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can someone direct me to a link or else let me know, how much less stem length do you need to make drops work, all other things being equal? I use a 105mm stem and a set-back post on my 19" monocog 29er, and am wondering if I should use a 19" frame with 80mm stem and straight post, or if I need to go to a 17" frame. I don't really want to do that because I want the headtube height and the shorter seatpost of the 19" frame. HELP!!!
 

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I went thru this math a bit when I was thinking thru a travel bike setup that could take both drop bars and riser bars, so I can offer some comments.

What are you trying to do? Put drop bars on a MTB for off-road touring? Commuting? Or are you shopping for an actual road bike or cross bike?

If you compare one person's MTB and road bike, its typical to see ~ 3cm shorter TT on the road bike. This is a generalization, of course. Despite this, you'll often see a similar stem length on both bikes, although with the trend to short stems on MTBs, the road bike stem is often longer.

In your case, you are propsing to go the opposite way -- a shorter stem on the drop-bar bike. I would discourage this if it is any sort of semi-permanent purchase or setup. If you're goofing for a weekend, go for it. If you are buying a road bike, do NOT buy one that will require an 80mm stem, which is unusually short even for an extra-small road bike. Given you are a "large" person (riding a 19" MTB) then you should be using about a 120mm stem on an ideal road bike. Maybe 110. Anything less is going to start steering weird.

The straight vs. set-back post question is essentially a question about seat position, which should NOT be influenced by this bar/TT debate. Avoid tweaking your seat position to make up for TT length. Ideally, seat position should be determined almost exclusively by your body. I won't go into the myriad of methods used to determine the position, but the position (horizontal distance from seat nose to vertical axis of BB) should be roughly the same on any bike you ride, assuming the same crank length. Getting to this position may imply straight post or set-back -- depends on seat tube angle.

The TT length is the critical measurement on a drop-bar bike. The head tube contributes to the bar height, but don't compromise your optimal TT length for some headtube length. Use spacers on the fork and/or a riser stem instead. Or look for bikes that have longer headtubes.
 

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I'm in the process of conveting my Inbred to drop bar. I should have it back together this weekend. I took into consideration the length of the drops protrusion forward from the flats, and secondly the effect of the riser stems angle on the reach.

I went from a 110mm 5 degree Thomson to a 80mm 40 degree rise stem. This was after taking into consideration the 65mm forward drop position of Midge bars. I still need to dial it in, so a different stem may be in the works, or less spacers on the steeerer. I had to put alot ( 1 1/2 inches worth) of spacers on in order to get the bars up enough.
 

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moondoggy said:
I'm in the process of conveting my Inbred to drop bar. I should have it back together this weekend. I took into consideration the length of the drops protrusion forward from the flats, and secondly the effect of the riser stems angle on the reach.

I went from a 110mm 5 degree Thomson to a 80mm 40 degree rise stem. This was after taking into consideration the 65mm forward drop position of Midge bars. I still need to dial it in, so a different stem may be in the works, or less spacers on the steeerer. I had to put alot ( 1 1/2 inches worth) of spacers on in order to get the bars up enough.
I'm about to do the same conversion on my Inbred; be interested in pics of yours when its done.
 

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Did this to my KM, still not 100% happy.
I used to run 120mm stems with 11º Salsa Bars, and 140mm with H-bars.
Now there's ~100mm x 40º with a 6mm taller (redline) fork, and 35mm more spacers under the stem. It still feels like a long and deep stretch. I cannot comfortable ride the drops. Looking around for either a cheap fork with longer steerer to add spacers, or one with longer axle-crown. The latter would reduce reach by itself, some 60% of the extra length will be deducted from yor reach.

My ideal road bike top tube must be around 580-590mm. The MTB's I've called ideal were between 616 and 648mm. I made the mistake to get one custom and one stock CX bike with 600mm stem, making even a 100mm stem feel "long". Short stems on road bike don't feel nice. Nervous, due to the narrow bar I presume.
I'm now looking to get 420mm rather than 400mm forks for both my CX'ers, not easy or cheap. For more relaxed handling, and possibly allowing a 110mm stem.

With the MTB frame, at least you'll have a long front center, offering stability to some degree. If you can handle a 17" frame for seatpost length, try an find someone to trade frames with (get an MTBR classifieds ad). The ~3/4" shorter top tube will help. Heck, I may have to do that with the beloved KM if I don't manage to get preferable handling and position. Or just give up on the Midge and go to tried and true (for over a century) swept trekking bars that I know I love, and work 100% with MTB frames. I wanted the Midge on the KM for commuting and the odd supercentury where the tops would be the optional position, not for all of the ride. That means TALL and SHORT, I've found.

The Redline Flight would be a much better do-both bike in this (Midge on MTB) respect than the Monocog. Top Tubes are ~20mm shorter for each size, promoting a "normal" length stem. That's a good 2" frame increment's difference! Also, steering geometry is a bit more"retro", slacker head tube angle, more offset, for the same front center and fork trail.
Now I've got a Flight on it's way to me, but for now I'm planning to treat it as a marvellous steel MTB, and I don't onsider Midge a real offroad option for myself, when I can get the likes of 17º Salsa bars and custom Black Sheeps to rock my bike world.
I'm in bad luck with my long legs, I really need a 21" to get proper seatpost insertion even with 410 and 450mm seatposts, others my height might get away with 19" and get decent fit with both MTB and Road bars. It will never be easy though, the difference between the bars really is a full 2 frame size increments in terms of reach.
 

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Clink said:
I'm about to do the same conversion on my Inbred; be interested in pics of yours when its done.
Drum roll....

Here it is in it's hot off the press mode. I've only ridden it around the back yard, and have yet to dial it in after an off road ride. Although uber-dorky looking, It has two inches of spacers stacked up and the bars feel like they are in the neighborhood of where they may end up at. The flats of the bar are two inches higher than the seat, and the drop grip position is one inch higher than the saddle. I run my bars alot higher than when I was a youthful lad, so the grip position is on par with my flat bar bike. As mentioned, I'll probably dial it in some more after a trail ride, but I think it's close.

So far, I really really like the drop bar ride. The leverage is amazing compared to flat/riser bars, and they are super comfy. I look forward to seeing how those observations hold up on terrain that is more challenging than the back yard. So far ...:thumbsup:
 

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moondoggy said:
So far, I really really like the drop bar ride. The leverage is amazing compared to flat/riser bars, and they are super comfy. I look forward to seeing how those observations hold up on terrain that is more challenging than the back yard. So far ...:thumbsup:
Looks great! I rode a Midge all last summer. I've moved away from it recently, but I may come back. I don't miss those levers though. :rolleyes:
 

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Looks good. I've got my bars, still looking for some 2nd hand brake levers and a stem. Bar height looks the 'recommended' compared to saddle height to me - not sure I've got so much steerer left on my fork! Make sure you post a ride report.
 

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First question is what type of drop bars are you wanting to use? IME for an mtb conversion (one which currently fits you using flat bars) and ultimately MTB use you are limited to drop bars with a very short drop and reach like the On-One Midge.

Basically my goal in setting up midges is to get the hands' position in the drops somewhere very close to where they would be with your current bars. The easiest way to approximate this is to check out your current set up using bikeCAD then model it up using your preferred drop bar dimensions and different rise/length stems. This should get you pretty close to what will work in the 'real world'.

I've got a drop bar specific proto in the works at the moment - will post some pics when it's done.

Sam
 

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Clink said:
Looks good. I've got my bars, still looking for some 2nd hand brake levers and a stem. Bar height looks the 'recommended' compared to saddle height to me - not sure I've got so much steerer left on my fork! Make sure you post a ride report.
Yeah, good point about the steerer tube. I did have to go buy another On One fork to make the conversion because my original one was too short. I'll definitely post a ride report this week.:)
 
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