I completed my drop bar MTB build this weekend. Rode it for the first time this morning.
The frame is an Airwolf YFM026 (Santa Cruz Highball geometry), combined with the Airwolf rigid fork (480mm A-C). I chose this frame because a bike shop in the Netherlands sells this exact frame as their beach racing bike. So basically, MTB frames with 2.35" slicks for riding on the beach, all specced with 40+ tooth chainrings. I went with a 40t chainring (boost) on mine, but there is clearance for a 42t minimum without changing the chainline!
I chose a Large frame (Iām usually on a Large at 184cm/6ft) and itās a little on the long side but definitely still fine with a 70mm stem. Iām very happy I looked for bars with a short reach so I could still use a decently long stem.
What rear cassette are you planning to run? Iām trying to figure out the right cranks to use to get smooth shifting and while I think I understand chainline Iām struggling to put the pieces together. I thought the 55mm chainline was the right fit for the SP-M05/Epic HT, but there donāt seem to be rings larger than 36T to pair with 55mm chainline cranks. I want to run a 9-46 11-speed in the back and a 40T (ideally oval) in front, Shimano GRX shifters and XT derailleur. Any tips?
Iām running a 55mm quarq with an off brand chainring, because almost no one is mounting a 44t mtb ring. Forgive the bad pic, but this drivetrain has about 600 miles on it and itās going solid.
Youāll need to forgive the flat bars in this thread, but I find that when I ride drop bars too aggressively, they always slip and rotate down, so for something that is sendier than your average gravel bike, I wanted flat bars for it.
If anyone has tricks to keep the bars from rotating while using it like a mountain bike, please enlighten me.
The issue I have is that only helps in a static position. Once you are hitting large compressions or impacts in the drops the loads are at a different angle, and they donāt stay. It is not isolated to a specific bar setup or hood position. Itās been happening to me for years. Once I start pushing 45mm tires to their limit, the bars end up rotating on a big impact or compression. Particularly on steep sections when an impact send more force through the hands than it would on the flat. I try to take most of that force through the feet, but being in the drops brings the body forward and makes it harder to keep all the weight through the feet.
True. Iāve got a Yoeleo on my gravel bike that was around $350 I think and itās seen plenty of singe track and done quite a few gravel races without any issues.
Iāve tried them. Full face plate, torquing bolts in a star pattern with a torque wrench, and re checking them after bringing everything up to torque. Only using 4 bolt stems with short reach bars to keep the leverage lower. Multiple stems and bars. Itās usually racing through singletrack/jeep roads and pushing the pace, as itās usually a relative strength. Iāve been playing with the mtb for gravel as an idea that might help with this, but Iām not convinced by my experiments yet
After some consideration, given the annoying complexities of the MTB transformation, it seems that a custom Ti frame is an excellent choice. Will talk to Mosaic next week.
Fit 44 chainring
Fit 2.4 Tires
Dropbar
Fit Suspension Fork.
Dropper
The only issue is weight. The standard is the Epic S-Works HT frame.
For sure weight, easily a pound heavier to start the build.
Also worth considering that youāre kind of gambling on geometryā¦ With this drop bar hardtail w/ suspension fork thing being relatively new, there isnāt a settled ābest practicesā regarding lengths and angles. So without actually knowing what youāre designing will feel like, its a pricey experiment.
The other issue is $$$ā¦ I have bothā¦ A custom Mosaic frame only will run you up near $5kUS, versus some NOS Epic HT frames for $2k($3k for S-works if you can find one).
Additionally, Mosaic might not be able to fully accommodate all those asks, or at least not without some compromises, especially in the BB/Chainstay setup as theyāre pretty set on 73mm shells and standard tubing chain stays versus plates or 3d printed junctions. So 44t and that kind of tire clearance is toughā¦ For example, their GTx series only has clearance for a 42t ring with 2.25" tires. But also, in a separate argument, Iād say these bikes donāt need a 44t chainringā¦
I was talking the other end of the cassetteā¦ if 44/52 works for you easy gear, a 38/44 will give you nearly the same, with nicer gapsā¦ A 38/10 gets you well over 30mph. Dylan ran only a 36/10 at Leadville, which is known for its fast pavement pack dynamics. A 42t or 44t is too much, with no real benefit. I know the 10t isnāt ideal, but also, youāre not going to be in that often, and a 38t probably gets you a better chainline for the most used gears, and a better chainline in the min/max gears. Its although worth considering, that a 2.25" tire at 38/10 gets you nearly 1.5mph more speed than a 40mm tire at the same cadence.
And the internal routing is another miss for Mosaic most likelyā¦ Youāll need a 52mm upper bearing for internal routing with a standard steerer(as found on suspension forks), so youāre looking at some aftermarket(Acros, Token, etc) option. I know there is the 44mm Enve In Route setup for Chris King, but blah! Also, a suspension fork is always going to have a big brake hose loop sticking out front, so Iām less concerned about saving 10" of rear brake hose by headset routing on mtbās.
