Share your knowledge, Conversion 101
 

The purpose of this thread is to share knowledge on how to build a conversion safely and cost effectively. Please post you words of wisdom. Please be positive when possible and constructive. We want to hear about all your lessons, and opinions about how to do things correctly. And Yes, things that are obviously simple to you may be a lesson for someone else, so please share.

If you are converting a road frame with vertical dropouts, spend the dough for a White Industries ENO eccentric hub. Don't bother with screwy gearing combinations trying to get a "perfect" chain length - get the ENO and be done with it and run any gearing you damn well please.

For single speed (not fixed) applications, a cassette type rear hub will make life a lot easier. You use spacers to replace all the cogs you don't need and to space the cog you want in a chainline as straight as possible with the chain ring.

A thread on freewheel will need to be replaced with a BMX freewheel. This will not provide a straight chainline and additional skilled work will be required to redish and respace the wheel.

Note: a not so straight chainline will run the risk of the chain dropping off the cog under heavy peddling

this really has nothing to do with safety or cost effectiveness, but as far as asthetics, try and find a frame without any braze-on cable housing guides. if you can find a frame with all clip ons (mine still has 2, but some have a lot) then it will look cleaner when you strip it all down. the other option is to cut them off and sand it down, but then you have paint issues

as far as safety, i don't recommend going without a brake your first few times on, just in case (or don't do any serious/fast riding until you get comfortable)

if you can afford it, get a new rear wheel with a real track hub (instead of redishing the rear hub and doing the "bum bike" aka "applecart" conversion by screwing on a BB lockring with loctite). track hubs are the safest way to go, and you can take the rear wheel with you when you upgrade frames one day (you will). try to find a fixed/fixed hub, so you can either run 2 cogs, or have a spare side in case you strip one. IRO/velocity hubs are solid and cheap. stay away from suzue basic/jr, quando, sovos.

Agreed, but . . . a lot of vertical dropouts can be safely filed, grinded, and otherwise made into semi-horizontal dropouts. I've found that mountain and hybrid frames tend to have enough material around the dropouts so I can cut up to 3/4 of an inch horizontally (which should be plenty), but road frames don't. ENO hubs are obviously preferable, but when budget is an issue and time spent isn't, a little dremelling can go a long way.

If you're going to get a new wheelset, especially if you're going to have a new rear wheel built, make the switch over to 700c. I didn't and its the only thing I really regret about my conversion; I now have a really nice but completely obsolete handbuilt 27 inch wheelset (rear built by the mechanic, front by me later on).

Recently I wrecked the fork on my Miyata conversion and need to get a replacement and am now stuck buying some junky 27 inch fork because of my nice handbuilt 27 inch wheelset.

Also, when scoping out a frame for a conversion, keep in mind that a large number of Schwinn's from the late seventies and early eighties were made in America with all sorts of non-standard sizes. You can tell these bikes apart by the one-piece crank, which have very narrow crank arms. Here's a good picture of what the crank looks like:

http://www.fixedgeargallery.com/2005/jan/veno.htm

These actually make really nice, beefy conversions, especially for longer riding. However, keep in mind that it will be a real challenge upgrading any of the components (even the pedals!) with more modern equipment, as the sizing on these bikes is not at all standard (most of the bolts are even american-sized, not metric). However, you can service the bottom bracket on these schwinn's with a screwdriver and a wrench, which to me seems totally in the DIY spirit of a conversion.

Anyone here familiar with wikis http://en.wikipedia.org/wiki/Wiki? A wiki is a tool which lets people work on one document as a community. Anyone can edit and add to the document as they see fit. The main benefit of a wiki over a forum is that the content on a wiki is in document format - not a list of messages as with BF. The most important information, whether added on day 1 or day 999, can be put at the top. This is in contrast to the forum format, like BF, where you may have to dig through 5 pages of mostly irrelevant posts to find the same nugget of information.

I think that setting up a wiki for the common questions on the SS/FG forum would be entirely useful. Imagine a community built "How to build/maintain/love your SS/FG guide" which could be expanded infinitely with everyone adding in their own two bits of knowledge.

Setting up a wiki isn't difficult and I could do such in a few spare hours. There are many great sources of information out there that are not tied together properly. Sheldon's info rocks, but it is not organized well. There is an enourmous load of advice on these forums but it is mostly inaccessible because the search function isn't perfect. A wiki could tie all of this together and provide a manual of sorts. Anyone game? Think the community would stand behind it?

Three lessons learned:

1) Chain - stay away from cheap sram-10 - it is not intended for shifters, so I thought it will be OK for FG
it is not. Get something more solid.
2) I went with cassette hub with home made fixing adapter, so I can swap the wheels between fix and road bikes - if you do that there will be two issues:
a) stay away from light alloy casette bodies (Gipiemme, Camapgnolo) - the single cog working back and forth will cut through them even if you use wide base cogs. I had to swap to Grimeca steel body, since the swap the drivetrain works perfect.
b) lower guality cogs and casette bodies are frequently eccentric - this would make chain tension vary.
Make sure they are round and true and fit each other - some of the Shimano compatible casette bodies (Cane Creek, American Classic) have slightly different dimensions - make sure your cog and casette body fit snugly together.
3) Fit the front brake! Doing the wheelie on a braked front, when a car passed me to brake just in front of me, left me thinking what would happen if I had just the leg brake AND reflexes to use it instead of the hand brake. If you are the roadie, make sure your brake is at the left hand side - I know it is not fashionable but at least it is where your body expects it to be.

If you pay for a shipment, I can send you 27" lugged, drilled fork.

Make sure you actually enjoy riding the frame you are going to convert. This may not be possible if all you have is the frame, but if a full built bike, make it rideable and ride it for a while first.

Al

Cleaning up and remounting tubulars is not fun, so avoid them unless you need the punishment or are willing to replace both wheels anyway.

Thanks for the post!
More points to share:
1. Do you run brakes and if so, where there problems w brake reach?
2. Did the slightly lower height cause any problems?

Good luck with finding that fork! Oh, looks like there is one already! :)

Good advice, but you don't need to change the front wheel until you wear it out or have cash on hand.
I run 700c rear, 27" front and one wouldn't know unless told.

Al

There are two things to stick to: 1) Measure twice, cut once 2) Run what ya brung.
In other words, don't be afraid to use what you have, but measure so that all the parts fit together. When researching my latest fixed gear, I found out what chainline the hub provided and found that my outer ring on my MTB triple had exactly the same chainline. They fit. So, I ordered the wheel/hub and bolted it in. But, measure the chainline on your cranks before you remove them so you know what you're doing. If the chainring is too far out by X mm, then get a bottom bracket that is X shorter than your current. The reverse is also true. Once you get the chainline straightened out, its a piece of cake to remove the shifty bits and shorten your chain to match the new setup.

Also don't waste time trying to convert a wheel that wasn't made for fixed gear or single speed. If you're going to do it, do it right. Worried about laying out the money for a fixed gear/single speed wheel? If you don't like fixed, then you can turn it around for only a little less than what you paid for it most likely (assuming you don't beat it up) and you're not out too much money.

Spacing: A proper track hub has 120mm spacing, and some Keirin rear hubs have 110mm spacing. Most road bikes have a spacing of 126mm on up to 130mm. If your frame is steel, you can just squeeze the stays together. If it's aluminum or anything else, you will probably need to add spacers to your axle.

Chainline: If your chainline isn't very good and you decide to get a new bottom bracket to fix it, MEASURE YOUR EXISTING CHAINLINE before you take off the cranks and BB. This will let you know exactly what length of spindle to get. Also, make sure you have enough clearance between your cranks and frame in order to take them in the amount necessary.

Sorry, I guess my point was that I didn't go to 700c wheels. I didn't do it because when I had my rear wheel built (at which point I was an absolute newb, didn't know how to change a tire), the mechanic told me I'd have to get a new brake (I had thought I'd run the freewheel, within two weeks I never considered it). So I went with the 27 inch. This was a mistake, because in about a month I had removed the rear brake anyways. I built the front as a 27 to match, not really sure why.

There's no noticeable height difference between 27 and 700c, as I think others will attest. Also, as posted above, there are no issues mixing the two sizes. If I were to do it all over again, I would have had a 700c rear built [edit: and removed the rear brake]. Later, I would have built a 700c front and at that point gotten a long-reach brake.

In fact a generic 27x1-1/8" tire is exactly the same contact diameter as a generic 700x32c

But if you don't run larger and mismatched tire sizes to compensate for rim size difference the differences in radius can be between 2-5mm depending on your tire choices.

If your picky and want your 27 to match your 700 (in looks and tire width, not in tire diameter), you can use 'IRC Triathalon/Kevlar' tires which are available as 700x25 and 27x1" which look the same. Link to tires here:

http://www.nashbar.com/profile.cfm?c...eid=&pagename=

Al

Yeah that's a good point about the contact diameter. Also, for those that do run the original 27's: if you need tubes, you can use tubes marked 700x25-32. This might save you from consternation if you go to a shop and don't see any tubes for 27 inch wheels.

The bumbike method is vastly underrated. You can make multiple bumbike wheels with old wheels, cog/lockring, loctite and JB Weld for less than a single new entry-level track wheel, and never have to worry about stripping threads or anything like that cause there's no chance that cog is ever coming off.

Sheldon explains all:

http://sheldonbrown.com/fixed-conversion.html

and

http://sheldonbrown.com/deakins/how-...onversion.html

and

http://sheldonbrown.com/fixed/

Agree that his website is a wealth of info and is a good read.

However, it is of value to hear advice and lessons learned from your forum piers too.

Keep the posts coming! :)

Now if we can figure out how to organize this into a easy to use format.

Gregg, how would your wiki idea work in this situation within the forum?

Gotcha. We don't have to reinvent the wheel, so to speak.

Tips are great, but I'd say sheldon covers the step-by-step of conversions pretty thoroughly.

Play Slayer's "Reign In Blood" album as loud as you can while working on your conversion. It will help to make it mean and fast.