Weird fork eyelet - Mounting a front rack
#51
Vegan on a bicycle
Thread Starter
The hard part is identifying and finding a suitable fork. Rigid aluminium forks that accommodate racks are not really fashionable.
It may be easier to have braze-on eyelets installed on this fork. Under the circumstances, that's the solution I'm hoping for, at this point.
It may be easier to have braze-on eyelets installed on this fork. Under the circumstances, that's the solution I'm hoping for, at this point.
#52
Vegan on a bicycle
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Guess I’ll have to give up on fitting that old Blackburn on to the front of my townie, since no one makes a hardware kit specifically for a 1976 Bridgestone.
Seriously, though, this is not a Mars lander or a Deepwater drilling rig; it’s a bicycle. This isn’t that hard.
I know we all want everything perfect, but sometimes the solution isn’t packaged, labeled and hanging on a peg behind the sales counter.
Seriously, though, this is not a Mars lander or a Deepwater drilling rig; it’s a bicycle. This isn’t that hard.
I know we all want everything perfect, but sometimes the solution isn’t packaged, labeled and hanging on a peg behind the sales counter.
But setting this up as a grocery bike, on which I'm likely to push the rated weight limit of the front bags and front rack, that's not a good idea. I really do need to minimise or eliminate the leverage forces on bolts used to mount load-bearing racks.
With this in mind, I'm starting to think "the solution" may be braze-on eyelets installed on the fork. I think that meets your criteria of not being packaged, labeled and hanging on a peg behind the sales counter. What I need to do now is find a frame-builder who can assess the feasibility of this, and hope that the manufacturer is willing to make a good-faith effort to cover that cost, after advertising the bike as being compatible with a front-rack, and advertising their front-rack as being compatible with this bike.
#53
Pedalin' Erry Day
Two thoughts that I'd add here: why not use a mid rider rack and just double up rack and fender struts on the same bolt? And second, I'd have to do a test fit to be sure, but looking at the pictures I'd think you could make a rack work with that lower threaded hole as long as the strut comes in from the front - just add a leather washer or two and that will take care of the dropout not being flat.
#54
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Ok, lemme get this straight; you intend on having so much load on this rack, that any possible offset from the dropout will fatally compromise the single M5 bolt tasked with supporting all this tonnage?
Being that none of the proffered solutions are acceptable, let alone "perfect;" the most obvious course of action is to have the desired mounts welded to the fork, and that the manufacturer should help cover the cost of modifications, because they didn't anticipate that you would want to install a particular rack on your second-hand bicycle? Got it
Being that none of the proffered solutions are acceptable, let alone "perfect;" the most obvious course of action is to have the desired mounts welded to the fork, and that the manufacturer should help cover the cost of modifications, because they didn't anticipate that you would want to install a particular rack on your second-hand bicycle? Got it
#55
Vegan on a bicycle
Thread Starter
Two thoughts that I'd add here: why not use a mid rider rack and just double up rack and fender struts on the same bolt? And second, I'd have to do a test fit to be sure, but looking at the pictures I'd think you could make a rack work with that lower threaded hole as long as the strut comes in from the front - just add a leather washer or two and that will take care of the dropout not being flat.
#56
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But yeah, a thick washer and a longer bolt would make it a dandy mount for a rack stay.
#57
Vegan on a bicycle
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Being that none of the proffered solutions are acceptable, let alone "perfect;" the most obvious course of action is to have the desired mounts welded to the fork, and that the manufacturer should help cover the cost of modifications, because they didn't anticipate that you would want to install a particular rack on your second-hand bicycle? Got it
Since the manufacturer advertised the bike being compatible with a front rack, and also advertised their front rack as being compatible with this bike... But now, only after I brought this to their attention, they say that was all incorrect... Yeah, it does seem reasonable to request that they make it right, or cover the cost of making it right.
Last edited by smasha; 03-05-23 at 06:03 PM.
#58
Vegan on a bicycle
Thread Starter
As I noted, above, that's actually worse than nothing. With a "naked" bolt, the downward leverage is only there when the rack is weighted. With extra fittings, the downward leverage is there when the bolt is tight, and increased when the rack is weighted.
#59
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If I was installing this rack, I’d either use a couple brass crush washers to fill that gap, or an aluminum sleeve, beveled to match the profile of the fork. I could probably do it in about an hour, with the materials in my garage.
You could also upgrade the mounting bolt itself; instead of the Grade 5 SS typically used, you could get higher strength Grade 8, or source some NAS “Aerospace” grade hardware.
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I think you’re grossly overestimating the force vectors involved here, and also underestimating the margin of difference in a flush joint -v- 1-2mm off spacers. A flush joint will support the hundreds of pounds you intend to carry, but a >2mm offset will cause the bolt to bend?
If I was installing this rack, I’d either use a couple brass crush washers to fill that gap, or an aluminum sleeve, beveled to match the profile of the fork. I could probably do it in about an hour, with the materials in my garage.
You could also upgrade the mounting bolt itself; instead of the Grade 5 SS typically used, you could get higher strength Grade 8, or source some NAS “Aerospace” grade hardware.
If I was installing this rack, I’d either use a couple brass crush washers to fill that gap, or an aluminum sleeve, beveled to match the profile of the fork. I could probably do it in about an hour, with the materials in my garage.
You could also upgrade the mounting bolt itself; instead of the Grade 5 SS typically used, you could get higher strength Grade 8, or source some NAS “Aerospace” grade hardware.
#61
Vegan on a bicycle
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I think you’re grossly overestimating the force vectors involved here, and also underestimating the margin of difference in a flush joint -v- 1-2mm off spacers. A flush joint will support the hundreds of pounds you intend to carry, but a >2mm offset will cause the bolt to bend?
#62
Vegan on a bicycle
Thread Starter
I'm assuming, this being a front fork, that the load on this rack would be no more than 20 lbs. And, of course, the washer and bolt head fit flush to the fork and rack. Assuming he's not going to give his girlfriend rides on it. Obviously, don't us an aluminum bolt intended for mounting water bottles.
I'm not sure what pictures you're looking at, but part of the issue here is that nothing but Silly Putty will fit flush with the bottom eyelet of this fork.
And with at least 7mm between the eyelet and where a rack flange would be, this is not a good idea with most any material used to make M5 bolts.
#64
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All I can really evaluate is the variation from “flat” around the bolt hole. I don’t have either your bike or the rack, so I can’t tell what sort of other clearance/interference you’re dealing with.
I’m sorry you ran into a hardware incompatibility. It’s frustrating when that happens.
You can either improvise / adapt or scrap it all and start over.
Based on my experience, this is not an insurmountable situation. There are a number of things that have been proposed that should yield sufficient results. Being that they are improvised solutions, you may have to try them to see if they work; there’s no off the shelf fix here.
Insisting on ideal seems a strange hill to die on for something as inconsequential as a grocery bike
#65
Vegan on a bicycle
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Based on my experience, this is not an insurmountable situation. There are a number of things that have been proposed that should yield sufficient results. Being that they are improvised solutions, you may have to try them to see if they work; there’s no off the shelf fix here.
Insisting on ideal seems a strange hill to die on for something as inconsequential as a grocery bike
Insisting on ideal seems a strange hill to die on for something as inconsequential as a grocery bike
So far as I may have used of the term "ideal" in this context, I mean I'm not going to have a catastrophic failure that pushes a loaded pannier rack into the front wheel, while I'm riding along a busy highway and/or doing 50kph.
To achieve that ideal, I want to get the rack flanges flush with the eyelets they're bolted to. This will likely require the installation of braze-on eyelets. I'd like to think this is not an insurmountable situation, but it's a PITA, and a disappointment, and the whole project is on hold while I wait for an update from a frame-builder.
Last edited by smasha; 03-06-23 at 06:58 AM.
#66
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* a drill press** will do fine, and you could probably just regrind an old drill bit rather than invest in a milling cutter.
** or even a Dremel type tool, a small spherical burr and a steady hand.
#67
Vegan on a bicycle
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I'd be inclined to mill* a flat around the hole so that a spacer can sit level. Use a cutter with a radiused outside edge to avoid creating a stress riser.
* a drill press** will do fine, and you could probably just regrind an old drill bit rather than invest in a milling cutter.
** or even a Dremel type tool, a small spherical burr and a steady hand.
* a drill press** will do fine, and you could probably just regrind an old drill bit rather than invest in a milling cutter.
** or even a Dremel type tool, a small spherical burr and a steady hand.
#68
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Looks like plenty of room for a 12 mm spacer.
#69
Vegan on a bicycle
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ITYF the clamping force of the screw is sufficient that the bending stress is not a problem as long as the spacer clamps properly between rack and dropout, and the screw head clamps properly on the rack. I'd use thread-lock, and check the screws after the first few loaded rides.
Looks like plenty of room for a 12 mm spacer.
Looks like plenty of room for a 12 mm spacer.
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imo, it would make more sense to use the "designed" fork that the OEM intended to achieve what you are after wrt using a rack.
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#71
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fwiw - you can cut a washed w/ a hacksaw, if you wanted to knock off the top of the bottom one
#72
Vegan on a bicycle
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I've got the Tubus Tara rack here, and playing around with it, the fit may not be as bad as I thought.
Pictured, below, is from the Tara installation manual. The red piece is an optional spacer/standoff, 8mm long x 8mm OD.
Based on this, an 8mm spacer with an 8mm OD should be fine... If it sits flush with the face around the eyelet.
So now I'm reconsidering a counterbore around the eyelet. I think that part of the dropout, below the weld, is solid. If that's the case, I don't think an 9-10mm ⌀ counterbore, about 2mm at the deepest point, would put me in any danger.
This would leave the rack close very the QR hardware, but not touching.
This would also put the rack a little off level, but I've seen much worse.
I'm not sure about adding braze-on eyelets now, as the flat-mount brake is kind of where I'd want to put eyelets, on that side. It may be feasible, it may not be.
As always, looking for constructive thoughts and opinions from everyone else here.
Pictured, below, is from the Tara installation manual. The red piece is an optional spacer/standoff, 8mm long x 8mm OD.
Based on this, an 8mm spacer with an 8mm OD should be fine... If it sits flush with the face around the eyelet.
So now I'm reconsidering a counterbore around the eyelet. I think that part of the dropout, below the weld, is solid. If that's the case, I don't think an 9-10mm ⌀ counterbore, about 2mm at the deepest point, would put me in any danger.
This would leave the rack close very the QR hardware, but not touching.
This would also put the rack a little off level, but I've seen much worse.
I'm not sure about adding braze-on eyelets now, as the flat-mount brake is kind of where I'd want to put eyelets, on that side. It may be feasible, it may not be.
As always, looking for constructive thoughts and opinions from everyone else here.
#73
Vegan on a bicycle
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#74
Vegan on a bicycle
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Just put half a washer under the bolt? I was thinking about that, but if the bolt loosens itself, I'd lose that half-washer. It's a high maintenance solution, and it still wouldn't sit flush.
#75
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post #20 here
but I agree. high maintenance because every time you remove the wheel you'll have to mess w/ it to keep the washer facing the right way
Last edited by rumrunn6; 03-10-23 at 05:42 AM.