Project bike

[Tel]

I was given this bike by my dad. As I've mentioned else where it was originally a Record Sprint with Aerospace tubing. He resprayed it and had extra bottle bosses (I don't know why) and the rear centre pull hanger added, oh and the braze on front mech boss had to be repaired too.

I've changed the bars from drops to straight which are ok'ish and now I want to convert it to a single speed/ fixed, I'm not sure which.

I was debating semi restoring it back to Record Sprint origins but working out the cost of powder coating and decals I might as well just get a replacement frame. Anyway for now I just want to cheaply convert it.

The one problem I have with a fixed conversion is that the drive side dropout is not elongated meaning that I wouldn't be able to get the chain tension. My only option here would be to hacksaw and file the dropout to make it suitable.

So the plan is to get rid of the gears keep the 36 inner chainring and have a 14 tooth on the back. Replace the centre pull brakes for something a bit more modern and neater (anyone have anything in their spares box? Nut fitting).

My questions are:

1. The bike has a freewheel (not cassette) what do I need to convert it? My research tells me just a cog, chain, respace the wheel and have it redished. Should I also convert to a solid axle? What thickness chain should I use?

2. How narrow can I get away with cutting the straight bars down to? They're far to wide at the moment.

I think that is all I need to know, for now...

 

[Tel]

For now I'm thinking of removing the outer chainring and front derailleur putting the chain on the 14t sprocket and running it as a single speed, I'll keep the rear mech as a chain tensioner but remove the gear lever and cable. The only problem with this is the angle that the chain will be sitting at, although to offset that I could mount the inner ring on the outside of the chainwheel.

 

[Tel]

Right I've cut 50mm of both sides of the bars, making them 480mm, which are much more comfortable!

I've also taken off the front mech, gear levers, outer ring, and the defunct Avocet computer. It looks a bit tidier now. I'll take a picture later.

14t Sprocket is on order and I have an old bb lockring in the garage. I ordered a 3/32 sprocket and guess I should get a new chain too.

Went for a ride around the block with my girls and found that I freewheeled most of the time due to them being so slow, this was going to be one of the uses for the fixed I'll have to see how it goes. I'm guessing I'll be able to control the speed with my legs...

(Any chance of moving this thread to the Fixed & Single speed forum? Thanks)

 

[Joe24]

Right I've cut 50mm of both sides of the bars, making them 480mm, which are much more comfortable!

I've also taken off the front mech, gear levers, outer ring, and the defunct Avocet computer. It looks a bit tidier now. I'll take a picture later.

14t Sprocket is on order and I have an old bb lockring in the garage. I ordered a 3/32 sprocket and guess I should get a new chain too.

Went for a ride around the block with my girls and found that I freewheeled most of the time due to them being so slow, this was going to be one of the uses for the fixed I'll have to see how it goes. I'm guessing I'll be able to control the speed with my legs...

(Any chance of moving this thread to the Fixed & Single speed forum? Thanks)

It wont be an issue, you will be fine. You will be able to control your speed better.
You might not be able to get your chain tension right either. If your just putting a sprocket onto the screw on hub, you can use your rear mech. It doesnt work with fixed. So, your chain tension might be out, or you might be lucky and have a magic gear.
Good luck with the build

 

[samid]

Re vertical dropouts, have a read here - might give you some useful ideas.
Re lockring - if you leave a front brake on (as IMHO you should) and don't skid-stop much, you don't really need a lockring. The sprocket gets tight enough very soon, so it won't unscrew during normal riding/controlling your speed with backwards pressure. If OTOH you take both brakes off - a BB lockring on a non-track hub is not enough, you need a proper track hub with left threading for the lockring (again, IMHO).

 

[Joe24]

Re vertical dropouts, have a read here - might give you some useful ideas.
Re lockring - if you leave a front brake on (as IMHO you should) and don't skid-stop much, you don't really need a lockring. The sprocket gets tight enough very soon, so it won't unscrew during normal riding/controlling your speed with backwards pressure. If OTOH you take both brakes off - a BB lockring on a non-track hub is not enough, you need a proper track hub with left threading for the lockring (again, IMHO).

You need to put the sprocket on very tight first, before you go out and ride it so it doesnt come off under braking. Dont just put the sprocket on, then tighten it up with the chain and go, you will need to tighten the sprocket up with a chain-whip.

 

[Tel]

Best buy myself a chain whip too then! Actually I need to get off the old freewheel so a remover for that is on order too.

Regarding the dropouts. As I said in the OP I'll need to take a file to the drive side to elongate it so that it is the same as the non drive side, I've taken a picture and you can see there is plenty of meat there to hack away. I've searched the net and others have done the same, actually there is a guy on here that has a Record Spint fixie http://www.cyclechat.co.uk/forums/showthread.php?t=24464&highlight=record+sprint I presume he must've done the same...

Here are some updated pics. Cleaning it would probably make a difference

Please excuse the crap pics

 

[Joe24]

You might not need to take any out of them drops, they might be long enough already.
If you use 3/32 sprocket, then you can just use a normal chainwhip. You can still use a 1/8th chain with the sprocket.

 

[samid]

Also keep in mind that 3/32 chains/sprockets/chainwheels work perfectly well with ss/fixed, no need to go 1/8 (except for the coolness factor, that is)

 

[Tel]

I'll wait until I have the sprocket before extending the dropout then but y'know I'm just not that lucky

I've ordered a 3/32 chain and sprocket after reading Sheldons advice.

I am keeping a front brake which leads me to my next question:

The front forks take a bolt & nut fitting brake can I drill it out to accept a recessed allen key fitting brake (forgive my terminology)?

 

[zzpza]

you mean like this?

mark...

cut...

​

file...

​

still needs more filing, but i can get an axle in there no problem.

n.b. you can use a chainwhip to put on and take off track sprockets, but for your old freewheel, you will only ever be able to tighten it. to remove it you will need a freewheel extraction tool. it fits into the splines on the inside non-rotating edge of the freewheel. see below...

also, it sounds like you are reusing a double chainring crankset. if you haven't already bought some, you'll need to replace the chainring bolts with shorter ones. you can get them off eBay for about £5 a set.

more pix from my build (it's a spare time proj for me):

Project Bike - Raleigh Sensor

hth.



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[Joe24]

Also keep in mind that 3/32 chains/sprockets/chainwheels work perfectly well with ss/fixed, no need to go 1/8 (except for the coolness factor, that is)

Rubbish, 1/8th is better. Much stronger so it lasts longer, and it shouldnt come off as easy as what a 3/32 chain does.

Oh, and for 1/8th sprockets, you cant just take them off with 3/32 chain whip. The chain wont fit into the teeth right.

 

[Tel]

Yeah just like that zzpza thanks for sharing that and I enjoyed looking at the rest of your pics.

Regarding the 3/32 chain fitting on the 1/8th sprocket is that the same for chainwheels?

I've researched drilling out the forks to take the recess brake fitting and it looks as though it's doable which is good because I can use an old set of brakes that I have kicking about.

 

[zzpza]

Yeah just like that zzpza thanks for sharing that and I enjoyed looking at the rest of your pics.

No problem Tel, glad it was useful.

Regarding the 3/32 chain fitting on the 1/8th sprocket is that the same for chainwheels?

FWIW, I have been running a 3/32" (sprocket, chainring and chain) on both my other fixies for over a year now with no problems. One of them's even a magic gear ratio fixie, so the chain isn't always as tight as it couldbe either.

I've researched drilling out the forks to take the recess brake fitting and it looks as though it's doable which is good because I can use an old set of brakes that I have kicking about.

I would be very interested to hear more about this as I have the same problem on my Raleigh Sensor. I have bought some NOS (but cheap!) Alessa brakes for it, but they feel rubbish compaired to modern dualpivot brakes.

 

[Joe24]

Yeah just like that zzpza thanks for sharing that and I enjoyed looking at the rest of your pics.

Regarding the 3/32 chain fitting on the 1/8th sprocket is that the same for chainwheels?

I've researched drilling out the forks to take the recess brake fitting and it looks as though it's doable which is good because I can use an old set of brakes that I have kicking about.

What do you mean?
If your making a fixed, you cant have an old rear mech there tensioning your chain, or one of those springy chain tensioners. Riding fixed puts forces on both sides of the chain, so its unsafe to use. Sorry if you didnt mean this.
If you mean can you use a 1/8th chain on stuff thats 3/32. The answer is yes. I have a 3/32 sprocket on my fixed, and on my old fixed i had a 3/32 sprocket and chainring and it was fine. If i were you though, i would have a 1/8th chainring. Much stronger ring.