raywood

I think I may have done something unintelligent. I'm not sure -- it would be my first time.

The situation is, I have purchased a used BOB Yak, and it has taken me on a voyage of discovery -- mostly involving bike fitting and trailer repair. Today's episode: I figured out that this is the older model Yak, and that's why its attachment pins didn't look like the ones in the photos.



Top: stock BOB Yak (old model) pin. Bottom: replacement pin from eBay: 50 for about the price of 10 from BOBParts.

Online discussions suggested that I would be best advised to keep a few spare pins, because they tended to get lost or to lose their spring. The good news is, I was able to find a great deal on replacement pins on eBay. The wire they were made of was just a tiny bit thicker than the wire in the stock pins. The difference was so minor that it's hard to see.

Ah, but they're not stupid, those people at BOB. I had to drill out the fork ever so slightly to accommodate the new pins. My concept of drilling "ever so slightly" was not to realize that the dropout material might be aluminum. That, and to use a 12 horsepower drill (I exaggerate slightly). And so now the BOB people, snickering in their tea, may be approaching the moment when I saved $5 on pins in order to pay them $60 for a replacement trailer fork.



Trailer dropout pinhole, post-ream

In other words, I seem to have drilled out a bit more material than would have been ideal. If it looks like there's still enough left in this photo, trust me: photos lie.

To summarize, we have a concern that, with any substantial stress on this pinhole (due to e.g., a heavy load hitting a bump on a turn), the remaining aluminum will fail, and the trailer will come loose from the skewer, with potentially dire consequences for rider, cargo, and rear bike wheel. (Bear in mind that this appears to be a 1997 model trailer, suggesting possible metal fatigue in any case.)

The question at hand, then, is whether anyone has any ideas on how I might beef up the dropout, add a supplementary retainer that would reduce reliance and stress on the pin and its irritatingly large hole, or perhaps just sell the trailer at a minor profit and be done with it. For perspective, here is how the dropout looks when mounted on the skewer:



Trailer mounted on skewer, without pin

So, what's the advice? Safe to ride? I'm afraid that's going to be a no. Repairable? If so, how? Duct tape, maybe?

Andrew R Stewart 

My Bob Frame/fork is steel, not Al. I question if the amount of drilling has substantially weakened the drop out. Could the fork drop outs fail? Sure but I doubt it. But look at where this slight weakening is located. On the drop out's lowest area, below the overlap with the QR end fitting. Should a crack start it likely will be also below the QR, below the vast majority of the drop out.

I only have experience with a half dozen Bobs and have not seen any drop out issues with stock drop outs. I have seen a number of broken (and lost) pins on the first generation. I suspect that any failure you suffer with will still be with the pins. But periodic examination is always a good and prudent thing to do.

If you were going to tour in the third world or deeper into the wilds where getting stranded was a life and death situation then I would suggest getting the second generation Bob as it has other upgrades then just the pin/dropout design. Andy

fietsbob

There are a couple BoB forks ... with a 29er MTB you need one specific to that wheel size,,


Yea, paint, grey, is the older model , put a twist drill in the hole for size testing , maybe clearing rust in the hole (twist it, held with a pair of pliers , should not need power)

then you know how big the hole is, to ask for the pin if you know what size drill fit..

then go to auto or hardware store .. the pin is a very common thing.... I used to have a trailer just like that...


[ might find the new fork retrofitt able




...

BobG

Does your oversize pin fit snugly into your oversize hole? As long as the pin spring shuts snugly over the nut I would think that you're good to go. I would think any road fatigue would occur above the axle in direction of red arrows.

I believe BOBs have always been steel. I once had the old version and it was steel. Judging by the rust in your photo I think yours is steel.

I'm not a structural engineer though. If in doubt order a new fork. They'll likely send you the new style with rubber cords, pegs and the upgraded spring clips. Its quite easy to remove...just two nuts. I used to take my fork off and stash it in the bag for air travel. You'd want to confirm that the new style fork will fit your old style trailer.

BOBG

AnkleWork

None of the above. The cost of a new "fork" is very little to avoid becoming a c-word and you'll worry much less.

CliffordK

Those clips are commonly available at hardware stores and fastener stores. No need for E-Bay. Buy the one that fits.

As far as your reamed hole, I wouldn't worry about it until it breaks. It shouldn't be taking a lot of force, just there to keep everything together. Especially if the trailer is loaded down.

The fork ends look like they're angled a little bit to help hold the trailer in place. I'm surprised there isn't a bit more hook to it.

Leisesturm

I have had my Bob Yak for ... 15 years? It is black. The cotters do not look like either of the pins illustrated above. I don't know ... I'm wondering if the o.p. has a Bob Yak at all or a knock off. In any case, that drop-out is not too drilled out to be useable. It is fine. I can't see Bob fundamentally changing the design of their cotters so radically that hardware store (or Ebay) replacements could work. Bob cotters have to be sourced from Bob. By the way I have a set of the solid axle (3/8") Bob Nutz that I no longer need. They are $30 from Bob. Mine are free to a good home. Apologies for the hijack.

fietsbob

Had a Grey one, bought spare cotters in a local hardware store ,,.... solid steel pins use them so pin cannot fall out..

BobG

Ray has the original style cotters. The one in his photo with the big loop is the BOB original. The one with the tighter loop is his ebay aftermarket copy. As opposed to the more current style that you and I have...

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