I can think of enough reasons of my own not to proceed with this enterprise, so I am really hoping to hear from the " can do, here's how" types on this one.
I had a guy come in to my shop this week carrying an old bent up Raleigh that his wife had driven over, and a new, light as paper Rocky Mountain "road" frame someone had given him. His hope was that I could salvage some parts from the (very) old bike, and transplant them to the new frame. I tried to discourage this notion, realizing that the cost was going to escalate well beyond what he was hoping for, considering that the only salvageable part was the crankset.
However, I should note that this guy is very tall, probably in excess of 6'6, and has a lot of difficulty finding a bike to fit, and I had nothing in the shop that was close to his size. I don't know the size of the frame he brought in, it is not marked, and I havn't measured it , but it is very large.
So, ok, at his insistence, we go ahead and order up a Sora parts group for it, complete with a 700c wheelset. It was only when I went to install the wheels that I realized this must be a TT frame as those 700c wheels are not going in there. (Yeah, I know, shoulda checked that out beforehand, but....). Alright, so we will put in 650c if that is what it takes, but I can't find a source anywhere for anything but ultra skinny tires, and this guy wants to ride on rail trails and the like, so I would really like to find something at least 32 wide. That is probably the widest the fork would safely accomodate. Even Harris lists nothing wider than 28, and none of my suppliers have anything even that wide.
So, all that is a long way to lead up to these two questions. First, is it safe to assume if 700 is too large that it is in fact 650c? Is there a dropout to brake mounting bolt measurement or anything like that which would confirm apropriate wheel size?
OK, three questions, where can I find 650c x 32 tires?
Thanks
Dan Burkhart
Cycling Equipment · Public discussion
Free frame not so cheap. 650c question.
Thread navigation
Jump through the discussion
Go to the original post, the replies on this page, or the latest preserved contribution.
Thread details
What we know about this thread
- Original section
- Cycling Equipment
- Published
- 14 April 2006
- Last activity
- 23 April 2006
- Original author
- Dan Burkhart
- Posts
- 8
- Discussion status
- Public discussion
- Total views
- 651
- Views / 30 days
- 0
- Topics
The navigation and discussion metadata provide context. Posts remain in their original chronological order.
-
-
Dan Burkhart said:
So, all that is a long way to lead up to these two questions. First,
is it safe to assume if 700 is too large that it is in fact 650c? Is
there a dropout to brake mounting bolt measurement or anything like
that which would confirm apropriate wheel size?
OK, three questions, where can I find 650c x 32 tires?Measure dropout to brake mounting bolt distance, it's roughly
equal to rim radius + brake reach. (I say roughly because
the bead seat and the brake track could be a few mm apart.)
Typical short reach brakes are 39-49 mm, 650c wheels are
571mm bead diameter so 285.5mm radius. 700c are 622mm
diameter, 311mm radius.
http://www.sheldonbrown.com/tire-sizing.htmlAFAIK there are no really wide 650c tires and they probably
wouldn't fit in a TT bike frame anyway. If the frame really is
for 650c and short reach brakes, you could try putting in
MTB 26" wheels (559mm bead diameter) and possibly
long reach caliper brakes, and use 26x1.25" or so tires.
The smaller rim could buy extra tire clearance.
You would probably have to respace the rear hub down
to 130mm. At least you probably have 26" wheels lying
around to try and see if they fit.This is kind of a hack. Does Cannondale
still sell the touring frames in really big sizes? -
quote=''Dan Burkhart said:
So, all that is a long way to lead up to these two questions. First,
is it safe to assume if 700 is too large that it is in fact 650c? Is
there a dropout to brake mounting bolt measurement or anything like
that which would confirm apropriate wheel size?
OK, three questions, where can I find 650c x 32 tires?Measure dropout to brake mounting bolt distance, it's roughly
equal to rim radius + brake reach. (I say roughly because
the bead seat and the brake track could be a few mm apart.)
Typical short reach brakes are 39-49 mm, 650c wheels are
571mm bead diameter so 285.5mm radius. 700c are 622mm
diameter, 311mm radius.
http://www.sheldonbrown.com/tire-sizing.htmlAFAIK there are no really wide 650c tires and they probably
wouldn't fit in a TT bike frame anyway. If the frame really is
for 650c and short reach brakes, you could try putting in
MTB 26" wheels (559mm bead diameter) and possibly
long reach caliper brakes, and use 26x1.25" or so tires.
The smaller rim could buy extra tire clearance.
You would probably have to respace the rear hub down
to 130mm. At least you probably have 26" wheels lying
around to try and see if they fit.This is kind of a hack. Does Cannondale
still sell the touring frames in really big sizes?[/QUOTE]Thanks. I did try a 26" in the front, but it will require an extra long reach brake. The fork has reccessed mounting, so I may face some challenges there. Also, it is a carbon fork, and the legs bulge inward, so in this case, the smaller rim gets you less clearance.
Dan -
"Dan Burkhart" <[email hidden]> wrote in
message news:[email hidden]...Quoted message said:
Quoted message said:
Dan Burkhart said:
So, all that is a long way to lead up to these two questions. First,
is it safe to assume if 700 is too large that it is in fact 650c? Is
there a dropout to brake mounting bolt measurement or anything like
that which would confirm apropriate wheel size?
OK, three questions, where can I find 650c x 32 tires?Measure dropout to brake mounting bolt distance, it's roughly
equal to rim radius + brake reach. (I say roughly because
the bead seat and the brake track could be a few mm apart.)
Typical short reach brakes are 39-49 mm, 650c wheels are
571mm bead diameter so 285.5mm radius. 700c are 622mm
diameter, 311mm radius.
http://www.sheldonbrown.com/tire-sizing.htmlAFAIK there are no really wide 650c tires and they probably
wouldn't fit in a TT bike frame anyway. If the frame really is
for 650c and short reach brakes, you could try putting in
MTB 26" wheels (559mm bead diameter) and possibly
long reach caliper brakes, and use 26x1.25" or so tires.
The smaller rim could buy extra tire clearance.
You would probably have to respace the rear hub down
to 130mm. At least you probably have 26" wheels lying
around to try and see if they fit.This is kind of a hack. Does Cannondale
still sell the touring frames in really big sizes?Thanks. I did try a 26" in the front, but it will require an extra
long reach brake. The fork has reccessed mounting, so I may face some
challenges there. Also, it is a carbon fork, and the legs bulge inward,
so in this case, the smaller rim gets you less clearance.
Dan--
Dan BurkhartI'm very curious to see how it plays out. Keep us updated.
--
Phil, Squid-in-Training -
Quoted post said:
AFAIK there are no really wide 650c tires
The Terry Tellus is 28mm - the only one over 23mm AFAIK.
Quoted message said:
... and they probably
wouldn't fit in a TT bike frame anyway.That's likely. That's easy enough to determine (measure the actual
width of the current tire, measure the current clearance and see if
the clearance is greater than 28 minus the actual width.Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame -
Dan Burkhart wrote:
About wheel/frame woes.Dan, the only possible idea I have for wider tires on a 650c-sized
frame would be to try the recently revived 650B (584 mm) wheel-tire
size. However, as 650B is a bit larger than 650c, and as the smallest
650B tires available are in the 30 mm range (apparently they go all the
way up to 42 mm if you can find them), I wouldn't count on them fitting
this bike. AND, if they do fti, the combination of larger wheels and
larger tires MAY make the bike not fit your customer. And -- is a TT
bike the ideal vehicle for off-road riding?On the 559 (26 inch mountain bike wheel) front, apparently Tektro is
just about ready to launch a very, very long reach sidepull -- in the
77 mm reach range. Alternatively, DiaComp has apparently come up with
some DC 750 centerpulls, either New Old Stock or new production, that
also has a reach as long as 77 mm.Harris Cyclery (Sheldon Brown's outfit) and Rivendell Bicycle Works
have some of the 650B stuff and possibly those big ol' brakes. Hope
this helpsRobert Leone [email hidden]
-
Mark Hickey said:
Quoted post said:
AFAIK there are no really wide 650c tires
The Terry Tellus is 28mm - the only one over 23mm AFAIK.There are also the Serfas Urbana 28-571 tire and various Bontrager
models of 25-571 tires.--
I do not accept unsolicited commercial e-mail. Remove NO_UCE for
legitimate replies. -
Phil said:
"Dan Burkhart" <[email hidden]> wrote in
message news:[email hidden]...Quoted message said:
Quoted message said:
Dan Burkhart said:
So, all that is a long way to lead up to these two questions. First,
is it safe to assume if 700 is too large that it is in fact 650c? Is
there a dropout to brake mounting bolt measurement or anything like
that which would confirm apropriate wheel size?
OK, three questions, where can I find 650c x 32 tires?Measure dropout to brake mounting bolt distance, it's roughly
equal to rim radius + brake reach. (I say roughly because
the bead seat and the brake track could be a few mm apart.)
Typical short reach brakes are 39-49 mm, 650c wheels are
571mm bead diameter so 285.5mm radius. 700c are 622mm
diameter, 311mm radius.
http://www.sheldonbrown.com/tire-sizing.htmlAFAIK there are no really wide 650c tires and they probably
wouldn't fit in a TT bike frame anyway. If the frame really is
for 650c and short reach brakes, you could try putting in
MTB 26" wheels (559mm bead diameter) and possibly
long reach caliper brakes, and use 26x1.25" or so tires.
The smaller rim could buy extra tire clearance.
You would probably have to respace the rear hub down
to 130mm. At least you probably have 26" wheels lying
around to try and see if they fit.This is kind of a hack. Does Cannondale
still sell the touring frames in really big sizes?Thanks. I did try a 26" in the front, but it will require an extra
long reach brake. The fork has reccessed mounting, so I may face some
challenges there. Also, it is a carbon fork, and the legs bulge inward,
so in this case, the smaller rim gets you less clearance.
Dan--
Dan BurkhartI'm very curious to see how it plays out. Keep us updated.
--
Phil, Squid-in-TrainingWell,we completed this project today, and delivered the bike to a satisfied customer. I ended up going with 26" wheels and side pull brakes. I tried a set of Tektro long reach, but they were not long enough. We put on a set of IRC 26 x1.0 tires, and the clearance looks good. Had to do a bit of modifying to the brake mounting bolts to get them to work with the recessed mounts. We cut the threads further up the bolt, cut them to length, and secured them with the reccessed nut. They seem to work fine.
I was concerned about pedal ground clearance, and it looks kind of close, but it takes a pretty good lean before contact.
I don't have the ability to post pictures, but I can e-mail them if anyone is interested. You might get a laugh out of it. It's pretty funny looking.
Dan
Active in the last 60 minutes
Active in this thread
0 users · 0 guests ·0 bots ·0 total
No signed-in users are active right now.
No known search crawlers active right now.