Birdy modification problems
 

Hi, I modified my Birdy 9speed monocoque (bought 2007) using Joseph Kuosac parts with work done by my local bike store. I changed the wheels to their carbon wheels with Kojak tyres, changed from a nine to a 10 speed capreo cassette (9-28) and a 56T chainring. The derailleur was changed to a long travel 105 with a 10 speed tiagra shifter. The bike is great to ride and much faster now BUT the gearing and derailleur are awful. The long travel derailleur almost touches the ground. The shifting is sort of awful as well, it shifts down well but shifting up it skips and slides. Any helpful suggestions? I was wondering about changing to a MTB short travel derailleur and matching shifter.

Before you go changing the rear derailleur again try to make sure that your rear derailleur is on the same parallel plane as the rear wheel/rear sprockets (you can use tool like, Derailleur Hanger Alignment Gauge to do this. Or go to your LBS to have them do it :-)

HTH,
awdnut

Thanks. This is how low it sits

From that pic, it seems to me that a fair few chain links can be taken out. That will get the derailer up higher and may improve shifting as well.

However, any bike mechanic worth his salt ought to be able to get the shifting right.

Thanks. I know a bike mechanic worth his salt and will take him the bike.

If the largest cog is 28T going to a MTB short cage rear derailer will make things worse, all things equal. I would change to a short cage (SS) shimano road derailer just to get more clearance.
Checking for a bent derailer/hanger is not a bad idea. I typically change the hanger by sticking a allen key into the derailer's mounting screw and eyeball it. Simply looking straight down at the derailer and cogs will give you a good idea whether the derailer is bent. Although I think a bent derailer (generally) results in symmetric problems.

How old is the housing and cables? Maybe you should -- or have a mechanic -- reconsider the routing and thoroughly grease the cables to get a smoother action. How old is the shifter and derailer?

actually the cage length is for chain slack take-up, reduce the amount of chain length difference

with just one chainring, and a 9-26t cassette you can use a short cage RD..

(Big+big )-(small+Small) is the slack difference in tooth counts.

[and if a 2nd chainring at all , keep the difference small.. say a 48-56..]

(non birdy owner)

http://i160.photobucket.com/albums/t...y/IMG_0353.jpg

If you look at this pic of my Birdy you can see the chain is also on the biggest cog on the back but that the derailer is a fair bit higher. This is due to a shorter chain. With the Birdy there are some things which are critical to the success of the rear derailer function: Chain as short as possible, derailer must have a long cage, or the chain won't be gathered adequately when folding.

The shifting problems sound like the cable adjustment must be increased, ie screw the barrel adjuster so the cable housing gets longer.

http://i160.photobucket.com/albums/t...e.jpg~original

Here's another view, not in lowest gear unfortunately, but I remember clearly I had to make the chain as short as possible. That is a long cage LX.

How old is the housing and cables? Maybe you should -- or have a mechanic -- reconsider the routing and thoroughly grease the cables to get a smoother action. How old is the shifter and derailer?[/QUOTE]
Thanks. It's all brand new - cassette, cable, derailleur, shifter.

Hey that's very helpful jur and thanks for the pic

Changing to twflon coated inner gear cables can solve alot of upshifting issues in my experience.
I often add a pen spring also at the end of the cable.

wonder if the sort of widget Bike friday makes , a finger like piece, which bends over the chainring

so the folded chain slack
gets taken up there, as well as at the RD,, it is clamped around the BB shell


adding :it'sa DIY fabrication project now, but, the 3 pulley shorter cage ... for ground clearance ,

but 3rd pulley for chain wrap ... is re making a Design the Sun Tour RD Used to make ..

I think I have seen this solution somewhere in a photo originating in Asia.

Here is an update. I took the bike to my LBS. And they could not make it shift nicely. It shifts horribly. We shortened the chain. We adjusted the tension. It shifts horribly. It seems that the problems are in the cassette. The cassette does not appear to rotate completely true. Also the new crankset is also slightly out of alignment. So perhaps its a problem with the parts. Options now include:
1. Change the capreo free hub to a standard free hub and put on a standard road 10 speed cassette.
2. Take off this new 10 speed cassette and the new derailleur and new shifter and return to standard 9 speed Capreo
3. Find an alternate vendor of 10 speed capreo cassette (but I am unsure who makes this - anyone?)
4. Make a 10 speed capreo cassette with a 10 speed ultegra or 105 and the bottom parts of the capreo cassette.

Welcome any thoughts.

AFAIK, the Capreo is only made in a 9-speed, by Shimano. So that 10-speed version is a custom job, right? So it is possible that various cogs have been put together without due regard to the hyperglide matching. Especially shifting to bigger cogs would be problematic. Each cog has a shifting gate that sits aligned with the next bigger cog's chain pickup edges. This is why the cogs have a smaller gap in one place, to make sure these items are aligned on the freehub. If a shifting gate does not have chain pickup ridges next to it, shifting can be crap.

I wonder if Capreo has been discontinued by Shimano. I can't find any info on their site. Perhaps it is not a good idea then to go with Capreo if it is obsolete? This is actually the main reason I have stayed away from this product.

http://bikeforums.net/attachment.php...hmentid=376084http://bikeforums.net/attachment.php...hmentid=376085http://bikeforums.net/attachment.php...hmentid=376086http://bikeforums.net/attachment.php...hmentid=376087http://bikeforums.net/attachment.php...hmentid=376088http://bikeforums.net/attachment.php...hmentid=376089http://bikeforums.net/attachment.php...hmentid=376090http://bikeforums.net/attachment.php...hmentid=376091Yes, its a Joseph Kuosac 9-28 Capreo based cassette. They make wheels and lots of aftermarket stuff for small wheel bikes. They do a 10 and an 11 speed cassette for a capreo free hub. I have the 10 and its nothing but misery so far ;). I have a feeling there is a simple solution somewhere and have written to them for help. Let me post a photo of the cassette. Here is a photo of the shortened chain as well showing the derailleur a little higher.

Chain round the wrong way?
 

http://bikeforums.net/attachment.php...hmentid=376092http://bikeforums.net/attachment.php...hmentid=376093

I notice the chain says LF on the right side of the bike - its a 10 speed tiagra chain (HG4601) which is apparently directional. Is this chain round the right way and if not how much would that affect shifting?

The chain is directional yes, but it looks to be fitted correctly. The writing is supposed to be on the outside. At least that's the way with the Ultegra chain.

So the sprocket is machined out of one billet... No possibility of mismatched cogs then. One would assume that they know where to put the gates and the pickup ridges.

Maybe a SRAM chain would work better. The Shimano ones are quite special.

Take the chain off and eyeball the derailer, that it aligns exactly with the intended cog in each gear. (I spent many hours just this weekend fixing bad shifting; somehow the supposedly matched XT shifter over-reached the derailer such that alignment was not perfect over all cogs. I modded the derailer quite a bit to fix it.)

I believe Utah Trikes (among others) offers a 10 speed version as well. From the feedback I've gotten, they shift well.

That being said, I wouldn't otherwise dismiss your concerns. Mixing 9 and 10 speed cassettes in general does sound like a recipe to have a poorly performing drivetrain.

Ummmm.... Really?

Let me google that for you

Second hit.

As an OEM buyer Bike Friday would know, , Not Sure if I came across Caprio on the Shimano website in the past years
while it was in sales mode.. but then again I never looked that hard , since I dont have much intrest..

oh, my..
canfield micro drive hub..

http://p.vitalmtb.com/photos/users/2...jpg?1316072559

http://fcdn.mtbr.com/attachments/29e...t-hub-9-32.jpg

Should be easy enough to mount up a standard road 10sp cass to check things out.

If the cassette does not appear to be completely true, it could be the freehub body which is the issue, not the cassette. Again, mounting a standard road 10sp cass should make this apparent or not.

Finally, we had issues in the shop adjusting early run Tiagra running gear until we were told by Shimano Tech to swap out cable housing ferrules from plastic to metal.

Good luck!

I just had this conversation with another bud from Australia. So you're not alone Jur.

Long story short, Capreo is still available here in the US. Bike Friday and the Harris Cyclery folks both say that there has been no shortage or word of its demise.

The best part ... now that 9-speed is passe, the cassette is dropping in price.