is your RIGHT pedal.

2 – Thread the pedal by hand onto the right side crank arm CLOCKWISE. This is the side of the bike with the chain. Tighten the pedal with the wrench provided until the pedal is securely fastened to the crank arm.
3 – Repeat these steps on the left side of the bike. This time, though, be sure to thread the LEFT pedal COUNTERCLOCKWISE to tighten.

RECOMMENDED: Apply a thin layer of grease to the pedal threads prior to installation.

NOTE: The pedals should thread in with ease. If it seems hard, stop, remove the pedal, realign the threads, and try again.

NOTE: Be sure to tighten both pedals with an adjustable wrench or 15mm open end wrench to the recommended torque specification otherwise they will unscrew while riding causing an unsafe condition for the rider and damaging the threads in the crank.


Front Fender

1 – Remove the long bolt, washer, and nut at the top of the fork. Locate the light mounting bracket supplied in the box with the light and slip it onto the long bolt.

2 – Slide the fender in place from the back. Insert the long bolt with the light bracket through the fork from the front of the bike. At the back of the fork, place the bolt through the fender mounting tab along with washer and nut. While pushing the fender tab up as far as it will go, tighten the bolt and nut to secure the fender to the top of the fork.

3 – Position the fender braces to the mounting holes on the fork drop-outs. It’s okay to squeeze inward as these struts are designed to be pliable. Partially thread the screw through the fender brace into the drop out and repeat for the other side. Once both braces are partially attached, tighten brace screws to complete attaching your fender.

4 – If the fender is not straight, that’s okay! As we mentioned before, the fender struts are pliable. Gently adjust the fender by hand until it’s straight.


Rear Fender

1 – If the red rear reflector is not already attached to the rear fender, install it now.

2 – Remove the fender attachment screws from the rear frame drop-outs.

3 – Position the fender struts to match the mounting holes on the rear drop-out and insert the screw through the end of the brace and screw into the drop-out. Repeat on the other side. If the struts are spread apart it’s OK to squeeze inward as these struts are designed to be pliable.

4 – If the fender is not straight, gently adjust the fender by hand until it’s straight



1 – Remove the two screws on either side of the back wheel at the top of the rear drop-outs (by the rear axle).

2 – Take note of the direction of the rack; the mounting arms should face forward. Place a rag over the top of the fender and rest the rack over the top of the fender, align the lower braces with the mounting points at the rear drop-outs using the screws to attach the braces. You may need to squeeze the braces inward in order to attach the screws to the bike. Start tightening the screws a little bit on each side. Make sure the screws are threaded properly otherwise you may strip the frame.

3 – Unscrew the two mounting screws on either side of the frame at the base of the seat post.

4 – Loosen the screws at the top of the rack securing the metal rods and pull the metal rods through to be long enough to attach to the frame.

5 – Adjust the rack so it is level and tighten all rack mounts down tight.



1 – Remove the screw, spiked washer, lock washer, and nut from your headlight.

2 – Place the spiked washer between the headlight and the mounting bracket (which you previously installed on the bike).

3 – Insert the screw through the mount, light, and spiked washer and install the lock washer and nut.

4 – Tighten and rotate into place.  



1 – Remove the 2 screws and flip the bracket over. Partially thread in one screw and clamp around the left side of the handlebar next to the grip.

2 – Pay attention to the orientation of the lever on the bell. Using the screwdriver, tighten the screws and rotate it into your preferred position.


Brakes and Gears

NOTE: We highly recommend taking your bike to a local bike shop and having your brakes set-up by a professional mechanic.


1 & 3 Speed Models – These models are equipped with a foot operated rear coaster brake. No adjustment is required. Simply push backwards on the pedals to activate the brake.

7 Speed Models – Your Critical City 7-speed bicycle is equipped with front and rear linear-pull brakes.

  1. Be sure that the brake pads are aligned with the curve of the rim and that they contact the rim surface flat and evenly. The brake shoe angle and height can be adjusted by loosening the Allen bolt attaching the brake shoe to the brake arm. Notice that the brake shoe can articulate a certain amount up and down and side to side.
  2. Loosen the brake cable anchor on the brake arm held by an Allen bolt allowing the brake cable to freely glide through its anchor.
  3. Squeeze the brake arms together until the brake shoes contact the rim surface. Pull the cable taut through its anchor and tighten the cable anchor bolt. Make sure the brake cable housing is seated properly at the cable stop ferrules before tightening the anchor bolt.
  4. Squeeze the brake lever hard several times to take the stretch out of the cable and make sure that it does not slip through its anchor. If the cable tension is too tight to allow the brake shoes to retract and clear the rim surface, loosen the anchor bolt and give the cable some slack. If the cable has too much slack and you cannot apply enough stopping force to the rim, repeat procedure “B” and take the slack out of the cable.

Be sure that the brake arms are evenly spaced from the wheel and there is some clearance between the brake pads and the rim surface. If the arms are not evenly spaced from the wheel, you can balance the spacing by tightening or loosening the spring tension using the small screw located at the lower side of each brake arm.


3 Speed Models – The gears on this model come adjusted from the factory. If the gears need adjustment – position the gear shift lever in 3rd gear. Remove the plastic cover from the right side of the rear wheel at the axle. Loosen the locknut at the gear cable adjusting barrel. Tighten or loosen the adjusting barrel until you just take the slack out of the cable. Do not over tighten the cable. Tighten the locknut against the adjusting barrel and re-attach the plastic cover. NOTE: Momentarily stop or lighten your pedaling when shifting.

7 Speed Models – The gears on this model come adjusted from the factory. If the gears need adjustment, please have this done by a professional bike shop.

NOTE: You must be pedaling while shifting for the gears to shift.



1 – Attach the plastic bracket to the handlebar.

2 – Slide the white reflector onto the bracket. It should click as it locks in place.

3 – Attach the wheel reflectors onto the spokes of the wheels (If not already installed at the factory).



  • Locate the tire manufacturer’s recommended inflation pressure found on the tire sidewall (listed as “PSI”).
  • Using a hand or floor pump with a gauge, begin to inflate the tire to half its recommended inflation pressure and check to see that the tire is properly seated on the rim. Be sure to inspect both sides of the tire for proper fit.
  • If the tire is seated unevenly or bulges out along the rim, let some air out of the tire and reposition the tire by hand so that it sits evenly on the rim.
  • Continue to inflate the tire to the manufacturer’s recommended pressure.
  • Do not exceed the recommended pressure as this will cause an unsafe condition potentially causing the tire to unexpectedly explode.
  • Do not use a compressed air device to inflate your tires as the rapid inflation of the tire can cause it to explode.
  • Tires and tubes are not warranted against damage caused by over-inflation or punctures from road hazards.



We strongly recommend you take your bike to a professional bike shop and have them check your work and fine tune the bike to ensure your bike is safe to ride.


Shipping on all orders over $65 heading anywhere within the contiguous U.S. is free. Shipping on orders under $65 will cost a flat rate of $7.98. You can also choose to have signature required when your products are delivered for an additional $5.98.

We try really hard to ship all orders within 1 business day, but sometimes we're backed up. Most orders will go out within 3 business. Your order will be delivered within 1-5 business days.

We ship most of our orders out through FedEx. Keep this in mind when you're choosing a shipping method. If you don't request a signature and you're not home when FedEx arrives, it is left up to the driver's discretion to leave the package or not. Sometimes we send smaller orders out through USPS.

Check out more information about our shipping policies here.

Returns Policy

Great news! We offer a 50 day return policy! Returns are accepted for the full product credit if received at our warehouse within 50 days of the date of purchase in the original packaging that is still in retail condition.

Please bear in mind that our refunds do not include reimbursement of shipping fees.

Check out more information regarding our return policy here.

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