FROM   £29.97 RRP: £44.99 YOU SAVE 33%
4.66666667 Read Reviews (30)
Add to Basket

Leave a review

Close X


Product Description

The Kryptonite Evolution Series 4 U-Lock is a true deterrent for any thief, so you can be sure your bike is safe - whether you’re at work, shopping or at home. Sold Secure Gold with £1,000 anti-theft protection this bike lock provides the highest level of security for moderate to high crime areas.

The patented double deadbolt locking mechanism has extensive holding power, while the reinforced internal housing has incredible resistance against twisting or leverage style attacks.

Anti rattle bumpers will prevent scratches to your precious bike frame, and the Evolution Series 4 itself weighs surprisingly less than you might expect from such a sturdy lock. It’s definitely light enough for you to put in your pack. The Kryptonite Evolution Series 4 U-Lock should be on every cyclists wish list.

Weight - 1.8kg (includes keys & fittings)


  • 14 mm hardened Kryptonium steel shackle
  • Patented double deadbolt locking mechanism for extensive holding power
  • High security ovalised cylinder that makes this a sold secure gold lock
  • Reinforced sleeve over crossbar and cylinder provides enhanced security protection
  • Reinforced internal housing increases resistance to twisting and leverage type attacks
  • Offset key location and overhead cam locking mechanism resists leverage attacks
  • Double deadbolt locking for extra strength against leverage attacks
  • Anti-Rattle bumpers keeps the shackle snug against the crossbar and prevent unnecessary noise
  • 3 keys, including 1 lighted
  • The Transit FlexFrame-U mounts quickly and easily
  • The Flex Frame-U fits bicycle frame tubing 25mm to 80mm and any shape
  • The mounting system allows for 360-degree rotation providing the ability to micro-adjust the lock angle
  • Rotating dustcover over cylinder protects from dirt and grime
  • Vinyl coated and weatherproof
  • U-lock dimensions: 10.2 cm x 29.2 cm x 14 mm

Weight: 0 kg

£5 Off Your Next Order - Review this product to get your voucher code Review

Kryptonite Evolution Series 4 U-Lock with FlexFrame Bracket Reviews

Overall Rating:5 - Rating: 5 / 5
Have been cycling the london streets for 2 years with this lock and no stolen bike! So good im buying a second lock for the lady!

Overall Rating:5 - Rating: 5 / 5
"very secure"
feels very sturdy seems quite resistant to attacks would be tempted to try more evasive actions against to see how strong it is but dont want to ruin a perfect lock

Overall Rating:5 - Rating: 5 / 5
"Robust security for your bike"
I wanted a strong U lock with a shank length that allowed you to fix the frame and rear wheel to a secure object and this fits the bill. The bright colouring makes it clear the bike is secured. Although not a backup for insurance the 1 year policy associated with the lock adds to your confidence in the product.

Overall Rating:5 - Rating: 5 / 5
"Great but too heavy"
I think its a great sturdy lock but personally I find it too heavy for carrying around.

Overall Rating:4 - Rating: 4 / 5
"Great lock excellent guarantee"
This is a quality lock at a great price. Kryptonite give you a £1000 anti-theft guarantee if you register the lock within 15 days of purchase which is really helpful and provides even more security. Comes with 3 keys I keep one on me have one at home and the other in the office. Weight is pretty good too whether you carry it in your bag or on your frame via the included attachment.

Overall Rating:5 - Rating: 5 / 5
Excellent product immaculate build quality and along with the brand name a massive deterrent to anyone looking to pinch my bike.

Overall Rating:4 - Rating: 4 / 5
"EVO 4 Lock"
this is a sturdy heavy dlock. Ive had for over a year and its had no real issues although Ive had to place a little lube on the prongs of the shackle a couple of times as seems to rust up slightly but no issues after little oil

Overall Rating:5 - Rating: 5 / 5
"Kryptonite for female urban commuters"
Good choice for female urban commuter looking for a midprice d lock. Initially borrowed this lock from my housemate and now converted. It is tough and yet also sits comfortably in my front basket.

Overall Rating:4 - Rating: 4 / 5
"Heavy solid reliable"
A good sturdy lock. Needs oiling otherwise it can seize up. Key doesn't seem the strongest I've ever seen but its worked for two years regardless!

Overall Rating:4 - Rating: 4 / 5
"Bike lock"
It looks like a good bike lock so hopefully it is It looks like a good bike lock so hopefully it is It looks like a good bike lock so hopefully it is

Overall Rating:5 - Rating: 5 / 5
"Kryptonite ulock"
Solid well made and easy to lockunlock. Very pleased with it so far.

Overall Rating:4 - Rating: 4 / 5
"A great lock"
This is a great lock. Its kept my bike safe across London and is not too heavy considering its rating. The plastic bracket could be a smoother operation but it does the job.

Overall Rating:5 - Rating: 5 / 5
"very strong cheapest price for this lock on the net"
i bought this lock because not only will kryptonite kind of insure it but because it is very strong and deters theives. its a shame it didnt come with the kryptoflex cable otherwise it would have been perfect

Overall Rating:5 - Rating: 5 / 5
"kryptoflex evo 4 u lock"
Looks and feels solid. Smooth locking action makes fitting a breeze. Works very well with Kryptoflex cable. Havent bothered with FlexFrame fixing bracket so cant comment on its efficacy. Overall very pleased with it so far.

Overall Rating:5 - Rating: 5 / 5
Very good item very security good quality excellent!!!!!

Overall Rating:5 - Rating: 5 / 5
solid very heavy so I need to get another one to leave at work and one for home.

Overall Rating:4 - Rating: 4 / 5
"Excellent one"
Seems strong and unbreakable it can prevent a thief from trying to steal your bike

Overall Rating:5 - Rating: 5 / 5
"Great lock great price"
Excellent lock great build quality easy to fit fast delivery great stuff!

Overall Rating:5 - Rating: 5 / 5
"Solid Lock"
This lock is exceptionally strong for the money has a very impressive tonnage pull breaking point.

Overall Rating:5 - Rating: 5 / 5
"Great item"
Great item bought at a good price as well discounted by Tredz. I have no problems leaving my bike outside.

Overall Rating:5 - Rating: 5 / 5
"Very good"
Good quality with a heavy sturdy design. 3 keys is excellent some other locks only come with 2. Very fast delivery

Overall Rating:3 - Rating: 3 / 5
"Solid lock"
Its big and heavy and seems like it does a good as a lock. Let down by the cheap plastic keys and a terrible and unreliable led light on one of them.

Overall Rating:5 - Rating: 5 / 5
"Great lock"
This lock is very strong and secure. I already have the same lock for another bike and would recommend them for quality.

Overall Rating:4 - Rating: 4 / 5
"Excellent Bike Security"
The lock is solid and looks safe and secure. It has good length although I would prefer it slightly wider for wider posts. It comes with 3 keys which is great. I dont find the weight too much once its in my pannier although other people have complained about it.

Overall Rating:5 - Rating: 5 / 5
"Kryptonite Evolution Series 4 U Lock"
Top quality lock a must for anybody that cares about their bicycle.

Overall Rating:4 - Rating: 4 / 5
"Good bike lock"
Keeps my bike safe and secure from people trying to get into it. Feel like I can bike in town safely.

Overall Rating:5 - Rating: 5 / 5
"Kryptonite evolution series 4 "
A heavy but stong lock leave your bike locked with confidence. Make sure if you have a cable with the lock as well stow it away mine some how unwound and I lost it out of my panniers.

Overall Rating:5 - Rating: 5 / 5
"Solid lock"
This lock is well constructed and has a really solid feel. Comes with three keys the action of which are very smooth. It gives one a sense of security when leaving ones bike in the city.

Overall Rating:5 - Rating: 5 / 5
"Rock Solid"
Very impressed with the quality of this lock feels very solid and hopefully unbrakeable. A great deterrent for your pride and joy.

Overall Rating:5 - Rating: 5 / 5
"Looks reliable"
I just literally got this hence the four star since im not sure. Seems totally strong which is why I bought it. My Abus silver rating got cut like butter. However cant hang it anywhere from bike as is too big and doesnt fit and is actually quite heavy... Have had problems with keys breaking inside locks with other brands hoping Kryptonite keys will be good! Any reviews on that would be good...worth checking reviews out for that in case...


How do I apply for finance?

Spend more than £280 at Tredz and you can spread the cost. Pay monthly over 6-48 months, interest free

  1. Fill your basket with everything you want from Tredz and go to the checkout.
  2. During checkout, select the finance option you want as your method of payment.
  3. You will be sent to our finance provider’s secure server to complete your application.
  4. Finance provider V12 will use the information provided to make a decision and complete checkout if you are approved.

How do I get a Cycle to Work bike from Tredz?

It's as easy as 1, 2, 3

If your employer is already running a scheme, you’re just three steps away from receiving your new bike and equipment

  1. Email us with a list of items at
  2. We’ll send you a quote within 48 hours, which you pass on to your HR department.
  3. Your employer will order your Cycle to Work voucher. Once you receive it, send to us, then we’ll deliver your new bike and safety equipment.

We accept cycle to work vouchers from all these providers:

UK Delivery Information

We are committed to offering fast and free delivery, whether you're ordering bikes, accessories or clothing. Our standard delivery service is FREE to mainland UK, regardless of the size and value.

Please note: bulky products and bikes shipped to outlying UK regions are excluded from free shipping - Click here for more info.

International Orders

Country Small orders Bulky orders Large orders / bikes Delivery (working days)
Austria £7.99 £18.99 £29.99 3-4
Belgium £4.99 £14.99 £24.99 3-4
Bulgaria £7.99 £18.99 £29.99 5-7
Cyprus £14.99 £29.99 £89.99 5-7
Czech Republic £7.99 £18.99 £29.99 3-4
Denmark £7.99 £18.99 £29.99 2-3
Estonia £7.99 £18.99 £29.99 4-5
Finland £7.99 £18.99 £29.99 3-4
France £4.99 £14.99 £24.99 2-3
Germany £4.99 £14.99 £24.99 2-3
Greece £7.99 £18.99 £29.99 4-5
Hungary £7.99 £18.99 £29.99 3-4
Irish Republic £4.99 £14.99 £24.99 2-3
Italy £7.99 £18.99 £29.99 2-3
Latvia £7.99 £18.99 £29.99 4-5
Lithuania £7.99 £18.99 £29.99 4-5
Luxembourg £4.99 £14.99 £24.99 2-3
Malta £14.99 £29.99 £89.99 4-6
Monaco £7.99 £18.99 £29.99 2-3
Netherlands £4.99 £14.99 £24.99 2-3
Poland £7.99 £18.99 £29.99 3-4
Portugal £7.99 £18.99 £29.99 3-4
Romania £7.99 £18.99 £29.99 4-5
Slovenia £7.99 £18.99 £29.99 4-5
Spain £7.99 £18.99 £29.99 2-3
Sweden £7.99 £18.99 £29.99 3-4

Easy Returns

Simply return the items to us in their original, resaleable condition, and securely packaged, within 365 days of receipt.

Collect Plus

Easy as one, two, three

For items under £75 and 10kg, you can use the Collect Plus service by printing your label off online and dropping your package off at a local store.

Step one - Repackage your item and include a returns form

Step two - Buy and print a returns label

Step three - Take your item to your local shop, pay your £4.49 and get a tracking receipt

Tredz Online Sales, Castell Close, Swansea Retail Park, Llansamlet, Swansea, SA7 9FH
E-mail: | Tel: 01792 799508