polarcreamsoda

i have a very very very very old raleigh grand prix 10speed that i have been dying to start a single speed project on. i am planning on starting from scratch with this bike and from starting from scratch, i mean repainting the frame and fork, new wheels and tires, new brakes etc etc. only thing i plan to keep from this bike is frame maybe a lil more. i need this bike to commute within the city of boston and possible ride to school with it. But i am the bigggest noob when it comes to single speeders though. i dont know where to start and what stuff i need . i am a pretty mechanically sound guy but i have also never taken apart a bigger bike. i tinker around my bmx bike alot but im sure that this bike is much different from my bmx. if i can get some help from any of gurus out about where to start, it would be awesome. here are some pics of my bike if you guys were wondering how old this thing really is.





this is my first post BTW, wooooop!

go cog

If you have a BMX, you may already have some of the parts you need!
The first link is for SS, the second for FG

https://sheldonbrown.com/singlespeed.html

https://sheldonbrown.com/fixed/index.html

BTW, woooooopeeeeeeeeeeeeeeeeeeeeeeeeee!

Joe Dog

That frame would be great. I had two old Grand Prix's and they were fun to ride. Follow the Sheldon link and have fun with it.

polarcreamsoda

thanks, i already read some of that. i saw i could use my freewheel from my bmx but id rather keep that together and get everything new.

is ther a definitive list of what i actually need? and i dont really understand all that junk with the rear wheel (hubs, cassettes and what not), i only know what a freewheel is.

bbattle

What's wrong with it the way it is? Just asking. Depending upon how you take your conversion, you may end up ditching everything but the frame, bars, and saddle/seatpost. It may be wiser to keep this bike as is and find an old frame to build up. Two bikes always better than one. Plus, you have one that's rideable while you are building the other.

Info on your bike

polarcreamsoda

i do have another bike to ride, thats why i consider this one as a project. i figured i should get new parts for this bike because it still has all the original parts from when it first came out. the wheels are warped, tires are bald and brakes are busted. i think this bike is need of a restoration.

bbattle

A new wheelset requires rims, spokes, front and rear hub. Rear hub can be fixed, free, or fixed/free, fixed/fixed. Fixed/fixed means it's a flip-flop hub that'll give you the option of two gears. These can be freewheel cogs or fixed.

You'll need to make sure the bottom bracket spindle length and the rear hub spacing are going to give you a straight chainline. Sheldon's site discusses this. I recently bought a square taper bottom bracket with a 103mm spindle to give me the 42mm chainline to match my rear hub. Slapped a Sugino RD crankset on it. Plus, there are these spacer things that'll help get things in line if necessary.

Your bike has 27" wheels on it. You can make new wheels with 27" rims but most people opt for the now standard 700c size; which is slightly smaller. Your old brakes may not work with the new wheelset.

Use the same width cog, chainring, chain; either 1/8" or 3/32. Decide what gear ratio you want then get the chainring and cog combo that'll get you there. Don't forget the lockring if you get a fixed cog. You may want to get a couple of cogs so you can experiment. Having a flip-flop hub makes this easy to have both on the bike so if the going gets tough, you can flip to the easier gear.


Have fun getting those cottered cranks off. When they say whack it with a hammer, they aren't talking love taps. Hit it like you live.

polarcreamsoda

hmm thats where i am lost at, the rear wheel. i am lost at trying to figure how i am suppose to get a straight chain on it. what are the advantages to having a fixes gear on one side of the flip flop hub and a freewheel on the other side besides having 2 different gear ratios?? wouldnt i be able to run 2 different sized freewheels on the flip flop instead??

bbattle

According to Sheldon Brown, a 103mm spindle on your bottom bracket should work well with a track hub to give you a straight chainline.

Now all you have to do is decide what rear hub you want. Fixed or flip-flop(fixed/free or fixed/fixed).

Yes, you can run different cogs on the flip-flop. I've got a fixed/free that's 15T fixed and 18T free. The 18T is a bit too easy for me but it came with the bike and I've only run freewheel once. The advantage of having a freewheel is the ability to coast should you desire it. I did when I found myself on top of a mountain with a 4 mile descent.

If you wanted, you could run two different freewheel cogs on a flip-flop. That's why getting a fixed/fixed flip-flop is the best. You've got options. You can try fixed; you can go freewheel. You can do both or just have two fixed gears or two free.

dwainedibbly

It looks like a fun project.

A little help in dating your bike: I bought a Grand Prix new in 1973 and it didn't have the "safety levers" on the brakes, so yours is probably newer than that (unless the brake levers were swapped out at some point, of course). It *does* have the cottered cranks, though, so it's probably a 1974-1976.

Harris had 27" fixed/free wheels on sale recently, if I recall correctly.

polarcreamsoda

well, over the weekend, i went out and bought all the stuff necessary to make it a singlespeeder. i upgraded my wheels from a 27inch to a 700cc. and i got a 16t freewheel on one side and a 18t fixed on the other. i didnt have a chance to upgrade the front wheel yet mainly because of my lack of funds. once i get that done, ill have to replace the crank and get a chainring. any of you guys have a recommendation for a gear ratio i should be running??? city flats and some hills.

one more question, im looking to only run a front brake on this bike, any of you have a recommendation for that as well????

thanks

iamarapgod

cottered steel cranks....classy

dwainedibbly

You'll need a long reach brake to make 700c wheels work on a frame designed for 27" wheels. Look at the Tektro R556. It's a modern, dual-pivot brake that will go up to 73mm reach (I think). I put a pair on an old Dawes that I made into a SS bike.

polarcreamsoda

sweet thanks, ill look into the tektros.

anyone know where i can get a a set of cheap bullhorn bars?!?!

bbattle

Since your smaller chainring is probably a 42, leave the crankset on there and give the 42-18 a try. It's low enough to get you up hills and low enough to practice your skids.

Before you ditch those old centerpull brakes on the bike, see if they'll work on your new wheels.

As for cheap parts, check with your LBS, see what they've got in the scrap parts bin. You might get some regular drop handlebars and flip them-chop them.

Cynikal 

No need. Your current brakes will work. I have the same bike set up as a townie with 700c's on it.

Cynikal 

Also, does your city have a bike co-op? This will be a good source of used cranks and other bits.

polarcreamsoda

my smaller chain ring is currently a 40t one, so im running 16t in the rear and 40 up front. seems to be working fine for me.

i was looking into cranks and bottom brackets as well. im going to get the bulletproof 165mm crank but i wasnt sure which bottom bracket would fit my frame and crankset. something to do with cottered cranks and having to convert them.

elbows

Cambridge has Broadway Bicycle School, which is sort of like a bike co-op -- they have used parts, you can use their tools/repair stands for an hourly fee, and they do instruction too, if you get stuck. They're good guys (or girls, actually -- most of the mechanics are women, which certainly doesn't hurt the appeal of the place).

They're a good source for fixed/single-speed parts (new or used), and will also build wheels for you if you need it.

brett jerk

take the road drop bars off the bike, flip em upside down and take a hacksaw to em

BAM

polarcreamsoda

i cant do that with these drop bars. the bars are bent.

sadly, thats why im looking to purchase new bars.

brett jerk

well if you're looking for cheap bullhorns, finding an old pair of drops and cutting them is the way to go

polarcreamsoda

yeah, i just need to find someone with some vises and a hacksaw or a pipe cutter.

trons

you just need a hacksaw.. no vise necessary