MiPeGr

So I'm thinking about adding fenders to my Topstone (AL 105), and I'm having a bit of trouble figuring out what will fit and what will not.

Ideally, I'd like to have a single set of fenders (full-coverage type, more-or-less), that would work for both 700c X 32 and 650b X 47, but I don't know if that's possible, since 650bx47 is a bit smaller diameter than 700xc32 and I don't know how closely the fender curve is designed to fit, or if it can be manipulated a bit.

I've come across one person who specifically mentions a 700x50 (Planet Bike Cascadia ALX) fender, so I know that width/size would work, but it seems a little narrow for a 47mm tire. But without a 650b set of wheels (yet), I can't just measure directly what the (fork/stay) spacing is. So I'm hoping all the other Topstone owners out there (and there sure seem like a lot of them), can offer me some advice. What about a 700x65mm fender? What about a 650bx55/60/65?

So what fender are you running on your Topstone, and with what tire? Please post pics of mounting points and clearances, if you can.

westrid_dad

I've posted some pics recently of my fender setup on my Topstone 105. I am running the SKS Speedrockers with a set of flaps from Ass-savers. I am only running 700c wheels currently, either the stock WTB Nano (700x40) or a set of Continental GP 5000s (700x28) on a difference wheelset.

Anyway, here are links to the posts, let me know if there are other questions on this setup.

SKS Speedrockers

SKS Speedrockers with Ass-savers flaps

MiPeGr

Thanks...I've seen those posts. I didn't call it out explicity, because the width of the speedrockers won't cover the 650Bx47's I plan on running off-road. Those could be a good choice for me if they were available in a wider form-factor.

westrid_dad

That's a good point. With my current gravel tires (WTB Nano 700x40), the SKS fenders do just provide enough coverage width-wise. I'm not sure how that would correlate to the 650Bx47 tires you're considering. That being said, I do think my WTB Nanos are running wider than 40mm.

antmaster5000

I'm curious if anyone has tried these with 650b wheels. Also have 650b x 47mm and these would be perfect for my bike.

MiPeGr

I just got a set of SKS Edge 55 fenders that I expect will be able to cover both my 650bx47 and 700cx32. Will be trying to fit them over the weekend & will follow up.

Chi_Z

it would not work, the radius of the fender would not match neither 32 or 47

MiPeGr

SKS website specs the Edge AL 56 (not 55 like I said above) for 650b and 700c 38-50. What am I missing?

Koyote

I'm only on my second cup of coffee, so might have done the numbers incorrectly...Or I might just be missing something, as I have never tried this. But here goes:

650b with a 47mm tire should be about 678mm overall diameter; 700c with 32mm tire should be about 686mm diameter. (That'll depend partly on the tires' profiles - some are rounder, some are more squat, and even that depends partly on the rim width.)

With a roughly 8mm difference in tire diameter, the same fenders might fit -- but the mounting will need to be adjusted for the wheel swap unless you will accept a sloppy fender line.

The problem that you will definitely face is having fenders that are the optimum width for one tire, and a very sub-optimal width for the other tire. I would think that you would want to use fenders wide enough to cover the 650bx47 tires, but then they will be ridiculously wide on the 700cx32 tires. Like, stupid wide. But if that doesn't bother you aesthetically, you'll get good coverage.

If it were me, and I wanted to fender a bike, I would pick a wheel and tire size and be done with it. On a fendered bike, just pulling off the wheels can be a bit of a hassle, and so I prefer to do it as little as possible.

MiPeGr

This particular aesthetic concern carries no weight with me. As for other hassles & considerations...I'll just have to wait to see until I have them installed.