I have a free bike - SS opportunity?

[Watchman]

I've just inherited a late 1990s Saracen rigid F&F - basically an old MTB.

It's mostly alloy (and surprisingly light) so the fact that it's been sat outside for the last 2 years hasn't done any damage to the F&F, seatpost, wheels, stem and bars but the drive-train and cables are scrap. I've decided to bin the chain, front and rear derailleurs, cassette and shifters, and try to make it into a relaxed-riding SS - I fancy some Northroad type bars to turn it into a "pub bike", although the real reason for doing this is simply because I like projects and I'm currently without one.

Anyway, I've started stripping it already. I'll keep the headset, BB and hubs because they only appear to need a clean and re-grease. They're not the best I've seen but certainly serviceable.

I also know which bars, stem, tyres etc I want but I'm not sure how to convert the chainwheel to a single. If possible, I'd like one of those narrow/wide chainwheels but ultimately I'm going to see what I can do with it on a budget (for a change).

The crank is a 5-bolt Shimano. The narrow/wide one chainwheels I've seen are 4-bolt ones, so I suppose I'll drop that idea. And they're expensive.

Presumably I want to try and position a single chainwheel around where the middle one is currently located? How? Is there anything special about a single chainwheel? Do I need to find one which is designed for this type of conversion - which offsets itself properly?

Also, are the kits to convert the rear wheel to SS fairly self explanatory, and do they come with shims to allow you to line-up the chain? Is it that simple?

Sorry for the questions, but if this bike is compatible with some of the parts I've seen on-line, I might have a go at this over Christmas, at which point I'll start taking pics.

[Disco You]

It's called a chainring, not a chain wheel.

As for at the back, what direction are your dropouts? If they aren't horizontal, or diagonal (i.e. they are vertical) which I suspect won't be the case, then you are in for a tricky time.

Edited by Disco You on Sunday 15th December 20:40

[anonymous-user]

They will be vertical dropouts so you will have to use a magic gear calculator like this http://eehouse.org/fixin/formfmu.php to find out which ratios you can use. Given its a steel frame, you could probably get some horizontal drop outs fitted if you really wanted to. Try these people http://www.ceeway.com/aboutus.htm

Even using the magic ratio, you will probably want to buy a single speed specific spocket and chainring because the stuff with shifting ramps can be really hard to set up as singlespeed. You'll need a spacer kit to keep the sprocket in place too.

Edited by anonymous-user on Sunday 15th December 20:43

[Watchman]

Disco You said:

It's called a chainring, not a chain wheel.

As for at the back, what direction are your dropouts? If they aren't horizontal, or diagonal (i.e. they are vertical) which I suspect. Itht be the case, then you are in for a tricky time.

Google and Ebay suggests chain wheel and chain ring are interchangeable, even in the UK.

Vertical drop-outs. There are conversion kits which come with a tensioner, so I don't think that's going to present any issues once I've got past the questions I had in my OP.

[Watchman]

pablo said:

They will be vertical dropouts so you will have to use a magic gear calculator like this http://eehouse.org/fixin/formfmu.php to find out which ratios you can use. Given its a steel frame, you could probably get some horizontal drop outs fitted if you really wanted to. Try these people http://www.ceeway.com/aboutus.htm

Even using the magic ratio, you will probably want to buy a single speed specific spocket and chainring because the stuff with shifting ramps can be really hard to set up as singlespeed.

Alloy frame and vertical dropouts.

Not put off using a tensioner. Would be prettier without but happy enough with a tensioner.

[gazza285]

Watchman said:

Google and Ebay suggests chain wheel and chain ring are interchangeable, even in the UK.

Just don't call them cogs...

[Watchman]

gazza285 said:

Watchman said:

Google and Ebay suggests chain wheel and chain ring are interchangeable, even in the UK.

Just don't call them cogs...

Ha - I corrected my friend about that only today.

[Watchman]

Damn, the crank is useless I fear. It has a 74mm BCD for which there does not appear to be any SS chainrings. Anyone know any different?

I'll check the spindle size - if that's standard, you can buy a pair of cranks and an alloy SS chainring for under £20. Budget creep already.

[graafian]

Watchman said:

Damn, the crank is useless I fear. It has a 74mm BCD for which there does not appear to be any SS chainrings. Anyone know any different?

I'll check the spindle size - if that's standard, you can buy a pair of cranks and an alloy SS chainring for under £20. Budget creep already.

74 is the granny ring bolt pattern, the middle ring lugs will be 110mm.
Compact cranks would be, 5 bolt that is, 94/58.

[Watchman]

graafian said:

74 is the granny ring bolt pattern, the middle ring lugs will be 110mm.
Compact cranks would be, 5 bolt that is, 94/58.

Thanks. I'll look again tomorrow.

[ndg]

No need for a thick/thin ring with a single speed specific ring (tall teeth). Try to go with a 1/8" chain and ring/cog if you can though. As said above, you will need a tensioner. Magic ratio's are great until the chain starts to wear.

To answer some of your original questions:
Yes, use the middle ring position.
To hold the chainring on you need shorter chainring bolts, as it's only holding one ring now, not two.
Yes the kit's come with a selection of spacers to allow you to align the rear cog - if it's a cassette and freehub, not a free wheel, you have checked haven't you? Single speed freewheels are easily available though.
Charlie's website below has some good video's on the conversion process.

For a 26er a good starting gear is 32x16 (For fairly flat off-road use - on-road would want to be higher).

Useful links:
http://www.velosolo.co.uk/shopsingle.html
http://www.charliethebikemonger.com/one-speed-kits...

I've had bit's from both of the above and really like Velosolo's quality.

Edited by ndg on Monday 16th December 05:35

[Watchman]

ndg said:

No need for a thick/thin ring with a single speed specific ring (tall teeth). Try to go with a 1/8" chain and ring/cog if you can though. As said above, you will need a tensioner. Magic ratio's are great until the chain starts to wear.

Thanks for this. I've had a look and a 3/32" chain seems most popular and most importantly, cheapest (Tesco sells a KMC one). Also, both sprocket and chainrings are cheap for 3/32. I don't have much power in my legs so that'll do for me. I'm not using it as a fixie, so I won't give it much stick.

ndg said:

To answer some of your original questions:
Yes, use the middle ring position.
To hold the chainring on you need shorter chainring bolts, as it's only holding one ring now, not two.

Again, thanks. I went back into the garage at midnight to have a closer look and I see exactly how that works now. The outer chainring is in-line with the spider. The middle one is inside. I can see how to mount a SS chainring now.

ndg said:

Yes the kit's come with a selection of spacers to allow you to align the rear cog - if it's a cassette and freehub, not a free wheel, you have checked haven't you? Single speed freewheels are easily available though.
Charlie's website below has some good video's on the conversion process.

It is a freehub. I had a BMX with a freewheel and this isn't that. It needs a Park Took FR-5 to remove it. I already have a FR-1 which is for the earlier cassettes.

ndg said:

For a 26er a good starting gear is 32x16 (For fairly flat off-road use - on-road would want to be higher).

I had a play with Sheldon Brown's gearcalc last night. If I were to go with a new crank with SS chainring (under 20 quid on Ebay so definitely in contention) then it comes with a 33T chainring. Coupled to an 18T sprocket, even my legs could punt that along. The SS conversion kit I've ordered comes with both an 18T and a 16T so if my legs improve, I can swap them over.

ndg said:

Useful links:
http://www.velosolo.co.uk/shopsingle.html
http://www.charliethebikemonger.com/one-speed-kits...

I've had bit's from both of the above and really like Velosolo's quality.

Thanks - I'm very grateful for the advice.

Edited by Watchman on Monday 16th December 08:44

[donfisher]

ndg said:

As said above, you will need a tensioner. Magic ratio's are great until the chain starts to wear.

IMHO SS Mountain bikes actually look better with the tensioner. The fact that it makes it easier to get the chain right is a bonus.

[Watchman]

donfisher said:

IMHO SS Mountain bikes actually look better with the tensioner. The fact that it makes it easier to get the chain right is a bonus.

I was thinking the same - and that it looks easier to remove/refit the wheel. That also led me onto wondering whether to go with a sprung or "fixed" tensioner. I went with sprung in the end because, although this started out as an MTB F&F, it'll only get used on roads and unpaved paths so isn't going to suffer a lot of chain slap.

[Fluffsri]

Watchman said:

donfisher said:

IMHO SS Mountain bikes actually look better with the tensioner. The fact that it makes it easier to get the chain right is a bonus.

I was thinking the same - and that it looks easier to remove/refit the wheel. That also led me onto wondering whether to go with a sprung or "fixed" tensioner. I went with sprung in the end because, although this started out as an MTB F&F, it'll only get used on roads and unpaved paths so isn't going to suffer a lot of chain slap.

Not a fan of the tensioner as it looks like an afterthought. I bought a slotted dropout frame so I could do away with fitting a tensioner but for the horizontal dropouts there isnt much else you can do. For the OP, look on Charlie the bikemongers website, he does SS conversion kits.

[Watchman]

Fluffsri said:

Not a fan of the tensioner as it looks like an afterthought. I bought a slotted dropout frame so I could do away with fitting a tensioner but for the horizontal dropouts there isnt much else you can do. For the OP, look on Charlie the bikemongers website, he does SS conversion kits.

Oh I totally agree but I'm just going to build this up to get a feel for it then, if SS is for me, I'll sell it on and buy a Niner One9. I've fancied on for a very long time but the thought of dropping ~£3K on something I'm not sure about was worrisome. This freebie is a chance to find out if I could live with it.

Believe it or not, I've already had an offer for it based on the parts I've already spec'd. Chap at work loves bikes but has no spannering skills. I'm already set to make £50 on it.

[ndg]

If it's for mostly road you'll be wanting 33x16 on it. Although it's easier to take links out of the chain rather than add them back in.....

[Watchman]

ndg said:

If it's for mostly road you'll be wanting 33x16 on it. Although it's easier to take links out of the chain rather than add them back in.....

True - although I haven't decided whether to use it for a canal-path run I know (which is a bit mud-slushy) and leave the spuddy tyres on it, or to use it on the road route I have and stick some touring tyres on it. I intended to loan it out to people too - lots of people say "I'd love to come cycling with you but I haven't got a bike". Now I can call their bluff.

Another factor is whether I leave the DMR V8s on it or put a set of SPDs on. I could grind a 16T relatively easily with SPDs.

I might start with the 18T and then change later, as you suggest.

[Fourmotion]

I did the same thing, thinking I had a free bike for SS. But I've just got to the end of my tether using my 2000 Rockhopper frame with tensioner. Under heavy load the wheel would pull out of the drop out, regardless of how tight the skewer was.

So I've just bought an on-one inbred with horizontal dropouts so I don't have the same problem. I'll be running a fixed tensioner simply so I don't have to adjust the rear wheel position and move the brake caliper when the chain loosens up.

For reference, the DMR tensioner wheel isn't wide enough to house a 1/8th size chain. I run an 8 speed chain instead. Although you will go through a few...

[Watchman]

Fourmotion said:

I did the same thing, thinking I had a free bike for SS. But I've just got to the end of my tether using my 2000 Rockhopper frame with tensioner. Under heavy load the wheel would pull out of the drop out, regardless of how tight the skewer was.

So I've just bought an on-one inbred with horizontal dropouts so I don't have the same problem. I'll be running a fixed tensioner simply so I don't have to adjust the rear wheel position and move the brake caliper when the chain loosens up.

For reference, the DMR tensioner wheel isn't wide enough to house a 1/8th size chain. I run an 8 speed chain instead. Although you will go through a few...

I'm really not strong enough to trouble a chain, or to pull a wheel out of its dropouts.

Ultimately I think I want this:



I just want to play with a SS bike for a while before I commit that sort of spend on a Niner. It'll only have to cope with unpaved cycle paths and occasional forest trails. Nothing you'd normally consider a hardtail for but I don't want a road bike. The roads are too poor for narrow tyres. I already have a bike with 28mm tyres and they're too narrow to give a nice ride for me, although when I do find a nice path, it really flies.