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eggnoggbubble 06-04-09 02:39 AM

advice on converting to a longtail
 
2 Attachment(s)
Hi,

My sirrus has a nasty crack in the headtube (see photo) which apparently means I need a new frame.

However i want to go longtail for utility and child-hauling, so I've looked at various options (BD, Yuba, radish) and have decided to go with a cheap entry-level solution: I picked up what around here (japan) is called a mama-chari - like a dutch shopping bike i guess (see attached) and I want to convert it to a longtail with an xtracycle. (I am using the dogbike as my inspiration here - http://www.bikeforums.net/showthread...hlight=dogbike).

I also need to add gears because its a singlespeed at the moment. I am thinking I could take the gear setup from my soon-to-be-defunct sirrus and add it to the new bike. Any problems likely?

Also, the bike is a tad small for me, a longer seatpost should help, but is there anything I can do to extend the handlebars forward a little?I am not sure if i will need to but I'd like to know my options.

oh, and I know very little indeed about bicycles (yet!!) so suggestions are welcome!

thanks

jgrant75 06-04-09 03:46 AM

you can switch the drive train out easy if the bottom bracket sizes match. if not, there is probably a solution out there.

you may want to switch the hub out to use a disc brake. its most dependable.

you could get a longer stem to move the handlebars forward.(or different handlebars, longer cranks or a setback seatpost.)

looks like a 1" x quill. some bike shops don't carry these and online is the best option for choices.
http://www.google.com/products?hl=en...ell=1&oi=spell

you probably want a 80-110mm long stem

badmother 06-04-09 05:07 AM

Hello. Happy yoy like the dogbike. I should post some new pictures, there is progress.

my main concern when making it (I wanted a steptrough) was if the frame was strong enough. If you look at your frame and the dogbikes frame yours has got a deepeer steptrough curve. This makes the frame weaker. Maybe it is compensated by your frames seattube being shorter than mine and therefor the seatstays being attached lower. Not sure if it makes sense.

I originally ment to use a mixte for my Dogbike2 project. If you are going to buy a bike for this project (I use dumpster bikes) iI suggest buy a mixte, or at least a steptrough that is not so deep.

http://www.bikeforums.net/showthread...ighlight=mixte

qmsdc15 06-05-09 04:07 AM

No, I do not think it is possible to use the drivetrain from the Sirrus. Your mama-chari probably is not the same rear hub spacing, so the wheel won't fit. Also the frame probably doesn't have a derailleur hanger, the part of the frame that the rear mech bolts onto.

Sirrus Rider 06-05-09 08:18 AM


Originally Posted by eggnoggbubble (Post 9039168)
Hi,

My sirrus has a nasty crack in the headtube (see photo) which apparently means I need a new frame.

However i want to go longtail for utility and child-hauling, so I've looked at various options (BD, Yuba, radish) and have decided to go with a cheap entry-level solution: I picked up what around here (japan) is called a mama-chari - like a dutch shopping bike i guess (see attached) and I want to convert it to a longtail with an xtracycle. (I am using the dogbike as my inspiration here - http://www.bikeforums.net/showthread...hlight=dogbike).

I also need to add gears because its a singlespeed at the moment. I am thinking I could take the gear setup from my soon-to-be-defunct sirrus and add it to the new bike. Any problems likely?

Also, the bike is a tad small for me, a longer seatpost should help, but is there anything I can do to extend the handlebars forward a little?I am not sure if i will need to but I'd like to know my options.

oh, and I know very little indeed about bicycles (yet!!) so suggestions are welcome!

thanks

My condolences on the demise of your Sirrus. :cry:

oldfolksmashers 06-05-09 10:42 AM


Originally Posted by qmsdc15 (Post 9046020)
No, I do not think it is possible to use the drivetrain from the Sirrus. Your mama-chari probably is not the same rear hub spacing, so the wheel won't fit. Also the frame probably doesn't have a derailleur hanger, the part of the frame that the rear mech bolts onto.

The main concern here is whether the Xtracycle is the same hub spacing and has a der.tab, which it is and does...

qmsdc15 06-05-09 06:57 PM

Oops sorry, I get the picture now. :o Eggnog, ignore my previous post.

eggnoggbubble 06-05-09 07:01 PM

hi

thanks for the hints, good point about the xtracycle being the key component that needs derailier tabs etc, I was going to change the gears and THEN add an x but I see it will probably be best to do both jobs at once.

thanks for the link on mixtes, I also have doubts about the strength but at the moment I basically want moderate haulage capacity (say up to 20kg) and child-carrying (currently 10kg but expanding fast) so I can carry my work stuff to work and pick my kid up on the way home. This is an entry-level solution that'll allow me to learn a bit about bikes and experiment with what works and what the limitations and option are (and its cheap). Long-term i envisage passing this bike on to my wife as i upgrade (am dreaming of a yuba, or maybe even a workcycle fr8 (with an x!).....)

thanks for the links on handlebar stems, I'll look into that if it's still a bit small after I switch to flatter bars and a longer seatpost

thanks again!

qmsdc15 06-05-09 07:05 PM

Check that stem before ordering a 1" quill. It might be .833".

Kimmitt 06-05-09 10:32 PM

That sounds essentially doable, and you seem to have id'd the potential points of failure.

badmother 06-06-09 12:20 AM

Make sure to post pix when done!

jgrant75 06-06-09 01:18 AM

yeah! post pics of your xtra/mamachari!!

flatter straight bars will do the trick for your stem length but watch out they arent to narrow... you want the bars pretty wide to stabilize heavier loads.

are you going to paint the frames to match while everything is apart?

Grim 06-06-09 08:36 AM

Have you checked with the manufacture to see if they will warranty that frame?

eggnoggbubble 06-06-09 07:50 PM

I will be sure to post pics! I'm on my lonesome trying this here in okinawa so it's good to have company (and advice!) on this forum. I am thinking about painting the x black to match, but we'll see how the project and time are progressing (if that sirrus crack spreads fast i may have to hurry - still riding that at the moment, with hose bands round the head tube in case of a sudden failure....).

I have a friendly old guy in a bike shop just down the road who i think will help me out with technical stuff, and maybe the paint job too.

anyway, this will be a slow-boiler of a project so there may be a gap before pictures (partly because i'm keeping my eye on local classifieds sites for cheap bikes for parts), but I will definitely post back.

one more q: any idea if there will be problems getting the gear cogs attached to that back wheel? If there is some issue there i am thinking I could just replace the back wheel with a mountain bike wheel, but i dont have a spare one of those yet.

thanks for all the tips

egg

Kimmitt 06-06-09 09:43 PM

Answer: Yes, there may be problems. Ask your local bike gnome for assistance.

badmother 06-07-09 04:16 AM


Originally Posted by Grim (Post 9052524)
Have you checked with the manufacture to see if they will warranty that frame?

Warranty is not the problem, it is cheap and it is fun.

What he needs to know is if it is going to break while using it, fast and sudden or slow.

I think ask that local bikeguy, he can tell, he is for sure used to different utility bikes.

I am still a bit worryed about your deep steptrough. When you make the bike longer you change the way the forces work on the frame (hope this is good English), same way as if you can not get a pedal loose and add a tube to the pedal wrench to make the shaft longer. That way you can put more force on it without using more of your power.

I am worryed that a bike can be much less able to take the same load transfered to a longtail as it could easely carry (although more cramped for space) as a normal bike.

I am sure you can manage to ask your local guy about this, showing pictures of what you want to do. Also I am sure your frame can be strenghtened by the right guys, but then you also want a good looking bike..

MTB rear wheel is for sure easy to work with.

Isn`t there quite a lot of 20" wheel bikes in your area (Asia)? What about beating me to making the first longtail from a 20" bike? Small wheels is stronger than bigger wheels, and carrying the load low is always a good thing. Also the whole bike would be shorter, but for the same utility value.

http://www.bikeforums.net//showthread.php?t=548605

http://www.bikeforums.net//showthread.php?t=503808

http://www.bikeforums.net//showthread.php?t=536477

I am sure for a folder the hinge would be the weak spot, but there are some strong ones, and there are some non folding 20" `s.

eggnoggbubble 06-07-09 06:07 AM

thanks badmother

i can see what you are talking about with leverage, I'll look into it, maybe i could get someone to weld an extra tube to effectively make the stepthru less deep. I kind of like the idea of a stepthru for a utility bike (after seeing your dogbike!), but i can see the downside, I'll keep an eye on that issue. My local guy basically deals in road racer repairs and kids bikes, not much utility cycling going on here in okinawa (not like in the china photos thread), apart from the really old guys with milk crates on the back (nothing wrong with that, but i'd like to retain SOME street cred).

my wife's uncle is a welder, however.....

i'll look around for 20" wheels, interesting option there.

thanks again

qmsdc15 06-07-09 06:18 AM

Grim is suggesting Specialized might replace the Sirrus. If they do not think this frame damage meets the conditions for a warranty replacement, they may have a frame replacement program where they will sell you a new frame for a reduced price. Typically they will want you to take it to a Specialized dealer, but if there aren't any in your area, the manufacturer may be willing to work with you the consumer directly.

eggnoggbubble 06-07-09 06:40 AM

thanks gmsdc15,

i missed the point about the warranty too

specialised uk said that they would backdate the warranty but I'd need to take it to a uk specialized dealer. There is a local dealer in okinawa but they're closed until the middle of this month (they had a fire) so i will be taking it to them. But it may be a problem that i bought the bike in the uk but want to warranty it in japan. So all is not lost on the sirrus just yet.

interesting that specialized might be able to work with me directly if i dont get any joy with the okinawan dealer, (i took it to them once recently and they just said i need a new....bike), i will bear that in mind.

ideally i'd like to keep the sirrus as it is for light-luggage and fun rides at the weekend, and use the mama-chari (with the x) for work and general light haulage.

I'll post again with news of how it is all working out.

thanks again

Grim 06-07-09 07:17 AM


Originally Posted by eggnoggbubble (Post 9056279)
thanks gmsdc15,

i missed the point about the warranty too

specialised uk said that they would backdate the warranty but I'd need to take it to a uk specialized dealer. There is a local dealer in okinawa but they're closed until the middle of this month (they had a fire) so i will be taking it to them. But it may be a problem that i bought the bike in the uk but want to warranty it in japan. So all is not lost on the sirrus just yet.

interesting that specialized might be able to work with me directly if i dont get any joy with the okinawan dealer, (i took it to them once recently and they just said i need a new....bike), i will bear that in mind.

ideally i'd like to keep the sirrus as it is for light-luggage and fun rides at the weekend, and use the mama-chari (with the x) for work and general light haulage.

I'll post again with news of how it is all working out.

thanks again

What worries me is a crack like that may be a issue with the material or the tempering after the bike (frame) was built.

All tube is welded even DOM. DOM just means that the tube was "Drawn Over Mandrel" to smooth out that seam. I'd be curious to know if once the head set is off it you can see the seam inside and if that crack is at it. Many Quality frames both aluminum and steel are heat treated aka "Tempered" after being welded and brazed. The uneven heating from the assembly process makes a brittle area along the heated area. The heating restores the strength along welds or areas where the frame was heated to assemble. I bet if the seam is visible it is parallel with the crack.

The question is was this a Friday frame that just was not tempered correctly or is the tube defective and does it effect more then just this one bike?

Now I have never seen a bike frame crack like that. I just cant understand how that crack happened if it wasn't a issue with the material (wall thickness or ID wrong so the bearing cups were too tight and the assembler forced it) or was it the material had a weakness it shouldn't have had? No mater what it is 100% a manufacture defect.



Edit: Did a quick search and this looks like it is not an uncommon problem.

http://www.bikeforums.net/archive/index.php/t-6308.html

http://www.google.com/search?q=speci...rlz=1I7GGLD_en

I did a second generic search without the brand to see how many hits I had to see if a trend in a manufacture. I looked specifically for cracks like yours. Looks to be more common in Aluminum frames and pressing in the bearing cups.

http://www.google.com/search?hl=en&r...e++crac&aqi=g1

This one is interesting in that Sheldon responded.
http://www.bikeforums.net/archive/in.../t-363925.html


After looking at a few pages of google search most of the brand name that was dropped was Specialized and Raleigh. A lot of reference to happening when bearing cups were noticed loose or were just replaced. That starting to lead me to believe it may be partly an assembly issue. The tolerance may be so tight and the assembler is forcing the cups in instead of taking some emery cloth and sanding the paint out of the inside of the tube to make the fit correct. It could also be that the cup was not square to the tube when the cup was being pressed in.

While I am seeing two brands being dominate discussions its nothing conclusive. I think I'm going to say this may be more of an assembly issue ferses a material or tempering issue. The tube Inside diameter was probably speced to the exact bearing cup size. The thickness of the paint was not accounted for. The problem could easily be corrected by the head tube being capped durring the paint process or the assemblers cleaning the paint out before installing. A second helpful hint would be to freeze the bearing race to make it constrict to reduce its circumference before installing. Warming the head tube and freezing the cup could make the cup just drop in and require little to no pressing that would be required when they are at the same temperature. This sort of assembly practice is common place in the auto industry.

That doesn't get the manufacture off the hook as it is still their fault if the bike has never been disassembled. It sounds like Specialized is trying to stand behind their product if they will overcome the location issue.

qmsdc15 06-07-09 02:12 PM

Wow, Grim, I get what you mean about doing the research before posting. Way to bring the A game, friend. As you know, I speak from hearsay and experience but am sometimes right, despite that.

A very old and long story, but I like to tell it. Feel free to skip ahead to the next post. I did have a problem when the Specialized dealer gave me some BS about how they don't warranty frames used for messengers, professional use, blah, blah.., so I asked another Specialized dealer who didn't want to get involved but he gave a number to call. I spoke to a guy at Specialized who said "No way we discriminate against messengers! Box it up! Have you had any other problems with our products?" They sent me a new frame, saddle (broken rail), and hub (multiple broken QR axles in the Specialized rear hub. When I finally replaced it with a solid axle, the drive side chainstay snapped at the dropout, I think all related to an alignment issue). Shipped to me before the damaged frame was received by Specialized.

The moral of the story is not that Specialized products break easily, I'm a big guy who rides hard on bad streets and rough trails. The moral is they stand behind their stuff.

Actually the replacement frame cracked a year later, and when I called the same number I was told "No one named Joe ___ ever worked here and we never sent a frame to a customer" Err, OK.

So eggnogg, they might have put an end to dealing directly with customers sometime between 1988 and 1989.

I took the stripped broken frame to dealer number two who by this point had forgotten that I'd bought the original bike from his competitor. He processed the warranty replacement. The second replacement frame was solid, never broke, I still have it. I would not hesitate to buy another bike from Specialized, great company. The frames that broke had a lot of hard miles on them before they cracked. The one that didn't break has a lot of hard miles on it too. I had another Specialized that didn't break before it was stolen.

True to my form, I'll say before reading Grim's search results that although I've never seen a head tube cracked like that and have limited experience with threadless headsets, but I can't help thinking the crack was caused by over-tightening the headset and is probably not covered by warranty.

badmother 06-07-09 02:39 PM


Originally Posted by qmsdc15 (Post 9056215)
Grim is suggesting Specialized might replace the Sirrus.

Good point, I missed that. Was thinking more of his new ride :D

Dan Burkhart 06-07-09 03:14 PM


Originally Posted by qmsdc15 (Post 9057887)

True to my form, I'll say before reading Grim's search results that although I've never seen a head tube cracked like that and have limited experience with threadless headsets, but I can't help thinking the crack was caused by over-tightening the headset and is probably not covered by warranty.

I seriously doubt that crack could have been caused by overtightening of a threadless headset. I believe there would just be no way you could generate that much force downward by tightening the top cap bolt before the star nut would begin to give.
Looks more like a materials defect or a faulty headset cup installation.(Not pressed in straight.), or not reamed to the proper dimension before installation.
Sometimes, steps get missed at the factory.

eggnoggbubble 06-07-09 06:17 PM

wow, thanks for the info, especially all that research Grim (I am humbled), like i say i dont know that much about bikes (yet) so I had no real idea if this was a common problem or something extraordinary. Your research and comments (and the replies) make me think that I need to pursue this a little more aggressively (well, proactively) with specialized.

Just to confirm: my sirrus has never been disassembled (other than taking the wheels etc off), and hasn't had any crashes or even off-road riding - its done about 10,000km of on-road riding, mostly commuting with moderate load (up to 10kg) on the back rack. Thanks for pointing out that this probably shouldnt have happened and is thus likely a manufacture/assembly problem. Its also encouraging to see that specialized take this kind of problem seriously.

The local dealer re-opens on the 13th of this month so i will take it in again sometime next week and see if i can press them to contact specialised on this issue. If not I will try to contact specialized directly (the email i got from the UK guy was pretty friendly, he may be able to point me in the direction of someone at specialized HQ).

thanks again, all things considered I'd really like my sirrus back (then I can tinker with the mamachari for fun)

I'll post to let you know what happens

EDIT: just looked thru grim's links, and at first it looked like i should stop riding that bike immediately - it may fail catastrophically (with catastropical consequences for me as i go head-first). However Sheldon seemed to think that may not be the situation. I have 3 hose-bands on the head-tube to hold it together if it fails (enough to get me off the bike in one piece). I am still using it for various errands, and a 17km (each way) commute once a week - what do you guys think? should i stop riding it immediately? I guess i could run around on that mamachari (singlespeed)....

eggnoggbubble 06-22-09 07:25 PM

sirrus is getting a new frame!
 
Hi guys,

just wanted to update this thread. I took my sirrus into the local dealer again, and told them about the backdated warranty, they contacted specialised, and got back to me yesterday - so long as i have the proof of purchase to show i am the original owner (I do - a bit faded but just about legible) then specialized will replace the frame! I'm gonna take the receipts in today, sounds like it should be no problem (apparently the fact that i bought the bike in england but am now in japan is no problem).

So thanks to everybody on this thread who posted with thoughts and research about this issue, i'd given up after the first visit to the dealer (when they said i needed a new bike) but inspired by the information i got here i persevered and it has paid off. I'm pretty happy as I've done a lot of commuting miles on that sirrus and have overall been pretty happy with it.

As for the cargo bike issue, I'll have to have a think. I was going to use the sirrus parts on that mama-chari, but obviously that plan is now abandoned. The more I've looked into it and thought about it tho', I'm think i've decided i want a mundo for kiddie-haulage and stuff, everyone seems to love theirs and it has the advantages of being relatively cheap, fit to haul as much as i dare pile on, and one-size-fits-all so my wife can ride it too (with a little persuasion...). Balloon tires are also very appealing - i find my sirrus is great on the open roads, but a bit of an uncomfortable ride over bumps in town. I may keep it for weekend jaunts into the countryside, and use the mundo for about town missions. I may x the sirrus, i may not.

Not sure how my wife will enjoy this conversation tho: "You remember how i said i needed a new bike, and you said ok? Well, it turns out i don't need a new bike, but can i buy one anyway?" I shall pick my moement there...

And the mama-chari? Hmmm, not sure there but it's doing good service at the moment going to pick my baby up from daycare in the evening (ride there with (small) dog in basket, put baby on my back, and roll gently and slowly back home with the dog running beside - i feel pretty safe with the baby on my back at the barely-jogging pace we are moving at). The upright riding position and easy foot-down are pretty nice for that daily mission.

anyway, thanks hugely for the input, like i say i'd given up, but now I'm getting my frame replaced!:)

happy rolling


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