I feel like this is one of those obvious questions, but I have been unsuccessful at finding an answer (even in the manual for the rack!).

I just purchased a bike rack (only holds 2 bikes) for my Subaru hatchback. I have found that I can mount the rack such that it doesn't press against the glass of the back windshield, but mounting it so low requires that I remove the front wheel of my bike (at least to make me comfortable, it probably would be fine).

Can I instead mount it so that the rack presses against the back windshield? Is this likely or possible to break the back windshield?

Note that my back windshield is not cracked, though the car is 10+ years old.

EDIT: The bike rack, which is a Thule Thruway Pro 2, uses two foam-padded bars as the main contact points between the rack and the car. I figure that this question is probably valid for any bike rack with padded bars as the contact points, not just Thule bike racks.

  • What part of the rack is touching the windshield? I have a bike rack which is actually designed to touch the windshield, but which actually has plastic cups to make contact. When you see how these things move at speed, I would not have thought metal against glass was healthy.
    – PeteH
    Commented Jul 21, 2014 at 19:05
  • @PeteH: The contact points are foam-padded bars, not plastic cups. See edit. Commented Jul 21, 2014 at 19:21
  • If you use it on good smooth roads, and with lghtweight bikes and you are a careful driver, then yes. Just clean the glass and the glass-touching part of the rack before use. But if the streets are like moon surface (like my country) I would look for another type of rack. Either a Roof Rack or a hitch mounted rack. Personally I had a Toyota Sprinter Carib and had the glass problem with my rack. Ended cutting the rack and using parts to make a customized one adding a few pieces of EMT tubbing.
    – Jahaziel
    Commented Jul 21, 2014 at 22:01
  • Here's a great comparison guide of different hitch types
    – KyleMit
    Commented Apr 20, 2015 at 14:08
  • The question is still unanswered. What about the pressure from the rack on the glass? Even with padding, will the weight against the glass cause it to break?
    – Mark
    Commented Apr 27, 2022 at 1:05

4 Answers 4


Being both a hatchback owner and a trunk rack owner, I can tell you yes...and no.

I've got a Saris Bones 3 rack and the feet have etched the window slightly. While the feet are of a more rubbery plastic, I think it's when there's dirt and grit underneath and moves (even unnoticeable movement) it grinds at the window. It usually cleans up pretty well, but I can tell where the feet marks are.

I would recommend putting a sock or other cloth over the feet (the body ones wouldn't hurt either). Also, make sure the contact point is clean, which means lossening or removing the rack to clean behind it.

Lastly, I've never had an issue with the rack slipping or moving, but most of the weight (even on your type of rack) will be going to the lower feet or bars.

  • +1 For cleaning glass and feet before use. Rubber feet work better being clean and used directly. Plastic(ish) feet work beter cleaning and covered, as you say, with a sock or even better, some pieces of old inner tube.
    – Jahaziel
    Commented Jul 21, 2014 at 22:07
  • 3
    A better way to avoid scratching is to use duct tape. Socks will let grit get in under the pressure points. The tape won't move on the glass, the movement will be between the tape and the rack mount points.
    – mattnz
    Commented Jul 21, 2014 at 22:07
  • @mattnz for bonus points, "helicopter tape" will be clear and very durable (and reasonably priced on the ubiquitous online market place).
    – Paul H
    Commented Apr 27, 2022 at 14:46

I purchased a trunk mounted Thule bike rack for my Lexus back in May.

Yesterday while driving the back glass exploded!

After opening the trunk it was obvious the pressure from the metal clips which were touching the glass caused the glass to break. According to the guy who replaced the glass, the window tinting film was the reason the glass didn't shatter into the car!

I hope this never happens to anyone and now I don't know how to get my bike around!

  • 1
    Good anecdote, metal should not contact the glass directly at any point. To be fair, I believe the instructions would have stated this.
    – renesis
    Commented Oct 6, 2015 at 20:49
  • Yes, only padded portions of the rack should touch the glass. In particular, one must be wary of any sharp corners of metal that might, from wind or vibration, hit the glass. Commented Oct 6, 2015 at 23:03

I highly recommend that you put a piece of wide Duct Tape on the CLEAN glass where the bike rack rubber/suction cups will contact. This prevents dirt from getting under the rubber/suction cups and scratching the glass. I only failed to do that once, and from that point, never failed to do it again.


This instruction shows it on a window. THRUWAY
And I would not assume that any rack with padded bars contact points mounts the same.

  • Thanks- yes, the manual does make it somewhat clear, if only implicitly. Though I think the other answer better fit what I was asking. Commented Jul 21, 2014 at 23:40
  • Cool but a diagram of rack on the window I would call explicit.
    – paparazzo
    Commented Jul 22, 2014 at 1:57

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