jsigone

Picked this up last night for $30 bucks. Plans to make it a SS, not fixed Size is like 60-62, kinda big for me, since my normal roadie is a 58. I have an inch of stand over so it's workable. Never converted a roadie before, just MTBs. Seems I can't remove the outter chain ring, so I have to rock the 53T and pick a larger cog on the back to get the gear ratio I need. I'm not sure if I can get a smaller chain ring up front, I'll have to check my LBS. Wheels appear to be 27's (a lil bigger then the 700's when I put them next to it). Not sure if I can run 700's on a bike designed for 27's since it's only about 15mm difference.

ggg300

take off front drls and shifter...set rear drl limit and shifter in place...single speed...

lube and run....


^^^that kinda cheap?

roadgator

sheldon brown discusses using 700c on 27 in frames, but unless those wheels are trashed and you have a set of 700's lying around there is no need to switch.

like ggg300 implied there are varying degrees of properness/cheapness to making a conversion. the main goal is to get a proper ratio and a reasonable chain line (dead straight inst necessary, but within a few mm is). this is achieved through various combinations of cranks/bb/wheeldishing. take a look at what is worn out and base your conversion around that. you probably wont have to replace everything, but the proper crank/bb combination can keep you from having to redish the back wheel. or conversely a center-dished wheel may allow you to use the existing crank/bb.

jsigone

I picked up some 27" tires and tubes from Performance. Now the bike is at least ridable. Also flipped the bars, added some cork tape, lowered the stem ALOT, raised the seat about 3". I removed the clamp of the shifters, so now they are just hanging. I became stumped when I got to the rear hub assembly. I don't know how to removed the cassette and what to use to make it SS w/ the freewheel. On my MTB, I just used PVC spacers and the lock ring made it all work.

So How do I remove the cassette and what is needed to make it a SS w/ the freewheel?

How do I remove the drive side crank arm? my ISIS tool won't work, i need to see if my buddy has some more tools I can use. Or aM I stuck with that massive 53-54T?

Can I replace the chainring/sproket with that of a BMX style on these

humancongereel

you could put a very large cog in back and use the front chainring. i would.

is that a freewheel or freehub? i'm going to assume freewheel, so you'd need a freewheel removal tool, a wrench (or vise...probably a vise) and....then....yeah, unscrew.

i'm going to guess bmx chainring and cranks won't work unless you have a compatible bottom bracket lying around.

jsigone

my first idea was to reuse one of the cogs in the back, the gears back there are 28,24,20 and I didnt count the other two. But not sure if I can do this, since it sound like I have to replace the entire freewheel assembly with a BMX freewheel. I thought I can just remove selected gears off the freewheel and space it somehow to get the chainline I need. ARGG so confused with this older bike

humancongereel

well, you could just bust off the derailers and shorten the chain and do nothing with the cogs in back. ghetto singlespeed.

Sammyboy

Stick with the 27s, you'll be that little bit faster. However, if you REALLY want 700's, you can get brakes to reach. I'd suggest going with a BMX freewheel - it's not like they're big money. And finally, you need a threaded crank puller - about $8.

shogun17

You have horizontal dropouts = easy. Shorten chain to right length and put the right cog in the right place to get on OK chainline. Or just redish the wheel with a BMX freewheel on the back. I took my freewheel (7 speed, freebie bike\/) off with a hammer, a screwdriver and a pipe-wrench. f*ck $20 each tools, You can pull a bike apart with an allen key (or two), a hammer, a locking wrench of some description and a screwdriver.

I just built a crappy steel sloping frame (freebie. stripped and polished.....badly. Its like 50cm, something close to that) with a 52t front ring and it looks mad, trying to decide whether good or bad mad. No logos, nasty yellow saddle, polished metal everywhere as much as possible. Keep the big ring on the big frame.

Aeroplane

Yep, unscrew the freewheel and put on a BMX one. It's not that hard to adjust the chainline, just adjust the spacers on the axle (use washers or whatever) until you get the freewheel lined up with your chainring of choice (I'd just use the big one and take off all the smaller ones; use a BIG freewheel). Then redish the wheel so that the rim is in the center of the dropouts again. Easy peasy.

MrCjolsen

You have a good canvas upon which to work. Univegas are good candidates for SS conversions - most modern stuff fits into the frames.

I see a wheelset sitting in the background. Are you using those? Have you tried to fit them and see if the brakes reach? If you can get the rear to work, it's a lot easier since cassette hubs just require a bunch of spacers and it's easier to get a perfect chainline.

They make long reach brakes. Tektro has some very basic 47-57 mm brakes for the purpose of running 700c rims on 27" bikes. If those still are not long enough, they make the R556 that goes to 73mm. Put a 700c rim on the bike and measure from the center of the brake bolt to the center of the braking surface on the rim. That's your "brake reach" and then you'll know what brakes to look for.

Why can't you remove your outer chainring? Those look like standard 110bcd cranks. If they're square taper, you can use any old set of mtb cranks and have many choices (in terms of used, cheap stuff) as far as chainring size.

Finally, my measured correct bike size is about a 59cm, but my current fixie is a 61. The important measurment isn't standover but rather the distance from the center of the seat tube to the center of the headtube.

jsigone

The set of wheels I have behind are for my geared roadie, so I can't use those + I already got all the tires and tubes to get me rolling on the 27's. I think the old tires there were on there have been on there for years, the side wall fell apart when I removed them.

The cranks are square tappered, just don't have the tool for that, I only have the ISIS remover. I'm going to take the bike to the LBS that deals w/ older style bikes. I'll see what he wants to remove the freewheel assembly and add the BMX freewheel. I read last night that I should stock up on some spokes and nipples jsut incase something happens when I redish the wheel. I'm also going to see if he has a cheap alternative for the cranks and main chain ring. I have some old MTB cranks at home but not sure the centering and if the other rings and rivited on or bolted. I may swing by my house and see before heading to the LBS. If I can't do anything about the chainring, I think I'll leave the inner ring mounted and just use that for the SS gearing, think that is a 39t, so if I get a 16 or 17t BMX I should be ok for now.

I'll keep you guys posted from the LBS results.

jsigone

Bike is at the shop now, some more probs came up, it appears that the rims I have doesn't have a lip inside to grab the wire bead of the tires, so the tires were sliding off the rim the rear one slide off and sliced the tube, so that was a nice flat. He's gonna charge me $20 to swap it with some other ones he has in the shop, said they should be better then what I have.

Guy is gonna charge me $10 for the BMX cog, he gave me some used MTB cranks w/ 5 spoke arms for $10 + 5 for the right size sproket and nuts and stuff.

Then $20 for labor for swapping the cranks, re sizing the chain, swapping the tires to the newer rims and installed the BMX cog in the back.

All for $65 out the door

Flamingmb

You want to know whats even cheaper than buying a bike used? Getting an abandoned one and fixing it up, thats how I got my SS. The bike was trashed with bend handlebars, flat tires, busted up pedals, and all the cables were either streched beyond repair or just snapped. Right now it is my favorite bike to ride though. Its a wonder what a coat a paint and some hard work will get you.

jsigone

After new tires and new..er rims and gear conversion looks like this now





Everything said and done, the total cost of this bike was $120

The gear ratio is bigger then I thought, 48T x 18T, 2.66 ratio My buddy and I got a 23mile ride in today along the coast starting from carlsbad. The ride was great, the gearing kicked my butt in the beginning as I was getting use to the bike and the gearing along with warming up. Highest speed was 28mph on the flats (damn bike is NOT AERO AT ALL), I managed to hammer up a small hill @25mph peak and topped it at 22mph and that was seated I found it actually easier to climb at the higher speeds because I'm in my cadence range. Not saying that I'll be able to do that on LONG climbs like...um Palomar or GMR (i'll be crying in pain ) I like the topend speed on the coast, but not so sure on the hills. I need to get a longer stem and find one that has some negative drop to put me in a more aero position. Rigth now, it feels like I sitting up a bit higher, and not allowed to put more weight over the front, which the cross wind was blowing me around. The handle bars are pretty comfy, a lil twitchy but just had to get use to it. Also out of the saddle was weird cuz I can't push weight over the front, but will be fixed w/ the stem

Here's a pic at Swami's beach

bonechilling

That, in my mind, is a perfect conversion.

kemmer

Good job, it looks great!

cs1

Unbelievable how slick it turned out. I can't believe the before and after pics. Good work

Tim

Guy Retreau

Not recommended without the use of a tensioning device for the chain. It the chain is shortened and it accidently get's picked up by the larger adjacent cog in the cluster. you risk of breaking the rear triangle or at least bending it badly. I know, I did precisely this on Saturday. If you run this way leave the derailleur on the backl and center it under the desired cog with the limit screws. Otherwise get a singlespeed freewheel or a device called a "singulator".