Didn't immediately find a thread for showing off and/or discussing converting old 26" mountain bikes to 700c commuters/allroad/gravel bikes. Let's talk and show each other. Here's mine! My 1989 Fisher Paragon, my first ever mountain bike. Shown with a couple different stems. It currently has the black English 3 speed style rather than the bigger cruiser bar. It is a fun commuter, dirt road bike. I used a couple horsehoes I found to make the brakes work. I really like the Clement USH 35c's, though fenders will barely fit if at all. But I rarely need fenders. Ok, show us yours! Also, questions about conversions welcome.

How about some close-ups of the brake setup? I've toyed with this idea but never got past the brakes. I'd like to see how you managed it and hear any reports about brake performance.

I've posted my Litespeed a few times on here.



It was purchased as a forkless frame, so the fork is an older bonded aluminum Schwinn road fork. The rear brake bridge wasn't drilled so I made a jig to drill it out through the center of the bridge, and parallel to the seat stays, and use calliper brakes. I currently have center pull brakes on the rears so I could use the canti cable stop. But, I don't really like them.

The rearend is WIDE. 135mm spacing on the rear wheel.

I run 25mm (or so) tires on it. I currently have a set of Tannus solid tires (23mm?) that I've been experimenting with for a little over a year. Odd tires, but they have advantages for a commuter.

Clearances are tight for fenders. No rack or fender mounts, but eventually I may get a rack on it.

I did this on my mid-90's Nishiki Cornice. It came with a dead Rock Shox fork I didn't want to get into rebuilding, so I sourced a cheap 700c fork with canti bosses (kind of cheating, there, I guess):


And fabricated an aluminum plate to mount to the old rear brake bosses to relocate the new rear brake bosses up high enough. The brake bridge on this bike was drilled and I could have gone the easy route and put a standard rear caliper in there, but I didn't wanna:


I borrowed a bunch of parts from other bikes to build it this way, so after riding it a for few days testing proof of concept, took it all apart to rebuild later with different parts (and maybe barcons instead of brifters). The brakes worked great, with new-ish standard grade brake pads.



The one weird thing about it that makes me hesitate to go all-in on this configuration is the larger wheels and high bottom bracket make me really tall in the saddle on this build; it's a bit disconcerting to be riding several inches higher up than on all my other bikes. And I can't just put a toe down when I stop. I have to get out of the saddle and put both feet down.

Still just an idea in my head but shown is a mock up. 91 GT Karakoram Elite with 700 X 35 tires. I can use short reach calipers but don't like the look of the bare posts sticking out. Concerned also that the bridge on the rear is not meant to deal with the braking force there. The horse idea has me wondering if it would protect that area and put the rear post to use. Hmmmmm. Want to find another front fork to clean it up while saving the GT one for when I convert it back to 26" wheels. No drewing allowed on the GT.

I actually tried a 700c conversion recently with a '94 Stumpjumper I had. It was not what I would consider to be a success, however - for all the reasons mentioned above.

The bottom bracket is up too high, and as a result the bike is a little unstable. Handling is pretty weird. I realize that IRD used to build Stroker ATBs for difficult applications, and that those bikes had huge ground clearance, but they also languished in the market. If you aren't climbing logs all the time, the stability and stand-over issues are a deal-breaker.

The rear brake conversion went off without much of a hitch, but I eventually just broke down and bought a used Trek XO-1 for cross-duty. The Stumpy will be converted back to 26 and will be relegated to downhill park duty this summer.

So, those who have done this - why? Just curiousity, or did you have specific purposes and/or terrain or handling needs that you were trying to address?

Sure. Will post them up this evening when I can take time to retrieve them. I have some from the build. Performance as been fine, once I got it adjusted. No real perceived difference from before. Basically, they are the same brakes I had on similar rim surface, and the adapters seem to set them up to work as intended.

Performing the conversion allows one to re-purpose an under-utilized 26" rigid mountain bike for cross- or road / utility duty.

Having said that, though, the conversion costs more coin than swapping the tires and flat bar for drops. Most are doing it for the challenge.

I did it because I found a bare Titanium Litespeed frame on Craigslist that was too good of a price to pass up, but unfortunately was a 26" frame. I do very little riding that would require a 26" MTB. My road bike at that time was having some serious paint and rust issues, and needed some TLC. So I was excited about going Titanium.

And it made for a unique challenge.

Compass has some new slick thin 26'(559) tires that are reportedly pretty fast on the road. So maybe there is no reason to convert to 700c, since you can get low rolling resistance an a plushy ride. A while ago I considered converting a mtn bike to 650B, but found that the bb height would be too high.

I too am in the "why would you do that?" camp. As was mentioned, mountain bikes have a high BB anyway, so there's no problem putting skinny 26" tires on there. I commuted for years on a MTB with 26 x 1.25 tires.

It is Esoteric!

I also appreciate the mechanical challenge of the conversion, but it seems the worst of most worlds: very high BB, room for only narrow tires, difficult brake-reach adjustments. Of course, if all you have is a bare frame made for 559mm wheels and a set of 622mm wheels, necessity is the mother of invention and all that.

Don't forget crankset and chainring clearance issues Also custom 135mm wheels.

But, I will say that my Litespeed makes a great rain bike/commuter/beater. And if the choice presented itself again, I'd do the same thing.

I did mine "just because." I was curious, and had the parts on hand. I'm probably going to next build the Cornice as a drop bar 69er, to see if I like the handling a bit better with the lowered rear end.

Here are some brake pics, and build pics.

With original wheels and slicks:




Working on things at the Boise Bike Project.


Thought I had some close ups of the finished product for the brakes, but this is all I have right now. It was before I had the adjustments right, and with an old wheel I was using temporarily. I will take some better pics tomorrow and post them.



I could put the original XT caliper brakes back on, but these v brakes that I added when it was still my mountain bike work better, even though they are not as stylish, and work just as well on my Alex cross rims it has now. So, they stay.

The adapter you see above in the bottom pic is from Xtracycle. You can still get them I think. I used one by Mavic up front, that a friend gave me. I like it even better, mostly because of looks. Will get a pic of it. Both seem to work.

As for why, I can only speak for myself. At the time I did the project, the first reason is because it is my first mountain bike, and I love the frame, and I wanted a steel commuter for distance. I was commuting on that bike 11 miles each way, and wanted a bigger wheeled bike to roll more freely. I did not have the Davidson touring bike I have now. I thought it would be fun to try, and then I could play around with bars, flats, swallow style, mary bars, etc. and have a bike I could "gravel grind" on as well. It has toured the San Juan Islands, done the commute, done some gravel and light single track riding, etc. And done it well. I guess I recall the bottom bracket moved up, but it has never seemed a problem at all, even fully loaded. It is sturdy, and can mule a lot of stuff. And, with the swept back bars, is comfortable to cruise on, and if I want to go faster and break wind, I can put my hands on the center of the bar. AND, I just acquired a Jones loop bar for it. That will be nice too. Oh, and I really did not have to buy any parts other than the adapter, and the handlebars I tried, which I would have bought anyway. I traded some old parts for the wheels, which I adapted in the rear with the use of a washer as a spacer. Works good enough for what I do.

Now, if I had the Davidson touring bike when I was messing with this, I might not have done it. I may have left it as you see in the first photo (EDIT: First in post 17), other than messing with bars, and used it for cruising that way. I have also bike packed for a natural hot spring tour, where I wanted my mountain bike tires on, for trail side trips, and I might decide to take it back to that status now that I have the touring bike for longer distance commutes and pavement. I may not though. I do really like how it rides.

It handles dirt roads and gravel really nicely, with the steel frame feeling comfortable and stable. It is sturdy so I don't worry about banging it around too much. I can see taking my touring bike out for a little dirt road spin, but I am not sure I want to do a full gravel grind chatter fest on it. And I like the flat-ish rather than drop bars for that use.

The project was fun, it has served me well, and I do not regret it in the least. As I say, it could go back, if I find I am not using the advantages of the larger wheels as much any more, due to the "new" touring bike, but that remains to be seen.

Here it is set up for backcountry touring, to hot springs in the central mountains of Idaho. This could be one reason I would switch it back. But I can do that when such a trip is planned, or use as it is currently set up if I choose to hike on the one single track where I needed more tire than I have in this set up with the Clement 35c's.

As per request.









As I said above, all works great!

+ 1. I'm skeptical of the utility of this conversion but I'm all for people tinkering with old bikes any way they want,

26 inch is great and there is decent tire and rim availability. I love my drop bar '93 bridgestone XO 2 with 26 x 1.75 tires as an all around bike for long days in the saddle and on gravel.

In my case, I picked up a 26" titanium frame off of Craigslist for $100. I don't ride 26", so it made a perfect base for "playing". And, eventually made a great commuter.

I haven't adopted the "Wider is Better" ideology yet.

+1
I did the exact experiment with the same frame. Exact conclusion -brought my mind and body back to earth. What was I thinking?!

Today's 29er hardtail with 1x11 and micro chainring are a BLAST! Taking it further, I've also swapped off-road tires to Hookworm semi slicks. The 29er hardtail with hyd. disc are truly versatile.