Back in October last year, after lots of post-ride, pub and office debates around 'gravel bikes just being 1990s mountain bikes', I decided to put the theory (which I don't agree with) to the test.
I'd had a once much-loved and now unused mountain bike hanging up in a dark corner of my garage for over a decade. Could it provide the perfect platform to put the theory to the test?
With unlimited funds, converting an old mountain bike for gravel could be relatively simple, as some of you suggested in the comments.
Perhaps finding and buying a pre-Boost 29in-wheel mountain bike – or any one of a multitude of 2000s hardtails – would be easy. I agree, but I put one other caveat on my project. It needed to be cheap.
I set myself a budget of less than £1,000 to complete the bike, including what the original bike would cost to buy.
So my donor bike is an old full-suspension MTB from around the turn of the century. I've tested a few new-school full-suspension gravel bikes: Lee Cougan's Innova Super Gravel, Cannondale's Topstone (I own one) and Trek's new CheckOUT.
The MTB's 100mm of rear travel is more than that trio of gravel bikes has, and the 160mm-travel Fox fork has more than the 100mm on the Lee Cougan and 60mm on the CheckOUT.
I'm of the mind that it might not be excessive, but I guess we'll find out…
Keep it as original as possible
I want to maintain as much of the original bike as possible, while updating the drivetrain is a must.
The triple chainset and 12-25(!) cassette are incompatible with any modern drop-bar shifters with hydraulic braking.
I wanted to keep the Mavic Crossmax XL wheels – one of the original tubeless (or UST in Mavic’s parlance) wheelsets and still one of the best designs for tubeless.
Up front, that 160mm-travel fork is going to need some work to get it running smoothly, and I’ll need to play with the setup to avoid having a front end that dives too much when I’m in the drops.
It'll be over to our ace mechanic, Will, to help sort that – and the same goes for the air-shock equipped back end. The old 4in-travel back end was more than ample back in 1999 for a do-it-all trail bike, but today 100mm of travel would place it closer to XC bikes than trail bikes. Or, in my thinking, pretty spot-on for a bit of extreme gravel riding.
Budget-conscious building
As much as I’d love to go wild on the build, getting plenty of 1990s-inspired parts and anodising going on, I’ve decided to stick to my guns and keep to my sub-£1,000 budget.
With similar bikes cropping up on eBay for around £100, that gives me a budget of £900 for the transformation.
So, my parts shopping list includes:
- Brakes and IS-to-flat-mount brake adaptors
- Shifters
- Rear derailleur
- Cassette
- Chain
- Crankset
- Bottom bracket
- New brake rotors and hoses
I was thinking about SRAM's Apex Eagle mechanical; I’ve found it works brilliantly on my Cannondale Slate. It would, however, have broken my budget, with its full price already over £1,000.
Instead, I thought it would be a great opportunity to try out Shimano’s wide range of affordable CUES components – especially because CUES is designed to be adaptable and versatile, and the drop-bar stuff has a real gravel bent.
Talking things over with UK Shimano distributor Madison’s Shimano expert Julian Thrasher, we agreed. Thrasher told me that, thanks to CUES compatibility over 9, 10 and 11-speed, it’s pretty accommodating to chainlines.
That's something mechanic Will thought might be a problem, with the Azonic’s chunky back end combined with a skinny 68mm bottom bracket shell (rather than a modern mountain bike's usual 73mm).
The only deviation is with the brakes; instead of the CUES units, I opted for a mix of CUES and Deore (because they’re available in post-mount), which are easier to run on the Fox fork.
What I would recommend to anyone trying this sort of update is check your details, measurements and frame standards again before checking out your shopping basket. You could be in for some expensive mistakes if you buy components that aren’t compatible with older framesets.
So, my mind was made up to head down the CUES route, and the bill comes in at:
- Shifters/brake levers: £159.99 left-hand, £169.99 right-hand
- Brakes: £34.99 each
- Brake pads: £29.99 each
- Rear derailluer: CUES Shadow+ 10/11 speed £59.99
- Crankset with 42t chainring: £79.99
- Bottom bracket: £24.99
- Cassette: 11-48t 10-speed, £64.99
- Chain: £29.99
- Disc rotors: Shimano SLX, £26.99 each
- Brake adaptors: Hope disc-mount adaptors, £21 each
- Brake hoses: £29.99 each
- Total: £875.85
That means, with the cost of the bike and the components, my bill runs to £975.95, leaving me the princely sum of £24.05 for bar tape.
It’s coming together
I expected something of a fight with the bike's components, which have been left pretty much untouched for a decade. Plus, I didn’t put the bike away clean.
Will and I were pleasantly surprised by all the major sticking points I expected of an old, somewhat neglected bike – things such as a seized bottom bracket, gluey headset and freehub, and corroded bolts.
In fact, none of these issues happened. The bottom bracket extracted smoothly. The grease was a bit black and gritty, but the threads on the shell were in great shape, and the new CUES bottom bracket turned and tightened in smoothly.
The headset still runs smoothly, and the Mavic freehub engages cleanly and spins freely.
Will needed to work a bit of magic on facing the disc mounts on the frame and fork because the centring and clearance were a little off.
We were impressed by the drivetrain being able to accommodate the less-than-optimal chainline and shifting perfectly – at least on the workstand. Hopefully, the same will be true when it comes to hitting the dirt.
I’m pleased with the progress and I’m loving how the bike is starting to look. Whether it’ll stay looking this way depends on how it rides, but if it does perform, I’m already thinking of a bit more of a 1990s mountain bike homage.
Hope has some very nice purple anodised parts and accessories; I may have to go down that route long-term.
