Cycling UK Forum

With manufacturers supplying more and more sprockets to rear cassettes,(is it upto12 now ?),it just made me wonder if any manufacturers had possibly "toyed" with the idea of supplying cranksets with 4 chainrings . Or did a manufacturer in the dim distant past actually manufacture one,but dropped it .
The reason i ask is,transmission manufacturers keep supplying cassettes with more and more sprockets,but surely there has to be a limit soon .

Google quadruple chainset and quite a lot comes up.

For example on Ebay for £22 ((Link Here):

A UNIQUE CHAINSET WITH 4 CHAINRINGS!, THESE WERE USED IN THE 1990'S TO GIVE YOU MORE VARIANT RATIOS ON 5/6 SPEED BIKES GIVING YOU 20 OR 24 GEARS! MADE IN EUROPE BY THUN A WELL KNOWN GERMAN MANUFACTURER OF CHAINSETS

Moore Large sold a bike under their brand names with a quad chainset and a supposedly chrome frame. There were two models with the same spec but a name change for their Emmelle & Free Spirit range of bikes.

there also was the mountain tamer which allowed the user of a freewheel sprocket as a 4th chainring. 16T granny for a lowest possible gear of 12", if you can balance well enough.

Very manythanks for the info guys .
Just makes me wonder why it's not more popular . Still maybe thats to come .

Those 90's Thun things simply didn't work.
They were the cheapest of the cheap rubbish....bendy thin steel rings rivetted to horrid cranks with inaccurate tapers, the run-out on the rings was about the distance between 2 rings.
(I had a "customer" bring in a horrible junk bike fitted with one from new...of course it didn't work....he tried to insist it was somehow my responsibility to make it work...I told him as the gear mechs were Shimano, if he showed me in the Shimano catalogue a 4-ring chainset, I would make his work. Unless you have worked in a bike shop, you have no idea.....)
I believe people have made 4 ring chainsets work....having the rings run true is a good start...
but these days front mechs. are getting more and more specific, eg 12 tooth difference between middle and big ring. so the extra ring would have to be an extra "small" ring, where the mech. is furthest fron the chainring....I can't see it being a crisp change, or an index-able change, and we do like our crisp indexed changes these days.

My Thorn tandem has four rings on the back, The inner ring is used instead of a crossover drive.

Of course that does not mean I have four rings for gearing,but I guess "if" a mech could cope it would work.

I'm beginning to get the impression from your replies that the 4 chainring system was a bit of a non starter . Would i be right in assuming that none of the major manufacturers produced this system .

maybe make the bottom bracket much bigger and put a hub gear type system in there? Shimano would love the idea just to make a new bottom bracket type lol

I remember an MTB being reviewed in the late 80s/early 90s with a quad chainset (I can't remember/find details) - probably a 4x6 or 4x7 but it never caught on.

mercalia wrote:maybe make the bottom bracket much bigger and put a hub gear type system in there? Shimano would love the idea just to make a new bottom bracket type lol

There are several independent systems available if you search around that put a multispeed IGH in a custom BB. here is one example.

Rick.

Our daVinci tandem has a quad 'front' chainset .

It's an ingenious set-up, with the cranks driving two independent freewheels which rotate the driving cogwheels at twice the speed and half the torque of a conventional crankset. The daVinci website makes it clearer than I can: http://www.davincitandems.com/drivetrain-info/

The upshot is that we have a smooth-shifting four-cog 'front' mech, and a ridiculously wide range of gearing with independent coasting. Brilliant! (And not all that ridiculous for a couple of old geezers on tour )

Whether this has any application for a solo bike is beyond me.

Drake wrote:With manufacturers supplying more and more sprockets to rear cassettes,(is it upto12 now ?),it just made me wonder if any manufacturers had possibly "toyed" with the idea of supplying cranksets with 4 chainrings . Or did a manufacturer in the dim distant past actually manufacture one,but dropped it .
The reason i ask is,transmission manufacturers keep supplying cassettes with more and more sprockets,but surely there has to be a limit soon .

I ask the question do we need more than 8 or 9sp cassettes with a triple up front?
I also ask do we need cogs as small as 11t or bigger than 34t?
How does a fourth chainring help when we have triples ranging from 22 to 48 or 24 to 53t,a fourth chainring doesn't offer anything but a wider Q and another intermediate set of cassette ratios which aren't needed.
What's worse manufacturers are now stealing a front ring from triple c/sets and replacing it with an extra cog or two on the cassette and claiming it's progress???
It's nothing but fashion!

With a quad the overlap would be about half the gears on the bike. With a triple it is possible to have close ratio rear cluster and large gap front changes and yet there will still be some overlap.
Under the preference of close ratio gears to allow you to always have the perfect gear as long as there are enough of them. On another thread I added a table of what I would consider the ideal gears for commuting, day rides and light touring.


rear Inner 22 Middle 36 Outer 52
13 / 45.7 / 74.8 / 108.0
14 / 42.4 / 69.4 / 100.3
15 / 39.6 / 64.8 / 93.6
16 / 37.1 / 60.8 / 87.8
17 / 34.9 / 57.2 / 82.6
18 / 33.0 / 54.0 / 78.0
19 / 31.3 / 51.2 / 73.9
20 / 29.7 / 48.6 / 70.2
24 / 24.8 / 40.5 / 58.5

Even here there is a little overlap, but that has its uses at times when it is more convenient to change at the rear or maybe the front. Also i never use the extreme angles to keep chain wear down.
As you can see here there is already a big gap between the chain ring sizes to try to avoid having too much overlap. The rear cluster is already very close ratio. What size should a forth ring be? 22/36/53 already covers gears up to 108" (based on 27"wheel for calculation purposes) which is higher than most people ever need. Unless going into the wilderness in the mountains with a tonne of equipment a 24" low should suffice.

I know many people are going back to a double rather than a triple nowadays but I still prefer a triple so I can have closer ratio gears. It works for me although I am yet to get the ratios shown above. I'm using 32/40/52 on the front so I have to have a slightly wider ratio rear group to give a low enough bottom gear.