Guest Review: Bontrager Interchange Nebula Fenders

Editor’s note: We got the following product review from longtime reader/commenter Raiyn Storm. He has graciously allowed us to post his thoughts and photos here for you. As he purchased the fenders for his own use, we’re going to forgo that pesky FTC disclaimer that normally appears at the end of our reviews here on And, as far as we can tell, the following is the first online review of this particular fender set…so enjoy!


I recently purchased a set of Bontrager Interchange Nebula fenders to use on my Town bike. I chose these fenders specifically because I wanted the protection that only full coverage fenders can provide with the ability to remove or re-attach them at a moment’s notice. While there are other “quick release fenders on the market I found their coverage to be insufficient for my needs. I tend to use my bike as a jack of all trades so being able to remove the fenders quickly and without tools is a plus in my book.


Below is the description of the fenders from Bontrager’s website:


* After initial installation, the Interchange system allows subsequent removal and application in seconds
without tools
* Lightweight polycarbonate fenders are weather and impact resistant
* Adjustable, oversized aluminum stays ensure a custom and secure fit
* Rear frame mounted fenders fit under racks, out of the way of trunk bags and panniers
* Includes integrated mudflaps designed for maximum water dispersion
* Can be fully disassembled for easy recycling

Basic installation is fairly straightforward and requires a 4mm Allen wrench, 8 mm open end wrench and a #2 Phillips screwdriver.


The Interchange Nebulas are attached by means of a quick release bracket in the front and tensioned chain and seatstay bridge mounts and clips. In addition, the fender stays are attached to a corresponding bolt-on “mushroom” (bolted to the fender eyelet) by means of a snap-on socket. Installation is a little more involved than regular fenders because the socket mount is threaded to adjust in and out of the fender stay and will need to be adjusted for your setup. Once adjusted, the socket is secured by a jam nut.




Even though the included directions seemed less helpful than something you’d get from IKEA, I have confidence that most people will be able to pull off the basic installation with minimal problems. I, on the other hand, had a few minor changes to make.
Knowing that I had a suspension corrected fork, I needed a way to get the fender close enough to the tire to function properly and still look right. I had initially planned an elaborate kludge involving P-clamps and plenty of extra hardware, but it proved to be overkill due to the relatively short axle to crown measurement of my Surly 1×1 fork. I ended up following what I feel to be a cliché by adding a (thankfully) small piece of metal to drop it to the correct height for my fork / tire combination. Another modification to the basic install was forced due to the seat stay bolt hole pointing down instead of being a horizontal hole. Because of this I decided to bolt it to my brake booster instead which still allowed it to follow the correct arc while potentially adding support due to it’s more centralized location on the fender arc.


I was able to try the fenders out recently in some mildly rainy conditions in the area and I’d say that the coverage provided by the front fender is better than one would expect from a typical set of detachable fenders, rivaling that of some of the best names in the business. Perhaps aesthetically I wasn’t as happy with the projection ahead of the front fork as I could have been but the coverage from the business end of the front fender and mudflap drops well below the bottom bracket making up for what I feel is a fairly stubby front projection when compared to more traditional fenders. I felt that the rear behaved as a normal bolt-on fender would in that you wouldn’t notice any real difference between it and the easily removed Nebula.


The Interchange Nebula’s are priced around $50 – $55 depending on the shop. The price is fairly in line with the better bolt-on fenders on the planet but offers the versatility of super quick removal for sunny days or for just putting your bike in the trunk after a late night at work.


  1. Raiyn

    I recently found that being able to remove the front fender is quite helpful when using bus racks.

  2. Mr. Plucky

    Where online can you buy the wider 45c version pictured in this review? I love these fenders! Sturdy, full coverage, convenient, and very lightweitght. Just make sure you mount the rear one properly in the upper bolt-on bracket provided. Although these mount literally in seconds, I carelessly missed this one step last week, and the fender rotated and I ran over it, making a small crack. Other fenders would have been in pieces. I’ve been using these for 18 months of Manhattan commuting, 30-60 miles a week. The only other problem was that one of the two front brackets keeps popping off the mount on particularly bumpy streets. I hold it down with the quick-release lever. I intend to buy the same model again, but the 45c version is hard to find.

  3. Raiyn

    First, these are NOT the 45mm version. Mine are the 26″ x 60.

    Second, I have NO idea how you managed to run over your fender by missing the upper bracket, you’d have had to have missed the chain stay clip as well, and even then I’m having trouble visualizing how this was supposed to have happened.

    Third, I special ordered mine through one of the local Trek dealers as nobody (not even the dealers) stocked them when I ordered them. As this is a Bontrager (read Trek) product you aren’t likely to find them at Jensonashbareiformancepoint, and I’d direct you to your local Trek dealer.

    Lastly, I have a sort of update on the fender set. A few months ago I ordered and installed a Topeak Super Tourist DX with Side Bar and promptly discovered that the rear stays of the Interchange fenders were incompatible with rear dogleg of the Topeak rack largely due to the single pair braze on’s provided by my bike’s frame. I ended up having to modify the stay system and rig an new upper mounting bracket off the rack’s light mounting point. Essentially the rear fender is no longer “quick release” though I’ve found that the ability to remove the front fender is FAR more valuable in my situation.

  4. Rob Slowen

    I have just purchased these fenders and am fitting them to a 2012 cannondale caadx tricross bike.

    I purchased them so I can quicly pop them on for wet UK commutes and remove them for racing and ‘proper’ rides.

    The problem I have is that the rear mudguard does not easily fit as standard and I thought I’d share as it might be the same on other cannondale frames.

    The diagram in with the fender also seems to show two brackets to fit the rear one to the chain stay – although no such bracket comes in the pack.

    So the rear fender ….

    Firstly …
    The ‘thin’ end of the fender that attaches at the chainstay end of the bike has a little hook on it which is supposed to simply hook onto the horizontal bar at the triangle of frame where the chainstay is.

    On the CAADX the frame is beefed up in this area and so the gap of the triangle is smaller and the tube thicker, meaning that the hook doesn’t fit over. (See the inset of the photo above that shows the rear fender for the piece I mean – it’s the first picture after the photo of the components included in the pack – the inset bottom left is the hook bit)

    As mentioned there are some brackets shown on the diagrams that suggest there are 2 different options to sort this out – however they were not supplied and so this makes no sense!!
    The stay at this end on the cannondale’s has a screw fitting which corresponds to a hole on the guar at the hook end – however, by screwing it into the frame, I lose the whole USP of being able to quickly remove the fender ….

    Secondly …
    As mentioned in the review, the seat stay bolt hole points down on some bikes (canondales)so the standard bracket does not fit as it is designed for horizontal bolt holes.

    The guy in the review has fitted his to his brake booster instead – for me it looks like bending the bracket eyed bit 90 degrees to fit to the underside of the frame …

    So I thought this might help some people – any suggestions would be welcomed ..

  5. Raiyn

    Solving the rear bracket problem is as easy as adding a 90 degree bracket like this one.

  6. Bradd

    I appreciate this review, and Rob’s response above, as I’m having issues of my own. I’d been worried about the front fender, as I have a hybrid with front suspension, but that part went very smooth. The REAR however…

    (1) “…has a little hook on it which is supposed to simply hook onto the horizontal bar at the triangle of frame where the chainstay…”

    My Raleigh does not even HAVE the horizontal bar, so there’s no connection point to clip into on the forward end of the fender. Like Raiyn – though for different reasons – it looks like I’ll have to go without the removable feature of the rear fender. Didn’t plan on removing it anyway, but it would be nice to have the option.

    (2) Can anyone tell me exactly where the little lever piece pictured in the top left of the ‘mounts & clips’ photo above goes? I don’t see it in the instructions for the rear wheel, and don’t see where it would go anyway.

    (3) “…there are some brackets shown on the diagrams that suggest there are 2 different options to sort this out – however they were not supplied and so this makes no sense!!”

    THANK YOU, I was wondering if I was simply crazy! WTF?!?!?!?

    I’m feeling like the guy doing the instructions should have put down the joint and finished illustrating.

  7. Raiyn

    @ Bradd
    The “lever thing” is the quick release upper mount for the FRONT fender as illustrated in the fifth picture as well as the final shot on the front wheel side. It looks different in the fifth picture because of the metal extension I fabbed to get the fender closer to the tire and it is in the closed position.

    A picture of the forward section of the rear triangle of your bike might help me help you figure out how to rig your fender. You can post it on any one of a billion photo sites (I’ve used Photobucket for stuff I keep and want to control and ImageShack for my throw-aways)

    As to the instructions, I did say they “seemed less helpful than something you’d get from IKEA”, but I’m pretty sure they got recycled a while back so I’m not sure what the “brackets” you refer to are.

    Lastly, to clarify, I added an additional upper mounting point to the rack. I’m still using the one I mounted to the brake bridge, but the new mount helps stabilize things since I had to relocate the fender stays to the same holes used to mount the mud flaps. (Same spacing – go figure) I might shoot some pics of the current mounting system depending on interest or if Ghost wants to add them to update this review.

  8. JM Palacios

    Just installed these on my wife’s Fuji hybrid bike. Had the same issue that others had with no place to clip the bottom clip of the rear fender because the piece was flat, not round. Solved that by just screwing it on and losing the quick release part. I can live with that, but not the problem that has since cropped up. She has a rear rack and the rear fender stays stick out farther than (and actually cross over) the rack stays. When she carries her pannier, it knocks the fender into the rear wheel. This makes the bike unusable until I can fix that. Anyone have any suggestions?

    I should add that, though the size says it’s for 35mm tires, I actually had to bend the sides of the fenders out to make them wider. I also had very tight clearance underneath the brake bridge and the rack, which didn’t help. The fender is pressed up right up against those. Unfortunately, the top mount doesn’t seem to want to hold it very well as it keeps coming off. All these factors probably contribute to the problem.

  9. Happy Riding

    I have a Bridgestone MB-5 (similar ilk of Specialized Rock Hopper, etc. of mid-90’s hard tail steel MTBs) & am turning it into a 26 x 1.25 commuter. I want dependable, removable fenders. I just want these to work and not pop off, but I haven’t bought them yet due to the problematic mounting issues mentioned. I have eyelets on both front and rear, a cross bar at the chainstay triangle, no suspension, so I hope these would work? I prefer not to be on the hook with Bontrager’s return policy of store credit or exchange for something I don’t want or another set of fenders that wouldn’t suit my needs. Should I take the plunge to buy these and try them?

  10. Raiyn

    Hello Happy,
    As the original poster I can tell you that aside from the few things I had to do to mount mine they’ve worked quite well. The front fender still works brilliantly as (I’m sure) the rear would if it were still in an unmodified state.

    The main thing that forced the modification to the rear fender was the lack of a second pair of braze ons in the rear of my bike which caused the interference mentioned in a later post. Had there been an additional pair like there are on on my better half’s one size larger version of the same bike (Trust me, I’m annoyed by this.) I’m fairly certain it would have been a non-issue.

    As your MB-5 is pre-suspension, you likely won’t have to do the extra drop piece on the front like I had to in order to compensate for the the extended axle to crown distance. Also Grant Petersen, (the guy who designed your bike and founder of Rivendell) would almost certainly have provided enough braze ons to make the job a snap, cause he’s all about fenders, racks and that sort of thing.

  11. Happy Riding

    Hello Raiyn,
    Your response is so much appreciated. I never intended to put racks or fenders on my MTB when I bought it, because it was for MTB riding. Thanks to Grant for the design foresight of MTBs converting to commuter bikes!

    Sorry, I still cannot figure out what Mr. Plucky is talking about in regards to the rear upper bolt on bracket, but if there are any questions regarding installation, I’ll post them here. This is such a wonderful site, with good information and helpful people!

    FYI for anyone interested in these fenders: Bontrager is discontinuing this model. I found a set, but they will be harder to find from here on out.

  12. Raiyn

    No problem Happy. I don’t think any of us started out with anything but off road in mind when we bought our MTB’s, but fortunately old school hardtails like ours are PERFECT for this sort of thing. As for Plucky, your guess is as good as mine was. I’ll keep an eye out for you.

  13. Happy Riding

    Hi Raiyn- I found the fenders, but getting them wasn’t so easy + other delays which is why my response is delayed! Good news is I rebuilt the bike (my 1st time ever) and it’s ready for riding finally! This is my current status:

    Front – It easily mounted with a close arc to the tire similar to your picture. Yet, the bracket that bolts through the fork doesn’t come down low enough, so the arc dramatically raises away from the tire in front of the fork to 1 1/2″ away from the tire. Where did you get that metal pc you added to drop the height down for your front fender? I think I’ll need that, too.

    Top Rear – The U bracket which holds the fender with its bolt that goes through the frame (missing a nut in my bag of hardware, btw) starts to pull the fender away from the frame. So it’s too high, too.

    Bottom Rear – The part of the fender that clips onto the lower triangle of the frame ends up far from the tire. The sides of the fender at this clip mounting point also rubs on the frame itself. I think my frame at that point is slightly more narrow than yours. I’m running 26 x 1.25 tires fyi.

    For the top u bracket: I’m thinking a similar metal pc to modify this to allow it to hold the fender lower to the tire? I have oem cantilever brakes, not a brake booster like you do for mounting purposes.

    For the lower mounting half hook: In your picture, the fender comes away a little bit from the tire, but my arc is much further. So I temporarily removed this half hook and held the fender in the proper arc to see how far away the fender is from the frame: 1 3/4″ How do I make up that distance and still utilize the half hook detachable method?

    I don’t see the option to upload pictures here. So maybe that changed since you uploaded yours. Maybe that would help you answer my mounting questions? Sorry I’m still new to this site and to modifying/rebuilding bikes…

    Any comments are appreciated!

  14. Raiyn

    Hey Happy,
    First, the bracket is nothing more than something I found at the hardware store. Since it’s been about three years since I put this together I can’t remember exactly what it was before I took a Dremel to it. Frankly, any bit of scrap would probably do, but Problem Solvers makes a bit called the “Fender Flute” that would do the trick perfectly. Though it’s a bit more expensive, it’s more than likely a stronger option if not overkill. (Doesn’t mean I’m not seriously looking at it)
    Top Rear- My mounting the fender to the brake booster probably allowed it to be closer to the tire than it would have been by means of frame mounting. There are two ways around this issue.
    One: Get a booster. eBay has several thought the ones from China seem cheapest. There’s a 2 pack for like $13 w/free shipping including any needed spacers (by the looks of things). They work fine with Canti’s in fact V-brakes are just a different kind of cantilever brake.
    Two: Rig a bracket. Be creative. I like using scrap aluminum for things like this, but a bit of a tough plastic would likely do the trick. Let out your inner MacGyver.
    Bottom Front- This is something I encountered with my better half’s bike. In her case the fender wasn’t intended to be removable so I did something like this:
    In your case maybe a modified eye bolt? Maybe ovalize the eye enough to work with the bracket? (Hammer, but protect the threads with nuts.) As to the width careful grinding with a Dremel or a file evenly on the sides is my best suggestion. Grind a little at a time and test fit repeatedly. DO NOT try to get it all the first time as you will take too much.
    Your tire width is fine. I’m using them with a set of Vittoria’s in a 1.75 width and as they sit they’re just about perfect. I wouldn’t go any wider.

  15. Raiyn

    BTW: Brake boosters are AWESOME. I got mine from Nashbar years ago and love them. Then again, I’m a Clydesdale who occasionally pulls a trailer on a pre-disc bike.
    I’m intending on eventually swapping out the canti only Surly 1×1 fork for the version with the disc mount but I have some other projects in the pipeline that have priority.

  16. Happy Riding

    Hi Rayin, thank you for your great ideas! An ovalized eyebolt that the bottom half hook bracket will fit into should do the trick. And, if I can get the fender closer to the tire, I shouldn’t have to grind or sand the fender at all!

    Top Fender Tabs front/rear: I think if I get some stiff metal pieces as you did, I can make them work using your method for dropping the height of both the front and rear fenders. I want a rear rack, so a brake booster might get in the way? I’m a lightweight and will carry commuter things, groceries, etc. in a basket on the rack.

    I just checked out that fender flute. It looks very sturdy, but if you haven’t had problems with flex at the bracket point where you remove/install the front fender with your inexpensive mod, I may opt for your cheaper method. The flute may have a cleaner look though, if one is concerned about that.

    On tire size, I don’t think I’d go wider than 1.50, so thanks for that tip, too.

    I didn’t know of that problem solver site, either, so all very good and helpful information! I’ll post back with hopefully a successful installation 🙂 Thanks a bunch!

  17. Raiyn

    @ Happy
    The only time I’ve had trouble with the bracket extension on the front is when I’ve forgotten about it when putting the bike into the trunk of my better half’s car. If I just remember to turn it so the brakes face down I’m good to go. The Fender Flute would be a stronger option (though a bit pricy) but the actual bracket might bend as opposed to my (I suppose) sacrificial piece.
    I have a rear rack on this bike now, there were no problems other than the ones I mentioned earlier (which you’ve read. It fits with the booster in place just fine. If you look at picture #7 you can see one of the rack braze-ons above the brake. In fact my rear booster doesn’t go much higher (if at all) than the seatstay brace. The slotted hole in the booster is the key it allows the fender more of a range of positioning for the fender.

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