Project #3: Singlespeed MTB

A singlespeed MTB.. why didn't I think of it before?  Well.. possibly because it sounds ludicrous.  A bike designed for cycling up and down large hills, reduced to a single gear?  Surely that's defeating the entire object of the bike!  I may as well buy a flippin BMX!

But it's not quite as simple as that.. MTBs aren't just gears - they're also frame geometry, wheels, tyres, and suspension.  Unlike the racing frames, they're built to ride over whatever is thrown in front of them.  This became apparent when autumn got into full swing, and I found myself cycling over slippery fallen leaves on slim road tyres and a rigid frame.  It was scary!  I was constantly worried that the wheels would slip from under me, and I'd end up under a bus.

The front wheel issue got me back on the MTB, and I realised how much better it was at dealing with leaves.  I missed the singlespeed, though.  I missed it's direct power, and the general feel of riding without having to worry about anything gear related.  Sure, I could ride without changing gear, like I generally did anyway, but it wasn't the same, somehow.

Onto the conversion...

Shopping list:

DMR STS Combo Kit (some spacers, a 16T cog, and a tensioner) - £33

Cassette removal tool - £6

A chain - £6

Total cost: £45

First, I took the rear wheel off, and removed the QR skewer.  The cassette removal tool included a guide, so there was no need to clamp it in place with anything. It slotted nicely into the hub.  Then I used a chain whip, which I've had for years for removing oil filters from cars, and an adjustable wrench to unscrew the locknut.

With the locknut off, the cassette came off easily, with the 11 and 12 tooth cogs falling away from the rest.  The other six cogs were screwed together using a bolt with the tiniest hex diameter I've ever seen.

Next, I added a couple of the larger spacers, put the cog in, and added the rest of the spacers, and put the locknut back on.  I put the wheel back onto the bike, and tried to tell if it would be a decent chainline..  I still have no idea!  It looked kind've straight, but I know from experience that it's very hard to tell by eye.  It wouldn't be hard to adjust later, so I left it like that, and turned my attention to the deraileurs.

The deraileurs came off simply enough - just some bolts to undo.  I wasn't intending to keep the gear cables, so I snipped them using my brake cable cutter.  Did I mention that I was doing this in my lunchbreak?  No time for fiddling with tiny screws and uncooperative wires!

With the deraileurs off, I attached the tensioner.  There are two parts to it - one bit that slots into the dropout, and is secured using the QR skewer, and the tensioner arm itself, which screws into that, and to the gear hanger.

Next was the chain, and this is where things started going wrong.  The problem with mountain bikes is that most of them, including mine, have vertical dropouts.  That means the wheel can't be moved back and forth to take up chain slack, so a tensioner is required to do that job.  When trying to join the chain, the links were only 3mm away from a near perfect fit, but they were 3mm too far apart, not too close.  I had to use the next link down the line, which made the chain VERY slack.  The chain was so slack that the tensioner couldn't operate in it's intended configuration (pushing up on the chain), as it hit the chainstay before taking up the slack, so I had to set it to push down instead.

That setup actually worked!  Well..  sort-of.   It turned out that 42-16 was a bit of a rubbish gear ratio, equivalent to 5th gear, but it felt more like 4th, and pedalling felt clumsy and faster than necessary.  That was going home, which is entirely uphill, so I was dreading trying it on the way into work!  Another problem is the width of the chain - it's exactly the same width as the groove in the tensioner, so it's being slightly gripped by it.  The sound it makes as it grips/releases the links is very weird!  Kind've like a fluttering noise.  To fix it, I can either buy a thinner 9/10-speed chain, or shave the tensioner a bit to make the groove wider.  I'm going for shaving, using a file!

So, once home, I got the old cassette out, found a suitably tiny hex key, and split the cassette into seperate cogs.  Seperate, filthy cogs. Some soap and water cleaned them up, and I had myself a 14-tooth cog for use in the morning.  It was getting too late to work on the bike, so I intended to do it during my lunch break..

Well, 4 miles on a 5.2 gear ratio, going downhill, put paid to that idea.  It was horrible!  I swung into Cringle Park, in Levenshulme, turned the bike on it's back, and got the tools out again.  Wheel off, locknut off, spacers off, 16T cog off, 14T cog in, etc, etc..  As an added bonus, the change in cog size meant the chain could be reduced to a less flappy length.  The tensioner was still close to hitting the chainstay, but it was doing it's job.  The ride from that point was far more agreeable!  :)

On my lunchbreak, I decided to try out a different gear ratio, using the 34-tooth chainwheel and the 12-tooth cog, to see if it improved the chain slack at all.  It didn't - it would've been extremely flappy again, so I left the chain the length it was, and went back to 42-14.

So, I guess I'll have to live with it the way it is.  I'd like the chain to be a little shorter, but it's just not possible with the cogs that I've got, and I'm not sure I want to go off buying cogs to see if they improve matters.  It's not bad, as such.  Just not perfect!

There are two final tasks to complete, now.  The 24 and 34 tooth chainwheels are still attached, and I want to take them off.  The crank arm isn't coming off without a fight, though.  The mallet just isn't getting through, so I need to ride it for a bit with the nut off.  I might spray some WD40 into it to see if that also helps.  I'm not sure if I should attempt this on the way home..  it'll probably wait until the most dangerous point before my entire chainset falls off.  :P

The other task is to replace the brakes.  My bike has Shimano Altus combined shifters and brakes (ugly things), so I can't just detach the shifters.  I've got some Acera levers on order, which have the added bonus of looking much nicer!

All in all, the conversion has been relatively pain-free.  The bike hasn't been rendered unusable for any length of time, which is a win in my book.  :)  

My MTB, back in the day

It does leave me with a new problem, however..  Apart from the tyres, all of the components are original, from when I bought it 8 years ago.  They're all a bit scuffed, and are making the bike look very shabby!  I found some photos of the bike from 2009, and it was looking much snazzier, despite having been riden through a muddy forest for a few hours.  So the new task is to start replacing parts to make it look a bit more presentable. 

At least I don't have to worry about replacing the deraileurs!

Here we go again..

I was supposed to sell my Hardrock once the second bike was completed...

Why would I need two geared commuter bikes?

I never get a chance to go offroad anymore, so it'll be useless..

It would help pay for the second bike..

It would quell some of the rage my partner was feeling toward me spending so much money on bikes..

She wouldn't like to see my browser search box..

"MTB singlespeed"


Here we go again!

Project #2: Carlton Thingumybob

So, the singlespeed project is a success!  So far. 

This is good news, because the singlespeed isn't my only ebay project - there is another!

Enter the arena; a Carlton somethingorother.  Built in Worksop in 1974, using 531 tubing, possibly resprayed metallic blue at some point, with no model name anywhere, and a frame layout that doesn't match any other Carlton that I've found pictures of.

No seat yet - I need to get the post measured

I guess the first thing to explain is why I thought it necessary to buy another bike.  I already had two, after all!  Well, at the time I was still pondering singlespeed or geared.  I wanted to try both options, and that meant either swapping components around on the one bike I did have, or buying a whole other bike.  I don't need much of an excuse to buy new things, especially when the new things are lovely retro bikes!  :)

The identity of the new frame has bugged me since I bought it.  I've hunted high and low for similar bikes, but none quite match.  The main issue is the rear brake hanger.  Almost all Carltons have a cable bridge above it, which aligns the cable directly above a centre-pull calliper brake.  Mine doesn't have one, which leads me to believe that it originally had sidepull brakes, or something attached to the seat bolt.  I've seen plenty of other 531-framed Carltons, but none that I've seen are missing the cable bridge.  The ones that are missing it are much older, or have different lugs/seat stays to mine.

So I don't know what it is.  Maybe that shouldn't matter.. Carlton used to be quite flexible when building frames, so maybe mine was a special request for someone who didn't like centrepulls.  Who wouldn't like centrepulls?  That brings me nicely to component choices..

For the brakes, I found a pair of Weinmann Symetric (sic) dual pivot brakes.  Dual pivots were better than the usual side pulls of the time, and better than the centre pulls, so seem like the perfect choice.  Unfortunately, the pair that I bought seem to have been intended for a bike with a plate of metal for a brake bridge, rather than a tube, meaning that the bolt on one of the brakes is incredibly short.  I've got a recessed nut on order that will hopefully solve this problem.

For the chainset, I bought a Nervar crank without really thinking about what I was doing.  The crank is an 80's model, probably from a Peugeot, which looks more modern than I realised.  I'm tempted to swap it for something more in keeping with the frames age, but I'm sticking with it for now.  As it's a French chainset, I had to buy a French bottom bracket.  The tool for fitting it turned out to be crud.  Wiggle advertised it as being good for both cassettes and bottom brackets, but it turned out to not be deep enough for a BB.  I bought a new tool the other day, which will finish the job.

The wheels are 27 inch, with a screw hub.  I bought a 7 speed freewheel for it.

The rear deraileur is a Shimano Arabesque long cage, bought before I realised different cage sizes existed.  The size shouldn't matter - it's just a little bit annoying.  At least it was cheaper than a short cage!  I also bought Arabesque shifters, as I like the retro design.  The front deraileur is a NOS 70s Nervar model.

What else is there?  A GB stem, Raleigh handlebar, Weinmann brake levers..  no seat post as yet.  Oh yes - the seat post!  When measuring the seat tube with a ruler (not the best method for determining seat post size), I noticed a 5mm crack coming off the bottom of the slit (is there a technical name for that?).

Cracked seat post, pre-drilling.  :(

This seems to have been caused by a previous owner over-tightening the seat bolt onto a seat post that was too small.  Internet knowledge said to drill a hole at the end of the crack, to stop it spreading.  I've done that, but now I'm incredibly cautious about what I'm going to do about a seat post.  A trip to a bike shop is probably in order, as apparently they have tools for measuring seat tubes.

When the bike is complete, it should be a nice middle ground between the MTB and the singlespeed.  It'll be interesting to see how it fares.

MTB and back again

For the past week, I've been back on my MTB.  Why?  Well, the front wheel of my singlespeed started making a sort of scraping/grinding noise, and I thought I should probably stay off it while I investigated the cause.  I didn't want it exploding on me, especially now that my journeys home are dark and wet.

It seems that the issue is the spokes.. either a loose spoke, or possibly the noise of the spokes rubbing together where they cross.  It's certainly collected some dirt between them.  I'll clean and oil them, and see if it makes a difference. 

Riding the MTB has been a bit of a revealation - I'd forgotten just how comfy it was!  The big tyres and springy suspension really take the edge out of the crappy road surfaces that I have to endure.  It makes me wonder what it must be like to be riding a full suspension bike, or a pootler with flex stem and suspension seat post.  It must be like riding on a cloud!  That would be awful, though.. I like to get some feedback from the road.  I remember hating powered steering when I first encountered it, because it removed most of the feedback and felt like one of my senses had been removed.  I got over it, though.  :)

It also feels safer to be on the MTB.  Going over potholes or rough surfaces doesn't feel life threatening anymore, allowing me to concentrate more on traffic rather than the road itself, and of course there's the riding position that allows me to see and be seen.  Leaves aren't much of a worry, either, what with the chunky tyres.

My Carlton Cobra singlespeed, at work.

Today, however, I am back on the singlespeed!  The MTB might feel safer, but it is also significantly slower.  It's incredibly annoying to be pedalling flat out, thinking I'm making really good time, then get home 10 minutes later than if I'd used the singlespeed.  Even more annoying is that I never really push myself on the singlespeed, because I spin out too soon.  So a flat out ride on the MTB isn't as quick as a (relatively) sedate ride on the singlespeed.  It just goes to show how much difference tyres, gears, and weight can make!

Extended testing, and a near-ish miss

I think I finally got the handlebars to stop moving! 

It was pretty hair raising on the way home last night.  I tightened the bolt up before I left work, but it continued to tilt forward every time I braked hard.  When I got to the traffic lights outside Mcvities in Levenshulme, I couldn't reach the brakes anymore, so figured it was probably time to get off and re-adjust.  :P  I tightened it as hard as I could, and it seeeeems to have done the trick!

A couple more things that I've found, now that I've cycled it to and fro a bit more:

The pedals weren't designed with flatfooted people in mind.

My feet seem to be wider than average, meaning that I either have to wear wide fitting shoes, or wear one size larger than needed.  I trip over myself when I'm wearing large shoes, so my footwear of choice are nice wide skate shoes!  That was fine on the MTB, but the pedals on the road bike are much narrower, and curve upwards on the outside.  I'm actually finding it more comfortable to pedal with the pedals upside-down.  :s  Time to investigate an alternative..

Something weird is going on with the back wheel.

I noticed something when I was unlocking my bike after work; the rear tyre looks closer to the left seat stay.  I can only think of two possible causes for this: badly aligned stays, or a badly dished wheel

Before I'd decided to go the singlespeed route, I'd re-spaced the stays from 126mm to 130mm, in order to allow it to take a more modern hub and freewheel.  I'd used the Sheldon Brown cold setting method of a plank of wood and a chair, and it had gone well - one adjustment to each side, with no mucking about.  I used his string method for checking alignment, and it looked perfect! 

But the wheel looks to be something like 5mm closer to the left seat stay, so maybe it wasn't as perfect as I thought.  It doesn't make sense, though.. I pulled each stay out by 2mm, and measured it each time to make sure I hadn't gone too far.  To make it like it currently is, I'd have had to have pulled only one side out by 4mm.  I suppose it could have been badly aligned before I got to it.

The other possible cause is the wheel itself.  It was cheap, so it may have been built badly.  Maybe they got the dishing wrong, and the rim isn't centered.  I'm not sure how to test that..  maybe put the wheel into the front fork.

Other than that, it's been good!  The cycle home last night went well, and I even managed a personal record on a Strava segment, although that may have had more to do with lucky traffic lights.  I still think I could possibly switch to a 16 tooth freewheel, as I hardly stood up on the way home, and I felt that I could do with more of a gain on the way into work this morning.  However, when I did stand up, my steering went to pot, so I think I need to get used to the new bike before I switch.

I also nearly got squished by a red light jumping HGV this morning.  I was on the A6, coming up to the traffic lights on the exit from Longsight, at the junction with the A6010.  The lights went to green just as I got to the start of the ASL box, so I kept going.  I glanced right to check the state of the cars who were still hustling for a lane position from the previous direction, and was extremely surprised to see an HGV jump the lights at that exact moment.  This wasn't an amber jump, or a milisecond jump.. this idiot jumped the light at least 5 seconds after they'd changed to full red! If I hadn't looked right, I'd be dead right now, or at least lying comatose in a hospital bed.  I braked in time, despite my crappy brakes, and managed to call the driver all sorts of names as he passed, and even managed one of the more universally recognised hand signals (seriously - who remembers the signals that're in the highway code?).  What an anus.

That's the first really bad moment I've had while cycling.  I can usually second-guess someone who's intending to turn across me or do something stupid, but it's the nutjobs that I don't see coming that scare me.  The risks that people take to get somewhere a few minutes earlier never cease to amaze me, although I suppose cycling is that in a nutshell.  I get to work much quicker on a bicycle, but the journey is riskier.

It lives!

I got the new inner tube fitted on Saturday.  The old tube had split next to the valve.  It wasn't a pinch, so either I over-filled it or it was a manufacturers fault.  Tubes aren't too expensive, so I'm not going to lose any sleep over it.  Even though the new tube is a really cheap Raleigh tube, it seems better than the old Vittoria one.  It supposedly has the same dimensions, but it's not so tight to the rim, making it a lot easier to fit.

I decided to take the bike to the end of the street and back, to see if anything needed adjusting.  The first adjustment was to tighten the nuts on the rear wheel, as I'm pretty sure they're not supposed to move forward in the dropouts upon pedalling.  :P  The second adjustment was to the cotter pins, which I hadn't had an opportunity to hammer in, due to a sleeping toddler.  I'd brought a hammer along for just such an occasion, although I hadn't expected the pedals to go so far out of alignment.  Pedalling with the pedals at 12:20 was a very strange sensation!

Something else that hadn't felt right were the handlebars, but the distance wasn't enough to get a good feel for what was right.  I made that adjustment this morning, on my journey to work.  I haven't ridden a racer in years, so I couldn't remember how the bars were supposed to be set up.  I'd put them on so that the bottom of the bars were horizontal, and the top of the bar was at an angle.  That wasn't right - I couldn't reach the brakes at all, so braking required going into the racing position.  That's not too condusive to rapid stops!

With the bars in the correct position, I continued on my journey, taking it quite slow just in case something fell off or broke.  oh, and also because cycling felt WEIRD!  I've been used to a mountain bike for years now; big handlebars, big tyres, front suspension, and quite a high perspective.  Now I've got narrow handlebars, tiny tyres, no suspension, and I'm closer to the road.  I could feel every little bump, and I didn't feel very stable at all!  I guess it must be like driving a racing car after having gotten used to the comfort of a normal car. 

As I still wasn't sure if I'd tightened the cotter pins enough (the drive side pin looks too far out to be properly seated), or if the chain would hold out, I originally intended to get off the bike for the one and only big hill on the journey; a valley coming out of Stockport on the A6.  In practising for singlespeed, I'd been sticking to 6th gear on my MTB, and going up the hill usually meant standing up on the pedals, which I thought might be a bit too much of a risk for a relatively un-tested bike.  But I don't like stopping if I don't have to..  and there was a geared road bike ahead of me, with a lycra-clad rider, and the oval tubes and ludicrous paintwork of a bike that must've cost at least twice as much as my bike..  a bike that I was gaining on at quite some speed, even though the rider was really going for it..

So I didn't get off and walk.  I pedalled, surprised at how easy it was.  Still wary of putting too much power down, I breezed past the roadie so quickly and easily, I thought that maybe he was having bike issues!  He didn't look like he wasn't trying.. it must've been horrible to be passed by a guy on a 35 year old bike, with brakes at two different positions (the brake levers still need a bit of adjustment, it seems), wearing massive baggy shorts and a huge rucksack with an adjustable wrench and a hammer poking out of it.  Maybe this is the magic of singlespeeds?  Maybe he was just a really crap rider?  I also overtook a singlespeeder later on, but I didn't count him because he looked like he was in some sort of work clothes, and he only had one brake, despite not riding a fixed, as far as I could tell (I'm sure I saw him coasting).

All in all, the first ride on my singlespeed was pretty good!  The ride feels weird in a few ways, though.. the bike feels too small, even though my leg is fully extended when the pedal is at it's lowest point.  The brake levers also seem to be in a weird position, which I think might be due to the handlebar adjustment - it's made them higher up the curve than before.  That might also be the cause of the short feeling, come to think of it.  Last of all, the gearing might be wrong.  It's currently 48/18, which should be a 5.2 gain ratio, but I think I might need a higher ratio - that uphill was too easy, and I ran out of revs going down the hill.  I'll wait for a headwind and see how it goes.  It could turn out to be a blessing!

1977 Carton Cobra SS Conversion

That's weird.. my last post was supposed to end with multiple periods, in a 'to be continued' style.  Either I mistyped, or the pesky blog thingie 'fixed' it.  hmmmm.....  Well, anyway - it was supposed to be continued, because I didn't mention what it was wot I won.  I was saving that for a later post.  This one, in fact!

I'll skip the ebay bit - it wasn't too interesting.  What I ended up with was a Nottingham-built 5-speed 1977 Carlton Cobra, in chrome with red and black lacquer sprayed over and around the lugs.  It was probably a magnificent beast when it was new, and it still looked good at a distance, but time had not been kind to it.  The tyres were cracked, the tubes were knackered, one of the wheels had a broken spoke, the chain was made of rust, the chrome was heavily pitted with rust, and the lacquer was very scratched.

1977 Carlton Cobra (rust not obvious)

The plan was mainly to modernize the bike to make it a comfortable commuting machine.  In this case, it meant new drivetrain, wheels, and tyres.  I got distracted, though; I didn't like the chrome.  My old bike was brushed aluminium, and I'd grown to dislike it, especially after seeing the bike that I mentioned previously.  It didn't help that the chrome was mostly rust.  For a little while, I considered keeping it chrome in a bid to keep the original look alive, and even tried restoring it using chrome restoring pastes and lots of wire wool, but my heart wasn't really in it.  I wanted it resprayed!

After some research, it turned out that powder coating is the cheapest and hardiest route to re-colouring a bicycle.  To have it coated would require stripping absolutely everything from the frame, so I started on stripping it down.  The wheels, handlebar, seat, brakes, shifter, and fork all came off easily enough, which left me with the cottered crank and bottom bracket.  They proved slightly trickier..

I started on the non-drive side first. 

• Plan A was to hit the cotter pin with a hammer.  Repeatedly.  When the pin started to mushroom, I stopped. 
• Plan B was to apply liberal amounts of WD40, leave it 24 hours, heat it up with a heat gun, and try again.  It still didn't budge.
• Plan C was to take it to the local bike shop, and get them to do it.  They were too busy, but suggested...
• Plan D was plan B, with added cola.  It worked!!  Sort-of.  The drive side pin was having none of it.  aaargh!
• Plan E was to drill out the cotter pin.  I drilled and drilled, but couldn't remove enough of it to allow the arm to come off. 
• I returned to plan C, but with a different bike shop.  He sawed it off.  Success!!

So, the next part of the plan was to get it coated.  During my research, one place had constantly popped up as the place to go; North Manchester Powder Coating.  There was a slight hitch, however - their phone line was disconnected.  There was no other number, no other contact method, and nobody on forums seemed to know if they still existed.  They were too far away to warrant driving over there 'just to check', so I had to find somewhere else.  Only two other places came up in searched.  Only one replied to my email, so they got the job - Stockport Powder Coating.

It took them almost 2 weeks to finish the job, and I'm still not sure about the final result.  The bike looks good, but my understanding of powder coating is that it's tough.  Mine doesn't seem tough - it seems more scratch-prone than paint!  I've added a coating of turtle wax, which is supposed to help protect against scratches, but I'm suspicious.. I think they didn't coat it properly, but only time will tell, and I haven't ridden it properly yet.

Not a very good photo.

Time for the next stage - putting the components back on!  Now, while I was researching how to remove parts from the bike, and what my upgrade options were, I came across something curious.  It's something I'd heard about before, and something that I'd pretty much dismissed as a fad for hipsters: singlespeed bikes.

The people posting about singlespeed bikes weren't hipsters - they were proper, grown up men, whose only slim fit clothes were made of lycra, and they seemed to be very enthusiastic.  The more I read, the more I wanted to know why they were so enthusiastic.  What was so great about singlespeed?  And so, the plan changed.  I had gears on my MTB.. why not try out this singlespeed malarky, and get use out of both bikes?

I ordered some cheap 700c singlespeed wheels with an 18 tooth freewheel, tyres, tubes, a replacement 48 tooth chainwheel, a crank spindle, and some ball bearings to replace those that had rolled off into the undergrowth when I'd pulled the fork off. Oh, and a seat - the old one may have been Brookes, but it was hideous!  The front wheel gave me some issues.  Apparently axle diameters have increased since the 70s, and so it was 2mm too wide for the front fork (the rear was fine).  I ended up widening the fork dropouts with a file, which was a bit scary. 

After everything was attached, I was faced with the chainline.  Raleigh only made one size of spindle for 70mm bottom brackets, as far as I know, so this was something that had been worrying me.  Sighting down the chainwheel didn't seem as reliable as I'd been led to believe.  One time it looked like the freewheel was 1cm to left, the next time it was 2mm to the right, then dead on, then to the left again..  in the end, I figured that it was pretty close.. maybe only a couple of millimeters out.  That'll do!

And so, last night, I put the chain on, and the bike was complete!  Of course, afterwards I found a different way of determining chainline, and I measured it with a ruler.  If I measured correctly, the rear is 40mm, whereas the front is 48mm.  That means the chain is 8mm out of alignment, so I expect the chain will explode off of the chainwheel sometime soon. 8mm is a lot, though.. I'm not sure how I'm going to fix that - I really don't want to take those BB cups off again, and what would I put in there? Raleigh didn't make shorter spindles.  :s

I was supposed to cycle the Cobra into work this morning, but the rear tube burst open when I pumped it up.  I'm not sure of the cause yet.. over-filled? Manufacturers fault? Pinched between the tyre and rim?  I'll find out when I remove it.  Whatever the cause, the hole was right on the valve, so I don't think it's fixable. I bought a pump with a gauge on it today, so I won't be able to over fill the new tube.

At least this means I can give it a short test run over the weekend!

Stuff bought for this project:

• A Carlton Cobra.
• Powder coat, in green.
• 700c singlespeed wheelset, inc 18 tooth freewheel.
• Vittoria Rubino 700x23c tyres.
• Vittoria 700x19-23 inner tubes.
• Raleigh A12 126mm spindle.
• Raleigh 48 tooth chainwheel (to replace the arm that I'd messed up with my drill).
• Charge Spoon saddle.
• Brake cables.
• Pedal clips.
• Chain.

Total cost: Not telling!  It was way more than expected.  Wheels are expensive!