# Mtn. bike to cross bike conversions. Anyone done one? Pics and specs pelase!



## redpoint510 (Mar 26, 2009)

Hi everyone. I have a 91 Trek 930 Singletrack that I just tore down and had powder coated. My plan was to make it a simple trail bike but I really don't want to use the fork that came with it and don't want to buy a suspension fork because cheap ones are junk and heavy and mid range forks are too expensive. I really want a cross bike and have been tinkering with converting this frame to a cross bike. 700c is no problem on the rear and with Paul V brakes on the rear I can adjust the pads high enough to grab the rim. I bought a new King ISO disc hub for the front and still plan to run a front disc with the cross setup using a Bontrager 700c aluminum disc specific fork. The fork is about $200 which isn't so bad.

My main question is, is it a worthy build or will the bike handle wonky with a 700c setup on it? I plan to use drops on it as well FYI. I already have begun the build with the previously mentioned hub, and had a King headset pressed in yesterday and put on a Thomson post and Flite saddle. 

Let me know what you have built or if you think I should stick with a mtn bike build here. Thanks!


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## rmp (Aug 25, 2004)

This was my last real attempt at a drop mtb. It was pretty stretched out IIRC - I searched long and hard for short, upright stems - certainly nothing high-end was available

<a href="https://www.flickr.com/photos/rmplum/208988733/" title="Fat Ti picture 2 by rmplum, on Flickr"><img src="https://farm1.static.flickr.com/79/208988733_7c82d042fd_o.jpg" width="722" height="740" alt="Fat Ti picture 2" /></a>


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## adimiro (Jun 28, 2007)

Nice Fat RMP :thumbsup: 

Can't speak about 700c wheel conversion, but I have used a Mtb frame with 26 inch wheels, Schwalbe 1.3 Cx tires, rigid fork, v-brake with travel agent, drop bars to get me through some local cyclo races.


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## rmp (Aug 25, 2004)

adimiro said:


> Nice Fat RMP :thumbsup:


yup, I regret selling that one. Nicest riding 26" hardtail I've ever had.


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## misterdangerpants (Oct 23, 2008)

rmp said:


> This was my last real attempt at a drop mtb. It was pretty stretched out IIRC - I searched long and hard for short, upright stems - certainly nothing high-end was available


Wow, that Ti Fat is wicked. :thumbsup: 

So, I converted my Ted Wojcik (w/Igleheart fork) to CX/urban cruiser and really like it. I wanted the bike to have the feel of the older drop bar mountain bikes, like the 1987 Bridgestone MB-1 and the 1989 Specialized RockCombo. I have plans to update the bars to the dirt drop style, but like the current setup for carriage road and urban riding. It's currently set up as a single speed, though it's easily converted back to a 1 x 9 configuration. It's quite comfortable and handles quite nicely.

Anyway, as for 700c conversion, similar to *admiro* mentioned, I can't speak about that, and would say just go with the 26" and use the tires like the Schwalbe CX Pro. That's what I'll be using come this fall.

View attachment 165699


View attachment 165700


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## Squidward (Dec 18, 2005)

Something to keep in mind when converting a mountain bike to drop bars: mountain bikes typically have longer top tubes compared to the equivalent road bike for the same rider. That means that you will need a stem that is about 5cm shorter than you normally run on your road bike. Really short stems are available but not all that common (at least in my experience). Don't expect to find a Thompson or Ritchey 4-Axis in anything shorter than 90mm, for example.


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## hchanrn1 (Jul 20, 2010)

A 700cc conversion would only work with a road conversion. Larger tires would not clear the rear triangle better the rear axle and bottom bracket. I converted my old trek 830 into a road bike. Got a good deal on a wheel set from bike wagon, 135 mm rear axle

http://www.bikewagon.com/Wheel-Goods/Wheelsets/700C/Maddux-Aero-F40-700C-p8803826-1-2.html

$60 shipped

put a $68 carbon fork (extra 20% off for recession special)

http://store.icyclesusa.com/1-18-satellite-carbon-road-bike-fork-700c-50mm-p430.aspx

brakes: $50 (additional 20% off)

http://store.icyclesusa.com/campy-centaur-dual-pivot-brakeset-fr-p1196.aspx


bottom bracket a little tricky...had to use a MTB square taper 15.00 on ebay (shimano). Found a square taper road crank set. The piece together all the cockpit stuff. Came to about $450 for the entire conversion. Sounds crazy, but I looked at $500 bikes...no doesn't come close with the components on my ride. Also lighter...

The bike rides really nicely.....looks wierd but works.

If anyone really interested in the parts list I can post....The fun part was putting the whole thing together and using all the various types and combinations of colorful words while doing it. Good thing I was in the garage and the kids inside.

http://www.flickr.com/photos/[email protected]/5131374723/in/photostream/

http://www.flickr.com/photos/[email protected]/5131975774/in/photostream/

http://www.flickr.com/photos/[email protected]/5131374149/in/photostream/


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## pretender (Sep 18, 2007)

Drops on a mountain frame is almost always wrong-o. Just stick with mountain bars. If you want to feel special, lop off the ends and make them narrower.


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## Ol' Dirty Biker (Oct 16, 2009)

Working quite well for me:


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## OnTheRivet (Sep 3, 2004)

Ol' Dirty Biker said:


> Working quite well for me:



With 2" of spacers under a rise stem "quite well" is not a term I'd use.


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## kona1skier (Jun 7, 2009)




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## Ol' Dirty Biker (Oct 16, 2009)

OnTheRivet said:


> With 2" of spacers under a rise stem "quite well" is not a term I'd use.


Good thing I qualified the statement with "for me". Admittedly, the bike looks nicer in its MTB configuration.


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## Ol' Dirty Biker (Oct 16, 2009)

That Air9 looks great. Much better execution than I managed.


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## tashi (Apr 11, 2005)

My DeKerf:










It's a size small for me (I'd normally ride an 18" mountain bike) and I've switched to a high rise stem that would for sure make On The Rivet cringe but the fit is good now (same reach as the road bike, about 1/2" higher). Schwalbe CX Pros in 26" save me from opening the 700c wheel on a 26" wheel bike can 'o worms.

The fit is good, the only thing I don't really like is the V-brakes. They drag quite a bit when it's muddy (immediately after the start usually).


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## misterdangerpants (Oct 23, 2008)

Here's another mountain bike that I gave the drop bar treatment.


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## MShaw (Jun 7, 2003)

The outer diameter of 700c wheels running 23c tires is about the same as 26x2.0 tires. Cateye's tire pdf is at the bottom of this page: http://knowledgebase.cateye.com/questions/66/Where+can+I+find+a+tire+size+chart? (I don't know how to link on this board, so ya get the long version) 700x23c = 210cm vs 205cm for a 26x1.95 Not a huge difference, no? 700x35 = 217cm which is getting a little bigger, but not a huge amount. You *should* still have clearance for 34-35c tires on yer mtn bike.

HTH

M


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## tashi (Apr 11, 2005)

Getting the wheels an tires to fit is generally easy, the trick is getting the brakes sorted if you don't have disks. 

Apparently Paul makes a BMX brake that works well, and Mavic makes an adaptor that'll destroy your mud clearance.



MShaw said:


> The outer diameter of 700c wheels running 23c tires is about the same as 26x2.0 tires. Cateye's tire pdf is at the bottom of this page: http://knowledgebase.cateye.com/questions/66/Where+can+I+find+a+tire+size+chart? (I don't know how to link on this board, so ya get the long version) 700x23c = 210cm vs 205cm for a 26x1.95 Not a huge difference, no? 700x35 = 217cm which is getting a little bigger, but not a huge amount. You *should* still have clearance for 34-35c tires on yer mtn bike.
> 
> HTH
> 
> M


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