MTB Gravel Bike Conversions

Posted by: pedalhound

One of my biggest issues with the Rootdown is the super low stack (I am old and like a more upright position) so that's the one thing really keeping me from trying this. The frame is just sitting in my garage collecting dust...this would be more of an ATB/bikepacking build than full on gravel, I have a Norco Search steel for that...but it can only take up to 45c tires...I want something a bit more beefy.

I doubt I will do it, but man it would be a fun project...lol.

If you have enough steerer it will work.  Even slap a riser drop bar on there for an extra 15-20mm.  The other thing I've found helps is keeping the stem short (I'm at 40mm) and low drop risers like the Corralitos which make the drops usable even as I rapidly approach 50.

As a roadie/gravel noob I've just discovered the joys of different pull ratios on shifters / mech. I was wondering why my GRX400 10sp levers weren't playing well with the Microshift 10 speed R10 mech. Turns out 10 speed GRX has a 11 speed pull ratio. D'oh.

I'm going to try a GRX400 mech and maybe try an 11 speed 105 (short cage).

There is a good shimano compatibility chart that shows what plays nicely with what.

https://productinfo.shimano.com/en/compatibility/C-454

I did a reasonably big road commute the other day and I'm really liking the bars, hydraulic brakes, dropper and overall geo. It's now a matter of fine tuning things.

Posted by: pedalhound

One of my biggest issues with the Rootdown is the super low stack (I am old and like a more upright position) so that's the one thing really keeping me from trying this.

If you don't want to go down the riser drops route, there are also a few short reach + high stack stems out there. I have used an Analog Gnomehopper and like it, and you can get any of the Ergotec offerings for cheap from some of the German sites (ROSE usually has Ergotec stuff for 30-40% off). I also have an Aerozine XNC10 but haven't got the frame it's going on yet.

Posted by: fartymarty

As a roadie/gravel noob I've just discovered the joys of different pull ratios on shifters / mech. I was wondering why my GRX400 10sp levers weren't playing well with the Microshift 10 speed R10 mech. Turns out 10 speed GRX has a 11 speed pull ratio. D'oh.

I'm going to try a GRX400 mech and maybe try an 11 speed 105 (short cage).

There is a good shimano compatibility chart that shows what plays nicely with what.

https://productinfo.shimano.com/en/compatibility/C-454

I did a reasonably big road commute the other day and I'm really liking the bars, hydraulic brakes, dropper and overall geo. It's now a matter of fine tuning things.

Just put an 11 speed 105 on and it's sorted it.  It's got a nice short cage too which I like.

Haha, if you want to buy it tashi ... I am down to sell it, just too lazy to list it, lol. It's an XL.

I put riser drop bars on my Norco Search XR and a shorter stem because I felt way too leaned over and my hands hurt like hell on longer rides and touring on it...this helped, but I think I need something more ATB style with a high stack.

That's some great info TristanC, I will check it out!

Yeah, this is why it's hanging in my garage right now collecting dust...lol.

I'm shopping around for a HT frame to rigid up for gravel/adventure/commuting and due to the shorter axle to crown I find myself wondering - how much BB drop is too much? 

I'm happy with the ~300mm BB height on my mountain HT, which will be lower under dynamic sag, but is 280 just rediculous for a rigid?

Posted by: velocipedestrian

I'm shopping around for a HT frame to rigid up for gravel/adventure/commuting and due to the shorter axle to crown I find myself wondering - how much BB drop is too much? 

I'm happy with the ~300mm BB height on my mountain HT, which will be lower under dynamic sag, but is 280 just rediculous for a rigid?

My gravel/adventure bike (Otso Warakin) is at 281mm BB height rigid, I don't think that's crazy for that type of bike.

Tristan - do you have piccys of the Warakin?

I'm considering a new frame and looking at a Super Something (Sklar) to replace the Krampus. Does anyone know of other frames that are a little more mtb than road / gravel geo and will fit reasonable tyres - say 29x50s. I don't want to go full dropbar mtb as the Krampus already does this.

I'm getting a bit of a taste for the road and want something a little lighter and more supple than the Krampus but not with a silly steep HA like most gravel bikes seem to have.  It also need to do singletrack....

Posted by: TristanC

Posted by: velocipedestrian

I'm shopping around for a HT frame to rigid up for gravel/adventure/commuting and due to the shorter axle to crown I find myself wondering - how much BB drop is too much? 

I'm happy with the ~300mm BB height on my mountain HT, which will be lower under dynamic sag, but is 280 just rediculous for a rigid?

My gravel/adventure bike (Otso Warakin) is at 281mm BB height rigid, I don't think that's crazy for that type of bike.

Your enabling is appreciated.

Posted by: craw

Posted by: fartymarty

I'm keen to see / read about others who have converted mtbs to gravel bikes.

I tried doing this a number of times over the years but it never really took. A few friends have similar monster bike conversions that hang in their garages unridden. But once I got a proper dedicated gravel bike with suitable geo (which is basically a 90s mountain 72/74 bike but with a tall head tube and 29" wheels and 40mm tires) I ride it all the time, at least as much as my enduro bike. 

For people who did these conversions and actually ride them regularly: what is the secret sauce to getting there? I never figured it out.

craw - looping back to your comment...  For me it has been getting the seated position right.  My L Krampus has a 441mm reach.  I'm 185cm.  So while it's short for a mtb it's long for a dropbar bike.  Hence the 31mm stem to get the bars close and Ritchey Coralittos which have a very short reach.  To offset the quicker steering from the stem i've got a -2 degree angleset which slackens the HA to 67.5 which is slack for gravel but i'm used to wandery front ends from my HT and FS bikes which are ~63ish.

If I had cash to buy a custom I would decrease the reach a little so I could use a 50-60 stem, steepen the HA a little to may 69 and increase the ST length - but still run a 125mm dropper.  I'd also lengthen the HT and get a rigid specific fork as I don't really want to run suspension on a gravel bike.

Posted by: fartymarty

Tristan - do you have piccys of the Warakin?

I'm considering a new frame and looking at a Super Something (Sklar) to replace the Krampus. Does anyone know of other frames that are a little more mtb than road / gravel geo and will fit reasonable tyres - say 29x50s. I don't want to go full dropbar mtb as the Krampus already does this.

I'm getting a bit of a taste for the road and want something a little lighter and more supple than the Krampus but not with a silly steep HA like most gravel bikes seem to have. It also need to do singletrack....

Here's the Warakin (RIP, flattened by Andre from Bamberg's Audi). It fits 700x50 no problem, but I typically ran it 700x38 for more road-oriented stuff. It's probably got a steeper HTA than you're looking for (70°-72° depending on size), but it was a great bike.

Otso also makes the Fenrir, which is more in the drop bar MTB direction.

Or just get yourself a Stooge Rambler and call it a day! That's my replacement frame, still slowly building it up.

My Landyatchz bb sits at -75mm; make of that what you will. It's probably a height in the 280mm range, depending on current tires and yadda yadda yadda.

Actual riding position from here can vary massively dependent on all the other numbers, obviously. STA, stack, reach. Lotta ways to rotate and move body position around that fixed point.

Posted by: velocipedestrian

Posted by: TristanC

Posted by: velocipedestrian

I'm shopping around for a HT frame to rigid up for gravel/adventure/commuting and due to the shorter axle to crown I find myself wondering - how much BB drop is too much? 

I'm happy with the ~300mm BB height on my mountain HT, which will be lower under dynamic sag, but is 280 just rediculous for a rigid?

My gravel/adventure bike (Otso Warakin) is at 281mm BB height rigid, I don't think that's crazy for that type of bike.

Your enabling is appreciated.