24-36-44 change to 24-40-44

For discussions about bikes and equipment.
Post Reply
Greystoke
Posts: 482
Joined: 8 May 2018, 7:41am
Location: Lincolnshire

24-36-44 change to 24-40-44

Post by Greystoke »

Will the above work ok?
Middle chainring sucking chain so needs replacing, other rings good.
I originally geared it so I had a 65" gear for general use. Two gears on big ring, then drop to middle and 2 gears again. But I can get a 64" gear and split the difference between chain rings.
Question is will it change from 24 to 40 ok?
I'm on 26" wheels and 5 speed at the back
User avatar
Chris Jeggo
Posts: 577
Joined: 3 Jul 2010, 9:44am
Location: Surrey

Re: 24-36-44 change to 24-40-44

Post by Chris Jeggo »

You don't say what front derailleur you are currently using.
During the early noughties I ran a 'half step and granny' set-up, 46-42-24, and followed the advice from my LBS that a double FD would work better than a triple FD. I no longer have that FD but I'm fairly sure it was a Shimano Sora: it worked.
A suitable double FD would need enough throw to cover three chainwheels, and chain line could well be critical. Your current FD obviously satisfies these requirements, though, so why not just put a 40t ring on and give it a try.
Last edited by Chris Jeggo on 23 Jan 2022, 6:17pm, edited 1 time in total.
Greystoke
Posts: 482
Joined: 8 May 2018, 7:41am
Location: Lincolnshire

Re: 24-36-44 change to 24-40-44

Post by Greystoke »

I believe it's the original shimano FD. Friction levers early 90's drop bar MTB tourer. Might be tourney...
pq
Posts: 1294
Joined: 12 Nov 2007, 11:41pm
Location: St Antonin Noble Val, France
Contact:

Re: 24-36-44 change to 24-40-44

Post by pq »

Obviously I have no idea whether that will work on your bike with your kit, but my fast tourer has 24/39/50 and it manages the 24/39 shift OK. Not brilliantly, but OK. That's on a 10 speed Campag system.
One link to your website is enough. G
User avatar
Tigerbiten
Posts: 2503
Joined: 29 Jun 2009, 6:49am

Re: 24-36-44 change to 24-40-44

Post by Tigerbiten »

Are you aiming for a true half-step setup or just going for a bigger middle chainring to fill the gap ??
If you're going for a true half-step setup then you need a 7% difference between the chainrings which is only 3 teeth.
And the only odd toothed ring you can get in that size has 39t.
So a 24-39-42 triple would be the ideal half-step and granny setup.
If you're just filling the gap then a 40t ring is fine.

Luck ........ :D
Greystoke
Posts: 482
Joined: 8 May 2018, 7:41am
Location: Lincolnshire

Re: 24-36-44 change to 24-40-44

Post by Greystoke »

i've looked at it today and i reckon it'll shift fine replacing the 36 with a 40. I figure i have too much overlap and duplicated ratios with the 36 chainring. A 40 chainring splits the difference better than 39 with the cogs i have on the back
peetee
Posts: 4292
Joined: 4 May 2010, 10:20pm
Location: Upon a lumpy, scarred granite massif.

Re: 24-36-44 change to 24-40-44

Post by peetee »

The limiting factor will probably be the depth of the front mech’s inner cage plate. The bottom edge has to be set above the height of the middle chainring. With that established it’s a case of trying it out to see if it gives a clean, reliable shift and the tail of the mech clears the chain in all sensible chainring/cog combinations.
The older I get the more I’m inclined to act my shoe size, not my age.
rmurphy195
Posts: 2199
Joined: 20 May 2011, 11:23am
Location: South Birmingham

Re: 24-36-44 change to 24-40-44

Post by rmurphy195 »

That's a biiiig jump from the smallest to the middle ring - is 16 teeth a bit much for your front mech?

Even 14 teeth seems a lot
Brompton, Condor Heritage, creaky joints and thinning white (formerly grey) hair
""You know you're getting old when it's easier to ride a bike than to get on and off it" - quote from observant jogger !
axel_knutt
Posts: 2880
Joined: 11 Jan 2007, 12:20pm

Re: 24-36-44 change to 24-40-44

Post by axel_knutt »

Greystoke wrote: 23 Jan 2022, 6:15pm I believe it's the original shimano FD. Friction levers early 90's drop bar MTB tourer. Might be tourney...
Whenever I buy new components I always write down the manufacturers specification so that I have a record before they go obsolete.
“I'm not upset that you lied to me, I'm upset that from now on I can't believe you.”
― Friedrich Nietzsche
Greystoke
Posts: 482
Joined: 8 May 2018, 7:41am
Location: Lincolnshire

Re: 24-36-44 change to 24-40-44

Post by Greystoke »

To be fair I reckon most, if not all, of my bike would be considered obsolete
Greystoke
Posts: 482
Joined: 8 May 2018, 7:41am
Location: Lincolnshire

Re: 24-36-44 change to 24-40-44

Post by Greystoke »

Well I've done it and does it work?
Yes and very well too.
I now have 10 nicely spaced gears before I need the really low gears.
Top job
pwa
Posts: 17366
Joined: 2 Oct 2011, 8:55pm

Re: 24-36-44 change to 24-40-44

Post by pwa »

Greystoke wrote: 29 Jan 2022, 10:59am Well I've done it and does it work?
Yes and very well too.
I now have 10 nicely spaced gears before I need the really low gears.
Top job
Do you think this choice of two rings with a small step, then a larger step to the granny, reflects a local terrain with lots of flat or rolling land, and steep hills confined to certain areas? I suspect that local terrain is what directs us to our preferred gear arrangements.
Greystoke
Posts: 482
Joined: 8 May 2018, 7:41am
Location: Lincolnshire

Re: 24-36-44 change to 24-40-44

Post by Greystoke »

The gear gaps were always a compromise. I spent ages deciding what to do. Interim changes worked but this is better for me.
I still have 5 low gears, on duplicated on middle ring big cog but I only have a 5 speed screw on freewheel so I think this setup is optimal
Post Reply