2012 Specialized Demo 8/ bikes

PB Forum :: Downhill
2012 Specialized Demo 8/ bikes
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Posted: Sep 8, 2015 at 0:10 Quote
Ah, those bikes in particular are a bit tricky.

Mcb has some good suggestions above -- I think a wider 7-speed, say a 10-28 or so would be your best bet. Combined with a small front ring you'll find it significantly easier to pedal up hills.

Personally if my bike had the funky 135 rear end, this is what I'd do:

-New conventional 135mm hub + rim with 11-32 cassette for most of the year
-Summer setup for lift access: stock 9-20 cassette
-Both of the above paired with a Saint shifter/Zee FR derailleur. The FR spec can go up to 32T, and is a clutch derailleur so it will be MUCH quieter than your existing Sram piece.

Posted: Sep 8, 2015 at 1:47 Quote
Assuming his set-up is 10speed converted to 7 you wouldn't be able to run a different 7 speed cassette as it wouldn't work, it would need to be a 10 speed cassette and lose the bottom three cogs

Posted: Sep 8, 2015 at 6:48 Quote
tf02 wrote:
My bike came with a 36T ring and 11-25 cassette. I ran a 34T and 11-32 for over a year with no problems, makes climbing fireroads and such doable.

It does get louder though -- even with a clutch derailleur, the chain slap and clunking of the mech is louder than with the 11-25.

More noise because of the smaller chainring having less chain tension? If you were running a Shimano mech, you could try cranking up the clutch tension.

Posted: Sep 8, 2015 at 7:34 Quote
I have just purchased a new Shimano saint crankset for my Demo 8. When I went to take off the Gxp bottom bracket, I noticed that the owner of the bike before me had stripped the treads on the plastic Sram Pressfit 30 bottom bracket adapter. I was looking into getting a new adapter but I have not had so much luck in finding another adapter. Anyone else had to change out the adapter? I'd like to be able to use the Saint BB that came with the crankset.

Posted: Sep 8, 2015 at 8:55 Quote
Mtb468 wrote:
I have just purchased a new Shimano saint crankset for my Demo 8. When I went to take off the Gxp bottom bracket, I noticed that the owner of the bike before me had stripped the treads on the plastic Sram Pressfit 30 bottom bracket adapter. I was looking into getting a new adapter but I have not had so much luck in finding another adapter. Anyone else had to change out the adapter? I'd like to be able to use the Saint BB that came with the crankset.

I hope this link works in your country

http://www.chainreactioncycles.com/sram-pressfit-30-to-bsa-adaptor-kit/rp-prod71306

Posted: Sep 8, 2015 at 10:41 Quote
tf02 wrote:
Ah, those bikes in particular are a bit tricky.

Mcb has some good suggestions above -- I think a wider 7-speed, say a 10-28 or so would be your best bet. Combined with a small front ring you'll find it significantly easier to pedal up hills.

Personally if my bike had the funky 135 rear end, this is what I'd do:

-New conventional 135mm hub + rim with 11-32 cassette for most of the year
-Summer setup for lift access: stock 9-20 cassette
-Both of the above paired with a Saint shifter/Zee FR derailleur. The FR spec can go up to 32T, and is a clutch derailleur so it will be MUCH quieter than your existing Sram piece.

Thanks for the input. It is looking like this is going to be pretty pricey. Maybe I should just Harden the F* Up and get a lot stronger this winter.

Posted: Sep 8, 2015 at 10:58 Quote
mcbbuilds wrote:
Assuming his set-up is 10speed converted to 7 you wouldn't be able to run a different 7 speed cassette as it wouldn't work, it would need to be a 10 speed cassette and lose the bottom three cogs

That's what I meant, a disassembled 10 speed, just wider range.

davecheng wrote:
More noise because of the smaller chainring having less chain tension? If you were running a Shimano mech, you could try cranking up the clutch tension.

Tried that, but there's a very fine line between tension and having proper shifts. Having a smaller range cassette is just easier on the whole system.

Posted: Sep 9, 2015 at 9:38 Quote
mcbbuilds wrote:
Mtb468 wrote:
I have just purchased a new Shimano saint crankset for my Demo 8. When I went to take off the Gxp bottom bracket, I noticed that the owner of the bike before me had stripped the treads on the plastic Sram Pressfit 30 bottom bracket adapter. I was looking into getting a new adapter but I have not had so much luck in finding another adapter. Anyone else had to change out the adapter? I'd like to be able to use the Saint BB that came with the crankset.

I hope this link works in your country

http://www.chainreactioncycles.com/sram-pressfit-30-to-bsa-adaptor-kit/rp-prod71306


I was looking at that as It may be the most reasonable option for the least amount of money. I was hoping to find another type since this was what came stock on the bike and stripped. It's just plastic so you have to be careful installing and removing the Bottom bracket. Thanks for the help though

Posted: Sep 9, 2015 at 12:32 Quote
If you going to pedal uphill with a bigger rear cassette, I suggest you get a dropper seat post too.

Posted: Sep 9, 2015 at 18:47 Quote
B888S wrote:
Bought this ride used about a month ago and have done nothing other than swap out the rear spring for one that better fits my weight. Just looking for some advice from people in the know due to the fact that my local shop does not carry or commonly deal with DH bikes.

Currently have the stock setup for the rear

SRAM X0 9 speed short cage rear
Shimano HG-70 Capreo, 7-speed, Micro 9-20 cassette
SRAM X0, 9-speed shifter
36T front ring
Custom DT Swiss, Capreo compatible, Star Ratchet, 135mm, 32h rear hub

Front Crankset also stock
SRAM X0 DH, carbon arms, micro-single 32T ring, PF30 spindle, 165mm, E.13 SRS chainguide

Complete specs for my ride

Can I just swap out the funky 7 speed 9-20 cassette for a 9 speed 11-34 like this combined with a 9 speed chain? Will it play nice with my short cage rear X0 derailleur?

My downhill season is likely over for this year, so I have a long time to make the changes before I take it back out next summer.

I am running a 9-42t capreo hub. Once you get past the bottom for cogs you can plug in any cogs. You're going to have some big jumps but it is doable.

Posted: Sep 9, 2015 at 22:26 Quote
I am guessing that you mean the first 4 cogs that are "special" to the Capreo system I would have to keep. Then I could swap out the last 3.

Could I just swap out the freehub body, keep my current 350 hub & wheel, add a 9 speed cassette and a new chain? If so, leaving my front 32T alone, what size rear could my short cage XO derailleur handle?

Posted: Sep 10, 2015 at 0:10 Quote
B888S wrote:
I am guessing that you mean the first 4 cogs that are "special" to the Capreo system I would have to keep. Then I could swap out the last 3.

Could I just swap out the freehub body, keep my current 350 hub & wheel, add a 9 speed cassette and a new chain? If so, leaving my front 32T alone, what size rear could my short cage XO derailleur handle?

Up to an 11-34 with no problems

Posted: Sep 10, 2015 at 6:28 Quote
And yes you could swap out freehub.

Posted: Sep 18, 2015 at 6:15 Quote
Finally another picture leaked.

2016 Specialized demo 8.2 Alu

2016 Demo 8.2 Alu

Posted: Sep 18, 2015 at 9:21 Quote
Flyboy7777 wrote:
Finally another picture leaked.

2016 Specialized demo 8.2 Alu

2016 Demo 8.2 Alu

will specialized have a budget option like the status? or will they have a price similar to that on the 2015 status?


 
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