Drop Bar MTB Geo

Hey brother, try this:

https://a.aliexpress.com/_mqituHM

Spacer kit for 142 to 148. Only issue is the silver 6 bolts, not to mention banking on you running a 6 bolt set up.

And you have to redish the wheel.

With 2 3mm spacers on both sides of the hub, why would that be needed?

I think ya’ll may be talking about 2 different types of rear conv kits?

One kind uses 3mm on both sides, one has just 6mm on the NDS.

sometimes shifting can be off (not getting all cogs) with the former kind.

Hey Pottery, can I get some more photos of that 2nd tan fork? Made by TOSEEK right? I am looking at that one right now on AliEx, 460 A to C I believe.

I tried one with a 454 A to C, but it was just a bit too steep, and bit too low of a reach. I needed too much spacers under my stem… i’m 6ft with a long inseam.

You’re talking less than 5mm of actual stack difference between these two mentioned, and less than a 1/4 of a degree of HTA. So you might want to bump up to at least the more commonly available 470mm options if you’re hoping to notice any difference…

Point taken, thanks. I am coming from a 72 degree head angle gravel bike, Carbonda 696, with a 100mm stem.

I don’t mind moving to a shorter stem with a taller fork, but I worry about that wheelbase being too long. Overall, I am building this to replace that gravel bike, I use it for racing, mainly because i’m really looking forward to running race kings or burts. Any suggestions from your experience would be appreciated.

2nd fork is a 500mm A2C Seido BPC (also sold under some other brands).

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ah maybe I misunderstood, do you mean the 2nd fork in the first pic of 4 forks or the fork pictured in the 2nd pic? the latter is an sp cycles 27.5 mtb rigid fork.

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Laurens Ten Dam (ex-pro cyclist turned gravel racer) is building a drop bar S-Works Epic World Cup as his Tour Divide bike. He will be using it for the first time later this month in the Andes mountains.

You can check out a highlighted story on his Instagram

Laurens ten Dam (@laurens_ten_dam) • Instagram-foto’s en -video’s

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For anyone needing a visual of what this conversion does to the numbers:

I’m considering a 480mm fork vs my current 454mm fork , Here are the 2 options: Red bike is stock size M, blue is the dropped front end with the respective forks installed.

I will use this to replace my gravel bike, a 56 Carbona 696, granting me the clearance for larger tires, like @Upcountry’s build. I plan to run this on my XC trails around the AZ desert. Here’s what I can expect to see compared to my current Carbonda gravel bike:

This site has been a great visual aide, I highly recommend it for visualizing the changes before you take the plunge. bike-stats - everything about bike geometry

Now my only remaining “unknowns” are around handling. I want to avoid wheel flop, twitchy steering etc. My Carbonda 696 handles well with its 100mm stem, reactive but tame, but with the chunky descends I do around my trails, I wouldn’t mind a little more relaxed handling. If you have experience in this realm, and can elaborate on this matter, please chime in. My bars are 40mm with flare to about 480 at the drops. 77 reach. I plan to get a hold of a few cheap/beater stems to test length, but not sure where to start.

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You can actually use bike-stats - everything about bike geometry to estimate your stem lenght aswell.
Under the visual of the different bikes, you can add stem lenght, bar width, bar drop, etc.
Just make sure you align based on the BB, otherwise it might give the wrong idea about the stack height.

As an example, this is my road bike vs drop bar MTB i’m building (I find i’m a bit short on reach on my road bike, so hoping this 70mm stem will be fine)

PS: If you want to put in the data for your dropped bars on the MTB. You have to chance, in the custom bikes menu, your MTB to a gravel bike with the same geometry data. Then go back to the comparison, and you can put in the data of your selected drop bar.

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Can you clarify how you’re expecting to fit the two options compared to the 696?

The 454 looks like it wouldn’t be possible to fit without a big change to setback, the 480 seems like it might work.

Unless I’m missing it, I don’t see trail and wheel flop in Bike-Stats.

Things I’ve noticed about these kinds of builds:

Too much trail and flop with narrow bars feels awkward out of the saddle until you learn to compensate with some extra effort to balance it all out. With more rearward weight distribution you can mitigate it somewhat but overall I found things felt more balanced with wider drop bars.

I also found that the long progressive front ends can get washy when you’re trying to stay seated since you’re not riding that geometry out of the saddle like it’s intended for. So it’s harder to stay planted on the gas in something twisty when you have to pause to slide forwards on the saddle.

You could try to run your position more forwards to get a better distribution but that gets hard on your hands and arms and you start losing glute engagement which I think isn’t the best strategy for longer gravel-type events.

I can’t say whether anyone will prefer it or hate it, but those are some things to look for if you try it out.

Sure, here’s my thinking:

A 20mm setback would put me in the correct saddle range. As far as the front end goes, I am thinking I will be open to a bit of a longer reach, as the stem on my gravel bike is slightly undersized, I switched groupsets to SRAM CX1 a while back, and the hoods are shorter.

This leaves me questioning a short stem on this sort of build, as I can make the numbers work, but it may behave terribly…

Ugh… checking the size small, the reach becomes much less while most of the rest stays the same. Allowing a 60mm stem with a 480mm stem. I might’ve screwed myself since I already picked up a size M.

It sounds like you’re got it pretty well sorted. I’ll mention that one thing that is easy to miss is that the Epic HT has a little kink in the seat tube, so I measured my actual seat post itself at a bit slacker than some of the number crunching would indicate. So with that, it was pretty easy to get my saddle setback in the right place without any special seat posts or anything.

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Got it, i’ll keep that in mind.

Do you see any drawbacks in a size small over medium as demonstrated in my visuals? I’ll have to bump up to a 450mm seatpost for a safe insertion depth, which isn’t a big deal at all. But before I initiate a return with Spcycle with my size M, I would love to hear from your experience on stem length and handling. With a size small, I am looking at a 60mm stem or longer. Did you like that handling? Does your experience have you wishing for longer/shorter stem?

A size M would have me on a 45mm stem or shorter. Drwelby shared his perspective:

“I also found that the long progressive front ends can get washy when you’re trying to stay seated since you’re not riding that geometry out of the saddle like it’s intended for. So it’s harder to stay planted on the gas in something twisty when you have to pause to slide forwards on the saddle.”

Do you think a short stem like a 45/35mm would ruin this build? Thx for hearing out all of my questions, this is all new to me, but i’m determined to make it happen!!

I don’t think a 35/45 stem would ruin the build but I do think such a short stem needs to be paired with wider handlebars, probably 52cm+.

I rode a 45mm stem on my drop bar MTB for a couple years and it was fine, some weaknesses in certain situations but never thought much about it as a negative. Moved to a 60mm stem recently and it was a surprisingly big change. Made the handling more intuitive - less tiller effect/plow effect during cornering when the surface changes suddenly and feels more settled and stable without feeling sluggish.

Similar geo but not as extreme on my bike - hardtail, 71°/69° hta/sta, 1105mm wheelbase, 50cm handlebars.

I’ve been looking at your M builds for a bit and I think the S is a lot better fit for what you want to do. M would be more of a compromise IMO.

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You could also kick the M back a bit with a 650b rear wheel.It will make the front end even slacker though. But if you’ve got an extra wheel it might be an interesting step in figuring out where your parts needs to sit in space.