K2 / Proflex Riders Group

General => Tech Forum => Topic started by: kiwi on January 31, 2015, 01:40:19 pm

Title: Upgrading and or replacing drive train
Post by: kiwi on January 31, 2015, 01:40:19 pm
Ok guys i havent actually ridden the 756 for AGES.The last time i did it had mysteriously developed a bottom bracket click....Being on the far side of the hill now,and 90kg on a good day i am thinking of a new drivetrain with easier gearing.I think i still run the same gearing it came with!Wheelsare std but i run a shimano shifters n levers ...didnt like the gripshift it came with
Advice please
Title: Re: Upgrading and or replacing drive train
Post by: Spokes on February 01, 2015, 01:57:32 pm
All my bikes run standard gearing. I tried running a bigger rear cassette on my OZ but the chain hit the swing arm so I dropped it back to standard. You might have more clearance with a '56 swing arm but I've never tried sorry.
You can always just use a lower gear  ;)

Chris
Title: Re: Upgrading and or replacing drive train
Post by: Colin on February 02, 2015, 02:16:12 am
Hi Kiwi!
90Kg and being "on the far side of the hill" are no excuses! get out and ride it! <GRIN>
(I'm pushing 100Kg with gear on and aged 50+)!!!!
But maybe you need to review your spring rates!

I wouldn't worry too much about the BB; these days I ride them to destruction as as they are disposable items, although I do replace them if they get too noisy and annoying!, but it masks the clicking noise from my Knees so there's a benefit!

I run Megarange gearing on most of my bikes (4000, Pine Mountain & Oz's), 11-34 on the rear and 22/34/44 on the front, but my XP-X (x56) is set up as a 700c Road Warrior so not quite so extreme gearing on that, 11-28 and 22/34/44, but I'm pretty sure I have run a 34 cassette on that as well, in off-road mode.

Same here! I replaced the Gripshifts with Shimano XT 739/740 shifters and they are much better, working well with the original XT rear mech and LX front.

Shifting is slick and perfect on all of them, with adequate clearance, altho' Chris and I have discussed the tight chain clearance on our Mod'd OzX's previously.

Good luck and lets see the Kiwi flying again!

Col.
Title: Re: Upgrading and or replacing drive train
Post by: Spokes on February 02, 2015, 05:53:44 am
My best advice is that the gearing won't matter once you fitness improves.  :)
Hope you enjoy getting back out on the dirt  :)

Chris
Title: Re: Upgrading and or replacing drive train
Post by: beeeerock on February 02, 2015, 03:48:03 pm
My best advice is that the gearing won't matter once you fitness improves.  :)


Forget the gear ratios, what is the recommended location for this equipment (below) on the bike, for those of us in the 50 and up range???  8)

Or maybe just put it in the Camelbak and stick the pads on the chest before starting the ride... LOL

(http://cdn2.hubspot.net/hub/235721/file-25819805-jpg/images/aed-inspection.jpg?t=1416514961569&t=1419000789000)

Title: Re: Upgrading and or replacing drive train
Post by: kiwi on February 03, 2015, 01:03:16 am
you guys live in flat lands.I went for a walk the other day.16 km and 1600 m of elevation change...i NEED a low gear!
Title: Re: Upgrading and or replacing drive train
Post by: Spokes on February 03, 2015, 03:36:59 am
To be honest where I live it's all mountains but I would think with anything lower geared I would struggle to keep the front end down on steep sections. It's hard enough now. Also by lowering the gearing more you would turn into a human giroscope. Peddling really fast but not going anywhere .
If it's specific recommendations you want I can recommend XT770 as a group set. It's not the latest so is very well priced and the lack of friction in its workings make it feel like it's lower geared thean it actually is. It flys along on my OZ. The XT770 Hollowtech 2 bottom bracket weighs virtually nothing so that's a plus aswell.

Chris
Title: Re: Upgrading and or replacing drive train
Post by: beeeerock on February 03, 2015, 10:34:05 am
you guys live in flat lands.I went for a walk the other day.16 km and 1600 m of elevation change...i NEED a low gear!

I hear you... this is similar to the discussion I started a while back: http://idriders.com/proflex/smf/index.php?topic=4227.0 (http://idriders.com/proflex/smf/index.php?topic=4227.0)

Bottom line: my 857 has non-stock ratios... 26x28 (1.08:1) is the best I can do for climbing.  It's not enough and is tough on knees.  It would have been 22x30 (1.36:1) from the factory I believe.  My Giant is 26x36 (1.38:1).  That's plenty.  If I went back to the stock cassette and front ring, I think it would feel essentially like what I experience on the Giant.

I think my terrain is similar to yours... a 6 km loop on a typical single track trail (let's call it 'blue' like skiing - not boring, not extreme) would add to a total up/down of about 500 m or more.  The routes you'd hike instead of ride are steeper and would total higher.

I don't think you mentioned what your ratios look like right now, but I'd expect getting into the 1.36:1 area should do you well -assuming clearances work!  The front wheel does like to come off the ground, so I don't think going higher would do you any favours...
Title: Re: Upgrading and or replacing drive train
Post by: kiwi on February 06, 2015, 01:06:00 am
bone stock...22 32 42 in the front i think 11 28 in the back.I know the front likes to come up ,and the rear hooks up well.I think i have a brand new rear cluster somewhere
Title: Re: Upgrading and or replacing drive train
Post by: jazclrint on July 17, 2015, 12:45:17 pm
I got my 5500 as a frameset, so I have to build it. I went with an SRAM XO with grip shift drivetrain. 11-34t cassette and RaceFace Next LP triples with 22-32-42. Eventually SRAM made a front derailleur that fit as well. I am currently in the middle of a 1X11 upgrade. But despite my best efforts it looks like that is going to include new wheels, and if I am going that far might as well go disc too.