Single speed conversion crankset

jimmyt-11

I have just purchased an old Rayleigh road bike and I'm looking to convert it to single speed. I am after some advice on a crankset.

The bike currently has a square taper bb. I am not going to be putting many miles on it. It's for me too poodle about on to try single speed. Hence i don't want anything expensive.

I have seen many options ranging from about £15.

Do i go with single speed specific or remove the extra rings from a double or triple?

Any help would be much appreciated

Thanks
James

woolwich

Once you have the chainline sorted both options are functionally the same.

The manufacturer of a new single ring chainset will be able to tell you the correct bottom bracket width to buy, possibly saving a bit of trial and error getting the chainline correct.

If you happen to have a double or triple lying about then give it a go, you will probably get close to a useable chainline with one combination. You can even tweek the line a little with washers at the front if it is very close.
You will probably need shorter chainring bolts though or pack out the existing ones.
Some folks don't like the look of having a chainring on the back of the spider but it wouldn't bother me for a hack.

Lastly for a first go at single speed I would pick up one of the freehub conversion kits. Nothing more than a bunch of spacers but with trial and error you can get things lined up good with them.
Drill out the rivets from an old cassette and have 9 or 10 different sprockets at the rear for free until you settle on a ratio that works for you.
Have fun

jimmyt-11

All seems good advice to me.

I don't really like the look of having the extra doing on the crank though. I took a triple off the bike but i don't think it's one that can be in bolted.

If i do but a new one i guess a need a different chain, which i guess we'll have to be single speed specific. Then i will need a complete single stored specific gear set?

antonyfromoz

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19649083#p19649083]jimmyt-11[/url] wrote:

All seems good advice to me.

I don't really like the look of having the extra doing on the crank though. I took a triple off the bike but i don't think it's one that can be in bolted.

If i do but a new one i guess a need a different chain, which i guess we'll have to be single speed specific. Then i will need a complete single stored specific gear set?

I have converted my commuting bike from a compact double to a 1x9 and I still use the original sora octolink square taper crank set with a raceface narrow wide chainring. If you just want to see how you like single speed then this is a combination that seems to work (at least for me).

imposter2.0

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19642884#p19642884]jimmyt-11[/url] wrote:

I have just purchased an old Rayleigh road bike and I'm looking to convert it to single speed. I am after some advice on a crankset.

The bike currently has a square taper bb. I am not going to be putting many miles on it. It's for me too poodle about on to try single speed. Hence i don't want anything expensive.

I have seen many options ranging from about £15.

Do i go with single speed specific or remove the extra rings from a double or triple?

Any help would be much appreciated

Thanks
James

Whether you keep your existing chainset will depend on what gearing you decide on, and whether your crank will take a chain ring of that size. Might, might not.

jimmyt-11

On further inspection of my crank the extra ribs are fixed on not screwed. So i am sure i need a new one.

Has anyone had experience with a cheap crank. Maybe from eBay?

Thanks

imposter2.0

Cheap single speed cranks are usually cheap for a reason. Can sometimes be a bit hit & miss to get the right chain line, even with the recommended BB..

jimmyt-11

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19650580#p19650580]Imposter[/url] wrote:

Cheap single speed cranks are usually cheap for a reason. Can sometimes be a bit hit & miss to get the right chain line, even with the recommended BB..

would a cheap one be sufficient for a very low usage bike though?

imposter2.0

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19650983#p19650983]jimmyt-11[/url] wrote:

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19650580#p19650580]Imposter[/url] wrote:

Cheap single speed cranks are usually cheap for a reason. Can sometimes be a bit hit & miss to get the right chain line, even with the recommended BB..

would a cheap one be sufficient for a very low usage bike though?

Yes, assuming you can get a half-decent chain line..

craker

jimmyt-11 wrote:

would a cheap one be sufficient for a very low usage bike though?

Yes.

Just before you spend your cash, what have you currently got and what are you going to replace? You probably don't need a crank in the short term, if you can convert your freehub to single speed just do that. Buy bits as you need them.

jimmyt-11

Yes that is issue i currently have but that's on another thread.

I'm sure I've got a triple. I think it's one piece rather than being bolted together though. I'll have to double check.

jimmyt-11

having double checked it cant be unbolted. and I don't want to have the extra rings on there

jimmyt-11

I ended up going for this

http://www.tredz.co.uk/.Sturmey-Archer-Sturmey-Archer-FCS730S-SIngle-Chainset_52869.htm

jimmyt-11

Can anyone advise whether the above would need a JIS or ISO bottom bracket? I can't seem to find out

imposter2.0

It will fit on either, but it will sit further out, or further in, depending if the chainset is JIS, or ISO, and if the BB is ISO or JIS.

If there is no info available on what BB type is recommended, then either get a chainset where the information in clearer, or use trial & error.