[Yak] Improper routing of hyperfold cable on tikit; and other issues

[Vik]

Hi Sean,

1) , 2) & 3) I don't think you'll be able to avoid some paint wear in  
metal on metal contact areas like this.  I'm also not sure that it  
matters.  I don't notice it when using the bike from an asthetic  
point of view and I've used my Tikit all last winter and all this  
rainy summer - I have zero rust in the areas in question.  I assume  
the same metal on metal contact that caused the wear keeps corrosion  
at bay.  I noticed these issues a while back, but I can't say it  
bothers me at all and I don't see any long term problems resulting.   
The paint will wear through, but I can't see you wearing away the  
metal and causing any damage.  I'm no expert though, but there forces  
and mechanics that I can see don't cause me concern.

4) my hyper-fold cable is routed so that nothing is underneath it  
other than the BB shell.  My insulation is just starting to wear  
through at this point.  I'm not sure what if any long term problems  
this may cause.  I'll leave that question to some folks with a better  
understanding of properties of the materials involved.  I definitely  
wouldn't want anything under the hyperfold cable as I can see that  
would cause issues.

5) if what we are talking about is the part of the frame where the  
seatpost clicks into the rear triangle I can't see how that would be  
a safety issue.  Even if you unclipped the seatpost while riding the  
rear triangle is held in place by your weight on the bike.  The  
seatpost assembly is held in place by your weight on the seat so it's  
not going anywhere either.  When you get out of the saddle on the  
Tikit the seatpost becomes unweighed, but there is no force to pull  
the seatpost up and rotate it forward to release it.  Worst case if  
that did happen the bike would still be rideable.  The only impact I  
can see with how securely the seatpost assembly clicks in is how easy  
it is to fold the Tikit and how much force you can use when lifting  
the bike by the seatpost. I don't see any safety issues here at all.

You mentioned my post on Bike Forums and don't seem to know why I  
prefer the easier seatpost release of one of my Tikits to the harder  
release of the second.  Well simply put since there is no safety  
issue with the easier release and since the seat won't release while  
riding - I prefer the easier release because it makes folding the  
Tikit even more effortless.

safe riding,


Vik
vikbanerjee at gmail.com
www.vikram-banerjee.com
www.thelazyrando.com
www.viks-tikit.com
www.viks-bigdummy.com




On 13-Sep-08, at 11:03 AM, Sean Luke wrote:

> Lalato over at Bikeforums (http://www.bikeforums.net/showpost.php? 
> p=7440450&postcount=18) noted a problem with his tikit, and I had  
> the same problem today.
>
> Specifically, at least some (if not all, not sure) tikits appear to  
> have improper routing of their hyperfold cables: it's routed so as  
> to crush the gear cable between the hyperfold cable and the bottom  
> bracket (or the second "bottom bracket"-ish item on the rear  
> triangle) when the bike is unfolded.  Eventually, the pressure gets  
> through the gear cable insulation and crimps the gear cable.
>
> I have rerouted the hyperfold cable to go UNDER the gear cable, but  
> am not willing to ride the bike yet until I fix another hyperfold  
> cable problem: it quickly eats through its insulation and will  
> start ripping into the bottom bracket paint now that it isn't being  
> separated from the paint by the pinched gear cable.
>
> I posted a week or so ago about paint chipping problems due to the  
> cup on the rear triangle, and didn't get any responses back :-( --  
> perhaps lost in the deluge of the BF repair turnaround-time  
> thread.  So I'm adding to it.  The Tikit appears to develop paint  
> wear in several important locations.  It's not an aesthetic issue:  
> it's an issue of exposing the frame to rust, and wearing away the  
> metal due to frame-on-frame rubbing. I'm wondering what should be  
> done about any of these:
>
> 1. The "cup".  I got some irritated email from folks about this  
> one, so it looks like I'm not alone (though not irritated  
> myself!).  The cup wears paint away from the top tube near the  
> bottom bracket.  Ideas about some kind of neoprene gasket we can  
> stick in there to prevent this?  (or if it's a good idea?)  Or how  
> to repaint the chipped out regions so as to protect them?
>
> 2. The tongue (on 2007, the item with the "slot", on 2008, now has  
> a "hole" for the pin).  Here the metal is exposed because of the  
> pin rubbing against it prior to going into the pin; and because of  
> the paddle rubbing against it when releasing the pin.
>
> 3. The paddle and pin.  Both have wear for the same reason as the  
> tongue.
>
> 4. The hyperfold cable.  The cable wears through its insulation  
> almost immediately.  It then either starts pinching into the  
> underlying brake cable or starts wearing into the paint.  Metal-on- 
> metal rubbing (cable-to-bottom bracket) is not a good thing safety- 
> wise. This definitely requires much tougher insulation or a rubber  
> gasket near the bottom bracket.  Or both.
>
> 5. The seatpost clamp.  At least on my tikit, the clamp is arranged  
> as a straight slot with a slightly wider diameter circular end.   
> Thus the pin pushes through the slot and then pops into the  
> circular end and holds there (supposedly) so it doesn't slide out.   
> However after riding, the seatpost clamp pin wears away the paint  
> on the inside diameter of the circular end.  Here the pin is  
> rubbing directly against the frame metal.  That's probably not an  
> issue if the pin is made of a softer metal than the frame metal,  
> and so we just replace the pin every once in a while as  wear  
> causes the pin to more easily pop and slide out of the clamp. But  
> if the pin's a harder or equivalent metal, we may have a  
> significant problem as that circular hole starts wearing away.  On  
> BikeForums there's been discussion of the pin too easily sliding  
> out of the clamp: Vik noted that on one of his bikes it slides  
> immediately (which he prefers for some reason).  I believe this  
> should be considered a safety issue.  Here's hoping that pin is  
> softer metal.
>
> #1, 2, and 3 are long-term frame wear issues; BF would be wise to  
> look into insulation options or these could turn into frame  
> warranty problems down the line.
>
> #4 and #5 are safety issues and it'd be good to address them sooner  
> than later.
>
> Ideas on how to deal with them?  Aesthetics aside...
>
> Sean
>