Genesis Equilibrium Build Log Part 2: Drivetrain thoughts

In a previous post here, I described some ways of configuring single speed for a road bike conversion. The Equilibrium frame has vertical rear dropouts. These do not allow chain tension adjustment for single speed mode. You need to have some, because a slack chain is dangerous!

A common solution is to use a chain tensioner:

These normally screw into the rear mech boss and use a sprung lever to tension the chain, usually by an jockey wheel or similar, running against the chain. It's even possible to use an old rear mech as a chain tensioner (e.g. by running the chain round the lower jockey wheel only).

However, I don't like these ideas much, as the silent, simple, smooth, single speed feel can't be fully achieved when there's a wheel tensioning the chain.

One option is to forget about single speed, and use a cassette and rear derailleur. It so happens that I have some wheels that are nutted solid axle, the rear having a screw-on freewheel, and I have a suitable 6 speed block. The only thing that bothers me is the possibility that at extreme angles, the chain may drop off the chainwheel. A prevention mechanism for that is to use a chainset with inner and outer chain guards, but that may be hard to find at a reasonable price. Another option there is to fit an old front mech to act as a chainwheel chain keeper.

The concept for this build is to keep it simple, cheap, and that means re-using parts that I already have, so far as possible. It looks like I'm going to have to experiment quite a bit. As I said, this may end up a weird bike!

Autumn: time for Cyclocross, Overshoes,...

...falling leaves and nuts!

Genesis Equilibrium Build Log Part 1: The Frame

Genesis Bikes' Equilibrium frame has earned a great reputation. They struck a happy chord with this one, producing by all accounts a comfortable, rewarding and beautifully finished frameset. I had the good fortune to pick up a new example at a bargain price. My intention is to build it up as a commuter as cheaply as possible. That means using as many of my own bits and bobs that I have lying around. So there's a good chance it will end up a bit weird!

This is nominally a 56cm frame, but the Genesis website specifies seat tube (c-t) 550. It has a relatively short effective top tube of 558, suggesting it will have an upright riding position. Head tube is smallish 150, and the seat post is going to be long, given the sloping geometry of the frame. It's made from Reynolds 725 tubing as shown by the classic seat tube sticker (the description of 725 below is from the Reynolds website):

"HEAT-TREATED CHROME-MOLY STEEL
Using an industry standard alloy with mechanical properties similar to our famous 753 brand, Reynolds mandrel butt and heat-treat this alloy so that thinner walls can be used compared to non-heat-treated steels. 725 can be TIG welded and used within our "Designer Select" combinations including 853 and 631 tubes.
Why it works:
UTS: 1080-1280 MPa, density 7.78gm/cc
Based on a 0.3% carbon steel alloy which has been heat-treated and back-tempered for increased ductility. The chromium content promotes hardenability and resistance to oxidation. The molybdenum works in conjunction with the chrome to stabilize the alloy and maintain strength after heat-treatment and in use."

I believe the forks are carbon with alloy steerer (standard headset required, 1 1/8" size), dropouts and brake bushing. Certainly a magnet does not stick to them as it does to the tubing. DT cable guides already fitted, hmm, but am I going single speed? Mudguard eyes (and a paint scratch):

Neat welding and easy on the eye. Seeing the top tube cable ends - reminds me that I always forget to use frame protector cable grommets. Let's see if I remember this time.

BB shell is standard 68. A very sensibly engineered bridge between the chainstays, should make mudguard fitting much easier:

Quite a lot of dust on the frame - needs a spray of frame saver inside and a good clean outside before I start. Seat tube is 28.6 for front mech (if I'm having one, that is!).  

Below, you can see the straight stays and the geometry. Given the short head tube, I'll probably not cut the steerer, but let's see. 

The rear brake bridge (long drop 57) and seat clamp (29.8). Tseat post is 27.2 diameter - I have one of those in my bits box, but will it be long enough?

Stays are quite thin at the tips and the dropouts seem well made. 

Initially I thought that the kink on the inside of the drive side seat stay (below) was a show room dent, but then I looked closely and it's clear that it is deliberate shaping. Quite obvious that the paint was applied after the shaping. The shop told me that other people had queried it, and they'd already clarified with Genesis that this was a deliberate feature. Presumably it's for chain clearance, but some have commented that it is ugly and unnecessary. 

All in all a lovely frame, and I'm feeling quite excited to build her up, as I said, using what I have "in stock". I will need to buy long reach brake calipers though. After the satisfaction and simplicity of my last single speed build, I'm definitely keen to forget completely about gears... 

Well done Genesis. Can't wait to see your new 953 road racing frame for the Madison-Genesis cycling team, Roger Hammond and Co. He's a cyclocrosser too, so I'll be cheering for them!

Round 8 Wessex CX League - Oxonian at Harcourt Hill, Oxford Brookes

On Saturday it rained cats and dogs. On Sunday, the cyclocross frogs came out to play. The amphibians frolicked on a very wet course - and it was cold too. These photos were taken early in the day. The avenue in the woods (below) may look dry underfoot, but I assure you it was not! It soon transformed into a muddy brook. Seriously, the water was flowing (towards you in the photo below). Pedalling through the woods, was more like paddling up and down stream. A very unusual sensation.

The path below was waterlogged too, and quickly cut up into a boggy slush. I wish I had taken "after" photographs to demonstrate what I mean about the "rivers" through the woods. That sign should have read, "Care! Deep water and strong currents!" 

Here are the youngsters hard at it. The hooded spectators are riders perusing the course prior to their race. Everyone is wondering why they didn't stay tucked up under the duvet this morning...

Of course, the sun started to (threaten to) show itself just as the race was ending. Here's the chicaney bit leading into the finishing straight. A nice design feature that made for a few excellent sprint finishes. 

Below is the finish line and time-keeper's gazebo. All in all, a well thought out circuit. Other features included two open earth sections that you had to ride rather like sand. Tyres clagged up quickly, but the mud shed fast afterwards. One of these "flower bed" sections came just after a double barrier. And then of course, was the infamous ditch that marks the entrance to the flooded wooded section. You get to the ditch via a narrow opening in a hedge. The ditch itself was full of cold muddy water and a decent leap was required to cross it. There were also a few bobbly bumps, ramps and such, that may well have caught out an unwary rider. 

But the most significant feature today was the waterlogged ground. Heavy going and grunt work. Luvvly Jubbly!

Round 7 Wessex CX League - Swindon at Rutherford Appleton Lab, Didcot

What a place! In amongst the egg heads' radio telescopes and laboratories, lies a stony, chalky hill. Someone with a sense of humour thought it would be entertaining to build a cyclocross course around it, like a helter-skelter, roller-coaster theme park kind of affair. It was so entertaining, that I didn't even notice this digger until after the race: 

The chalky hill was just rideable and hard work. I wish I'd taken photos from the summit of the hill, and in particular, down a chalky side towards a fence that goes alongside a right hander on a grassy ledge. Quite spectacular. One could imagine how an overcooked descent could slam the rider into the fence at best, or send them over it, like when those crazy Tour de France riders sometimes misjudge an alpine corner. And I wish I'd taken a picture looking down THE steep muddy bank, where there were spills and thrills aplenty, but alas, I didn't get the chance. 

Many punctured on this course. Some considered it not a "real" cyclocross course, but more like a mountain bike circuit. Well, it had a few hundred yards on flat concrete, quite a lot on grass, plenty of banks and off-camber sections, some of which forced a dismount. And it was hard work, windy and cold. Sounds like cyclocross to me! And cyclocross has always been cool:

Now that's what I'm talking about!

And, before I forget, a huge round of applause for the brand-spanking-new-looking changing rooms and shower block. Never has a hot shower felt so good!

Round 6 Wessex CX League - Reading CC at Prospect Park

Rain over the last few days created luxurious mud baths around the course. The section in the woods was surprisingly dry, but there were a couple of peaty mud corners that were tricky to negotiate. A couple of the ubiquitous Cotswold Veldrijden warming up:

Seriously, the blues are everywhere. Lovely kit though, I've got to admit. 

This part of the course had puddles - you can just about see them below. Who knows whether a tree root lurks under the surface, just like the Loch Ness Monster...

This is what I call a determined youngster, no fear going straight into the mud.

The steep uphill banks were muddy, which made a challenging course all the more demanding. Altogether, a superbly organised event in tricky conditions.

Round 5 Wessex CX League - GWR Team Swindon at Supermarine RFC

A sunny autumn day at Supermarine rugby club, founded in 1958 by the workers at Vickers/Armstrong. In the background, you can just about see the archery targets of the Supermarine Bowmen, who were out training this lovely, but chilly, Sunday:

Once again, an entertaining course. On each lap, many things came in pairs. There were two twisty grassy sections. Two flattish stretches across the playing fields each swooping into a right hander. Two barriers far enough apart that it was better to ground the bike and roll it between the hurdles. Two wooded sections. Each wooded section had a brief excursion out of the woods before shortly diving back into the trees.

It had rained heavily in the week, so some of the course was muddy. I have no pictures of the muddy sections, but it was the kind that sticks like clay in shoe tread and doesn't allow you to clip in to the pedal. The mud was worst coming out of the second wooded section. Interesting study in mud here. To exit the woods you had to cross a bank, which required a dismount and running up and down the other side. The bank had sticky clay type material on both slopes. Immediately after that was a twisty section through peaty, loamy stuff. On some of these turns by the end of the race, running may have been faster than riding. So, different kinds of mud just a few yards apart.   

A twisty grassy section at the end of the lap had some slight off camber bends, which did catch out a few riders (not me thankfully). Here's an intrepid junior negotiating it nicely:

The only downside today was that from the start, a wide stretch of grass, to the first wooded section in single track, there was a drastic funneling effect. This created a huge traffic jam, like a hopper jamming. Ho hum, you can only play the cards you're dealt. At least there weren't any major crashes.