A few quick SS conversion questions

JPBoothy

Über Member
Location
Cheshire
Firstly, let me apologise for being too impatient to trawl through the many SS/Fixie threads (which I'm sure already contain the answers) but, as always your knowledge and experience would be greatly appreciated. I have decided after many months of pondering to convert one of my two Cannondale CAADX bikes into a SS as I never use the gears on it and mainly use it locally for flat(ish) trips to the pub & shops anyway.. The questions that I have are - (1) Are all SS chain-rings recessed to fit onto any 'spider' or are some just flat? I am hoping to use my original FSA crank arms. (2) Are standard road wheel hub splines strong enough when a sprocket converter kit is used? and, (3) Without horizontal drop-outs is it always necessary to use one of those 'damn ugly' pulley tensioner's?
 
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ColinJ

Puzzle game developer
(1) Are all SS chain-rings recessed to fit onto any 'spider' or are some just flat?
I just used the outer chainring from a double chainset when I built my SS bike. I put washers on the other side of the spider to make up the thickness of the missing chainring.

(2) Are standard road wheel hub splines strong enough when a sprocket converter kit is used?
Mine seem to be! I have done thousands of miles on my bike. I didn't even use a converter kit, I just took one sprocket out of a cassette and used that. I filled in the space with lots of spacers from old cassettes. I took the sprocket and spacers off the other day and the splines looked fine.

If you make sure that you get a perfect chainline and proper chain tension then you shouldn't have a problem with the chain falling off.

(3) Without horizontal drop-outs is it always necessary to use one of those 'damn ugly' pulley tensioner's?
I agree with you about chain tensioners! They don't only look naff (I use one) - they can also be slightly noisy. My otherwise quiet transmission is marred by a slight whirring/rumbling from the chain tensioner. (That could be because I modified mine. I am going to try changing it back to see if that helps.)

If you choose the right chainring and sprocket combination, you might get lucky and start with a chain with no slack. I managed to do that with a SS bike that I made for my turbo trainer. The thing is, it wouldn't stay like that for long. I was surprised how quickly the chain starts to lengthen with use. My road SS needs virtually no help from the chain tensioner with a new chain, but within 100 or so miles the tensioner needs to start doing its job.

One idea that I had was to run a new chain until it started to look a bit slack and then replace a pair of links with a single half-link. I haven't tried it, but it might be possible to get it to work? I might buy some half links and try it. If you try it first, let me know how you get on!
 
Firstly, let me apologise for being too impatient to trawl through the many SS/Fixie threads (which I'm sure already contain the answers) but, as always your knowledge and experience would be greatly appreciated. I have decided after many months of pondering to convert one of my two Cannondale CAADX bikes into a SS as I never use the gears on it and mainly use it locally for flat(ish) trips to the pub & shops anyway.. The questions that I have are - (1) Are all SS chain-rings recessed to fit onto any 'spider' or are some just flat? I am hoping to use my original FSA crank arms. (2) Are standard road wheel hub splines strong enough when a sprocket converter kit is used? and, (3) Without horizontal drop-outs is it always necessary to use one of those 'damn ugly' pulley tensioner's?
1. No idea but it should not be an issue as the kit should contain spacers for the rear hub to align the cog with the chainring. Just work out what ratio you want and buy a chainring with the correct BCD.
2. 99% sure they would be as the kits would not be used otherwise. Perhaps get a good quality kit.
3. I’d say roughly the chances of the chain fitting when using vertical drop outs are about 20%. You could try your luck, it would help if you had a few chains lying around with different amounts of wear on them.
 
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JPBoothy

JPBoothy

Über Member
Location
Cheshire
Thanks both for the advice.. My concern with the Chain-ring/spider was that there could be a step if one was flat and the other rebated and, as I'm not trying to 'cobble it' together on the cheap I would rather go for the right tool for the job.. @ColinJ you suggested washers but on which side of the chain-ring did they go? Are they possibly to eliminate the 'step' that I've mentioned? Did that mean you used the original length bolts too? With regard to the chain tension, I also thought about eliminating any slack by carefully choosing the right size chain-ring/sprocket combination but how would I know without going through an expensive trial & error process? It seems a shame to loose that nice virtual silence that you get from a SS by fitting an 'ugly' whirring tensioner but I suppose it is still better than the chain slap and whirring of a rear mech.. I didn't realise that the chain stretched so quickly as I already have a lovely steel Genesis SS road bike and can only ever recall altering the tension when fixing a puncture.

Thanks again for your tips :okay:
 

ColinJ

Puzzle game developer
My concern with the Chain-ring/spider was that there could be a step if one was flat and the other rebated and, as I'm not trying to 'cobble it' together on the cheap I would rather go for the right tool for the job..
My SS project was just a way of using a frame/fork which had been donated to me. I had enough spare parts to build most of the bike and only had to add about £70-80 worth of new bits so it was done on the cheap, but that was always my intention. I wanted a bike that I enjoyed riding, but could use for shopping trips without worrying about it getting stolen. I would not be happy if it did go, but at least it wouldn't have cost me a lot of money. Also, the fact that it is fairly obviously a 'hack bike' means that it is much less likely to be worth someone risking cutting off the huge D-lock that I use.

@ColinJ you suggested washers but on which side of the chain-ring did they go? Are they possibly to eliminate the 'step' that I've mentioned? Did that mean you used the original length bolts too?
On the inside of the spider. I used the original big ring but removed the little ring, which left those 'steps'. I had to file flats on one side of the washers to get them to fit. Yes, bodgery, but I wanted to see just how cheaply I could build what was still a pretty decent bike. The washers are hidden away on the inside so they are not obvious at a first glance. Everything looks normal from the outside. Yes, the original bolts were used.

With regard to the chain tension, I also thought about eliminating any slack by carefully choosing the right size chain-ring/sprocket combination but how would I know without going through an expensive trial & error process?
I already had a spare 52 tooth big ring and had decided to use that. I worked out that a 19 tooth sprocket gave me the best compromise gear ratio with that ring (high enough to not spin out too often, but low enough to get up Cragg Vale - a 5 mile local hill with an average gradient of 3.2%, and with just a short stretch at about 8%). It turned out that a new chain with that setup had almost no sag on my 58 cm frame. The chain tensioner was barely touching the chain. Pure coincidence though, I hadn't calculated it!

I didn't realise that the chain stretched so quickly as I already have a lovely steel Genesis SS road bike and can only ever recall altering the tension when fixing a puncture.
It was a big surprise to me! The tensioner was almost quiet with the new chain but it didn't take long for the chain to elongate and the tensioner to start working. The chain elongation seems to happen quite quickly at first and then slow down. Or maybe it is just that the initial wear is so obvious - going from no sag to some sag is more obvious than some sag to some more sag!
 
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JPBoothy

JPBoothy

Über Member
Location
Cheshire
I just found THIS, which should help with calculating gear ratios, chain lengths etc.
:wacko: I accept that I'm not the sharpest tool in the box but WTF.. They have been trying to graph & chart (sorry they're KPI's these days) me to death in work for years now but to no avail.
 

3narf

For whom the bell dings
Location
Tetbury
[QUOTE="JPBoothy, post: 6074576, member: 42604] I'm not trying to 'cobble it' together on the cheap I would rather go for the right tool for the job..
[/QUOTE]

It will be a compromise as long as you're trying to use a vertical dropout frame... if you really want it to be neat and look right, find a frame with horizontal dropouts or better still, a purpose-built singlespeed frame!
 

ColinJ

Puzzle game developer
It will be a compromise as long as you're trying to use a vertical dropout frame... if you really want it to be neat and look right, find a frame with horizontal dropouts or better still, a purpose-built singlespeed frame!
The frame that I used for my singlespeed turbo trainer bike has semi-horizontal dropouts which are just long and horizontal enough to let me manage without a chain tensioner. It is nice having a really smooth and quiet transmission.

If I could afford it I would definitely buy a singlespeed bike with horizontal dropouts to replace my current one.
 
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JPBoothy

JPBoothy

Über Member
Location
Cheshire
The frame that I used for my singlespeed turbo trainer bike has semi-horizontal dropouts which are just long and horizontal enough to let me manage without a chain tensioner. It is nice having a really smooth and quiet transmission.

If I could afford it I would definitely buy a singlespeed bike with horizontal dropouts to replace my current one.
I do have a purpose built SS (Genesis Flyer) already but it is strictly a road bike really as the max tyre size with my mudguards is 25c but, as I have two Cannondale CAADX's ( x1 Drop & x1 Flat bar) and enjoy riding the trails more than the road it seemed the logical option. I did consider buying a Genesis Day one 10 which is a purpose built SS Gravel bike but I prefer my old school cantilever centre pull 'frog-leg' brakes to the mechanical discs of the Day one. The Flat bar CAADX is a really comfortable bike to ride and I don't want to part with it really. I do like the fact that the Day One can take quite wide tyres though.
 

ColinJ

Puzzle game developer
I do have a purpose built SS (Genesis Flyer) already but it is strictly a road bike really as the max tyre size with my mudguards is 25c but, as I have two Cannondale CAADX's ( x1 Drop & x1 Flat bar) and enjoy riding the trails more than the road it seemed the logical option. I did consider buying a Genesis Day one 10 which is a purpose built SS Gravel bike but I prefer my old school cantilever centre pull 'frog-leg' brakes to the mechanical discs of the Day one. The Flat bar CAADX is a really comfortable bike to ride and I don't want to part with it really. I do like the fact that the Day One can take quite wide tyres though.
I wouldn't get very far on the local gravel with MY CAADX converted to singlespeed! In fact, after riding up this steep gravel track...

537209


... from the valley below on the original gearing I decided that I needed to fit lower gears - details HERE.

NB If you haven't seen it already, make sure that you read THIS THREAD about a CAADX fork recall. Yours may not be affected, but mine IS! I was just about to get it sorted out when the coronavirus came along. I'm putting it off for now but will get it done as soon as I feel ok about carting the bike off to a Cannondale dealer.
 
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JPBoothy

JPBoothy

Über Member
Location
Cheshire
Oh bugger, one of mine is a 2016 Disc version with UltraX written on the on the inside. This is the one for tackling the hills on though not my Flatbar 2012/2013 cantilever braked model. Although I'm sure that the 'beautiful' terrain in your area would finish me off. My friend had a replacement fork on his Ultegra/Hydraulic Disc CAADX under the recall and there is no offer of a 'like for like' it is just a basic black one for everybody. I know it is a case of safety coming first but as my forks are black with Cannondale written in bright blue and have a flash of hi-viz orange/red on the them the black ones would look a bit naff so I'll take my chances I think. Thank you for the link though :okay:
 

ColinJ

Puzzle game developer
I know it is a case of safety coming first but as my forks are black with Cannondale written in bright blue and have a flash of hi-viz orange/red on the them the black ones would look a bit naff so I'll take my chances I think. Thank you for the link though :okay:
Yeah, I like the look of my CAADX fork too, but I do high speed descending on sometimes less-than-perfect surfaces so a fork failure could be catastrophic for me. I'll get it sorted.

I need to find a Cannondale dealer to do the job for me. I emailed a couple of them before lockdown but they never got back to me. I don't know why businesses bother with email addresses if they can't be bothered to check/reply to mail! I'll start phoning round once the virus situation eases off a bit more.

If I can find a dealer within cycling distance I'll risk riding the bike to them if they promise to do the job while I wait. If I do, I will not be doing my usual 60+ km/hr descents on the outward leg! :laugh:
 
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JPBoothy

JPBoothy

Über Member
Location
Cheshire
Blimey after a 60km descent I would be thinking more about changing my shorts than my forks.. I've noticed that my Flatbar CAADX also has UltraX written on the inside of the fork but as it is not a disc fork I'm assuming that one will be okay.
 
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