Trek 460 to ss/fixed question
 

Hey everyone,

I recently got into an accident that totaled my frame (trek 400). I purchased a trek 460 and want to salvage parts from the 400 over to the 460, while converting it to a fixie or SS. The frame has a semi vertical dropout (not sure if that's what you call it). However I'm wondering if there might be chain tensioning problems with type of frame/dropout.I'm a total novice, so I'd appreciate any help!

Can you post a picture of the rear dropout? Or at least find one online that is the same thing and link to it? That'll help a lot.

http://i54.tinypic.com/6h3o5e.jpg
taken with my phone... hopefully its showing up for you guys.

edit: reupload

Sorry, no image for me.

How old is the 460? That might give a clue about what type of dropout it has.

can you see it now?

That dropout will work. A little on the short side, but looks you'll have enough adjustment for chain tension.

Yep, that's what would be called a short semi horizontal dropout. Chain length and gearing selection will be critical to keep the adjustment range within the short travel of the dropout but with a bit of care and some ring and sprocket juggling you'll find a setup which won't require a tensioner.

One thing though. If you want to make it a fixie I would not trust the forward facing dropouts with QR skewers. A series of the often used sudden lockups could loosen things enough to allow the axle to walk out of the dropout slots. Instead I'd strongly suggest changing out the rear wheel axle for a solid axle and use track nuts to secure the rear wheel. The box end half from a cut down 15mm combination wrench will fit nicely into a saddle pouch along with the usual flat changing stuff for any field work you need to do. And in fact even for a single speed I'd still switch the axle out for a solid rear if it were my bike.

Will you be using a single sprocket and spacers on a freehub wheel or are you going to cold set the frame to allow using a fixie/SS flip flop rear wheel?

thanks for the awesome reply!

i have a rear wheel a buddy sent me for my birthday, it has a fixie/ss flip flop hub. what do you mean by cold set? (I'm still pretty ignorant of bike machinations)

"Cold set" means to bend the frame into alignment. Consult the guru: http://sheldonbrown.com/frame-spacing.html

Bike folks like to say "cold set" to avoid saying "I will bend your frame to make it straight." This is almost always harmless to a steel frame.

thanks! how can i get something like that done? is it high cost?

Edit: from what i understand, cold setting is done to ensure the rear wheel fits into the spaying of your dropout. i have a 126mm dropout spacing, and (i think) this wheel is 120. the wheel seems to fit onto the frame as it is now.

Simply you can use spacers washers and tork the bolts down to make it fit for single speed freewheel and it should be ok but not fixed. This bike is just not a real good choice for conversion bike.

what sort of bike do you recommend? I'm on a tight budget, so I'm really hoping this frame will workout... do you think i should avoid doing this all together and try and get a better frame? (I'm going crazy without a bike right now)

You can do the bending to size the frame for the single speed wheel yourself. But since this is obviously an older bike with a 126mm spacing you may not want to bother. It's not that big a deal to just flex the stays in by 3mm per side.

I'd say the frame will be fine. Especially if you do it as a single speed rather than a fixie. And frankly if you're like me and have far too many years of freewheeling behind you getting into the whole fixie mental state where you don't forget and try to launch yourself isn't that easy. Especially when the fixie would be just one of many bikes. In your case it'll obviously be your only bike so as the old saying goes YMMV.

If you're a bit handy with metal you COULD make up an axle tug for the drive side. It would be a piece that slips over the axle and extends back behind the dropout and then bends inward. It would need to be a fairly solid piece but if done nicely it'll avoid the risk of the axle pulling forward and causing a wheel lockup or derailment or other issues. And it would certainly remove any worries about using a forward facing dropout.

But really if you stick with single speed and go with track nuts on a solid axle you don't have anything to worry about. I ran an SS on a frame with dropouts similar to yours for years before I sold the bike to a buddy and got a Redline 925 to replace it. So go ahead and build it up. The key will be finding the right front and rear sprockets that allows for the chain to be the right length that it works with the short dropouts.

Thank for the info, this definitely helps.

theres one thing that I don't think I'm understanding (and this could be just flying over my head), why is going fixie for this type of frame less of an option than SS? With my limited understanding, it seems like a simple flip of the wheel, with the only difference being that the cog is fixed to the wheel.

I think i may be overlooking a basic understanding of how fixes work.

Well fixies tend to put a lot more stress on the rear wheel, dropouts and driveline than a single speed freewheel. Requiring a completely different drive train to be safe and ride good. To make a fixie you need a bike with long 2 inch or so heavy horizontal dropouts. Preferably with a nice strait gage lugged steel frame as opposed to stiff double butted cro-mo frame. Plus you need to change or rework nearly every part on the bike for it to work good. If you just need a bike to ride go with the bike you have as a single speed. If it turns out you need a chain tensioner you can just use an older derailer on the rear free hanging and adjust it to your chainline.

Plenty of bikes of this type have been converted to SS/FG. I foresee no significant problems. The relatively short dropouts are only an issue if the OP has different size cogs on the flip/flop hub and wants to switch between them. Even with the short slot a 1-2 tooth difference ought to be fine.

Simply not true. Fixed gear bikes put no more stress on the dropouts or frame than a multigear bike. Drivetrain issues are trivial to deal with unless your frame has vertical dropouts (which the OP's frame does NOT have) and you have to find a "magic gear."

Don't worry, you are correct. There is a LOT of mis-information on this thread.

1st off, that frame is perfectly fine for fixed gear use. Those dropouts are long enough to run ANY gear ratio you want (I owned a similar 460 and a couple other bikes with the same dropouts.) You might not be able to run a flip-flop though, depending on what ratios you choose, as one might put the axle in one end of the dropout and when you try the other gear you'll run out of room.

If your bike is spaced to 126mm and your wheel is at 120mm, add 3mm of washers to each side of the wheel to make it fit the frame. This isn't totally necessary, but will make installation and setting the chain tension easier.

Don't be afraid of forward facing dropouts. I've used QR on a beater fixed gear MTB before and never had an issue. I was very rough on that bike including frequent skid stops and riding down stairs. If you use QR, you simply need a properly tightened good quality steel enclosed-cam skewer. If you run a nutted axle, get some good track nuts with serrated washers built in. These may chew up your DOs a little but ensure a very tight hold.

All of this is total BS. There is nothing special about a FG drivetrain to require a different frame, special dropouts, etc. The OP's frame is more than qualified for geared use, or SS/FG.

+the frame is fine.

You're fine with those dropouts. Use any gear you want, and set the chain length accordingly (add or remove links to get the right length). You only need 1/4" movement at the drop for tensioning. Your's are plenty long.

Them drops are fairly rigid so I'd space the axle 3mm each side. Saves the money for a reset and ensures parallel dropouts. Won't matter much anyway, but might as well be straight, huh?

I'm with FJ, the frame is fine. The only VERY SLIGHT concern is that if for any reason the rear axle isn't good and tight you could possibly, maybe, might see the axle slip forward in the forward facing dropouts. That's why I suggested going with a solid axle and track nuts. It's easier to get a good tight connection with the track nuts even with a short wrench. The QR skewer that FJ describes is the old style steel Campy or Shimano style. THey work great but you need to set them so it takes a mondo effort on the lever to ensure a good firm connection. To me it's just easier to go track nuts and a healthy but not crazy pull on a short wrench.

Note, in case you don't know the spacer washers they are talking about should be located between the bearing cone and the locking nut. The locking nuts generally have serrations or a cup edge of their own that bites into the dropouts. You don't want to mess up that with a loose washer just slipped on before the axle goes in.

I ride a 1984 460 fixie conversion. Currently running 53X18 without a half-link, used to run a 52X18 with a half link (replaced the half link with a full length when I went to the 53) which gave me a measure of comfort in the relatively short horizontal dropouts. I commute to work on this thing every day. I mash, I spin, I even skid sometimes. I also run a 120 hub that is spaced to 130 and stretch the stays ever so slightly to get it in. No problem, no need to cold-set. I could buy a pair of 3mm spacers but I'm lazy. Here it is:
http://re-turn.blogspot.com/2009/11/...ixed-gear.html

I'm just going to parrot what everyone else has said; to put it bluntly, zukahn is simply wrong. The frame will be fine fixed, there is no magic to the fixed gear drivetrain, it puts no more stress on the frame than any other drivetrain, and you don't need that much adjustment. You could even use a quick release, and you would probably be fine. If you're new to bikes, BCRiders advice makes sense, it's hard to mess up track bolts and easy to get a quick release wrong.

I rode a very similar conversion and loved it.

And Jake, you rode a fixed gear down stairs? That takes some skill. Kudos.

Cool! Your "before" pictures looks exactly like mine. Here's my 1984 460 converted to fixed gear. Sold because it was much too big for me at 5' 9".

http://i812.photobucket.com/albums/z...s/IMG_1024.jpg