One of the lads I bike with wants to change the gearing on his road bike. He had the cassette changed to one with a wider range when he bought the bike, but would like to go smaller than a 34 tooth ring at the front.

Would it be possible to swap his FSA chainset (50/34 with external BB) for something like 26/38 SLX chainset? He mainly uses the bike for family rides, so isn’t bothered about losing the 50 tooth ring….

Cheers,

Alex

I would have thought it should be fine. The only issue I can foresee is the lowest point on the front mech might be too high in the 26 and the chain might drag over it.

Iain

It’ll need an MTB front mech as well, as the axle will be 5mm longer, so the chainring will sit 2.5mm further out and you won’t be able to make the mech reach the outer unless you start filing the tail of the spring, or fit a triple front mech, at which point you may as well fit a mountain bike front mech.

They’re not 100% the same in terms of cable pull, but close enough to work.

That said… a 38 is a small front ring for a road bike, what cassette has he had fitted? I’d be questioning if a road bike is the appropriate tool full stop for what he’s doing? Rather than turning it into some frankenbike.

26 smallest front ring? He might as well just walk, as I’d reckon that it’d be almost impossible to control a road bike going up a hill in 26/32 or whatever gearing he ends up with.
I’m no great rider but I don’t think there’s any road climb I couldn’t get up in 34/29 (cassette kept on the special shelf for particular events) I even made it up both the Mortirolo and the Stelvio on 34/27 without too much pain.

I fitted a 9 speed MTB triple chainset to my partners bike. The thing to watch are that the chain line is different. We used a squared taper bb and this gave a different chain line, a more modern one with external bearings will be worse.

We used a MTB front mech and shifters, but the front mech is still mounted higher than is ideal as if it’s the correctly mounted the back of the cage can hit chain stay.

If you use the original shifter it will pull a different amount of cable but you can clamp the cable differently and this might work. The technical section of the CTC website has all kind of strange bodging information.

“26 smallest front ring? He might as well just walk, as I’d reckon that it’d be almost impossible to control a road bike going up a hill in 26/32 or whatever gearing he ends up with.”

You can buy a touring bike with 22 32 as the lowest ratio

I can control my bike riding 22 34 on the road. Its actually easier on the road than off road with all those routes and rocks getting in the way

Book marked for when I to do a feeble version of a road bike

Cheers for the replies – will have a look at the CTC website. As for being the wrong tool for the job, yes I’d agree. He used to have a hybrid with an MTB triple chainset on it which was perfect, but when he upgraded his dad persuaded him to get a discounted road bike from a friend’s shop which was a mistake.

I’ll report back (probably in a couple of weeks mind…) on how it goes!!!

You can buy a touring bike with 22 32 as the lowest ratio

I can control my bike riding 22 34 on the road. Its actually easier on the road than off road with all those routes and rocks getting in the way

Touring bike geometry and road bike geometry is very different. Race bikes can be decidedly twitchy at those very slow speeds – touring bikes are designed to be far more stable at lower speeds, loaded etc. Mountain bikes even more so, irrelevant comparison.

Whilst I wouldn’t go quite as far as aP, I agree with the sentiment, that if he’s got a road bike and only wants to bimble about with the family I’d look to change the bike. He buys a chainset and a front mech now, then realises 23c tyres aren’t great on towpaths, so he fits wider tyres, then needs deep drop brakes, it’s still not the right bike. Sell, replace. If he bought it cheap he won’t take such a hit.

I use 11 /28 9 speed on the back with a 22/32/44 mtb chainset on my Audax bike .Gives me a great range for when totally done in on long hilly events .The inner ring rarely gets used but its there for emergencies!

What cassette has he got on the back – it is supposed to be possible to get a 36 ring on the back with the right rear derailleur and possibly changing the top jockey wheel to a 10T – and I am about to try it this weekend.

Middleburn are doing a super-compact chainset for road and cx bikes – in both square taper and X type, will give you 30/46:

http://www.middleburn.co.uk/products/cranks/road-touring-cyclo-x/ro2-x-type-94bcd

A 30 front to 36 back is going to be very spinny.

30 46 sounds great chasinset to me!

Of course 34 34 is low for a proper road bike

However Hyrids are sold with 34 50 chainset and even vesatile bikes for sold as suitable for off road and touring really don’t go that low on the gears

I also note that Contador managed stay on his bike in the Giro with his 30×34 gear. It appears that no one else found it quicker to walk