Flash

I was preparing to install a Blackburn Expedition rack on my 2002 Bianchi Volpe and found there is not enough clearance between the smallest cog and the screw head. I decided to take Blackburn's advice and reverse the screw (screw head on inside of dropout eyelet) since this affords more room, but this setup doesn't work. There's not enough room for the chain to jump from the outermost cog to the next one in. The screw head would block it.

Am I missing something obvious or am I going to have to remount the Blackburn on my mountain bike and look for another rear rack for the Volpe?

Thanks!

Rich Clark

Just use a spacer or washer on the outside and the shortest bolt that'll end up flush with the inside of the dropout.

Be sure to use blue Locktite on all the bolts on your rack so they don't vibrate loose.

RichC

Flash

Rich,

Thanks for the tip, but I think I may be a bit dense on this one. I've attached a crudely drawn schematic which shows my problem. With your solution, I'd have a shorter screw but would insert the screw through the rack and attach the nut on the inside of the dropout eyelet, correct? This still leaves me with a nut jutting out too close to the cog, I think. In my attached image I've tried to show the method I attempted, with the bolt inserted from the inside of the dropout eyelet and the nut fastened on the outside of the Blackburn arm. I thought the bolt head would give me enough clearance (as Blackburn thought it would), but the chain hits the bolt head when shifting to next cog in.

Thanks for helping, image attached.

Flash

I think I see what you're getting at. Lose the nut altogether and use the washer/locktite to keep it tight? I've attached another crude drawing showing what I think you mean. Is this correct? Thanks for all the help and sorry for the ugly drawings!

Also, re: loctite are you referring to threadlocker 242 in the blue bottle?

Cheers.

John E

Flash is correct. I have used this technique on numerous older frames on which I have crammed 6- or 7-cog freewheels. Instead of a washer, I use a nut, as follows:

1) hand-thread nut all the way down to the head of the screw;
2) press the screw shaft through the mounting hole in the rack;
3) thread the screw shaft into the dropout until it is flush with the far side;
4) without permitting the screw to rotate, run the nut down the shaft and tighten it securely against the rack strut;
5) LocTite is optional, but never a bad idea for mudguard and rack mounting.

Rich Clark

The eyelet dropout should be threaded. The bolt you're using should match those threads. From the outside, just stick the bolt through the hole in the rack support and thread it into the eyelet. When the end of the bolt comes flush with the inside of the dropout, stop. Now you can see the thickness of washers/spacers you need between the bolt head and the rack support. Remove the bolt, add the spacer, screw in the bolt.

Because you don't have the safety margin of having extra length of bolt sticking through the dropout, the Locktite (yes, blue 242 threadlocker) is a really good idea.

RichC

Flash

Thanks Gents! Nice to have options. Two more questions:

1. some advice on when and how to apply the loctite since I've not done this before.

2. Shall I use the nuts that came with the blackburn or perhaps something with a slimmer profile?

Thanks.

Rich Clark

I'm guessing the nuts are supplied only in case you don't have/can't use the threaded eyelets in the dropouts. They're redundant if you do.

Just put a drop of Locktite on the threads at the end of the bolt and screw it in.

RichC

Bikes-N-Drums

I had the same problem with mine but instead of using the recommended 25mm screw I used the 10mm on that side only and did not use the nylock nut. So far no problems.

John E

Today's safety tip: Inspect those mudguard and rack attachment bolts/nuts frequently, as they can vibrate loose. LocTite, lockwashers, etc. are also recommended.