Modern MTB geometry

"dvt" <[email hidden]> wrote in message
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Quoted message said:

I would like to know a bit more about the geometry of
modern MTBs and how it affects handling. For background, I
got started in the early '90s with a Bridgestone MB-1 MTB
with a rigid fork. It was a *beautiful* bike. Alas, it
didn't last forever.

Rode one in Germany..borrowed from my sister-in-law on a
trip there one year. Great bike..wonderful geometry. Fit
me perfectly and was really quite a nice bike. Shame they
went away.

Cheers,

Scott..

dvt said:

I would like to know a bit more about the geometry of
modern MTBs and how it affects handling. For background, I
got started in the early '90s with a Bridgestone MB-1 MTB
with a rigid fork. It was a *beautiful* bike. Alas, it
didn't last forever.

Now, after a few year hiatus from MTBs, I'm interested in
getting back to the dirt. I loved the way the old bike
handled, and based on one test ride and a bit of reading,
it appears that newer MTBs are much different.

The old MTB had a 73° seat tube, 72° head tube, a top tube
of 58.5 cm (23"😉 with a 130 cm stem, and a seat tube of 53
cm (~21"😉. The wheelbase was short even in its day at
104.6 cm.

Comparable modern MTBs come close in the angles, with the
head tube usually a bit shallower. The top tubes are much
longer and the stems shorter. These factors add up to a
longer wheelbase, usually 110 cm or more.

I did a short, non-technical test ride of a Trek MTB a
year or two back. It felt like the front wheel was too far
in front of me and the handling was slower. I didn't like
it. So my questions are twofold.

First, should I just get over it? Is the newer geometry
better for some reason that will become obvious when I hit
the single track? Is the longer front end simply designed
to improve descents? Or something else?

The longer front end is designed to keep you from going over
the bars, and to help traction on steep/loose climbs,
especially for beginners. But as you describe, the front
wheel can feel too far away, and even cause washouts in
corners -- unless you weight it consciously. These newer
bikes are copies of the Fisher Genesis geometry. They're
good on technical terrain or fast descents where you're more
dynamic/active over the bike anyway. But for my taste they
take too much body english to ride normally.

Quoted message said:

Second, do you have any suggestions for a MTB that might
be more like my old Bridgestone MB-1? I want some
suspension, so I know a new bike will be somewhat
different, but I sure liked the handling of the old one.

Thanks for any advice you can send my way.

Try a Klein. It has the steep head angle, short but not
extremely short chainstays, and a not-so-long front end -- a
happy medium. Basically, it's just like a Bridgestone, but
with slightly shorter chainstays.

Matt O.

Matt O'Toole said:

dvt wrote: [snip]

Quoted message said:

The old MTB had a 73° seat tube, 72° head tube, a top tube
of 58.5 cm (23"😉 with a 130 cm stem, and a seat tube of 53
cm (~21"😉. The wheelbase was short even in its day at
104.6 cm.

Comparable modern MTBs come close in the angles, with the
head tube usually a bit shallower. The top tubes are much
longer and the stems shorter. These factors add up to a
longer wheelbase, usually 110 cm or more. [snip]

Try a Klein. It has the steep head angle, short but not
extremely short chainstays, and a not-so-long front end --
a happy medium. Basically, it's just like a Bridgestone,
but with slightly shorter chainstays.

Rocky Mountain's steel hardtails might interest you. The
Blizzard (frame-only, Reynolds 853) and Hammer (Reynolds
725) have shorter top-tubes than even the Klein, but with a
similar wheelbase for any given frame size. According the
the companies' Web sites, the 19.5" Rockies are 0.7 inches
shorter than the Klein Atitude of comparable size.

I only suggested steel because you loved the ride of your
Bridgestone. Rocky Mountain also makes the Vertex aluminum
hardtails, which have slightly shorter wheelbase and top
tube than the steel bikes.

My '99 has essentially the same geometry as the '04.
Handling is sweet--much more to my taste than other
available options. While others might argue, I believe
contemporary sloping top tubes are better for technical
riding than the more horizontal tubes on bikes of the
early 90's. If you look hard enough, you may discover a
bike you like better than the MB-1. Then again, memories
can be hard to beat.

--Kevin

I agree that many of the new bikes are great, great rides.
If you want suspension you will have to get used to a
different feeling geometry than your old Bridgestone, but
most riders dont have too much trouble making the adjustment
and feel they have improved their experience with the new
geometry. Some of the new bikes are still quite "twitchy."
The 18" Salsa Bandito with Fox forks feels tall and steep
and is responsive almost to a fault, very different from the
sluggish and stretched out Fisher, which is a great
descending bike but not great climbing bike.

But maybe you don't really need shocks after all. You
weren't just imagining the great feel of your old bike.
Depending on the smoothness or lack thereof of the local
trails you might want to go with a fully rigid Ritchey P-
whatever. This bike will be everything your old Bridgestone
was times 10. I used to ride a Bridgestone MB-0 and it was
just an imitation Ritchey. Some singletrack is made for a
bike like this. Anyway you get enough suspension with 2.1's
on a steel frame.

Robert

Matt O'Toole said:

They're [modern MTBs] good on technical terrain or fast
descents where you're more dynamic/active over the bike
anyway. But for my taste they take too much body english
to ride normally.

So it isn't just my imagination. That's good to know.

Quoted message said:

Quoted message said:

Second, do you have any suggestions for a MTB that might
be more like my old Bridgestone MB-1?

Quoted message said:

Try a Klein. It has the steep head angle, short but not
extremely short chainstays, and a not-so-long front end --
a happy medium. Basically, it's just like a Bridgestone,
but with slightly shorter chainstays.

Thanks for the suggestion. I'll look at them. I think they
price may be a bit higher than I want to spend for a bike
that gets ridden a few times a month. Or maybe I'll like it
so much that I'll change my habits...

--
Dave dvt at psu dot edu

R15757 said:

The 18" Salsa Bandito with Fox forks feels tall and steep
and is responsive almost to a fault, very different from
the sluggish and stretched out Fisher, which is a great
descending bike but not great climbing bike.

Thanks for yet another suggestion. I'll look at it.

Quoted message said:

But maybe you don't really need shocks after all. You
weren't just imagining the great feel of your old bike.
Depending on the smoothness or lack thereof of the local
trails you might want to go with a fully rigid Ritchey P-
whatever.

On the old rigid bike, I would get a sore lower back after
an extended ride. Especially if the ride was bumpy. I hope
that suspension will help with that problem.

Quoted message said:

I used to ride a Bridgestone MB-0 and it was just an
imitation Ritchey. Some singletrack is made for a bike
like this.

When I rode mine, it sure felt like some trails were made
for that bike. I think the MB-1 was very similar to the MB-
0. And the Ritchey logos all over the bike were a pretty
good clue as to the bike's designer. Memories...

--
Dave dvt at psu dot edu

Kevin Cullen said:

Rocky Mountain's steel hardtails might interest you. The
Blizzard (frame-only, Reynolds 853) and Hammer (Reynolds
725) have shorter top-tubes than even the Klein, but with
a similar wheelbase for any given frame size. According
the the companies' Web sites, the 19.5" Rockies are 0.7
inches shorter than the Klein Atitude of comparable size.

Thanks for the suggestion. I'll check it out.

Quoted message said:

I only suggested steel because you loved the ride of your
Bridgestone. Rocky Mountain also makes the Vertex aluminum
hardtails, which have slightly shorter wheelbase and top
tube than the steel bikes.

I'm not a believer in the differences of frame materials,
especially when suspension is involved. So maybe I should be
looking at the Vertex.

Quoted message said:

Then again, memories can be hard to beat.

You are probably right, but I sure hope you're wrong. 🙂

--
Dave dvt at psu dot edu