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I wanted to start a forum for current, future, or potential Stumpjumper 15 owners to compile questions, answers, tips, problems, etc. Below is overarching information about the bike and our coverage of the bike thus far. ▪️Overall Details - Carbon models - Alloy models - 145mm of rear wheel travel // 150mm fork (160mm compatible) - S1/S2 - mixed wheel only // S3-S6 - 29-inch (mixed wheel compatible with aftermarket link) - FOX Float with Specialized patent-pending GENIE shock on most models - Coil models available (FOX & Öhlins) - S1 - 210x52.5 shock // S2-S6 - 210x55 shock -...
This forum topic has 83 replies.

dolface Liked a reply to forum topic 32-inch Wheels and Mountain Bikes

9/16/2025 1:36am
Given that I'm 5'7" and likely not the target market for 32" I'm still excited to see how it all shakes out; it's entirely possible that something that benefits all riders comes out of it. If nothing else I'm looking forward to seeing the various ways builders come up with to design frames around bigger wheels.
This forum topic has 90 replies.

sollie Liked a reply to forum topic 32-inch Wheels and Mountain Bikes

9/16/2025 1:36am
I'm 6'7", and I'm so excited by the potential. All I'd say is that if you aren't interested in these wheels, don't use them. But please don't ruin it for me. It's ok if not every product is for you... lord knows 99% of bikes don't fit me, and I still enjoy learning about them.
This forum topic has 90 replies.

sspomer Liked a forum topic 32-inch Wheels and Mountain Bikes

9/16/2025 1:35am
It seems that whether we like it or not, 32-inch wheels and mountain bikes are going to be a thing. That thing may not permeate too deeply into all riding categories, but multiple sources from a variety of different brands have recently confirmed bigger wheels, both front AND rear, are in mountain biking's future. As a result, here's a dedicated thread to the new wagon wheels. Intel is that the larger wheels will be for mostly XC (no idea how the UCI wheel size limitation will work out), but 32-inch wheels on trail bikes are also likely. Again, it's not...
This forum topic has 90 replies.

brianholinko Liked a forum topic Vampire Bikes

9/16/2025 1:34am
This forum topic has 13 replies.

_Lan Liked a reply to forum topic Frame Design

6/26/2025 8:40am
I agree with your observations. Here's my latest creation. split High pivot pinion gearbox downduro bike. 210mm travel for 75mm stroke. around 120% anti-squat, 90% anti-rise, 25% progression. Next design will have a motor in it as I feel this analog one outside of small design details, is about perfect for my use with the current available components.
This forum topic has 194 replies.

Eae903 Liked a reply to forum topic Frame Design

6/26/2025 8:40am
I am super down to learn how to do it manually, I want to understand what I am doing when I design bikes and how to manipulate the linkages to get what I want out of the bike.
This forum topic has 194 replies.

Big Bird Liked a reply to forum topic Frame Design

6/25/2025 10:27pm
You get a like for full sized paper design. Oh, and some cool bikes! For the record. Here are my homemade bikes. https://dirtmountainbike.com/bike-reviews/homemade-bikes-big-bird
This forum topic has 194 replies.

earleb Liked a reply to forum topic Frame Design

6/25/2025 10:27pm
All fabrication done by myself in the garage. I have small benchtop mill, benchtop lathe, and an oxy-propane brazing set up. Jig is also garage made out of cold rolled steel a design copied from a number of Colorado builders that use a similar design. The first single pivot frame was build with hand files, hacksaw and a vise. No jig and no machines, just a couple of pieces of cheap aluminum angle to float the rear axle in space relative to the front end. A full size paper drawing was done to figure it all out.
This forum topic has 194 replies.

earleb Liked a reply to forum topic Frame Design

6/25/2025 10:26pm
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the same thing. The window of preferred anti-squat and leverage ratios is narrowing in on roughly 100% anti-squat at sag and a LR of 20-25% linear progression starting around 2.8 to 3.0. Anti-rise seems to still be down to designer tastes or a compromise of the chosen linkage platform / shock location. The more time you spend in Linkage the more you realize everything has already been done...and thus why the window of optimized designs...
This forum topic has 194 replies.

Eae903 Liked a forum topic Frame Design

6/25/2025 10:25pm
I'm looking to start a discussion on frame design! I'm currently a mechanical engineering student who wants to design bikes for their career. Looking to have a space to bounce ideas and collaborate!
This forum topic has 194 replies.