Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Folding Bikes Discuss the unique features and issues of folding bikes. Also a great place to learn what folding bike will work best for your needs.

Reply
 
Thread Tools Search this Thread
Old 06-04-09, 09:56 AM   #1
pyarnall
Newbie
Thread Starter
 
Join Date: May 2009
Bikes:
Posts: 3
Downtube handlebar stem alignment mod

I have acquired two new 9FSs in the past two weeks. I spent a lot of time researching folders and the Downtubes seemed to be the best bang for the buck. Now that I have had them and ridden them I can say that I am very pleased with the choice. Great value.

The one feature that is missing, in my view, is mechanical "keying" of the handle bar stem to the base tube. Every time I adjusted the handle bar height it took me several tries to get the bars perfectly square to the front wheel.

The Dahon folders have a design feature for doing this. I decided to add a few small parts to achieve this function on my DT. I have installed this mod on both bikes and it is working very well.

If you are curious, I have posted a small group of photos of the mod on my photography site. This will take you straight to the gallery, or you can get there from my website, imagesbypyarnall under "Pages". http://www.imagesbypyarnall.com/ibpy.../downtubestem/

Contact me if you would like more details. I now consider it an added layer of safety in case the clamp is accidentally released while riding, though that seems admittedly unlikely.

P Yarnall
pyarnall is offline   Reply With Quote
Old 12-19-09, 01:16 AM   #2
Brimstone
Senior Member
 
Join Date: Oct 2006
Bikes:
Posts: 54
Nice but...wouldn't a line with a Sharpie marker have been a lot easier? That's what I do with my seatpost.
Brimstone is offline   Reply With Quote
Old 12-20-09, 02:37 PM   #3
pyarnall
Newbie
Thread Starter
 
Join Date: May 2009
Bikes:
Posts: 3
Quote:
Originally Posted by Brimstone View Post
Nice but...wouldn't a line with a Sharpie marker have been a lot easier? That's what I do with my seatpost.
Easier than what? I can tolerate a slight misalignment in the seat with respect to the frame, but not the handle bars. When I use the bikes around home I might not change anything for weeks, but I also take them with me on camping outings. In that setting the bikes might be folded and unfolded several times a day. Getting the handle bars square on two bikes after every set up was a real annoyance. The mere act of securing the stem clamp which adds a torque reaction to the front end, in turn resisted by trying to wedge the front wheel between your knees usually resulted in several tries to get things "square". Add to that the occasional height change and the realigning process had to be repeated. Drove me nuts.

In addition to keeping the handle bar stem aligned, it also adds a safety feature..... if the clamp comes loose I do not loose the ability to steer the bike.

In any event, since I have a design and prototyping background, I am accustomed to fixing or improving what ever is in front of me. For me, this was clearly a problem that needed fixing. If it is not a problem for you then it does not need fixing. I posted my efforts to suggest a possible solution to others who might share my annoyance at the lack of an alignment feature..... a feature found in many other folders.
pyarnall is offline   Reply With Quote
Old 12-20-09, 05:43 PM   #4
AEO
Senior Member
 
AEO's Avatar
 
Join Date: Jun 2007
Location: A Coffin Called Earth. or Toronto, ON
Bikes: Bianchi, Miyata, Dahon, Rossin
Posts: 12,258
nice mod.
I had that sort of problem with my dahon, where if I put down enough power, I would twist the bar alignment.
__________________
Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
http://sanfrancisco.ibtimes.com/arti...ger-photos.htm
AEO is offline   Reply With Quote
Old 12-20-09, 06:00 PM   #5
chucky
It's got electrolytes!
 
chucky's Avatar
 
Join Date: Aug 2009
Bikes: Self-designed carbon fiber highracer, BikesDirect Kilo WT5, Pacific Cycles Carryme, Dahon Boardwalk with custom Sturmey Archer wheelset
Posts: 1,388
Nice mod, but now you can't rotate the handlebars sideways. I find this ability almost as convenient/important as being able to fold the frame in half.
chucky is offline   Reply With Quote
Old 12-21-09, 06:59 AM   #6
pyarnall
Newbie
Thread Starter
 
Join Date: May 2009
Bikes:
Posts: 3
Chucky, I overcome that issue by simply pulling the handle bar stem all the way off the base tube when folding and just nestle the handle bar assembly into the folded assembly. When traveling the bikes are usually on a hitch platform which has only a limited amount of clearance to the slide in camper just above it, (camper extends past the bed of the truck). With the handle bar and stem completely withdrawn from the stem I can get the whole package height further reduced. Admittedly it adds (literally) a few seconds to the set up but that is more than offset by not having the alignment hassle.
pyarnall is offline   Reply With Quote
Old 12-21-09, 08:32 AM   #7
chucky
It's got electrolytes!
 
chucky's Avatar
 
Join Date: Aug 2009
Bikes: Self-designed carbon fiber highracer, BikesDirect Kilo WT5, Pacific Cycles Carryme, Dahon Boardwalk with custom Sturmey Archer wheelset
Posts: 1,388
That won't work for me because I still need the sideways (unfolded) bars to roll the bike around (whether the frame is folded or unfolded). I also hook the sideways (unfolded) bars over my shoulder and carry the folded bike under arm.

I'm sure it's a great mod for some people, but I think I'll continue aligning my bars by bracing the wheel against the straight of my foot.
chucky is offline   Reply With Quote
Old 12-21-09, 03:52 PM   #8
jur
Senior Member
 
Join Date: May 2005
Bikes:
Posts: 6,788
Nice mod. Reminds me of some of the mods I have done over the years.

Suggestion: Shortening the square rod will allow you to rotate the bars by pulling the stem up just a little way.
jur is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 05:38 PM.