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  1. #1
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    Wasn't sure where to look/ask - bolt hole for fender between chain stays off center?

    Heya,

    I'm new here as a poster but have been browsing the forums for a while. I bought a Trek 7100 Hybrid something like 5~6 years ago and rode it for a couple of years before moving to a place that I had no safe areas to ride so it ended up in storage.

    I've gotten it back out and tuned up and it's in great shape so I've been putting a lot of miles on it. I love riding and I'm also working on losing weight so it's a win/win.

    That said it's been raining around here more than I've ever seen it rain so I ordered a set of Bontrager NCS Fenders for the bike. I ran into an issue where it seems like the bolt hole in the part between the chain stays right behind the crank is off-center [towards the right side of the bike]. The fenders fit the tires very well but if I bolt it behind the crank it's extremely close to the tire on one side and about 10~15mm away from it on the other side [I didn't measure, eyeballing it].

    When I look at the rim/tire/axle/etc everything looks fine - the wheel is perfectly centered between the seat stays and is straight with the bike. The back brake is centered on the wheel perfectly as well. There does not seem to be any sort of adjustment to the back wheel and I can't 'adjust' this bolt hole behind the crank so I'm not sure what to do.

    I did think about getting a wider set of fenders so I would not be so close to rubbing [as the fenders would still do their jobs] but that seems like a bit of a kludge. I did also think about maybe fabricating a bracket or something that goes from one chain stay to the other side that I can bolt the fender through so it's centered but I'm really not sure.

    Has anybody else seen this issue and is it common? It seems to me like that threaded hole is in that spot for fenders and it makes no sense for it to be off-center from the wheel.

    I did also think about maybe getting some SKS fenders and just drilling the hole out a bit towards the side so I could slide it over but since it's a curved material I'm concerned that doing this would result in the fender cracking/breaking at the bolt hole.

    I love this bike but I want to be able to ride it after the rain without getting a line of dirt/water up my back or if I get caught out on the bike when it's raining so I definitely want the fenders on there. I suppose I can live with it being off-center so long as it works but I'd really prefer it to be centered to the tire to get the best use of the fender as well as so it doesn't look like it was installed by a monkey.

    Open to all suggestions/advice/criticism and I appreciate you taking the time to read and respond.

  2. #2
    aka Phil Jungels Wanderer's Avatar
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    If it was me, I'd just drill a hole in the center, and be done with it. I doesn't have to be very big, as a very small bolt will hold the fender fine. Bolt, locknut, and you are done.

    "Retirement is the best job I ever had!" Me, 2009


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  3. #3
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    I actually was going to do that but when I looked ... it would have to be a **really** small bolt hole or I would have to drill through some thick solid aluminum and tap it to make it happen. It looks like this:
    2014-05-15_12-59-18.png

    The circles on the left and the right are the chain stays, the blue part is a 'tab' that's built onto the piece that has the hole for the fender, and the red is the bracket itself that is solid aluminum. It's thick enough I could probably drill and tap it but I'd have to be really careful to go straight as not to pop out of that bracket and I suspect drilling it would substantially weaken it as it goes between the two chain stays.

    It looks like my only option to 'fix' the alignment is to drill the fender. I could *maybe* drill a very small hole next to the pre-existing hole but I'm really not sure about that.

  4. #4
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    I have a friend that does welding and fabrication for a living. I may see if he can fabricate me an aluminum bracket that I can bolt to the existing hole and then drill and tap for a new hole - only problem is that doing this will remove some clearance between the tire and fender front to back which is already tight unless I put the bracket on the other side of the pre-drilled/tapped hole and bend it around the tab...

  5. #5
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    Use a strong zip tie and hook up the fender however you want.
    http://treadrightly.blogspot.com/

  6. #6
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    Zip tie is so ghetto but it's a consideration .

  7. #7
    PatronSaintOfDiscBrakes dynaryder's Avatar
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    I'd just ziptie it. Note,PB does include zipties for the rear fender's upper mount because some bikes don't have a hole,or have it facing the wrong way,in the steatstay bridge. So zipties are OEM.

    C'dale BBU('05 and '09)/Super Six/Hooligan8and 3,Kona Dew Deluxe,Novara Buzz/Safari,Surly Big Dummy,Marin Pt Reyes,Giant Defy 1,Schwinn DBX SuperSport/Qualifier,Brompton S6L,Dahon Speed Pro TT

  8. #8
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    Yeah, I am going to see how it looks with the bolt in it with the wider fender - if it still looks crappy I'll probably drill a couple holes for a zip tie and just tie it to the post.

  9. #9
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    The SKS fenders seem to be a much higher quality material than the Bontrager NCS fenders. SKS feels like it has flex and can bend without cracking while the Bontrager feel more rigid/fragile.

    I did use my drill and I slotted the hole to the side a bit so I could line it up with the tire. I did have to use a very short headed bolt to clear the tire inside the fender as well - used the one that came with the NCS fenders as the bolts that came with the SKS were too thick to not rub the tire.

    All in all it took me about 2 hours to install the fenders/adjust them/etc but I'm very happy with them compared to the Bontrager NCS. They also look much cleaner because they don't have that 'NCS' adjustment where you have the two plastic pieces in the middle and the double strut for a short span - the struts for the SKS almost disappear against the spokes of the wheel.

    I'll post up a picture later - they're on my phone and it's downstairs charging .

    That said - is there a section here on bikeforums where I can put the Bontrager NCS up for sale? Probably just $20 + ship - they're definitely still usable I just didn't really like them.

  10. #10
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