fallinlovewithA

Hi, I am a R&D engineer at Dahon ( shenzhen ) developing a small chian drive system for our small wheel folding bikes. I understand that Shimano once marketed a 10 mm small pitch chain but stopped due to unknown reasons. Do you know were I can get more information why they stopped ?

I appreciated any help from you

Many Thanks


Corbin zhang
em: globalviewonvc@hotmail.com

Shenzhen

Dahon

China

Trakhak

They never announced their reasons for withdrawing their "Pitch 10" chains, cranksets, etc., from the market, but Shimano probably had few customers willing to risk buying components that were so absolutely incompatible with the universal standard of 12.5 mm chain pitch, despite the claimed 10% reduction in weight compared to standard chains, derailleurs, freewheels, and cranksets. Pitch 10 components did appear on track bikes for a while, but I don't remember seeing or hearing of any bike manufacturer offering a multispeed bike equipped with a Pitch 10 system.

HillRider

If Shimano couldn't impose their design on the bicycle industry, you haven't a prayer.

LóFarkas

Drop into the singlespeed and fixed gear subforum for extensive info on 10 pitch stuff. Some people there are fond of the stuff and even have some 10 pitch stuff. My understanding is that it was bound to die out, as it provided zero to unnoticably small advantage and, of, course, was proprietary. Currently, practically no 10 pitch chains remain.
I promise you one thing: If you guys make some 10 pitch chain, some people will buy it, regardless of price, and I do mean regardless. And you can't ask any nasty sexual favours they won't do for that stuff

MudPie

For a folding bike, have you considered a timimg/sychronous/cogged belt drive? I'm sure it's been thought of in the past. Are you designing a multi-speed folding bike?

jjs273

I still have 10mm Dura Ace on my track bike. When it came out in 1979 or so, I saw the literature
and pictures for the multi-gear system. I love the size of the components, the acceleration, and overall look
of the group. Reasons I can think of for not persuing this direction are as follows.
1. Hub threads and shell have to be made smaller to handle smaller inner circumference of cogs.
On my track bike, 16t is the smallest cog you can run with standard threading.
2.Poor chain deflection. The chain has to pivot more to engage the next cog.
3.10mm is noisy. No matter how much lube you use.
4.Marketability, in the 80's Shimano was still trying to beat Campy in shifting performance, and this idea wasn't going to do it.
Just some ideas.

jjs273

fore

shimano has a micro-drive system out that uses a standard 1/2" pitch chain. i forget the name of it, but i believe it's a more logical solution than going to a smaller pitch chain.

Capreo. Shimano Capreo. I knew this tech reference would come in handy... 9-tooth high cog. i believe the spacing is the same as standard shimano stuff so you can use whatever shifters you desire.

bostontrevor

10mm required new chain, new hubs, new sprockets, new chainrings, new chainwhips. Basically just about anythnig that touched the drivetrain was incompatible with 10-pitch with the exception of the spiders on your crank arms.

Not hot just for some minor weight shaving.

As far as I understand, it was solid gear though. It received NJS certification which is pretty rigorous.

HillRider

Capreo was developed specifically for small wheel bikes, particularly folders like Bike Friday and (for our friend, the OP) Dahon. It provides a 9T small cog so huge chainrings aren't needed to get an adequate high gear with 20" wheels and a standard geared off-the-shelf crank can be used. The hubs are unique to handle the small inside diameter of the 9T cog but the rest of the drivetrain is normal, including the chain.

spunkyruss

I agree with Hillrider, the Capreo components are a much better solution to the problem of adequate gearing on a small folding bike.

As others have said, the cost:benefit ratio (specifically, dollars spent:grams saved) of the 10mm-pitch chain was simply too high.

rafi

The track group received NJS certification, but was subsequetly taken away because it was deemed that the 10 pitch system gave the rider an unfair advantage. To my knowledge, the road group never came out.

Check this: https://www.bikeforums.net/showthread...ighlight=pitch