Converting Cannondale Fatboy 29er

[Mishj]

Good evening to all and apologies if this is in the wrong section from a newbie.
I recently (march last year strangely enough) got back into doing a bit of cycling after many many years out and only doing the odd casual ride on my Raleigh max ogre (now about 30 years old) and more recently a used Cannondale Fatboy 29er as my trusty old Raleigh is very long in the tooth.
I also have an older Claud butler road bike *borrowed* recently from my brother which I like as it has 700x23 tyres on and has less rolling resistance and therefore reasonably quick over the tarmac. I am now caught in two minds what bike I would want to fully upgrade to, road, gravel, hybrid etc???
My question is rather than possibly look to purchase a gravel / adventure bike that sort of covers a multitude of sins, is it possible both cost efficiency and physically to convert the Cannondale which is quite light compared to my other older 2 bikes, into a type of gravel bike with the correct drivetrain brake/gear levers etc. I did read somewhere that Cannondale use very odd equipment that makes updating or converting them a difficult and expensive task and made me think that it wouldn't be possible.

Hope that all makes sense, and
if anyone has any ideas I'd be grateful for the advice and guidance.
Thanks for taking the time to read my post.

 

[Cycleops]

A link to the particular model you want to convert or a picture would be useful.

 

[tribanjules]

Fat boy or bad boy?

 

[figbat]

The Bad Boy 29er looks pretty well suited to gravel as it is - maybe a more gravel-oriented tyre selection would help off-road but if you’re ok with flat bars then you’re done.

If you wanted drop bars then you’d have to look at brakes and shifting - I assume it’s hydraulic so new levers won’t be cheap. The one I am looking at is 9-speed so you won’t find a hydraulic option to retain your transmission, so will have to go 10-speed at least, meaning a new cassette, derailleurs (ideally both) and chain. You could go 1x if you wanted but dedicated 1x hydraulic setups are pretty expensive still.

Anything is possible though. I built a gravel bike from a ‘90s MTB and in doing so converted from canti- to discs, 3x7 to 1x10, 26” to 700c, flat bars to drops... all using parts I had lying around or bits off of eBay/Facebook etc.

 

[raleighnut]

Skinnier tyres might help, nothing ridiculous just drop to 32 or 35 and pump em up a bit harder

 

[SkipdiverJohn]

The Raleigh MTB is perfectly capable of dealing with the rougher stuff, so I would just look at whether I could get some slightly wider and more comfortable road tyres to go on the Claud Butler. Most of their bikes used to be high quality, so it's quite likely it's a 531 frame so well worth sorting out and riding as much as possible.

 

[DCBassman]

Skinnier tyres might help, nothing ridiculous just drop to 32 or 35 and pump em up a bit harder

^^^This, for the Cannondale. Some folding 25mm tyres might make the CB a little lighter and a little bit more comfy.

 

[MichaelW2]

I wouldn't get hung up abour the shape of the bars. If you are comfortable riding existing flats on tracks and road, go ahead.
Switching flat bars to drops is not a trivial move, it screws up ergonomics and you have to deal with controls compatibility issues.

 

[SkipdiverJohn]

Switching flat bars to drops is not a trivial move, it screws up ergonomics and you have to deal with controls compatibility issues.

Often the geometry of a frame will be designed specifically for flats or drops. If you change from one to the other you can really mess up the reach. I have a lugged 501 MTB frame with quite a long top tube (it is a 23" size) which is a bit stretchier than ideal even with flats. If I was to fit drops, it would become virtually unrideable unless a very short stem was fitted to compensate. Generally it's best to buy a bike that was specifically designed for the type of bars you want, unless you own a drop bar bike with too much reach in which case fitting roadster flat bars might improve the comfort. Drops converted to flats tends to work better than converting flats to drops.
I will soon be converting a 531 touring frame originally built for drops to flats to build up a lightweight 3-speed town bike, the TT is 22 1/2" long on a 23" seat tube. I know the sizing will work, because of my other flat bar machines. If it had a long TT, say over 23" and was built with flats I would not try to convert to drops!

 

[Mishj]

Sorry for the long gap in the reply, and thank you for all comments and help, some very valid points to consider. Just to clarify on a point that tribanjules mentioned, it is actually a bad boy 29er 2016.
I'm not adverse to the idea of changing rear cassette etc and have been looking into if I could go for a 11-36 rear cassette and trying to put a 50/39/30 on the front, which would mean I possibly wouldn't have to change the shifter or front derailleur by keeping it triple. I figure perhaps that might give me the best of both worlds (cake and eat it and all that) !!
Has anyone else dared to use a similar set up??
Thanks for all of your guidance, I'll keep you posted on once I decide.

 

[DCBassman]

11-36 rear cassette

12-36 is more available in 9-speed, and has a more even spacing (Shimano). I have two very different bikes using this cassette, one a 26" rigid MTB with 48-38-28 triple, the other a flat-bar 700c road bike with 52-42-30 up front. I would guess 50-39-30 would be really good with this cassette, and I would modify my road bike if I could, but cannot find a suitable chainset as yet.

 

[SkipdiverJohn]

I'd go for a 48/38/28 triple, not anything larger. With an 11T small sprocket you'd have gearing around 130 inches on 29" diameter tyres. It's pointless having gearing this high, you wont have the torque output to be able to use it. A 100" top gear is enough for any normal, non-pro racing, rider. The important gears are the low ones, and the amount of choice available in the gears that you will actually be using in real life.

 

[ColinJ]

I'd go for a 48/38/28 triple, not anything larger. With an 11T small sprocket you'd have gearing around 130 inches on 29" diameter tyres. It's pointless having gearing this high, you wont have the torque output to be able to use it. A 100" top gear is enough for any normal, non-pro racing, rider. The important gears are the low ones, and the amount of choice available in the gears that you will actually be using in real life.

I agree that 130" is higher than most of us will ever need, but 100" is slightly low as a top gear unless you never pedal downhill. I have 48/12 on my best bike and I spin out on local descents. (The long gradual ones where I do want to pedal, not the scary steep ones where I am braking!) Ideally, I'd have a 48/11 top gear, but I wouldn't be willing to give up my nice low bottom couple of gears to get that '11' sprocket.

 

[SkipdiverJohn]

Depends how fast you want to go. If I pedal at a high cadence of 80 rpm, I'm turning the cranks 4,800 times an hour. In my typical highest gear of 48/14 that gives me 22 mph on 27" or 700c tyres, which is plenty fast enough, and a lot faster than I ride most of the time when I might be doing 14 or 15 mph on a clear flat road.

 

[Reynard]

Actually, why don't you do what I did (if you're OK with basic bike mechanics, you'll be fine), which was to take a Raleigh Max and put new (lighter) wheels, commuter tyres, trigger shifters and touring gearing on it. It's become my winter bike, but alas I haven't managed to get out as much of late as I'd have liked.

Albeit my Max is 1998 vintage, so a little bit younger, and it's a junior frame as I'm, well, undertall. But with the upgrades, it tips the scales at about the same as my Wiggins Chartres 26 hybrid fitted with rack, panniers etc (12-ish kg), which is somewhat less than the original bike. It's a little bit of a staid ride on dry tarmac, but brilliant fun on wet roads, mud and gravel.

Oh, and I went for Spa Cycles' budget touring triple, which is a 48-38-28, and it's teamed with an 11-32 8-speed on the back. I had to cold set the rear triangle to get the new back wheel in, but done carefully, it's not a difficult thing to do.

You can find the thread about the project HERE

I will be upgrading the bars and seatpost from steel to alloy, which will also shed some lard...