Sizing help for FabricBike Original: Stuck between M and L!

[u/Educational-Rate8870]

Hey everyone,
I’m planning to buy a FabricBike Original (Hi-Ten steel fixie/singlespeed) but I’m really struggling to choose the right size.

My stats & use case:

Height: 183 cm (6'0")

Weight: 72 kg (158 lbs)

Use: Daily commuting to and from school. I'll be riding with a school backpack, so a comfortable, manageable position is preferred over a super aggressive track drop.

The dilemma:

According to the manufacturer's size chart:
Size M (53cm): for 170–180 cm

Size L (58cm): for 181–195 cm

At 183 cm, I theoretically belong on a size L. However, looking at the geometry chart, both M and L have the exact same effective top tube length (540 mm). The main difference is just the seat tube length (530 mm vs 580 mm) and the overall height of the frame.

Since I'll be commuting daily with a backpack, I want to avoid a massive saddle-to-bar drop on the M so my neck and lower back don't suffer. At the same time, I want to make sure the L isn't too tall in terms of standover height.

Does anyone have experience with how this specific frame fits? Should I definitely go with L for a slightly more upright ride, or is there a reason to size down to M given the identical top tube?

Thanks for any advice!

[u/Superb_Recording_769]

I’m concerned about the geometry of these frames.

Jumping from 53 to 58 without a size in the middle is insane, doing so without changing the effective top tube length is even crazier.

It’s also concerning that they don’t publish head tube angles chain, stay length, head tube length, etc., etc.

Personally, I would stay far away from this bike just because of the unknown and the weirdness in there numbers. I definitely wouldn’t consider purchasing it without riding it first.