Sizing Issue...shorter seatpost to fix it?
Sizing Issue...shorter seatpost to fix it?
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Hard-Drive

Original Poster:

4,227 posts

249 months

Thursday 4th February 2010
quotequote all
Right, the missus' new bike has arrived...it's a Trance X5, and it's replacing her WSD Rockhopper HT. The Trance is a 16" (S) and the Rockhopper is a 15.5". Unfortunatly, as the bike came from an internet retailer on the C2W scheme, there was no option to try it first. She's just over 5'3".

Out the box, the Trance looked huge, but then again it would as it's a much beefier bike than her old round tubed Rockhopper, and a quick run round with the tape measure confirmed that the main cockpit measurments are almost identical, the only difference being reach (easily adjusted with a 60mm stem) and height of the bars is about 30mm higher (which are on quite a few spacers, and of course will be higher anyway due to increased fork travel). Crucially, the standover height (obviously with the suss on full extension) is actually the same, due to the swoopy top tube profile of the Trance. And interestingly, although Giant have dropped the XS from the 2010 range (this is an 09 bike) there's actually very little difference geometry wise between S and XS, and if she went for a womens version (Cypher) the frame actually seems bigger for any given size than the mens (women have longer legs and all that). She can't get that bike on the C2W scheme.

The one issue is the seatpost. The seatpost the Trance has come with is big, well over 350mm. As the main rocker pivot pierces the seat tube, there's not the scope to drop the post very far, and she can't get it as low as she'd like for downhill. Looking at the manual, the Trance only needs 80mm of instertion at full height, so the obvious thing to do is to work out the measurments and chop the excess off the bottom of the post. Thsi will give lots more than the current 45mm of adjustement between fully down and min insertion.

Even if she could get an XS (which she can't) the seatpost would still presumably be an issue...the Maestro rear triangle is one piece, which therefore must dictate that the rocker link and pivot are going to be in the same place working from the ground up, so although you may get slightly more standover height with an XS (however this is not the issue), saddle fully down is still going to be the same, and the only fix is a shorter seatpost.

As everything else seems fine or easily fixed fit wise, does a shorter seatpost seem like the logical answer? Have any other slightly smaller riders come across this issues on a FS bike? Is this a case of Giant being lazy with the spec? (Fully extended the post is ludicrously high, I'm just shy of 6' and could not ride it like that!)

ratbane

1,393 posts

236 months

Thursday 4th February 2010
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FS bikes will appear larger until you sit on them and they sag.

If the standover height, and top tube reach feel ok, then just cut the seatpost down to suit.

snotrag

15,403 posts

231 months

Thursday 4th February 2010
quotequote all
Yup, she needs to get on it and feel it. You will always have a 'bigger' looking bike if its full suss.

Ignore the height first - check the reach is correct, and also the bar height.

If thats correct, then just chop the seatpost to suit. Use a pipe cutter if you havent got a tube cutting guide/clamp, and remember to de-burr the edges to avoid scoring the seattube.

Hard-Drive

Original Poster:

4,227 posts

249 months

Thursday 4th February 2010
quotequote all
Great advice guys, thanks. Looks like she'll be keeping the Trance then...and a fine ride for a grand it is too!