Little chainring smaller than big sprocket.

[JohnW]

I've noticed, as I get older, every ten years after 60 the little ring on the chainset gets smaller. I am now running a 26T little ring on a 28T large sprocket, and with the bike up on the stand and watching the chain move to the little ring from the middle when the chain is on the big sprocket the path taken by the chain seems to be subtly different from the change when the chainring is bigger than the sprocket.

I've found the accurate positioning and limiting of the front changer is even more critical when the chainring is smaller than the sprocket, to avoid unshipping the chain.

Is this just me?

[Brucey]

I don't think you need to hit 60 to want smaller chainrings....

Also, I do think modern (i.e. narrower) chains are less likely to 'land' on a small chainring if it is a long way down from the outer or middle ring.

The solution is usually a guide of some kind (dog fang or whatever). These simply were not necessary in the past, but without one you can soon wreck an aluminium or carbon frame, so they are almost mandatory these days with some setups.

cheers

[Mick F]

I put a 28t inner ring on Mercian a year or so ago. 30t biggest cog.

When I had a 30t inner, I needed a "dog fang" but since being 28t, I don't get any issues.
Actually, I made my own dog fang thingy.

As for lower gears, Mercian's bottom gear of 28/30 = 24.5" seems quite high now that I have a Moulton TSR90.
Bottom gear is 34t ring/28t cog + 1st gear on the Sturmey Archer = 16.7" .............. I can climb a vertical wall with that one.

[blackbike]

I fitted MTB 42/32/22 chainsets and 12-28 cassettes on my two tourers and two road bikes when I was in my late 30s and I have no problem keeping up with the road bike riders I go out with from time to time.

The gearing fitted on most bikes is far too high for normal people, especially on road bikes, with most cyclists labouring in too high gears at too low cadences for the best speed and efficiency.

Now that road bikes have become popular with recreational, weekend cyclists it isn't unusual for me to see people with road bikes getting off and walking up hills which are not that steep at all, and which they could mange on an appropriately geared bike.

[JohnW]

Dog fang 'thingy' - ? Tell me more someone.

[rjb]

Here you go, whole topic devoted to it in the tech too good to lose section. viewtopic.php?f=5&t=59793.

[keyboardmonkey]

I've found the accurate positioning and limiting of the front changer is even more critical when the chainring is smaller than the sprocket, to avoid unshipping the chain.

Is this just me?

I was in my forties when I fitted my touring bike with a 44/32/22 chainset and 12-32 cassette. I did overshift once when trying to drop on to the smallest chain ring (on a little dip I'd forgotten about along the sublime road between Hawnby and Osmotherley for those that know it), but other than that no problems. One day I'll get around to adjusting the limit screw. I did use the bottom gear later (going up Rosedale Chimney with 70+ hilly miles in my unfit legs that day), but the problem there was keeping the front wheel on the tarmac

Oh, and no worries about having a lowly top end of 'just' 98". (Square taper BB + Simplex down tube shifters.)

[steady eddy]

I run a 26t chain ring to a 32 rear sprocket without any problem. Not a dog fang in sight. Using a Campag triple front mech in a Shimergo I have had to hang it almost on top of the outer 48t ring to get it all to work with Campag shifters on a Deore crankset and a Shimano back end but it has proved very reliable.Wonderfully ergonomic shifters with super smooth chain movement - the best of both worlds.

[reohn2]

I've noticed, as I get older, every ten years after 60 the little ring on the chainset gets smaller. I am now running a 26T little ring on a 28T large sprocket, and with the bike up on the stand and watching the chain move to the little ring from the middle when the chain is on the big sprocket the path taken by the chain seems to be subtly different from the change when the chainring is bigger than the sprocket.

I've found the accurate positioning and limiting of the front changer is even more critical when the chainring is smaller than the sprocket, to avoid unshipping the chain.

Is this just me?

To avoid any misunderstanding about chain catchers.
Dog Fag and some home made devices are to stop the chain getting between c/set spider and frame and or spoiling paintwork or in the case of CF frames possibly chewing into the frame itself should the chain derail.
The N-Gear Jumpstop and the Pennywasher device courtesy of Crepello/Colin531 and a couple of other suspects,are designed to stop derailment and guide the chain back onto the inner ring.

[gloomyandy]

SRAM YAW based front mechs come with a built in chain guide/catcher that works well and is very easy to adjust. I've had no issues at all with front shifting on my 42/26 front 11-36 rear setup. I'm surprised that more people don't use SRAM to be honest. I have SRAM on all of my bikes and seem to have far fewer issues then many of my Shimano/Campag based club mates!

[MikeF]

Dog fang 'thingy' - ? Tell me more someone.

One of these http://www.billys.co.uk/english/group.php?prod=chng-js is maybe what you need.

[Sweep]

The N-Gear Jumpstop and the Pennywasher device courtesy of Crepello/Colin531 and a couple of other suspects,are designed to stop derailment and guide the chain back onto the inner ring.

Pray tell, what's the pennwasher device? Sounds interesting. A colin invention?

I fitted a dig thang to my dahon sports bike years ago as it so clearly needed one - the single chainring paired with a dualdrive hub set-up meant that a lack of chain tension at certain points caused frequent chain drop-offs. Those numpties at dahon had clearly not ridden their creation much before throwing it out the factory door. Later they fitted one as standard. Wish i'd known about dog thangs before i inflicted a few frame scratches/chain jams on my 'dale.

[531colin]

Its all here https://forum.cyclinguk.org/viewtopic.php?f=5&t=59793&start=45 as somebody linked earlier, in "too good to lose"

[thirdcrank]

I've noticed, as I get older, every ten years after 60 the little ring on the chainset gets smaller. .... Is this just me?

This makes me think of your other current thread about changes in the forum. A few years ago I posted on a thread about low gears intending it to be a bit tongue-in-cheek saying something like "you know you are getting old when your biggest sprocket is bigger than your small chainring." I was admonished by a certain CTC technical officer whose presence and role have been much missed on here. BTW, I dropped down to 26 x 27 in June 2000 when I was 55. I can't remember now if my smallest chainring is 22 or 24, but the memory is something else where the performance drops off.

[Gattonero]

Chain-catchers can be done at £0 cost, by reusing reflector brackets. Surely, not the strongest ones, but will do the job nevertheless, and if the chain rubs are very quiet, as opposed to metal ones.
Obviously, will work only on frames with round section seat tube.