knurt

Hi!

I am not a bike mechanic and I need help. English is not my mother tounge, and i have used "Google translate" for this post. Distances are shown in metrics.

I have bought a rack for the front wheel which is meant to be mounted on the wheel axle on the front hub (on the outside of the front fork). The problem I have is that it then takes away about 3 mm from the wheel axle on each side of the wheel. The two axle nuts that are to hold the wheel can be screwed on, but it feels very unsafe and I am afraid that the axle nuts are threaded on too short a distance on the wheel axle.

Other information:
*) It is a suspension front fork, which also has mounting holes for fender stay.
*) The front wheel is mounted on a dynamo hub (Shimano nexus DH-C3000-3N-NT). On the wheel axle of the hub, it appears that there is a narrow (approx. 3 mm) lock nut on each side of the hub on the inside of the front fork.

I have been thinking about some options:

1) Buy two of the "Thule Internal Hub Hitch Adapter for Shimano IGH" (see attached pdf with pictures) too make the wheel axle longer. Unfortunately one of these cost about the same as the rack, which I find quite expensive.

2) Mount the rack as intended and hope that the shaft nuts do not come loose due to short screw thread. Do I need to be worried or does it work despite the short screw thread? How long should the screw thread be at least for the wheels to be securely fastened?

3) If option 2 does not work, could I mount the rack on the wheel axle on the inside of the front fork? Wouldn't this make the wheel sit too tense between the front fork and make tension on the front fork?

4) If option 3 does not work either, could I remove the lock nuts that is on the wheel axle on each side of the hub, and instead mount the rack stay on the inside of the front fork?

5) If option 4 does not work either, I will probably mount the rack stay to the mounting holes for the fender. I will then need to use a distance sleeve between the mounting holes on the rack stay and the mounting holes for fender due to long distance (approx. 2 cm).

6) If none of the above options are ok, can you replace the current wheel axle to a longer wheel axle?


Which of the options are best? Are there other possibilities? I believe option 1 and option 5 to be the most realistic, but I hope any of option 2, 3 and 4, could work.

I took some pictures that I attach in a pdf document, so you can more easily understand what I mean.

Would be terribly grateful for help and advice on this issue.

JohnDThompson 

I agree with your concern about insufficient thread engagement on the front axle. But I suspect that is only part of the problem you will face with this rack. You say the fork is a suspension fork; how is the upper part of the rack secured? Will it allow the suspension to move once the rack is installed?

knurt

I have managed to secure the upper part so that it is secured regardless of the movements of the suspension fork. It is hard to explain how, so i will attach a picture.

dsbrantjr

My concern about option 5 is that the distance sleeve (I call it a spacer) will induce a bending stress onto the mounting fasteners which may cause them to bend or break. Would it be possible to bend the rack stays to eliminate the need for the spacer? The ideal solution would be option 6 but I do not know if it is possible to install a longer axle.

knurt

I thought about that. I planned to write that as option 7, but decided not to. If I bend the rack stay it is permanent, I don't want to do that if it is possible with any of the other options.

Moe Zhoost

Option 1) These adapters are made for bike trailers and so are more robust than you probably need for your purpose. The price reflects this.
Option 2) You could try this if you have at an absolute minimum 6 threads engaged, The rule of thumb is that you should engage a length of threads equal to the diameter of the axle. If you try it, ride gently at first and test the nuts often.
Option 3) This will result in the same length of axle remaining.
Option 4) This would cause problems with your wheel bearings. Perhaps you could grind the lock nuts to make them a bit thinner. Same with the washers.
Option 5) This is what I would do. Just bend the rack stays gently to fit. Every rack I have installed required some bending.
Option 6) On a conventional wheel you could replace the axle, but I believe the axle on these dyno hubs is integral with the internal rotor.

Good luck.

knurt

Thank you for response.

knurt

i bent the rackstay end so that it fits the fenderstay mounting hole better, I think this is the best solution. Thank you very much.