Convert roadbike to SS MTB
 

I have an older 10speed schwinn worldsport that I use as my backup fixedgear bike and am considering buying some 27" knobby tires like these, to go on my original wheels and use the bike as a singlespeed mtb. Has this been done? Does this kind of conversion have a name? Anyone know of anyone who has done this and if there are things I may be missing that I should look out for? Suggestions?

It's worth a try. I rode my fixed gear in mud and found it difficult, because the bike got stuck. You might enjoy the challenge. My guess is that it's not a popular thing to do, because it's hard, but that doesn't always stop people.

35mm tires are pretty narrow. More of a CX tire. I ride 35mm tires on some trails that are old RR beds and ATV type trails. I don't even think of using them on the maintained MTB trails because they are way too narrow and will tear up loose terrain.

I recently put together a SS CX bike out of a 84 Bridgestone 400. I'm running 32's on it with plenty of clearance with some center pull brakes. Not a MTB, but fun off road.

So is it a 10-speed or a single speed?

Regardless, cross-like bikes are fun and provide a lot of versatility. I ride my cross bike at the mountain and I have a lot more (albeit slower) fun than I do on my mountain bike. That said, you might have issues with what I assume are steel rims. They will bend more easily than alloy.

It was originally a 10 speed, when it is converted to a light mtb/cx it will be singlespeed (free.) At the moment I use this bike as a backup fixed gear
What size tires are you using on your cross bike?
Good thought about the wheels, since they are roadbike wheels they probably arent made to take the stress of a train ride, especially with no dampening of the suspension.

I run 38mm tires on my fixed gear road bike. It's pretty fun off road and I've taken on the local mountain bike trail a few times. You've got to pay more attention to your lines and can't just bomb over everything like a real mountain bike. That said, it's a blast... A fun way to experience off road riding. One thing you may want to consider in the future is converting to 700c wheels. That will allow you to run a larger tire. You'll need longer reach brake calipers, but it's something to think about.

No, you'll need shorter reach calipers. 700c are taller than 26".

The OP is talking about putting knobby tires on his road bike with 27" wheels. 700c wheels are a little smaller, hence needing longer calipers and allowing more room for rubber.

i just did this to my schwinn world. running smoothish 700x38s. taking it off road tonight, when my friend gets off work. i still need a freewheel, as well as a front cable hanger. but around town, its nice to be able to hop over curbs without worrying as much about pinch flats or the rim bottoming out.

its my main fixed gear, but most of the mountain biking around here is either jumps (which im not a fan of) and fireroads with some technical singletrack. i think i will be fine with a ss, but the fixed will give me some problems with pedal contact. its already helped with short cuts through soft grass (after a rain). im going to keep it this way for a while.

Luckily my brakes adjust for 700 and 27". yea, 26" would be a different story.

I stand corrected. Thank you and sorry.

Just ordered 2 knobby 27x1 3/8 tires from my lbs. We will see how it turns out.

So could you clarify? Are you planning to make it fixed gear or single speed with a freewheel?

This is where skidding actually comes in useful, you have to get your pedals into position ahead of time and skid through obstacles when your riding fixed offroad. Its takes about an order of magnitude more skill and effort than a SS, but it's a lot of fun, if you don't mind sucking at it.

Skidding on trails will lead to degradation and is frowned upon. This is why I'm not a fan of fixed off road riding.

It will be setup ghetto SS when I get the tires. So I will still be using the 5 gear cassette in the back. I don't want to put much money into this bike Eventually if it works out I will switch to 700c rims and a flip flop rear hub with fixed and free cogs.

I am interested in a fixed gear mtb, but I think the ground clearance on the schwinn would be pretty tight. I love a challange and I think after getting familiar with the bike set up as SS I will change to fixed.

go for it, i regularly ride my ss cross bike on the mtb trails with 30c tires, smaller tires forces you to be smoother and more nimble, its good for practice. have fun!

I'd like to see a picture of the bike in question. From there, I might make useful suggestions.

http://farm1.static.flickr.com/29/36...a2b9bd0d83.jpg
Not mine, but the same bike.

OK, thanks. What's your budget? I think replacing the rear wheel with a flip-flop wheel would be most elegant. If you want to save money, you could buy the hub, freewheel and sprocket, and you could rebuild with your existing rim (and maybe the spokes) yourself.

It might be possible to remove one of the chainrings, making the bike lighter and even better looking.

Next, remove the derailleurs and shifters and gear cables. If it's going to be only fixed and not freewheel, you can remove the rear brake.

Actually, you can put a fixed sprocket on that hub if it's a traditional freewheel and not a cassette. You'll have to find a lockring, though, and it won't be reverse threaded. Reverse threaded is ideal but not necessary unless you're strong and heavy.

throw on some flat bars, uncut, also. that should make it more comfortable and handle better off road