Catbike review

[Oldfrt]

Are you sure the chain was sized properly after the boom length was set I don’t get any chain slap on mine.  The only problem I have had was when the bike fell while I made a pit stop, then chain fell off the little idler and it took a couple of minuets for me to figure out why I had a chain rubbing. 

I haven’t had any chain rubbing on my seat stay and the chain tube still looks good with no appreciable wear indicated, I have just under 600 miles on it.  I do get more noise out of the tube when on the top sprocket when at a high cadence.  I do keep the bike on smooth pavement as much as possible and stay away from any gravel trails.

If I go with a Schlumph High Speed Drive on mine then I will make a bracket to lower that small idler and use it to accommodate dual teracycle idlers since there is no need for the chain deflection with one sprocket.  This may solve your problem; unfortunately it isn’t a cheap fix.

You might want to look at getting or making something like the adjustable idler mount that Utah trikes has.  If you lower the bottom idler (the one under the seat) it should move the chain line farther away from the seat stay, the same result can be had by lowering the small idler, I may be doing that so I can use a teracycle idler when the little one wears out. 

I don’t see anything wrong with trying the two chain tube routing, it would defiantly remove the side pull coming off the large sprocket on the return, and the only downside would be the additional friction on the chain with the extra tube.  They put the small idler up there to keep the chain off the wheel on the return; otherwise it would have the restrictions like the rest of the low racers where you can’t turn the wheel without contacting the chain with the wheel.

Dennis

[trplay]

Yes the chain is the proper length.  I think I might try the two chain tubes but will wait on Trikebldrs thoughts.  I hate to shorten the chain only to have to put links back in because there is some obvious reason this is a dumb idea.  It seems I have a streak of bad ideas going right now.

[Oldfrt]

I understand, do you ever get the feeling they rushed the short frame version to market?

Dennis

[trikebldr]

Oldfrt, trplay's bike is the short-frame version and they are competely different. The solution for your's won't even fit on his. All you need to do is get a longer bolt for that upper idler and add a second idler. Personally, I would mount both idlers on a clamp-on unit from Terracycle right at the base of your headtube. I explained all of this earlier in this thread (reply #3 on the first page) with pictures of a white version of your bike showing new idler location and new chain routing. That third pic of a blue one is YOUR bike!

Trplay, the chain rub on the seat tube is an easy fix with a simple 6" piece of chain tube, especially since it is just the return side. With properly flared ends you won't hear a thing from it!

But, the total fix for your short-framed version would be to mount the original double idlers under the seat about 3" farther forward on a Terracycle clamp-on mount. This will shift that pesky return chain far enough away from the seat tube to not rub anymore. After doing that, the cure for the chain running long the tire would be to get a power side idler from Terracycle and mount it alongside the original upper idler on a longer bolt and run your power side chain over the new idler. This clears the tire and also gets rid of the chain crossover. The only drawback to this will be that it MAY, and I repeat, MAY require that you shift your front derailleur up a bit to get it to clear the new power side chainline. I know you don't want to hear this part, but the REALLY right way to complete this would be to replace the original boom with a trike boom that has the der post at the correct angle to accommodate this new power chain angle. However, if you don't want to go this far, simply shifting your der up a bit will get the job done.

Did this all make sense? I found a pic online that was profile enough of a short-wheelbase version and did some drawings from it to verify these changes would work. The clamp and new power idler from Terracycle will cost $96, and Pat will work with you to get the correct bolt length to fit the orignal double idlers on the clamp. Any hardware store can supply the longer bolt for the addition of the new idler up front. Below is the link to Terracycle's page where you can see that "Catrike Clamp-on Front Power Idler Kit". It is about the sixth pic down in the listing on a red frame.

http://www.terracycle.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=T&Category_Code=IdlersALL

[trplay]

I dont think the issue is rushing the short frame. Its more  that they do not have an effective R&D program.  More specifically a testing program before  they field a product.  They use the customer which is cheaper. But this will cost them in the long run,  it always does.  This issue isn't just on the short frame others have checked their standard frames and found the same thing.  I suspect once you put more miles on less than smooth roads  you will have the same issue.  Time will tell.

[trplay]

Thanks for the reply Trkbldr.  I know you're correct in the redesign I just hate going that way with a brand new bike.  I'm going to have to think on this a bit.  My DF frame sure looks pretty and efficient after all this crap. 

[trikebldr]

Yep! I hear ya! But, this is just something we all have come to expect when buying a Cat-anything and want it to be perfect. Big Cat simply engineers his products for efficient and economical production to keep the cost down for us. Adding idlers would drive the cost up too much to suit him.

Just a final thought here; if you are decide you are willing to invest the almost $100 in the new clamp and idler, I will send you the new trike boom that I have on hand. It is yellow and a standard length, but can be cut down to fit. If it works to give you the perfect chainline with no problems, then it will prove that a new black TRIKE boom will be worth the efforts and cost. You would be a pioneer! If it doesn't work, I will buy the clamp and new idler from you. If it does work, just send the cut-to-size boom back to me and I will get it powdercoated black, then face the ends of the shell for you, all for just $100. I only paid $50 for the boom, and I think I can get it re-coated for less than $50. 

Bottom line is that it will all cost you about $200 if it all works well. If it isn't what you want, it will cost you nothing except shipping of the boom, clamp and idler back to me.

Wait a minute!!! I have clamps and idlers if the Mushie's frame tube is the same diameter as the tube on a trike! If you will pay shipping costs, I will ship the boom, clamp and idler for you to try. If you need to you can cut the boom down to fit. If it all fits, though, my idler will cost more because it is one with the titanium cog and has ceramic ABEC7 bearings in it. I want it back!!! It's also slightly modified!

So, what do you think? Are you game for one of my hair-brained ideas?

[trplay]

Oh you're killing me with desire.  Right now I am pretty maxed out BUTgive me a little time to let it all sink in.  Meanwhile I scurried to measure the boom which turns out to be 45.1mm.  Do we have a fit?

[trikebldr]

I don't have my mikes handy, but my silly millimeter ruler says 45mm. If you compare your's to one of your trikes, that will tell you. However, remember that Paulo changed the OD of the boom tubing about a year ago without telling us about it until a bunch of trikes had VERY slopping fitting booms and they had to make up a new shim to make them fit. Since my spare boom is less than three months old, and so is your bike, I would be willing to bet a lot of money that they are the same diameter. Big Cat isn't going to introduce a totally different material into their production line.

Tonite I will grab my caliper and see if it measures exactly 45.1mm like your's, but I am 100% sure that it will. What is the der post diameter of your's? What is the total length of the boom on your bike, fom end to end, totally?

Damn, how come everybody with interesting projects has to live so far away from me?

[trplay]

check this chain line.

[Oldfrt]

That looks a lot like a Challenge Jester, I wanted one of them instead of the Musashi but it was just a lot easier dealing with a statside manufacturer and a local established dealer.

Dennis

[trplay]

Those are beautiful bikes but my interest lies in that chain line.  To my inexperienced eye it looks like my Moosashi could run the identical path.  Of course even if it could I have no idea if the Zockra chain line has its own problems or not?  Trikebldr,  I'll be pulling my boom tomorrow for measurements.

[trikebldr]

Trplay, you are absolutely right! If you just lift your return chain off the upper idler you would have what they have. It would eliminate two problems. First, no more crossover, and then no more seat tube rub.

The downside is that it limits the amount you can turn, and both chains will flop around a whole lot. If you can live with those limitations, go for it and simply lift your chain off the small idler to try it. You won't even have to remove any links just to try it if you leave your chain on the big ring up front.

I did a side-by-side pictorial comparison between your moosh and that swoopie bike and they come out almost exctly alike as far as where the chains run by the front wheel.

[trplay]

total length boom =  12 inches   tip to tip

boom diameter       = 45 mm sometimes 45.1

Der Post                 =  32.1  sometimes 32 mm

Possible problem:   the distance where the adjustable idler would go on neck only allows a flat space (attachment of clamp)  of 6.1 mm because of welding gum.

I tried the method used on the Zockra bike on the Moossashi and it was awful.  The weight of chain w/ slop will cause continuous contact with fork.    I must be missing something?

[trikebldr]

I don't think you're missing a thing! Bike like the Zockra are purpose-built machines intended to go fast on smooth pavement. (I'd pay good money to see somebody enter one of them in a MTB race!) They are focused on simplicity and light-weight, and another idler arrangement would add complexity and weight. Strictly race stuff! Racers couldn't care less if they stand up on the podium showing chain tattoos and no paint on the right side of their bike. If it gets them across that finish line first, who cares?

Maybe a pair of long tubes to keep the chain from rubbing the forks would work acceptably? They can be anchored at the idler bolt.

You and I, however, are concerned with more everyday praticality. Like I said in my last post, "If you can lve with (it)...". I couldn't! Even as much of a weight weenie as I am, certain minimum requirements must be met for enjoyable riding.

TWELVE INCHES?!!!!?!!!!!? Are you kidding? Is it bottomed out to make it fit you? Sounds like a bottom bracket shell welded dirrectly to the end of the frame tube would have worked. I didn't know you were a midget! Just funnin' ya!