Dolan Pre Cursa build diary

At the beginning of December, after breaking up with my regular commuter, i decided to jump in and build my own bike.  Cycling has a very high turnover of parts with most companies replacing their existing ranges every year. As a result,  the off-season is a great time to pick up parts as all the major online retailers, wiggle, chain reactions, ribble, etc., and all the independents, have full clearance sales with some great deals. 

Although not particularly practical for Durham, where every journey involves a decent hill and any journey ending at the train station having a nasty kick at the end, I have always loved the look of the Terry Dolan track frames. Ever since watching the Boardman hour documentary, and seeing Chris Boardman's Terry Dolan build bike frame being unceremoniously rebranded, I've always wanted to ride a Dolan loud and proud! The Dolan Pre Cursa is a modern classic with a cult following in the fixed gear and single speed forums. In matt black with white Dolan logos and with a seat clamp included for £100 delivered, its also fantastic value. Choosing a track frame over a regular road frame would limit the gearing choices to either fixed, not great for the Durham hills, so single speed it was! I'm going to include a bike schematic from jimlangley.net which should help with the terminology.

From www.jimlangley.net

Important frame specifications included an english thread bottom bracket, a 27.2mm seat post and a 1 1/8th inch integral head tube. I want back to Dolan to for the headset, Alpina 1 1/8'' (36/45) and seat tube, Alpina alloy seat post 27.2mm. The headset choice was a bit confusing with both the 45/45 and 36/45 options, with the 45 being the campagnolo spec. and 36/45 the standard spec. headset. From what i could tell, the numbers refers to the difference in bearing height and also the angle of the chamfer on the bearings. I eventually guessed and went for the 36/45 as this headset was specified on 3rd party websites selling complete Pre Cursa bikes.

I picked up an Exocet fork from Planet X, which with a weight of only 390g for £50 seemed like a bargain. Its a bladed carbon TT fork usually found on their signiture TT frame. The fork was described on their website as having a "1'' 1/8 steerer tube", however in the picture, it seemed to be wider at the bottom than the top. I put this down to my inexperience and bought it anyway. When delivered, I discovered it was actually a tapered fork with a 1'' 1/4' the bottom and 1'' 1/8' at the top. Slightly disheartened but armed with a metal file, I "made good" the fork in about 2 hours, constantly tapping, trying to assess the thickness of the carbon head tube! Luckily, the fork looked like it was manufactured by joining the carbon headtube to the fork legs so there was plenty of headtube wall to sand down and still leave the fork strong. Obviously this wasn't ideal but at least it gave the bike a very individual look and might be the only example of this combination of frame and fork, even if it was due to my complete incompetence!  The headset subsequently joined the fork to the frame with no further problems.

The fundamental wheel choices were to either pick up a a regular pair of road wheels with a freewheel cassette, a pair of track specific wheels, or a pair with a flip flop rear wheel with both single speed and fixed options. Track wheels were discounted as they don't have a freewheel and while the flip flop wheels were attractive for their flexibility, they seemed overpriced for what they were. I went for the bombproof shimano R500s which for some reason were cheaper in their bladed spoke guise.

Miche drivetrain components dominate the entry level track market and i went for the primato bottom bracket with english compatible threads, and paired that up with a 48 tooth miche xpress crankset. Unlike regular road bottom brackets, track bottom brackets have cups which  fit straight into the bottom bracket and leave the cups flush with the bottom bracket. As a result, the bottom bracket looks very clean but they are a bit more tricky to fit. Track Chainrings are usually 1/8'' gauge and will require a correspondingly sized chain, while road rings and cassettes (with more than 3 gears) are normally 3/32''. I wanted to have a range of options for the rear gears so i picked up a shimano 12-30 rear cassette and broke apart the gears. I started with the 14 toothed gear and I picked up some great cassette hub spacers from Velosolo. If you are looking to use a mix of components, the rule is that you can you can use a 1/8 inch chain with a 3/32 chainring or cassette, but you cannot use a 3/32 chain on a 1/8 ring or cassette. I used a KMC B1 chain to complete the system, which came with a quick release link, making drive chain assembly quick and easy.

Planet X were having an 80% sale on some of their stems so i went for an FSA OS120 road stem which fit straight onto the 1 1/8 head tube. As i didn't require any head tube spacers, I cut the head tube slightly below the level of the headset. The hardest part of the whole assembly was getting the star nut into the head tube! Eventually, I 'prepared' the star nut by bending the sections with a pair of pliers, then placing the fork on a piece of wood on a concrete floor and forced the star nut home with a hammer, using a screwdriver as a makeshift guide and chisel  The top cap and top cap screw were then fitted, taking up all the slack in the headset, with the bottom of the head set now resting flush with the fork crown. A Deda RHM01 road handlebar was then fitted to the stem. Over sized handlebars are 31.8mm in diameter instead of the classic 26mm standard bar diameter. The extra cross section allegedly adds more stiffness to the whole system, however, I've never previously found any handlebars to flex significantly in the past. Predictably, the steering on the bike felt solid with no flex even with all you weight over the bars.

To be strictly "road legal", apart from the reflectors and bell, bikes in the UK are required to have two independent breaking systems, acting on each wheel individually. A normal road bike would have independent brakes for both the front and back while a fixed gear bike can count the braking action of the drivechain as the rear brake. Currently the bike only has a front brake as the track frame doesn't have a drilled hole for a standard rear brake. I have found a conversion kit which basically sandwedges two metal plates on the inside and outside of the dropouts, and provides a brake mounting position slightly above the existing rear bridge. The other alternative is to drill the rear bridge but it is already quite thin and the idea of introducing a stress riser in an 8mm aluminium tube is asking for trouble when decent alternatives are available. I went for a shimano tiagra front brake which had a 49mm drop from the brake hole in the fork to the bottom of the wheel rims. This was paired with a crane creek cross top lever, 31.8mm, which attached to the oversized section of the handlebars.

Frame: Dolan Pre Cursa - £100 - Dolan-bikes
Fork: Planet X Exocet - £50 - Planet X
Headset: Alpina Integral - £15 - Dolan-bikes
Crankset: Miche Xpress Track - £54 - Wiggle
Bottom Bracket: Miche Primato - £13 - Wiggle
Cassette: Shimano tiagra 12-30 - £20 - Wiggle
Chain: KMC B1 - £5 - Wiggle
Handlebars: Deda RHM01 Road - £20 - Wiggle
Stem: FSA OS120 - Planet X - £10 - Planet X
Brake Levers: Crane Creek Crosstop - £25 - Wiggle
Calipers: Shimano Tiagra 4600 - £20 - Wiggle
Seatpost: Alpina alloy - £10 - Dolan-bikes
Saddle: Selle Italia SL XC - £15 - Wiggle
Wheels: Shimano R500 - £80 - Ribblecycles
Pedals: MKS AR2 - £18 - Wiggle

So about £455 for all the hardware you need, add a bit more for tires, tubes,tape and cables, as compared to £450 for the pre assembled Pre Cursa from Dolan. Building your own bike is definitely a good learning experience once you crack the language barrier, with the added bonus of knowing you'll never run into the same bike! Its a bit like building your first computer, it might not make you a better user but its that 5% extra general understanding that you get by diving in and giving it a go that you might never go through if you always buy off the shelf. As you progress through the stages of the build, frame & fork, rolling chassis, mock-up, etc, you start to get a feel for the character of the bike and by the time you go for your first ride, the bike's personality is already well ingrained in your mind. What that personality might be however is completely out of your control...