I am starting with some small projects before taking on a full frame. One of which is modifying an existing frame to re-route hose guides on underside of the TT and SS, and also add rack mounts to the front fork (Salsa Cromoto Grande).
I’ve finished up the cable routing. Still a lot of skill to gain in heat control!
Question 1:
My plan for the rack mounts is to use standard M5 bolt hourglass style rack braze ons on the front of the fork legs. My plan is to attach them using System 48 filler. I also have LFB on hand, but thought System 48 would require less heat and also seems to build up some decent small fillets (like you would find on a seat stay bridge). Does this plan seem solid? Any advice?
Question 2:
Are there any existing standards for rack mount locations that you all use?
From what I gather, 165mm from the fork eyelet is quite common. I don’t have the rack yet (won’t pick it up until end of month on a work trip to the US, but most likely a Nitto M18 or a Velo Orange front rack). It seems like there is a lot of flexibility in the rack setup that doesn’t require exacting precision, but wanted to get a gut check from you all.
If possible, I like to add these mounts with the rack in hand. Some companies, like Ortlieb, will provide a measurement to abide by.
I do also have a Surly fork, and a few others with mounts on them made by large companies that I use as reference when necessary.
I always use silver. Bronze isn’t necessary, and as you said, gets incredibly hot. You may find that getting those two mounts parallel to each is hard. One way I like to do this is put a spoke through the holes, and weight it down in the middle with a Cobra clamp or similar. It does a good job of keeping them in place and not allowing the heat to move the mounts around.
Picture isn’t exactly what I described, but a similar way of dealing with tricky mounts.
You referenced two rando-style front racks with adjustable struts. They have no relationship to the rack mounts at the dropouts. I would aim to add the mounts roughly where’d you mount canti bosses.
If you want the mounts positioned for a low rider rack, refer to the technical drawing for the Tubus Tara, the gold standard for low rider racks.
Waiting to get the rack is probably the best idea! Just itching to get on with it so I can start paint work and not delay the whole build. Shipping stuff to Canada is expensive. Will take a peek for any published specs! I don’t have any other forks on hand to reference for mount locations.
TY for tips on fixing them in place. I was thinking maybe an M5 threaded rod to keep them on them same plane, and then a piece of flat stock on the backside of the fork legs with a clamp between the stock and the rod to keep it into position, but maybe I am overthinking it and a spoke + weight is all I need!
So far what I’ve been referencing has been images on the web, like this one, which seems to have them connecting to mounts much further down than where you would find a canti. (Plan for this rack is to hold a Wald basket)
I am just west of Toronto in Milton, so a bit of a drive, but so glad to hear from someone somewhat local and appreciate the offer so much!!! We may have to compare notes on material suppliers at one point!
Thank you! Framebuilder supply I’ve ordered from, and Nova and Cycle Design. I may try to gang some stuff up at one of those places in Buffalo and drive down to pick it up.
I had no clue you could buy stuff from Marinoni. I ordered a custom Columbus SL track frame from them years ago and it was a wonderful experience.
Cycle Design is incredibly expensive for us Canadians. GasFlux is a great alternative (and for me, preferable) and available in Canada without international shipping. The LFB rod and Harris silver from canadaweldingsupply is great, too. The Canada sourcing thread has links to Canadian companies carrying these products as well.
I would aim to position the mounts so the struts have a short run to the rack. I’m willing to bet that the rack in that photo wobbles more than necessary because the struts are really long. You can see in the photo that it looks like there’s a dedicated mount higher up for that kind of rack.
Thank you! Good call. I was thinking about that and also weighing it against more triangulation to get the struts under the leading edge of the rack. This is also making me think exploring something like a Surly 8-pack rack since it would be easy to add two more rack mounts around the fork crown and it would probably be more secure than something like the Nitto with one strut going to the fork crown.
I know for rando-style racks (minimalist, bag support, not pannier, etc), the standard is ~140mm vertically from the fork crown. I think @Alex can confirm this, but this post & this post seem to back that up.
140mm from the crown and 165mm from the dropouts is always what I’ve used. I use water bottle bosses in the blades for the mid fork ones because I don’t keep that rack mounted. I use barrel bosses for the rando/porteur rack bosses because that rack is always mounted.
Out of curiosity, is there any standard measure for the fork crown / upper fork mounts like you would find on a lot of Surly unicrown forks (and also Tumbleweed). The ones on either side of the crown hole. Did a bit of hunting around the web but haven’t come across any drawings or measurements for these.
I haven’t found one. For forks with crowns the right spot is really unique to each crown design. I’ve had enough rack failures (one is enough) that I’ll always make my racks use 4 point mounting if possible, but those locations always end up being custom.
Nothing like having the rack in hand to work with to make sure there’s enough adjustability and space for the tire, etc. even with the Surly 8-pack. For that rack I think I did ~20cm from the upper hourglasses bosses to the mid blade ones. That rack is adjustable but weird to get right IMO.
I believe the 140mm is from the crown hole to the mid-blade bosses, that is for the Rawland rack as well but not for other fixed leg racks so be careful. The 140 from the hole doesn’t put the mid blade bosses in the same location as the Tubus spec of 165 from the dropout eyelets. So your fork can soon get very holey if you want to use a lot of different racks! The Tubus Duo is a through hole as well at 165, which can be threaded or not but with tapered legs make sure the bottle bosses faces are parallel.
There are so many numbers to watch out for with forks. If it’s a disc fork with anything cage bosses face them forward or be sure to angle them no more than 35 deg back and starting at least 120mm from the axle (verify this distance). If they’re higher up they can be canted at a higher angle but the caliper and cable will get in the way of you’re not careful.
This is super helpful. Based on the advice in this thread I am holding out until I get the rack. I was leaning towards ordering a Surly 8 pack today based on what @Alex mentioned about sticking with designs that have 4 points of connection which was how I ruled out the Rawland. The intended use case is to attach a Wald 139 basket up top a little grocery getter. My plan was to just braze on your glass style mounts vs. Brazing in a bottle boss (though I have those on hand too if you think that is a better way of connecting).
Any things to keep in mind for getting this rack setup?
