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  1. #1
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    Attaching racks to an MTB

    I am mounting a rear rack to an MTB and I see that I don't have brazeons. Looks like I will need to attach it to the seatpost clamp bolt. This bolt is aluminium. Should I replace the bolt for stainless?, will it work fine for the long haul?.

    I plan on atteching the stays of the rack to the frame with just the two screws (one on each stay) to the threaded holes on the dropouts. This will work as all my racks have but I wonder again for the long haul if this is good enough, I read travel logs where these screws sheared off, and then you are left on the road with the sheared screw inside the hole which might not come out without a drill and an extractor tool. Is there a better solution?

    Finally, does a front rack make any sense on a suspension fork?

    Pictures of solutions to these various problems will be appreciated.
    [SIGPIC][/SIGPIC]www.tangotandem.org

  2. #2
    Senior Member robow's Avatar
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    Here are just two options for mounting a rack on your front shock, the top is a Delta Front shock rack and the other is the Old Man Sherpa front rack



  3. #3
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    So what you are saying is that your bike has braze-ons or continuous elements in the drop, the kind of thing originally put there for fenders, and you will be attatching the lower legs there. But you don't have BOs at the top of your frame, and you would like to attach it to the bolt in the seat post cluster, or directly to the seat post?

    The ideal rack has two bolts at the seat stays, this creates greater stability than a single point of attachment (other locations include the brake bridge where present). Many racks come with P clips to attach to the seat stays if these BOs are not present, and those clips are steel, if a little fiddly. they are wide enough to give you a stable base, but you have something to keep your eye on compared to brazed on slugs since there is some possibility of loosening you don't get with the slugs. A little blue loctite would help. also silicon sealant on the P clips will get mostly squeezed out, but will hold the clips better than just putting them directly over the paint.

    Can the bolts be sheared off? A lot of long range touriers say that the bolts used on racks are undersized for their needs. They recomend 6 mm bolts rather than the 5mm stnadard. The 5mm is really an accessory size, for stuff like water bottles and mud guards. Using it for racks is convenient when you have those threaded holes already provided for on most bikes. Some people have successfuly opened up the 5mm holes and tapped 6mm threads. All of my bikes are probably cast in the drops, but the fender mounts are cast like BOs so there isn't much meat left if you open the little darlings up for a 6mm threaded hole. So I get by on the smaller bolt. When buying bolts be sure they are a high grade bolt. Do not be tempted by SS bolts, get hard steel that has been chromed, these are the standard. Use loctite to assemble the bolt, and use your rack within it's load limits.

    Pic shows stardard cast drop with fake BO in upper left area. It's 12 mm across, but barrelled a little so if you expanded it to a 6mm threaded, there would be about 2mm of space around the narrowest part.
    Attached Images Attached Images

  4. #4
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    Quote Originally Posted by Peterpan1 View Post
    So what you are saying is that your bike has braze-ons or continuous elements in the drop, the kind of thing originally put there for fenders, and you will be attatching the lower legs there. But you don't have BOs at the top of your frame, and you would like to attach it to the bolt in the seat post cluster, or directly to the seat post?
    I though I could go with the two brackets that go from the rack to the seat stays going instead to both sides of the bolt in the seat post cluster, I have seen some bikes rigged that way, but none where very serious.

    After some surfing I came to the real answer to my problem which is to go with a rack that mounts to the V-Brake bosses such as:
    http://www.oldmanmountain.com/Pages/...RearRacks.html

    I really don't like mounting things on a frame without brazeons, looks nasty, probably end up mangling the paint, and I am ever afraid of denting it, let alone that it might loosen up.

    If you use Loctite to set the screws do they come off later?
    [SIGPIC][/SIGPIC]www.tangotandem.org

  5. #5
    Just ride it. MrPolak's Avatar
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    Quote Originally Posted by Xanti Andia View Post

    If you use Loctite to set the screws do they come off later?
    Loctite actually makes bolts easier to remove because it keeps rust from forming. Yes, they do come out later. I use Loctite quite a bit when wrenching on my cars.

  6. #6
    Senior Member BigBlueToe's Avatar
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    It seems like panniers on a suspension fork would get shaken around a lot - more than on a rigid. Am I wrong? Does anyone have experience with such a rig?

    I'm thinking about doing the Utah Cliffs Route (from the ACA) this summer, and am wondering what the best rig would be. I could ride a Surly LHT (and maybe put wide, cyclocross tires on), a Rockhopper hardtail with XC fork, or a rigid Stumpjumper. I've also got a Bob trailer - the one without suspension.

    What would you ride on such a route (lots of dirt roads, some pretty gnarly, some pretty steep?)

  7. #7
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    I could ride a Surly LHT (and maybe put wide, cyclocross tires on), a Rockhopper hardtail with XC fork, or a rigid Stumpjumper. I've also got a Bob trailer - the one without suspension.

    I have a Litespeed Pisgah with a Fox RLC 80 that I use for off road touring. I use a round handle bar bag and a stem bag up front as they have very little effect on the steering.

    I bought a very large frame bag and a seat bag that holds my sleeping bag and vest in a compression sack.

    I can carry 13-14 lbs of gear this way and I found that keeping weight off the back wheel makes climbing much easier.

  8. #8
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    If panniers are attached to the fork, the fork warranty is voided.

  9. #9
    eternalvoyage
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    Quote Originally Posted by Xanti Andia View Post
    I am mounting a rear rack to an MTB and I see that I don't have brazeons. Looks like I will need to attach it to the seatpost clamp bolt. This bolt is aluminium. Should I replace the bolt for stainless?, will it work fine for the long haul?.

    I plan on atteching the stays of the rack to the frame with just the two screws (one on each stay) to the threaded holes on the dropouts. This will work as all my racks have but I wonder again for the long haul if this is good enough, I read travel logs where these screws sheared off, and then you are left on the road with the sheared screw inside the hole which might not come out without a drill and an extractor tool. Is there a better solution?

    Finally, does a front rack make any sense on a suspension fork?

    ...

    I though I could go with the two brackets that go from the rack to the seat stays going instead to both sides of the bolt in the seat post cluster, I have seen some bikes rigged that way, but none where very serious.

    After some surfing I came to the real answer to my problem which is to go with a rack that mounts to the V-Brake bosses such as:
    http://www.oldmanmountain.com/Pages/...RearRacks.html

    I really don't like mounting things on a frame without brazeons, looks nasty, probably end up mangling the paint, and I am ever afraid of denting it, let alone that it might loosen up.

    If you use Loctite to set the screws do they come off later?
    It's possible to suspend the front load:

    http://www.faiv.de/

    *****
    This is better than having the load 'unsprung,' or having it move with the wheel.

    *****
    Medium strength threadlocking compound (like Loctite) is better than the lower strength versions. The high strength threadlockers can make it extremely difficult to remove the bolt.

    What has worked best for me is using grade 8 or harder steel bolts (not stainless -- I have sheared those; they are not as durable), plus medium strength threadlocker, plus nyloc nuts (with threadlocker on the nuts as well).

    This system is very reliable.

    *****
    http://en.wikipedia.org/wiki/Nyloc_nut
    Last edited by Niles H.; 01-22-08 at 02:56 PM.

  10. #10
    eternalvoyage
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    Quote Originally Posted by Xanti Andia View Post
    I am mounting a rear rack to an MTB and I see that I don't have brazeons. Looks like I will need to attach it to the seatpost clamp bolt... will it work fine for the long haul?
    I've done this, and it has worked very well. A harder steel than stainless would be best. If you need to, you can coat it to protect against rust.

    [assuming that the seatpost clamp is neither too high nor too low....]

  11. #11
    eternalvoyage
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    Quote Originally Posted by Xanti Andia View Post
    Finally, does a front rack make any sense on a suspension fork?
    Yes, it makes sense for some of us at least.

    I find that the bike is safer this way.

    There have been times when major accidents have been avoided this way. You have better control in some situations.

    Long tours (and cyclists' health) have been seriously derailed when riders have hit unexpected potholes in roads. I've done this with front panniers on a suspension fork, and the fork saved me. I've also hit unexpected obstacles and other rough spots that would almost certainly have caused accidents without the suspension.

    The suspension can add enough control to prevent many of these accidents.

    *****
    [There are certainly some trade-offs involved with suspension forks; and whether the advantages outweigh the disadvantages would depend on individual circumstances.

    For me -- for all-around use -- I prefer having the suspension.

    In fact, I prefer having both a suspension fork and a suspension stem working together.]

  12. #12
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    Thanks everybody, all my questions have been answered (but don't anybody be affraid to elaborate, digress or disagree!).
    [SIGPIC][/SIGPIC]www.tangotandem.org

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