1x10 drivetrain

[rbike]

Hello,
Been using a MTB for quite a few years now, and looking at what Shimano and Sram have been doing for past few years, I checked my type of riding.
I ride mostly in the way, that I find some ascent around 500-1000m (1500-3000ft), I climb it and then I go downhill with moderate speed. I have an old 7spd drivetrain 22-32-42 x 11-28. I really use mainly 22 and 32 front sprocket and almost never 42 (I do not pedal when going downhill). I checked speeds that I use and they mainly are 1st – 6th speed when on small front chainring and 3rd to 6th when on middle (32) front chainring. So, if I put this in numbers I basicaly need this ratios: smallest (easiest) 0,78 – biggest (heaviest) 2,46. I use 26 inch wheels. Going a little further I could live without 2,46 and use 2,2, and my wish is to have easiest 1st gear – maybe 0,66.
So I could upgrade to 1x10 spd (Shimano XT) 11-36, with 24 front chainring (ratios: 0,66 – 2,1. There is no problem with the 10spd sprocket and derrailleur, however I can not find anyone who made cranks this way. There are lots of guys that put away smallest and biggest chainring, keeping the middle (like 32 teeth) but no one leaves only the smallest one. However the smallest one is outcentered – more to the left side.
My question is this: I would like to position the only (24 teeth) chainring (that is centered more to the left) in the middle of the rear cassette (centered with rear 5th gear). So - is this neccessary – better for the chain wear and performance – or should I just forget about it and take away biggest two chainrings, dump the front derraileur and shifter and leave like it is?
Thanks for any replies.

 

[gtRTSdh]

24T front chainring that is narrow enough for a 10sp chain will not last very long. If you really want to centralise your 24t, than a sqtp crank with a really long BB spindle will get you there, but the q factor of your cranks will increase by the same ammount, not good for your knees.

 

[gtRTSdh]

what would really suit you is a gear hub, rohloff being the pick of the bunch, & shimano do one as well at about half the price.

 

[secret_squirrel]

You will struggle I suspect. Best option may be a set of SRam cranks and one of these (28t)
http://www.mountainracingproducts.com/mrp/bling-ring/

half decent thread on STW about it http://singletrackworld.com/forum/topic ... ng-options

Simple fact is your requirements are pretty unique and likely not fully satisfied by the market. I suspect a large percentage of us only pedal up the hills for the pleasure of barrelling down them as fast as our little legs can pedal

 

[NeilM]

Why not consider 2 x 10.

I have it one one of my bikes and I find it a good all round set up, with some nice low climbing gears, and high enough overall gearing for fire or tarmac roads. Plus, components is easily available to buy or build.

 

[gtRTSdh]

Period STX or STX RC, would look good as they transmitted all the torque through the inner chainring bolts, they had a unique middle ring that the big ring bolted to.

http://www.ebay.co.uk/itm/NOS-Shimano-S ... 232b956670

good pictures in here:

http://www.ebay.co.uk/itm/new-SHIMANO-S ... 4d08cfad9d

 

[Elysarian]

considering going 2x10 myself, I really have no use for a 22 front/32 rear combination and rarely used to use the granny ring BITD tbh (IIRC I had 28/28 then)

also giving thought to a 1x10 once I get my fitness levels up again but with a 38 or larger front ring in my case... will need some chainline adjustment though if I go that route!

 

[secret_squirrel]

One thing has me puzzled though - the weight reduction over a triple is minimal especially at 2x10. Is it really worth losing the range - especially since on a 11 - 42 I could pedal out on a grassy field / fire road DH?

 

[NeilM]

One thing has me puzzled though - the weight reduction over a triple is minimal especially at 2x10. Is it really worth losing the range - especially since on a 11 - 42 I could pedal out on a grassy field / fire road DH?

I wouldn't really expect much weight difference, after all it is only the weight of the outer chain ring.

As for range, I guess it depends what you are using the bike for. I have found that the gearing works well for me, although I do spend a lot of time on the larger of the two chain rings.

Horses for courses I guess.

 

[rbike]

Thanks for replies.

Been checking for older cranks and found some Alivio. The three chainrings are welded alltogether. The smaller chainring is a little bent (machine pressed) in the way, that is positioned more to the left. This way middle ring is centered in the middle. If all three rings are put away, the only (one) ring would be centered in the middle. So this I think might be a good solution for me, gtRTSdh. And it would look good, yes.

Will be taking in observation also q factor since my knee problem.
I ride in that way due to bad knee, which makes me problems on a descent. So bike is a perfect solution. I go uphill and I do not have to walk down.

Been looking at gearhub and I think it is worth to give it a try. User opinions/reviews are a bit discouraging due to malfunctions or short lifetime.

I am realy wondering – would only one chainring (the older – 7 speed) work with new 10 speed chain? I guess not, because it (chainring) is too thick.

I agree the weight will not be much difference. According to weight weenies three steel rings weigh 350g (alivio), the smallest only 50g, derrailleur a bit more than 100g, shifter a bit more than 50g (twister), so 400-500g. Not much. However if not needed can be put away.

If Sram would make a cheap version of 11-42T, I would not think twice. However at this moment price is too high.