compact(2 ring) mtb crank

[GoLefty!!]

Ah, excellent stringbean. I used those components when I wa sin Europe but there is no local supplier. Who do you purchase those from?

[stringbean]

www.starbike.com

[Ox_Wagon]

Captain Dura you cant move your cranks closer you would have to adjust your limit screws on your front derailer

and the 29tooth chainring should be able to be ordered through any LBS i know cool heat has stock because i picked mine up today

 

What LBS did you get it through and ball park price?

[Ox_Wagon]

From a old thread:

https://www.bikehub.co.za/forum_posts.asp?TID=32256&KW=

The BCD determines the smallest chain ring that you can fit. To quote Http://www.sheldonbrown.com/harris/chainrings.html<?: PREFIX = O />

Campy road  = 135 BCD = 39

Shimano road = 130 BCD = 38

Road Compact, MTB STD (old type) = 110BCD = 33

MTB Compact (on all new MTB, 4 arm) = 104 BCD = 32 (29) (Even "Pink frilly shirt" BigBen has on on his MTB's)

There is also ?supposed? to be a small difference between the spacing of the chain rings. Shimano recommends that you use their ?special? flatbar shifter instead of normal MTB shifter.

http://cycle.shimano-eu.com/catalog/cycle/products/group.jsp?FOLDER%3C%3Efolder_id=2534374302049903&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1220548200443

 

The 2x9 MTB setup is a relatively old idea(Cannodale's coda cranks etc), but they fit a 29 instead of a 32. 29 are just very hard to find expecialy in ZA. (Turtlek?)

http://www.chainreactioncycles.com/Models.aspx?ModelID=30179

http://www.chainreactioncycles.com/Kits.aspx?ModelID=3345

 

[turtlek]

Captain Dura you cant move your cranks closer you would have to adjust your limit screws on your front derailer and the 29tooth chainring should be able to be ordered through any LBS i know cool heat has stock because i picked mine up today

 

?

 

What LBS did you get it through and ball park price?

 

 

 

i got it at health and sports zone in kempton park special order from cool heat they called on the tuesday and it was there on the friday

[Ox_Wagon]

Price and make?

[turtlek]

Shimano xt and it was about ZAR650

 

 

 

i just called my buddy at cool heat and i got the last one in Sa i will however try to source one for you if you want me toturtlek2008-10-14 03:02:19

[Ox_Wagon]

Thanks, but no.

[turtlek]

Thanks' date='?but no. [/quote']

 

 

 

but why hahahahahahahahhahaha you could always have mine at a price that is!!!!!turtlek2008-10-14 03:06:13

[linnega]

It is an interesting question.  Looking a the GI (gear-inches) on a standard 22-32-42 setup, all combinations from 22x12- through 22x23 are redundant, as they have almost identical GI to other combinations using your 32/42.  My concerns would be that there are some fairly large gaps particularly around the granny gear combos (29x23 to 29x34) and a granny gear, as mentioned earlier, limited to the equivalent of 22x26.

 

I would investigate it further if I didn't feel I needed a super granny gear for the really steep stuff, but am tempted by the simplicity of two chainrings.

[oclv110]

Me too linnega. Just think that you will be able to set up your gears much better. Investigate further and tell us more.

[linnega]

Interestingly with a 22-32-42 and 12-34 cassette, there are 15 useable gear combinations that are not duplicated.  As mentioned above 6 of the 9 options with the 22 are duplicated elsewhere, but worse is that 5 combos are duplicated with the 32 chainrings as well.

With a 29/44 chainring, and the same cassette you get 16 useable gear ratios and the increments in the middle of the cassette are small if you are happy to jump from big blade to small blade to achieve the smaller gear ratio changes.

My calcs below using the late Sheldon Brown's gain ratio to measure gearing:

Useable options 29/44				Useable options 22/32/42				Redundant combos 22/32/42
34x29	1.6			34x22	1.2
30x29	1.8	13%		30x22	1.4	17%
26x29	2.1	17%		26x22	1.6	14%
23x29	2.4	14%		34x32	1.8	13%		23x22	1.8
20x29	2.7	13%		30x32	2.0	11%		20x22	2.1
30x44	2.8	4%		26x32	2.3	15%		18x22	2.3
18x29	3.0	7%		30x42	2.6	13%		16x22	2.6	23x32	2.6
26x44	3.2	7%		26x42	3.0	15%		14x22	3.0	20x32	3.0
16x29	3.4	6%		23x42	3.4	13%		34x22	3.5	18x32	3.4
23x44	3.6	6%		16x32	3.8	12%
14x29	3.9	8%		20x42	4.0	5%
20x44	4.2	8%		18x42	4.4	10%				14x32	4.3
18x44	4.6	10%		16x42	5.0	14%				12x32	5.0
16x44	5.2	13%		14x42	5.7	14%
14x44	5.9	13%		12x42	6.6	16%
12x44	6.9	17%

>

linnega2008-10-14 04:02:16

[Spaceboy]

Except for the super expensive FSA ceramic bearing variety, are there any 29/44 MTB cranksets readily available at an affordable price? I am quite interested....but there is no way I am gonna drop R5k.

[Ox_Wagon]

Thanks' date=' but no. [/quote']

but why hahahahahahahahhahaha you could always have mine at a price that is!!!!!

 

 I still waiting for you to come back to me on other stuff so I will pass

[turtlek]

Except for the super expensive FSA ceramic bearing variety' date=' are there any 29/44 MTB cranksets readily available at an affordable price? I am quite interested....but there is no way I am gonna drop R5k.[/quote']

 

 

 

i saw a TCS cannondale the other day being ridden by petri with one on it not too sure of the make contact crux pearl to find out where you can get one

[turtlek]

Thanks' date='?but no. [/quote'] but why hahahahahahahahhahaha you could always have mine at a price that is!!!!!

 

?

 

?I still waiting for you to come back to me on other stuff so I will pass

 

 

 

yes i know i am pretty bad at coming back to people sorry ox wagon will sort it out just now