Tom Bowers Cycling - I Made My 5.5kg BMC Even Lighter - Diminishing Returns Hit Hard

Description

In Part 2 of my attempt to build a genuinely raceable 5kg hill climb bike, things start to get a lot harder.
After Part 1, I took on loads of your suggestions and made a series of logical weight-saving changes, removing inefficiencies, optimising parts I already had, and revisiting some decisions from earlier in the build.

Want to try any of the parts I mention check out the AliExpress link https://s.click.aliexpress.com/e/_EjQrqc0 or enter the search code [AYB4DU] on the AliExpress homepage to see all the AliExpress bike parts I’ve featured recently

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2026/01/12 00:00:00 PST - 2026/01/18 23:59:59 PST

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Timestamps
0:00 Intro
0:57 Your Suggestions
2:48 OSPW
4:10 Tyres
6:06 Skewers
6:44 Shifter Clamps
8:00 Chainring
9:10 ZTTO SLR gen 3 Cassette
11:10 Shorter Chain
12:28 Conclusions and Final Weight

#aliexpresshaul #bikeupgrade #aliexpress #roadbike #weightweenie

Keywords: 5kg bike build,5kg bike,sub 5kg bike,lightweight bike build,ultralight bike,hill climb bike,hill climb cycling,BMC hill climb bike,BMC lightweight build,weight weenie bike,cycling weight saving,road bike weight reduction,cycling upgrades,bike weight reduction,AliExpress bike parts,AliExpress cycling,AliExpress bike build,cheap bike upgrades,cycling engineering,custom bike build,road bike build,cycling performance,climbing bike,road cycling content

Bike part mentions in this video

Bigrock Carbon Crank162.5/165/167.5/170/172.5/175 Cycling Parts 354g Bicycle Crankset For BCD 110 Axis 24mm For Sram Cranks

Bigrock Carbon Crank162.5/165/167.5/170/172.5/175 Cycling Parts 354g Bicycle Crankset For BCD 110 Axis 24mm For Sram Cranks

Created: August 14, 2025

The reviewer mentions the Bigrock cranks as an upgrade installed in a previous video (part one). They state that the cranks were installed with their stock spider and a 4-bolt chainring, which was light but didn't save much weight versus their previous SRAM Red crankset. However, the Bigrock cranks did fix the chainline 'in a quite considerable way.' The reviewer notes the cranks are set up to work with 3-bolt SRAM direct mount chainrings, which allowed them to upgrade to a lighter E13 direct mount chainring for further weight savings and a cleaner look.

AI-Summary

Pros

  • Fixed the chainline 'in a quite considerable way.'
  • Set up to work with 3-bolt SRAM direct mount chainrings, enabling a lighter chainring upgrade.

Cons

  • When installed with the stock spider and a 4-bolt chainring, it 'didn't save me much versus my SRAM Red crankset.'

Key Points

  • Installed in a previous build (part one).
  • Used with a stock spider and a 4-bolt chainring initially.
  • Uses a 3-bolt SRAM direct mount standard.
  • The chainline improvement was significant.
AFFILIATE by MyBikePartsACTIVE
aliexpress.com
πŸ‡©πŸ‡ͺ
€234.99
πŸ‡¬πŸ‡§
Β£206.79
Rating there:
5.0 (25 reviews)
Last checked:
5 months
ago
OGEVKIN Bike Stem Extension Carbon Computer Mount Holder Rack for GPS/Cycling Computer/Camera/Light Bicycle Accessories 3K Black

OGEVKIN Bike Stem Extension Carbon Computer Mount Holder Rack for GPS/Cycling Computer/Camera/Light Bicycle Accessories 3K Black

Created: December 27, 2025

The OGEVKIN Bike Stem Extension Carbon Computer Mount Holder Rack for GPS/Cycling Computer/Camera/Light Bicycle Accessories 3K Black is not mentioned in this video.

AI-Summary

AFFILIATE by MyBikePartsACTIVE
aliexpress.com
πŸ‡ΊπŸ‡Έ
$14.37
πŸ‡«πŸ‡·
€14.19
πŸ‡¬πŸ‡§
Β£11.99
Last checked:
21 days
ago
Kocevlo SL Road Carbon handlebar ultra light 150g Compatible internal cabling system Gravel road bike handlebar 31.8mm

Kocevlo SL Road Carbon handlebar ultra light 150g Compatible internal cabling system Gravel road bike handlebar 31.8mm

Created: June 12, 2025

The reviewer briefly mentions the Kocevlo SL Road Carbon handlebar ultra light 150g Compatible internal cabling system Gravel road bike handlebar 31.8mm but does not provide detailed analysis.

AI-Summary

Pros

  • It is ultra light at 150g.

Cons

  • No cons found in the analysis.

Key Points

  • Ultra light 150g
  • Compatible with internal cabling system
  • 31.8mm diameter
  • Described as a gravel road bike handlebar
AFFILIATE by Tom Bowers CyclingACTIVE
aliexpress.com
πŸ‡ΊπŸ‡Έ
$60.38
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€52.99
πŸ‡¬πŸ‡§
Β£46.09
Rating there:
4.7 (88 reviews)
Last checked:
7 months
ago
AFFILIATE by MyBikePartsACTIVE
aliexpress.com
πŸ‡ΊπŸ‡Έ
$60.51
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€53.69
πŸ‡¬πŸ‡§
Β£46.39
Last checked:
7 months
ago
Bike Quick Release Skewer,Titanium Alloy Axle,Ultralight QR HUB Lever for MTB Road Bicycle,Ti Skewers for 100/130 100/135 Frame

Bike Quick Release Skewer,Titanium Alloy Axle,Ultralight QR HUB Lever for MTB Road Bicycle,Ti Skewers for 100/130 100/135 Frame

Created: January 13, 2026

The reviewer is replacing their existing ZTO titanium/aluminum skewers with a new, lighter set of 'risk' skewers from AliExpress to save weight.

AI-Summary

Pros

  • They are extremely light, weighing under 40 grams.
  • They are the lightest ones the reviewer could find.

Cons

  • The reviewer implies a potential downside of ultra-light skewers in general is that they sometimes lack large end caps, which these new ones might also have.
  • The reviewer notes they must be tightened down properly to avoid problems.

Key Points

  • The new skewers weigh under 40 grams.
  • They were purchased from AliExpress from a brand called 'risk'.
  • The reviewer is switching from ZTO titanium/aluminum skewers.
AFFILIATE by MyBikePartsACTIVE
aliexpress.com
πŸ‡ΊπŸ‡Έ
$16.17
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€11.79
πŸ‡¬πŸ‡§
Β£9.59
Rating there:
4.8 (48 reviews)
Last checked:
4 days
ago
Risk Titanium Alloy Shifter Lever Clip Ring Fixing Bolts, Bicycle Shift Clamp Ring Bolt Screw Nut For SRAM Shimano R8000 FORCE

Risk Titanium Alloy Shifter Lever Clip Ring Fixing Bolts, Bicycle Shift Clamp Ring Bolt Screw Nut For SRAM Shimano R8000 FORCE

Created: January 13, 2026

The reviewer installs the Risk titanium shifter clamp hardware as part of a weight-saving upgrade. They state it works perfectly and provides a significant weight saving compared to the stock clamp.

AI-Summary

Pros

  • Provides a significant weight saving (10g total for both shifters).
  • Works perfectly.
  • Is from a favored AliExpress brand (Risk).

Cons

  • No cons found in the analysis.

Key Points

  • Stock clamp weighs 8.5g.
  • Risk titanium setup weighs 3.5g.
  • Saving is 5g per shifter, 10g total.
AFFILIATE by MyBikePartsACTIVE
aliexpress.com
πŸ‡ΊπŸ‡Έ
$24.05
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€14.49
πŸ‡¬πŸ‡§
Β£11.99
Rating there:
4.9 (34 reviews)
Last checked:
4 days
ago
ZTTO Ultralight 11/12 Speed Road Bike Cassette 11s 12s 11-28/30/32/34/36T ULT Sprocket Freewheel 112g~146g 11V 12V Gravel K7 HG

ZTTO Ultralight 11/12 Speed Road Bike Cassette 11s 12s 11-28/30/32/34/36T ULT Sprocket Freewheel 112g~146g 11V 12V Gravel K7 HG

Created: January 13, 2026

The reviewer discusses their experience with the ZTTO Ultralight SLR Gen 3 cassette, which they have purchased as a replacement for a previous ZTTO cassette that failed. They note it is a newer, supposedly improved generation.

AI-Summary

Pros

  • Offers a massive weight saving (around 127g).
  • ZTTO has reportedly gone back to the drawing board to improve it.
  • The weight has been increased slightly from the first generation, which is theorized to improve durability.

Cons

  • The reviewer's previous first-generation ZTTO cassette failed 'pretty disastrously'.
  • They are skeptical about its durability, especially under high power (e.g., 450+ watt hill climbs).
  • They explicitly state they are not ready to endorse or recommend it yet.
  • They position themselves as a 'guinea pig' to test its longevity.

Key Points

  • This is the new 'SLR Gen 3' version.
  • The reviewed sample weighs 127.1 grams.
  • It is about 15 grams heavier than the failed first-generation model.
  • The reviewer hopes using a smaller 34-tooth chainring will put less stress on the large aluminum sprockets, potentially extending its life.
AFFILIATE by MyBikePartsACTIVE
aliexpress.com
πŸ‡ΊπŸ‡Έ
$94.75
πŸ‡«πŸ‡·
€76.69
πŸ‡¬πŸ‡§
Β£65.39
Rating there:
4.9 (181 reviews)
Last checked:
4 days
ago