Bad Boy 8 fixie conversion
I would like to present to the world my latest and greatest bicycle, the Cannondale Bad Boy 8 fixie conversion. Its my first fixed wheel bike and I hope you'll agree she's a beauty.
I bought the Bad Boy 8 second hand off ebay for £550 which I felt was a fairly decent price as it had done a few hundred commuter miles but had been well cared for. It came with a bunch of extras including a decent bike lock and some top end commuter cateye lights.
After riding it for a while with the Shimano Alfine hub gears I decided they weren't for me. Had the rear wheel and hub been a lot lighter I might have been pursuaded to stick with it but due to the increased weight and the shiny silver hub on an otherwise matt black bike I decided it had to go.
I bought a Surly flip-flop hub, Surly cog and lockring from a really good guy who sells his stuff through ebay, Charlie the Bike Monger. He advised me on the correct parts to buy and which rim would fit the style of my bike. I decided on a Mavic A317 disc hub, a sturdy touring rim with a semi aero profile designed for disc brakes. It looks similar to my front rim and fits the all-black look of the bike.
Beeline bicycles in Oxford built the wheel up using black DT Swiss 1.8 spokes in a 3 cross pattern. Although they did a good job in the end I wouldn't recommend them due to the lengthy miscommunications between their minions 'bike experts' on the shop floor and the bike mechanic. It took them about 3 weeks and four phone calls to make up the wheel which is pretty terrible really, especially when you're as excited as I was. Update: Beeline have read this article and requested I change the information to reflect what they believe happened. I find this insulting as this blog is about my personal experiences and if in my opinion Beeline Bicycles did a poor job I feel I have every right to write about it here.
Fitting the wheel was a little complex as the chain had to be tightened. The Bad Boy uses an eccentric bottom bracket to achieve chain tension so I had to work out how to do this with minimal documentation. Cannondale have an old pdf you can download explaining how the eccentric bottom bracket works, but it relates to their Tandem frames. The Bad Boy uses two wedges rather than the one shown on their pdf. Mine were slightly seized so I got the gas burner on them to heat them up and then tapper the screw which is used to pull them together to push one of them out. I also had to take off the cranks which luckily is a fairly easy process. The non-drive side truvativ gxp firex crank arm just screws off by leaving the outer nut screwed in and unscrewing the inner nut pulls the arm off.
Once the left arm comes off the drive side arm just pulls out. I was then able to adjust the eccentric bottom bracket by using the external bottom bracket tool to rotate the bottom bracket plates until the correct chain tension was achieved. If anyone is going through this process and needs clarification just drop a comment on this page and I'll go into more detail if necessary.
The weight of the bike has been reduced further by adding a carbon seatpost and handlebar from my previous courier bike. I've left the front Avid Juicy 3 disc brake on while I get my head around the subtleties of riding fixed wheel.
My first ride was a 40 mile round trip to Oxford and back and involved three near crashes when I forgot I was riding fixed wheel and nearly stacked it. Other than that I really enjoyed the experience, cornering is really fun and I love the feel of control over the bike and the constant movement of my legs. Hopefully these next few weeks will get me used to the bike before heading back to Australia to resume bicycle courier work. I think this is an almost perfect urban courier bike, it has the all-weather disc brake on the front, its super-light weight, has the required subtle 'bling' factor and hopefully isn't totally nickable.
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That is a very cool fixie… it looks ruthlessly slick. Great work.
Yum! it wasnt a sin and illegal in several states id marry such a device.
Do you still have and pos want to sell the afine hub?
gogetcarter@tiscalidotcodotuk
Hi did you use the original chain My problem is that I have run out of eccentric bottom bracket adjustment on my standard badboy ultra 8
I am unsure of the chain type and size I need a split link but dont know which link would be suitable
Craig, just grab yourself another chain. The Ultra 8 uses an Inox chain, 3/32" type (not the 1/8" type found on many track bikes). You'll need to make sure you have this chain width as well as a compatible sized rear cog. No need to buy another Inox, although the chain seems of high quality I found it makes a fair bit of noise and next time I'll get a different brand. Don't buy a cheap chain though, its worth getting something strong and durable.
Have you worked out what gear ratio you want? I was running a 13 tooth cog on the back and it worked well for me although I started on a 14 to get used to riding fixed. I recommend Charlie The BikeMonger for a good friendly source of track cogs and parts.
When you fit the new chain be very careful about how many links to remove. Ideally you'll want to remove enough so that your new chain is fairly tight when your eccentric bottom bracket is in it's most slack position, allowing you to further tighten the chain as it stretches and wears. I've just fitted a new set of cranks and a new chain and cog and the bike is running very nicely indeed.
My only gripe about the eccentric bottom bracket is the noise it makes, a creaking sound which sets in after a few days of use. It can be eliminated by cleaning the bottom bracket and re-greasing but I haven't found a long term solution yet. Let me know if you have the same problems and know of a good solution.
Nice work!
I'm contemplating a Bad Boy 8 myself, I wonder if you know how much one weighs? You must have saved a bit of weight on yours by removing the IGH?
Is the creaking bottom bracket a big problem on this model or something that just needs fixing on your bike?
Cheers,
Matt
Hi Matt, the Bad Boy is a very beautiful bike and rides extremely well. I think the creaking bottom bracket is a common problem on these types of bike (eccentric bb). I haven't found the right solution to eliminate the creak but cleaning it regularly certainly helps for a while. I believe using some copper based grease may help but I haven't tried it yet.
Copper grease should help. I'm not sure of the eccentric b-b construction but you might be able to wrap some plumbers PTFE tape around the b-b cartridge - this might also help?
Re. the weight of your bike, do you know what it is? I'm very tempted by this bike, just want to make sure it's light enough compared to my Trek hybrid (that weighs about 28 lbs / 13 kg with accessories).
I've tried wrapping PTFE tape around the bb unit but that didn't help, maybe made it worse if anything. I think the key is to not over-grease it and clean it on a regular basis.
The original weight of the bike was quite heavy due to the hub gears. Once that is stripped away the bike is light as a feather. I'd try one out in a shop to see whether it is going to suit you and to test the relative weight.
Yep, I need to try one in a shop; for that money I want to see one before I buy!
Hi Tancredi,
I am looking at converting a bad boy to fixed gear by using a front disc hub, and then mounting a sprocket onto the 6 bolt disc mount. I think it looks like an interesting solution:
http://www.velosolo.co.uk/shophub.html
I was interested in knowing what diameter your seatpost and bars are too, as I am looking to try and shed as much weight as possible, and arent sure of a suitable replacement for either component.
Thanks for your help
Ben
Hi Ben,
Just wondering what the advantage is in building up a wheel based on that hub? Wouldn't it cost about the same to build a wheel with a track hub? I built one using a correctly spaced Surly flip flop hub and it worked very nicely.
The seatpost is a 27.2, my bars are 25.4 diameter but it would depend on which stem you fit. Have fun converting!
Yeah it would, but personally I feel that the mountain bike hub may be stronger than the track one. If I did get a track hub, there is a nice looking Token one I've seen, but Im still not sure if it would be up to the job. I've had a look on Charlie the Bike Monger and there is quite a lot of good stuff on there.
Thanks very much for the dimensions. I think im changing the seatpost and bars, but keeping the stem, unless I find a bit extra cash somewhere!
Thanks for all your help. I hope your Badboy is still running well!
Ben, these days I ride an old '93 Marinoni racing frame with Velocity Deep V's. I find the velocity's are pretty much bomb proof and you'll find many single speed and fixed gear riders use them with no issues at all. There are plenty of flip flop and track style hubs which are very hardy and stand up to street riding abuse.
If you get your Bad Boy up and running as a fixie post an image somewhere, I'd love to see it. All the best!
Hey this looks really good. I actually came across your page last year and I have returned again because I think it's the way forward for me and the bike. Unfortunately Evans Cycles are really reluctant to convert the rear wheel so i'm trying to locate an enthuastic person who will do it. Also I was wondering if drop down handle-bars would work well with this bike or would it screw up my back because of the geometry?
Hi Nabs,
Drop bars may well suit you depending on the kind of riding you do and the general fit of the bike. I found I had to add riser bars to stop my neck from aching as the top tube on the Cannondales are pretty long.
If you get your bike converted post a photo somewhere. Good luck!
Hi Tancredi,
very nice job. I love Bad Boy, i ride one myself, it's a BB singlespeed lefty 2008. Just for fun i converted it last week to fixed gear in a very cheap and fast way: i bought a 15t cog for 4.25 E, drilled 3 holes in it and screwed it on the disc support. This way i have a flip-flop hub with less than 5 euro!
Luckily the chain was a bit loose and i could fit the 15t cog (original is 14t) having the chain perfectly tight.
Now i would like to restore the original set up, but then i really need to tighten the chain. Could you explain how you moved the eccentric bottom bracket, and what tools do i need? Thanks!
Cheers
Andrea
Hi Andrea,
Great idea, nice and simple fixed gear.
To get the chain tensioned properly you need to undo the bolt that runs through the ebb (eccentric bottom bracket) unit. Don't undo it all the way, just enough turns (maybe 15 or so?) so that it sticks out enough to give it a good whack. You need to hit it so as to pop out the other side's wedge that its screwed into. The ebb unit has two wedges (if I remember right) that this bolt goes into. They get pretty stuck which is why you have to hit the bolt knocking the far wedge loose. Once one is loose you can normally get the other one loose quite easily and then turn the unit.
I find its a good idea to take the thing apart and give it a good clean each time, making sure you re-grease it before putting it back. I found that a thin layer of grease was the ideal amount to avoid the unit clicking when I pressed down on the pedals.
Hope that helps. Have fun!
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