Trashing a classic? Or keeping the flame burning?

When someone says “I’ve got a made in America cannondale m700 for sale if you want it? Won’t be much” to me it’s a red rag to a bull. They are a classic frame. That era of Cannondale were full of quirky classic twists that make them such an iconic piece of bicycle history.

Flat extended dropouts, smooth welds, horizontal top tube, oversized tubing, 1” 1/4” headset, and (annoyingly) an imperial/metric thread mix. Only on an all American early 90s ‘dale. YEEHAW!

My bicycle collection is burgeoning. I have steel frames, carbon road bikes, a TT bike respray project, gravel bikes, vintage bikes, singlespeeds, and the rest. So taking on another wasn’t really on the cards….. unless I could get it past the gatekeeper (wife) as someone else’s….. I quickly found a new owner and the build was on!

If you frequent my social then you’ll know I love a singlespeed. I ride singlespeed road and gravel most of the wet and muddy months of the year. It really does help to lengthen the life of your “summer” bikes. It also provides you some no holes barred leg bashing in the worst weather, and I love that. Does that make me a masochist? Probably.

Step forward the bikes new owner, Mike. We ride together a fair bit but he tends to hide indoors all winter and miss out on the New Forests off-road bounty. This is partly due to him not having having gravel bike but also because he doesn’t want to get his Rapha clothes dirty. I could definitely sort both of those issues.

The plan is to build the cannondale into a “ride it hard and put it away wet” lightweight singlespeed gravel bike. Something you can pull out of the garage in any weather and not give a rats ass if you end up in a river. Built in the same mould as my Saracen Dirt Trax.

My Dirttrax is a 26” wheel aluminium frame from the year 2000, it’s shod with a 700c carbon ritchey fork and 700c wheels. Flat carbon bar, carbon seat post, 30×11 gearing blah blah blah. It was actually surprisingly easy to convert it to 700c. The outer diameter of the 700x38c wheels is pretty similar to that of a 26×2.3 so they slotted straight in. The only hurdle to overcome on a 26” frame is the brake height. Fitting a 700c fork fixed the front but on the rear it needed brake callipers risers.

Now to the build. I quickly sourced forks, wheels, cables, brake levers, chain, stem, brake risers, and tyres as they are all fairly standard. I had saddle, seatpost, handlebars, pedals, brakes, cranks, chainring, and singlespeed cog in the parts bin so it just left the headset to sort. This was a little trickier. The cannondale is built with a 1 1/4 headset, the forks are 1 1/8. There are options on the market for reducer headsets but that means being limited to a couple of choices. It’s a reducer headset or headset reducers, the latter is what I opted for. Headset reducers are shims that press into the frame and allow the fitment of a 1 1/8 headset into a 1 1/4 head tube. This opens up a huge choice of headsets. FSA headset ordered and I’m ready to build.

First job was to put together a rolling chassis to gauge how it all looked. And yes it looked awesome.

But we had a couple of issues…. my tyre clearance calculations were slightly out….

Upper mudguard bridge
Lower chain stay bridge

The tyres (Hutchinson Touareg 700cx40) I was using were a bit of a tighter fit than I had banked on. I had my heart set on the bike running on these.

The frame was a rescue, so though little of committing to getting the tyres to fit. I got the dremel out and committed what some would say is sacrilege. I cut the upper bridge.

Some would cringe at this, I had no qualms. The bikes being rescued and reborn as something very cool. One obstruction out of the way it was time for the lower bar.

My initial approach was to reshape the lower cross brace by crushing it. After all, all the other tubing on the chain/seat stays was formed in this way. I’ve shaped steel this way before and, despite being very aware of aluminium’s propensity toward work hardening and fracture, I was confident I could do the same. I reached for my water pump pliers and some wooden chocks.

My pliers are of a decent size and can exert some serious force so I was initially quite reserved as I only wanted to shaped the tube by about 3mm. Thinking i would easily crush the tube, just a couple of mm to give the requested clearance, I squeezed on the pliers gently. Nothing happened. I squeezed harder. Nothing happened. I squeezed with all my might until my palms hurt. Nothing happened. How tough were these cannondales made? I grabbed a small vice and tried the same. Again nothing. WTF?

My only other option what to shape the tube by cutting it like the top bridge, and then fill it with chemical metal. Out came the Dremel. Cutting into it the disc just kept going with no sign of a void. “It can’t be solid” I though to myself….. it was! Cannondale had used a solid rod to join the two chain stays together. It was like it was designed to be shaped.

Stage one

Firstly I mapped out the outline then used a hacksaw to cut slots in to the bar to the depth to be removed. These could be levered out.

Halfway through

Then it was a simple case of snapping those fins off and grinding down the stumps. Then shaping out the ends.

First trial fit

Reinstalling the wheel gave me an idea of how I was getting on. Dead pleased with the clearance gains, it just needed shaping properly.

Now that’s good

As you can see the finished article looks almost factory. Loads of clearance and a great shape to it. As far as it being bare metal goes, I’m going to leave it. The surface will soon oxidise and self protect to a point. If the bike rides well and owner enjoys it, I’m sure we can look at a paint job in the near future.

All of the ‘fabrication’ work out of the way it was simply time for assembly. All the parts were bolted up, cables were fitted, chain was on and it was time for a test ride.

It flew!

It weighed nothing, and the tubeless tyre setup made the wheels really responsive. I had one slight issue though, under heavy power the chain slipped. There wasn’t enough wrap around the rear sprocket, and I couldn’t shorted the chain anymore. The only way to get the correct amount of chain wrap or to tighten the chain would be to increase the size of one of the gears. Not having a replacement rear the front was increased from 40t to 42t. It worked a treat.

Now all that was left to do would be to fit to the owner. So sent him a text to collect his new steed.

I’d have to say this was a great fun build. I loved the cannondales quirks and the ‘off menu’ alterations I had to make to make those 700c Hutchinson tyres fit.

It’s also been out on its first gravel ride! The new owner loved it, and he proceeded to rip my legs off all the way round too. It’s fast, light, and comfortable.

700c conversions to 26” mtb work very well for fast, low maintenance, and lightweight gravel bikes. Maybe you should try one!

My next build though is a steel 650b Jamis Dakar sport….. 1989 tange prestige….

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