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Old vs. New DH Geometry

M

MarkDH

Monkey
Sep 23, 2004
351
0
Scotland
Hey,

Been thinking that I have maybe another season left on my '03 Giant DH Team (with 8" Boxxers) before it should be put out to pasture, and as you might imagine I have been wasting time in work looking at bikes that I won't be anywhere near purchasing for at least a year. :)

Anyway, it's got me thinking about what I like and don't like about my bike and what I want in my next one. Having thrown my leg over a variety of bikes, I think that the geometry is the most crucial thing to look for. My Giant has what I would call a 'traditional' feel to it, in that it doesn't really feel particularly like a DH bike until you get it moving and it starts swallowing bumps. I also feel like i stand 'on' the bike rather than 'in' it. In contrast, the more modern bikes that I have sat on/rode recentley like the Sunday, 224 Evo and Empire have that 'attack' feel to them. I feel like I'm standing up straighter (maybe due to BB height) but at the same time with more weight over the bars, more agressive basically, I'm sure you know what I mean.

What i can't figure out is exactly why the difference is there and why I can't get my DH Team to ride or feel like the newer bikes? I run my shock fairly soft and the BB doesn't seem crazy high, and I'm running 8" forks which weren't around when my frame was made making the front higher and slacker. Basically, I thought it would be an interesting discussion to see what differences in geometry have occured in 6-7 years, and what factors have the most impact, with the end result being that I can maybe include some more frames on my short list without having to find one to sit on.*

Please discuss. :)




*Obviously the geometry bit on a bike website is no substitute for actually riding a bike, but as we all know that isn't always the easiest thing to do, and besides I like a bit of geek talk to pass the time!
 
Uncle Cliffy

Uncle Cliffy

Turbo Monkey
Jan 28, 2008
4,490
42
Southern Oregon
Over the years, bike's have become even more use specific... If I remember right, the Team DH frames sat pretty high compared to a lot of current DH bikes. Most race bikes these days seem to hover around a 14 inch BB height with sub 65 head angles. This is good if you ride steep grades all day, but tougher if your terrain is flatter.

I've spent a lot of time on a Flatline lately with a few rides on a Sunday, V10, and Demo. All of these bikes have a low CG and feel ultra stable at speed. I remember bikes didn't use to feel this long and low, but I also remember how they felt in the steeps. These days I don't get that OTB feeling. Maybe my skills have improved, maybe it's newer geometry. Cornering has improved exponentially as well. Since I can't jump on any older bikes currently, I'm not sure if it's me or the bike sometimes...

I can't remember the Team DH, but I did ride one once. I remember not liking the stand-over much... Saying that though, courses have changed over the years and I think DH specific bikes have reflected their environment...

Wow, I didn't really answer anything huh? At least I raised my post count?
 
buildyourown

buildyourown

Turbo Monkey
Feb 9, 2004
4,832
0
South Seattle
Look into a shorter i2i shock, to lower and slacken the geo. You may lose some travel, but the bike will be more capable overall.
Lower bars. Get a direct mount stem and a flat wide bar to compensate for the 8" fork. Newer bikes have wider bars, that may be one thing you are feeling.
 
chic06

chic06

Chimp
Sep 16, 2008
45
0
Those giants don't have bad geo, but if you want the bike to feel a little more like a dh bike you could replace the shock as mentioned earlier. The stock size for those was 9.0x2.75 if you got an 8.75x2.75 it'll lower your bb and slacken your angles without losing any travel.
 
jonKranked

jonKranked

Detective Dookie
Nov 10, 2005
85,860
24,454
media blackout
buildyourown said:
Look into a shorter i2i shock, to lower and slacken the geo. You may lose some travel, but the bike will be more capable overall.
Click to expand...
chic06 said:
Those giants don't have bad geo, but if you want the bike to feel a little more like a dh bike you could replace the shock as mentioned earlier. The stock size for those was 9.0x2.75 if you got an 8.75x2.75 it'll lower your bb and slacken your angles without losing any travel.
Click to expand...
If you go this route, check to make sure the swingarm or any of the linkage has adequate clearance. You can do this by cycling the shock on the frame without a coil.
 
djivotno

djivotno

Monkey
Oct 3, 2008
108
0
If i remember correctly, the 03 DH Team, had 222x70mm shock (8.75x2.75') if you go to a 216x63 you should have no clearance issues (as the shock has the same compressed lenght as the 222x70mm) but it will reduce the travel. The 04 DH Team should be the one with the 230x70mm (9x2.75') shock. Switching the shock, will reduce the Head Angle by about 1* and will lower the BB with about 1cm (1/2 inch). I'd go for it :) It might need lower spring-rate :monkey:
 
M

MarkDH

Monkey
Sep 23, 2004
351
0
Scotland
Don't get me wrong, I just got the forks recently and had the shock Push'ed a few months back, and I am happier with it now than I've ever been. Thanks for the suggestions of shorter shocks but I think it would be best to run it the way it was designed, no to mention a lot cheaper.

I've just found that when looking at geometry figures on manufacturers websites I don't really know what I'm looking for in terms of BB drop, CS length etc. I guess the best way to go about it is to compare them to the stats of bikes you have sat on, but then not all manufacturers give comparable levels of info. :disgust1:

Eh, conclusions.... just get a shot on the damn bike you want to buy! :clapping:
 
joelsman

joelsman

Turbo Monkey
Feb 1, 2002
1,369
0
B'ham
bikes have gotten slacker, and a bit lower, 67* used to be considered slack, now it is steep for dh. BB's were around 15in for many bikes about 5yrs ago, some higher even higher, most race bikes were not over 15in but many fr bikes were, SC pfree was 15.5, banshee was up there, and asx is was too.
 
no skid marks

no skid marks

Monkey
Jan 15, 2006
2,511
29
ACT Australia
I'd be interested(but not enough to look)to compare the new Morwood to your old Giant. I don't think your geo is the main problem, more parts selection and set up. It should be slack enough with bigger forks, as long as your BB isn't over 14-14.5". Check your head angle, buy an angle finder from the hardware, they're cheap as chips, and handy.
 
stoney

stoney

Part of the unwashed, middle-American horde
Jul 26, 2006
21,596
7,245
Colorado
I went through four Giant DH frames between 03 and 05. I had them setup for both air and coil shocks 9x2.75, 8.75x2.75; always with a 7" Boxxer World Cup. The shorter shock was great for the geometry, but overly exposed the links below the BB. Two of the frames I went through were due to "incidents" with the linkages and the ground. The suspension felt to ramp up a bit faster with the shorter shock, but it was negligible. I ended up riding the bike more with the larger shock though. I'd swap to the short shock for smoother fast courses where I wanted to be lower and slacker, but the risk of taking the links off was way too high on rocky trails.
 
M

MarkDH

Monkey
Sep 23, 2004
351
0
Scotland
no skid marks said:
It should be slack enough with bigger forks, as long as your BB isn't over 14-14.5". Check your head angle, buy an angle finder from the hardware, they're cheap as chips, and handy.
Click to expand...
I think this is why it would be impossible to get an old style bike set up like a new one. To get the bike slack enough and the bars high enough would mean raising the BB at the same time, so it would raise your centre of gravity and defeat the purpose of making a more stable and aggressive bike. I do run 19mm rise Sunline V1 bars, but my bars have always been notably lower than those on a mates Sunday and now his 224, whilst also having a higher BB. I could raise the bar height I suppose but I've never found a set of high rise bars with a sweep I like, thinking about it though I may experiment with some more spacers under the stem. :)

As for the original geo. figures, I did find the once in the Giant archive through Google but they seem make it as hard as they can to find them.
 
Gary

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,635
5,549
UK
Mark, you could run a 2.35 rear tyre (but 2.5 front) and remove all the spacers you can from under the top crown and drop your stanchions by that amount - bars will be same height but H/A slacker, my sunday's noticably slacker and lower than stock by doing this. I also run more rear sag than most so in use it's even lower/slacker.
 
M

MarkDH

Monkey
Sep 23, 2004
351
0
Scotland
Gary,

Didn't realise you had tweaked your bike from stock. I used to run 2.35 on the back, but after CRC made a cock up and sent me 2x 2.5, I don't think I'll go back. I just find it gives better grip as a 2.5 and with the bigger volume I don't really have to worry about pinch flats.

I think the head angle may be slack enough as it is, in fact when anyone else sits on my bike it seems to tip backwards alarmingly! I was actually thinking of running more preload and LSC on the shock so that it doesn't do that as much when riding, but this might raise the BB too much. I think I'll try spacers under the stem or top crown and take it from there, maybe as you say drop the forks a bit if that doesn't raise the bar height enough.
 
Ian F

Ian F

Turbo Monkey
Sep 8, 2001
1,016
0
Philadelphia area
I don't know about "new vs. old" but improving "attack feel" can be done in a few ways...

Drop the fork travel from 8" to 7". I remember trying a Shiver on my M-1 and disliked how it raised the front of the bike compared to the '99 Monster T and '00 Boxxer (both of which are about the same, geometry-wise).

Make sure the fork and springs are tuned for your weight. Softer springs may help.

Lower stem rise and or bar rise.

Try a longer stem - this made the biggest difference for me. I ran a 70mm, 0-rise stem (Thomson) on my M-1, which really helped me with keeping weight on the front wheel compared to a 50mm, +10-rise stem.
 
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