La Bicycletta

Xstr8edgtnrdrmrX

Diamond Member
This looks like what I need here. It's modern so parts will be easy to find. It's light. It looks way cool. And it's 26 in rims. For what I use a bike for - daily riding for exercise and errands - I think this is perfect:


It says full suspension, but I can only locate suspension on the forks, making this a hardtail MTB.

is it actually a Scott 980cb? I can't get CL at work, but looked up the model number at Eurobike...it is a hardtail
 

rhumbagirl

Senior Member
is it actually a Scott 980cb? I can't get CL at work, but looked up the model number at Eurobike...it is a hardtail
Don't know. Who is Scott? I'm probably going to throttle back my search while the Wheels Manufacturing 4130 axle gets shipped to me. All the indicators are pointing to a 26 in wheel with freehub and 8-spd derailler set and new shifters. But I do need a used bike while I screw with the current one.
 

rhumbagirl

Senior Member
So I got tired of explaining bicycle measurements to sellers on ebay and made this colorful chart. Stack and reach are probably the main measurements for standup riders, although the effective top tube length would help determine frame size. But how do you explain to the average joe what a plumb line is and how to use it? I think it would very challenging for the average joe to hold the plumb steady while measuring the horizontal distance to the top-center of head tube simultaneously.

1641967576509.png
 

cbphoto

Diamond Member
So I got tired of explaining bicycle measurements to sellers on ebay and made this colorful chart. Stack and reach are probably the main measurements for standup riders, although the effective top tube length would help determine frame size. But how do you explain to the average joe what a plumb line is and how to use it? I think it would very challenging for the average joe to hold the plumb steady while measuring the horizontal distance to the top-center of head tube simultaneously.

View attachment 112611
Looks like what someone actually needs is a custom frame set. 🤔
 

rhumbagirl

Senior Member
Looks like what someone actually needs is a custom frame set. 🤔
What do you think about Specialized MTBs? Here's a 2002 Rockhopper on ebay for $499 used. I think that's what they cost new:

 

Xstr8edgtnrdrmrX

Diamond Member
So I got tired of explaining bicycle measurements to sellers on ebay and made this colorful chart. Stack and reach are probably the main measurements for standup riders, although the effective top tube length would help determine frame size. But how do you explain to the average joe what a plumb line is and how to use it? I think it would very challenging for the average joe to hold the plumb steady while measuring the horizontal distance to the top-center of head tube simultaneously.

View attachment 112611

I think the average joe selling a bike on CL,eBay or whatever is not going to put the effort into doing this much math honestly...

But you could explain a plumb line as a string with a weight on the end that determines "true vertical", and that the angles in your diagram are based on this true vertical establishment...

hell, I have been biking for 40+ years, and still really only know the difference in angles by feel...like, i know when a bike feels right. Only recently have I really been able to translate the numbers to a feel
 

rhumbagirl

Senior Member
hell, I have been biking for 40+ years, and still really only know the difference in angles by feel...like, i know when a bike feels right. Only recently have I really been able to translate the numbers to a feel
Maybe. Maybe I can ... well I *should* be able to measure the angles of the head tube, seat tube, top tube and bottom tube - and calculate the reach and effective top tube length.

Sally can't tell Oscar has a harry old ass:
Sine, Cosine, Tangent = Opposite / Hypotenuse, Adjacent / Hypotenuse, Opposite / Adjacent
 

Xstr8edgtnrdrmrX

Diamond Member
Maybe. Maybe I can ... well I *should* be able to measure the angles of the head tube, seat tube, top tube and bottom tube - and calculate the reach and effective top tube length.

Sally can't tell Oscar has a harry old ass:
Sine, Cosine, Tangent = Opposite / Hypotenuse, Adjacent / Hypotenuse, Opposite / Adjacent

I learned more about how the angles affect my riding in BMX than anything else.

A higher HT angle makes the bike more twitchy
A longer chainstay makes the bike more stable
TT length determines "fit" of bike and cockpit
BB height and ST angle affect standover(?)
A lower ST angle and HT angle makes the bike more slack <---from MTB
 

rhumbagirl

Senior Member
I learned more about how the angles affect my riding in BMX than anything else.

A higher HT angle makes the bike more twitchy
A longer chainstay makes the bike more stable
TT length determines "fit" of bike and cockpit
BB height and ST angle affect standover(?)
A lower ST angle and HT angle makes the bike more slack <---from MTB
I think the BB drop is small on a 26 in MTB because the small 26 in wheels puts the frame and the BB (and crank) closer to the ground. Don't want riders' feet hitting the ground while pedaling.

A longer chainstay makes the wheel base longer which removes stability at slower speeds.

Agree that BB height would affect standover, but not sure how ST *angle* does (ST height, definitely).

Agree on slack. That's something I'm not concerned about at 9-12mph average speed. I'd rather have stability up hills and turning tight corners (I ride on sidewalks, navigating around people, dodging glass, nails, pot holes).
 

Xstr8edgtnrdrmrX

Diamond Member
I think the BB drop is small on a 26 in MTB because the small 26 in wheels puts the frame and the BB (and crank) closer to the ground. Don't want riders' feet hitting the ground while pedaling.

A longer chainstay makes the wheel base longer which removes stability at slower speeds.

Agree that BB height would affect standover, but not sure how ST *angle* does (ST height, definitely).

Agree on slack. That's something I'm not concerned about at 9-12mph average speed. I'd rather have stability up hills and turning tight corners (I ride on sidewalks, navigating around people, dodging glass, nails, pot holes).

yeah 26ers are definitely closer to the ground by nature. My commuter is an old Trek 830 26er...it is perfect for that kind of riding. I can't believe it was actually sold as a MTB originally!! I would have destroyed that bike on the dirt

my current 29+ MTB still "bottoms out" sometimes if I am not carefull about how I approach things on the trail

and honestly, I would rather ride dirt than city riding because I can't stand drivers, but I do commute in the summer
 

cbphoto

Diamond Member
What do you think about Specialized MTBs? Here's a 2002 Rockhopper on ebay for $499 used. I think that's what they cost new:

I think you’d be settling, but I’ve not ridden that design for any distance.
 

rhumbagirl

Senior Member
I think you’d be settling, but I’ve not ridden that design for any distance.
Maybe. I did happen upon the Specialized "Stumpjumper", which is supposedly a souped-up Rockhopper. The problem is the Stumpjumpers I've located so far are too big in the frame size. The Rockhopper 17" above was even too big - 15.2/14.75 reach, 22.5/21.25 effective top tube length (their's/mine). Apparently the frame size for some MTBs are not aligning to the same for my Diamondback 18". I don't think they treat women's and men's bikes differently like they do shoes, but I suppose it could be the reason.

Anyway, I like the look of the Stumpjumper, and just want to find one with a smaller frame. Reach and Effective Top Tube Length are still the numbers that don't lie. Standover is important, but I don't see that number flying around a lot in the specs.

Correction: Reach for the Rockhopper is 15.2 in (not 15.5). This represents only 0.5 inch difference, but the Effective Top Tube difference is 1.25 in. That means the seat is 0.75 in further back than mine.
 
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cbphoto

Diamond Member
Maybe. I did happen upon the Specialized "Stumpjumper", which is supposedly a souped-up Rockhopper. The problem is the Stumpjumpers I've located so far are too big in the frame size. The Rockhopper 17" above was even too big - 15.5/14.75 reach, 22.5/21.25 effective top tube length (their's/mine). Apparently the frame size for some MTBs are not aligning to the same for my Diamondback 18". I don't think they treat women's and men's bikes differently like they do shoes, but I suppose it could be the reason.

Anyway, I like the look of the Stumpjumper, and just want to find one with a smaller frame. Reach and Effective Top Tube Length are still the numbers that don't lie. Standover is important, but I don't see that number flying around a lot in the specs.
As I’ve been following this thread, I’ve poked around at various bicycle sites. I’m still shocked that two different tires sizes is considered an option, and there’s 29” tires and front forks without the fork! I’ve been out of the loop a long time.

Old-King-Front-3-4_2000x.progressive_d902a155-d82e-415c-8e89-11d01574195a.jpg


The Stumpjumper was the first model Specialized introduced in the 1980s. It morphed a few times and by the early 1990s the Rockhopper was introduced at a lower price point. I have an original Stumpjumper and it’s old-school frame design: the seat tube is long. I don’t know what the geometry is on anything later than what I own. The newer designs would probably suit you better if you like to jump & fly & slide. If you like to cruise and speed around with street tires on asphalt, an old Stumpjumper would be perfect. I believe they also came in very small frame sizes.

Still, I’m honestly very surprised you can’t find a new, decent MTB with 26” wheels.
 

rhumbagirl

Senior Member
... and front forks without the fork!
That's both cool and silly at the same time LOL. I wonder what kind of metal they're using for that front hub. I'm not a materials engineer but isn't titanium the hardest metal??

Anyway, I found a triangle calculator on the web, and it works for all triangles, not just right triangles (triangles where one of the vertices is 90 deg):


(If you don't know where the beta symbol is on your keyboard - I don't - then just find it on the page and copy n paste)
 

cbphoto

Diamond Member
That's both cool and silly at the same time LOL. I wonder what kind of metal they're using for that front hub. I'm not a materials engineer but isn't titanium the hardest metal??
Yes, those bikes are all custom-built using titanium.

Anyway, I found a triangle calculator on the web, and it works for all triangles, not just right triangles (triangles where one of the vertices is 90 deg):


(If you don't know where the beta symbol is on your keyboard - I don't - then just find it on the page and copy n paste)
On a Mac, using option-s I get: ß
 

rhumbagirl

Senior Member
As I’ve been following this thread, I’ve poked around at various bicycle sites.
That's quite a list of custom frame shops in the USA. The first one I clicked on - Spectrum Bikes - closed last year. The second one - K. Bedford Customs - was pretty cool stuff (eg titanium frames!).

I suppose the next question is can they make a custom Stumpjumper frame, so all I would have to do is buy any old Stumpjumper and transfer the parts over. Although at that point, you'd be dumb not to go get the newest parts out there. $$$
 

Xstr8edgtnrdrmrX

Diamond Member
That's quite a list of custom frame shops in the USA. The first one I clicked on - Spectrum Bikes - closed last year. The second one - K. Bedford Customs - was pretty cool stuff (eg titanium frames!).

I suppose the next question is can they make a custom Stumpjumper frame, so all I would have to do is buy any old Stumpjumper and transfer the parts over. Although at that point, you'd be dumb not to go get the newest parts out there. $$$

you should look into waltworks frames as well : https://waltworks.com/framesandbikes/

he is a very very cool guy who has been making frames forever
 

MrInsanePolack

Platinum Member
I just read this article:


What say you, bike people? Should Walmart stop selling bikes to those who just want a bike and arent serious riders? I get the gripe, but average kids mom and dad arent going to buy a $500 first bike that he might not even ride. Would removing cheap bikes from department stores deter folks from wanting to ride a bike?
 
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