Mountain Biking - gary fisher frame size help

My brothers gary fisher frame broke an we are getting a warantee exchange, our problem is that he has been riding a 21.5" fisher wahoo which he could never feel centered on and had a hard time getting enough weight on the front wheel to keep from washing out around corners he also could not get behind the seat far enough for steep descents and quick stops. He is 5'11 and rides aggressively on the downhills on rocky and rooty trails he likes my 19" wahoo better than his but is thinking of going smaller to the 17.5"
We have both compensated for an oversize frame by using a shorty stem I think 60mm and 2" riser bars but he still thinks he may want a smaller frame than mine. Would it be a mistake to go smaller, the new frame has a 69degree head angle but his old one had a 70.5 degree head angle so the smaller frame would have pretty much the same wheel base as my 19" only the cockpit would be smaller. One problem with the smaller frame is that the head tube is about 1" shorter than the larger frame which would put the handlebars down and forward a bit, I thought if you could just put a ton of spacers under the stem to raise it back up where we need it maybe the small frame would work ok. I just wanted to see if anyone sees a problem with him being 5'11 and riding a 17.5" gary fisher hard tail or if he really needs to go with the 19". We would go test ride one but nobody has any in stock so we have to order the frame and hope for the best.

Thanks for any help.

I'm 5'11" and I ride a 19" in Trek/Fisher. I have to use a short stem (80-90mm) due to the way I ride, but a 17.5" is too small for me.

I'm 5'10.5" and ride a 19" GF HiFi and feel very comfortable on it.

I think you short people should be on 17.5" frames.

I think you short people should be on 17.5" frames.


I think you're right but the bike shop thinks 17.5 is too small, I believe the treck 19 or 20 inch frame had a shorter top tube than the fisher 17.5 and most other manufacturers have shorter top tubes also so since we have always both believed that our bikes were too large for us, it is hard to accept what we're being told at the shop since he only has trek bikes for us to test ride and they're built very different from fishers, were not sure what to do. We have heard that downhillers and free riders often use a size too small so were not sure if that would be a bad idea for cross country riding since we're more interested in the downhills anyway and the uphills are just there to get in the way of the next downhill. Another words we would rather be comfortable standing and descending than sitting and climbing, however we don't really want climbing to be outright torture if the bike is too small either.............................................................................................. .................................................................................................... .....:geek:

I'm 5'11" and I ride a 19" in Trek/Fisher. I have to use a short stem (80-90mm) due to the way I ride, but a 17.5" is too small for me.

My question is are you riding a trek or a fisher, I know they are the same company but the treks have a shorter toptube than the fishers, my brother test rode a 18" trek and wasn't sure that it was large enough but when I look at the geometry, I believe a 20" trek was shorter than the 17.5" fisher so his test ride was not an accurate comparrison. By the way I don't know how you ride but we like to drop our seat and ride standing up as fast as, we, out of shape guys can ride until we are too tired to go on that way and then we raise the rectum rod of torture (aka seat post) and crawl back to the truck while sitting on our brused and painful uretheras.
Like I said we like the downhills, its eisier to stand up on them and their more fun.

We already ride with shorty stems and riser bars so is their any real reason why we couldn't put a longer stem on a smaller frame and stack some spacers on top of the head tube to compensate for the head tube being almost an inch shorter than the one on the 19" frame, this might leave about 4" of steer tube above the head tube, would that be a problem?