10 speed cassettes for touring

[RussellSeaton]

Not a product endorsement or advertisement.  But the folks on this forum with 10 speed bikes now or contemplating buying a new bike with 10 speed may find this information useful.  10 speed bike being one with 10 cogs on the cassette.

IRD (Interloc Racing Design) is now offering 10 speed cassettes in 11-32, 11-34, to go along with its 12-28.  Shimano spline and Shimano spacing.

http://www.cyclingnews.com/tech.php?id=tech/2006/news/11-22

http://store.interlocracing.com/10elcas.html
Not cheap at $170.  Actually D--N expensive at $170.

[Sailariel]

Russell, That`s quite a casette-thanks for the info. It is a bit pricey. Been climbing pretty well with my 12-30 7 SPEED. GRANNY GEAR Is 28-30. I have been experimenting carrying 40 Lbs. Got pretty wiped doing 50 miles. Will have to train more. Travelling across the U.S. with my wife driving a mini motor home is still in the offing.

[DaveB]

The only problem will be that "10-speed" rear derailleurs are exclusively road derailleurs and are rated to handle a 27T (Shimano) or 29T (Campy) maximum rear cog.  This max can be exceeded by a little but I don't think any of them will tolerate a 32T cog and certainly not a 34T.

You will have to use an MTB rear derailleur to allow use of these cassettes.  They will be marketed as 9-speed derailleurs but that won't matter.

[RussellSeaton]

The IRD website says 9 speed mountain bike rear derailleurs are required instead of 10 speed labeled rear derailleurs with their new 11-32 and 11-34 10 speed cassettes.  With Shimano and Campagnolo, there is no real difference between their 9 and 10 speed labeled rear derailleurs.  I use a 9 speed Campagnolo rear derailleur with 10 speed shifters and cassettes and 10 speed rear derailleur with 9 speed shifters and cassettes.  Makes no difference what speed a rear derailleur is labeled.

[biker_james]

I'm glad to see that someone is making these. The way road groups are converting to 10 speed, it nice to know that those needing lower gears have more options than just the bottom end groups.
Not that I'm going to rush out to convert to 10 cogs in the back any time soon.

[edmilkman]

10 speed x 3 chainrings !!  Yeah, I see no advantage at all when my 9 speed still has 11-13.......30-34. And I can order those cassettes for way less than $50 I think.  You need a more expensive and narrower, weaker, harder to clean chain I bet as well. If you do like me - touring with the same bike as you take day trips with, you can just swap out a lightweight rear wheel with road gears for a heavy duty touring wheel with the 34 tooth on it. Then put the BOB on the skewer and go.

[DaveB]

One other potential problem with 10-speed is that the chains are even narrower than the already thin 9-speed chains.  The chain could be the (pun unavoidable) "weak link" in the system.  

10-speed has proven adequately strong for road and sport bike use but I wonder if it will tolerate the demands of loaded touring.  I think that is the reason MTB's have never gone to 10-speed.

[RussellSeaton]

"10-speed has proven adequately strong for road and sport bike use but I wonder if it will tolerate the demands of loaded touring.  I think that is the reason MTB's have never gone to 10-speed."

What extra demands does loaded touring put on a chain compared to road and sport riding?  Most touring bikes have lower gears than road and sport bikes.  So the rider is able to spin an easier gear to climb mountains.  Many road bikers will stand and grind up hills putting far more force onto the chain and other drivetrain components than a tourist spinning easily up a mountain.  Many road bikes will double shift quickly to find the right gear when hitting the bottom of a hill.  Or shift under pressure in the middle of a hill when they discovered the grade changed.  Putting lots of force on the shifters and chain and cogs.  Something most loaded tourists do not do.  Most tourists shift before the very last fraction of a second.  Or with road bikes many people shift after the last second and force the chain over with considerable force and grinding and noise.  I'd say road riding can and does put far more force on chains than loaded touring.

10 speed chains most likely do wear out quicker than 9 speed chains.  Not sure there is any difference in holding derailleur-shifter adjustments.  Neither comes out of adjustment much.

As to why mountain bikes have stayed 9 speed?  Dirt/mud on the drivetrain may have more detriment to 10 speed than 9 speed since the cogs are closer together.  I've heard some mountain bikers use 8 speed because of the mud/dirt aspect.

[DaveB]

Most touring bikes have lower gears than road and sport bikes.

That, in and of itself, is a problem.  Low gears put much higher loads on a chain than tall gears. Look at the lever arms, a 42T chainring puts half the load on a chain that a 21T does at the same pressure on the crank. MTB's break chains as a result of their extremely low gears, 20x34 is common, not just wear from abrasive riding conditions.  

Compounding the problem is the extra luggage weight (20 to 50+ pounds) on the bike and you have tourists putting significantly more demands on their chains than regular road riders.      

[RussellSeaton]

Most touring bikes have lower gears than road and sport bikes.

That, in and of itself, is a problem.  Low gears put much higher loads on a chain than tall gears. Look at the lever arms, a 42T chainring puts half the load on a chain that a 21T does at the same pressure on the crank. MTB's break chains as a result of their extremely low gears, 20x34 is common, not just wear from abrasive riding conditions.  

Compounding the problem is the extra luggage weight (20 to 50+ pounds) on the bike and you have tourists putting significantly more demands on their chains than regular road riders.



Which puts more force on chains:  5 mph spinning at 90 rpm in a 24x34 low gear.  Or 5 mph grinding at 51 rpm in a 42x34 low gear.  Or 5 mph grinding at 41 rpm in a 52x34 low gear.

As you can easily see, lower gears reduce strain on the chain because the cyclist is able to spin up steep hills.  With higher gears, such as on road bikes, the cyclist must stand and stomp and grind at a slow rpm to keep moving.  Stressing the chain much more per rpm.

The total amount of force needed to go a certain speed is the same no matter how many rpms.  So the total force is divided by fewer revolutions of the chain if your low gear is higher.  So each turn of the pedals puts more force on the chain, given a certain speed, if you are in a highr gear than a lower gear.