BB spacer / chainline questions

hoberinos

So, I'm building up a Yeti 575 (s/h frame and forks, mostly new other bits) - It's going to be ace!

Got my shiny new XT Hollowtech II bottom bracket fitted by my LBS as I didn't want to make a balls up of it. Went to pick it up and the guy said:

"I added one spacer to the drive-side (as per Shimano instructions for a 73mm shell), but if it was my bike I'd put the spacer on the other side. You'll get a better chainline."

Anyone with experience agree / disagree with this?
I'm going to build it up as is and look at the chain line once it's done. If it's a problem, I'll get them to switch it round.

But, Shimano would have done their research on this, right??

supersonic

Shimano have said what gives what chainline.

Now it maybe that the Yeti works better with a different front chainline - in which case use the spacers differently ;-)

hoberinos

Thanks supersonic,

I assumed he meant that the Shimano instructions were simply wrong!
Your explanation makes more sense...

I don't know enough about chainlines to make an informed decision either way.

Chunkers1980

I had this problem.

I only fitted one of the spacers on the drive side as to me it looks like the chainline is better with the cranks closer to the frame...

supersonic

Chainline can be a funny bugger. 45-55mm is the standard range, with most specifying 50mm, or the older 47.5mm.

Why change? The diameter of the seat tube and front mechs play a role. The fatter the seattube, the further the mech has to sit out, so some frame manufacturers specify a longer chainline to compensate. This improves shifting.

With cranks, different length axles and spacers allow you to choose and match.

GhallTN6

I built a Yeti 575 just before christmas with the same Bottom bracket/chainset, I did it as Shimano suggested and I've had no problems, didn't even think about any other way to be honest, very smooth.

It rides like a dream by the way, very sure footed and confidence inspiring, you'll love it!

hoberinos

Thanks GhallTN6,

I'm really looking forward to finishing it to see how it rides!
What weight did you end up with? I'm expecting around 27-28lbs.

Also, OT, but what shifters / brakes are you running?
I'm using sram X9 with Formula oro K18's and I'm finding them hard to position right on the bars. I was using the X9 with Hope Mini Monos on my old bike without a problem – running brakes inboard of shifters.

Cheers.

GhallTN6

Sounds like you did a similar thing to me, take as much of an old bike to put on the Yeti.

I moved the xt shifters, Mavic 717 whells (xt Hubs), xt rear mech and Hope mono mini brakes from my last bike, after putting in sinered pads the brakes seem to work well, although to be honest I've not done any really long runs as yet.

I went a bit mad on the credit card though and got a carbon riser bar, Thomson Elite Seat Post, Thonson x4 stem, Hope headset and Fox Talas RLC 15qr forks.. full xt running gear.

I was mega suprised, I weighed it about four times as I just couldn't believe it, i was hoping for the same 27 - 28lbs, but it came out just over 26lb... not bad for a bike that can handle pretty much everything apart from hardcore downhill stuff.

Oh, and this bike can climb, as well as, if not better than my previous 4" Marin Mount Vision..

hoberinos

Very similar!

I've gone for a new XT chainset (old one was isis), old X9 rear derailleur and shifters, new XT front mech. New Sram cassette + chain.

ebay bargain Fox Talas RLC 15qr!

New Mavic 317 on Hope Pro II front wheel.
Old Mavic 317 on Deore hub (to be replaced).

ebay bargain Formula oro K18 (although considering using my Mini Monos - I love them).

Then the rest I'm going to 'borrow' off my Spesh Stumpjumper fsr until I buy new bits (stem, seatpost, handlebars etc...). Once returned will either sell or keep as spare / girlfriends bike.

Is TN6 your postcode?
What carbon bars did you go for?

GhallTN6

Yep, TN6 is my postcode, I did Pitch Hill and Holmbury Hill's last weekend, and did some new trails that I hadn't done before, really steep and knarly with drop-offs and the likes, first time down them, and no probs on this bike, once the seat is lowered a tadge and you can get over the back nothing is too much.

I had to get a new front Mech as I needed a dropdown one, and you need a 30.9 diameter seatpost which I didn't have.. so once I started spending I couldn't stop.. I went for the pewter one, I'm pleased I did, it's not too in you're face.

The handlebards are Easton EC70 ML carbon Riser XC, seem to work really nice.
How much did you pay for you're forks, I got a 2009 Talas RLC set for £600, I found it really hard to find the 15QR ones on ebay.

what trails do you ride?

hoberinos

I did Pitch Hill and Holmbury Hill's last weekend

Really!?!? I did too!
Only the second time I've been round there – not sure why, it's brilliant and drains really well. We did Holmbury and Leith Hills...

I got the forks for £380 and the 2008 (carbon rear) frame for £670 – both used.
Was pretty lucky to find the forks – I've had them sitting round doing nothing for almost 3 months, so haven't properly tested them, but they should be great.

Usually just go round Bedgebury, but I've been to Afan a few times and the Alps too!
I'm not very good at finding new trails - where do you ride?

GhallTN6

have a look at it here
http://www.facebook.com/album.php?aid=1 ... 1ebadf2827

hoberinos

GhallTN6 wrote:

have a look at it here
http://www.facebook.com/album.php?aid=1 ... 1ebadf2827

Very nice build.


Just finished mine!


Currently weighs in at 28lbs (still with some old kit on so should be able to shed around a pound with new rear wheel and some carbon bits). Your 26lbs is impressive!

How do you find the sizing on yours?
Mines turned out a bit bigger than I was expecting. I'm just over 5'5", and the small frame feels bigger than my small Stumpjumper. Stand-over height is dangerous!!

GhallTN6

That's one classic build, those forks look long, are they still 140's..?

I went from a small 16.5" Marin to the Medium 18" frame, I'm 5'10", yep, was worried about how big it felt, the top tube looked really beafy, but don't worry, give it a couple of rides and you'll be wondering how you ever managed without it.

28lb is still a great weight for that bike though, can't believe you got it all at that price!

One thing for sure, we won't miss each other on the trail.
Enjoy the ride.