MB donor for conversion

[Cofla]

Hi all,

I just bought an old mountain bike that I would like to use as a donor for a Cruzbike conversion:



- the bike is a 3-4 years old mb for children (i.e. it is not very high, hence I assume it's suitable for a conversion),
- it has 26" wheels (just as a normal mb), dual suspension, 3x7 speeds (I already removed the old chain and the derailleur from the bike, as seen in the picture),
- I intend to replace the thick 26x2.1 wheels with either 26x1.9, 26x1.7 or even 26x1.5 (as in the Sofrider) which would reduce 2 or 3cm from the height of the frame's cross bar (hence from the final height of the seat),
- I am 1.70 m tall man (crotch height: 72 cm).

My questions are:
- do you think this is a suitable donor-bike?
- when buying a conversion kit, are there any special things to do on the frame (drill holes, remove cables, bend the handlebars)?
- the next picture shows 2 possible seat positions: I guess that the position A would be obtained naturally using a straight seat tube... but how could it be possible to get the more reclined position B ? By using a bent seat tube? How do you bend a tube?

Thank you very much for your answers. If this is not the first Cruzbike conversion of Scandinavia, perhaps it will be the first in Finland!

Regards,
Bernard.

P.S.: I had some technical problems when posting this message, there might be few hours difference between the topic creation and this message posting... Sorry!

 

[defjack]

  The top tube angle is

The top tube angle is pretty steep so it would be hard to fit the seat right. It should look like this. Jack

 

[Cofla]

New message

I had a little technical problem with my computer and could not publish my original message on time.

Thanks defjack for answering my "then not yet written" message, I hope you can fully read it now...

-Bernard.

 

[defjack]

  That bike will work

That bike will work fine.You can lower the seat back by lowering the seat post just cut it down if its to long.I like touring bars they work great . Check out the Wald 8095 I even have them on my Silvio. Jack

 

[Cofla]

Seat angles

Thanks again defjack for confirming the bike is OK for conversion. Great to know!

About the seat:
- What do you think is the best angle for driving a Cruzbike?
- Do you think I still need to drill holes or do something particular on the frame once I get the kit?
- And does the kit contain a seat post?

Finally, where did you get your cool touring bars?

Regards,
-Bernard

 

[defjack]

  You wont have to drill any

You wont have to drill any holes but some cables will need to be changed. The kit doesn't come with a seat post just use the one you have. I got my bars from amazon I think Wald stuff is pretty common so they should be easy to find. I don't get any back or butt pain with the seat reclined around 45 degrees. Jack

 

[Cofla]

All is clear

I believe you have answered all my questions about this conversion: I'll probably order a kit this week end. I'll keep you informed with the advancement of this project.

Thanks defjack for your time and expertise!

Regards,
-Bernard

 

[Cofla]

Kit ordered

Hi,

I ordered on Sunday a conversion kit, waiting for the package to arrive... might take a week!

 

[Cofla]

Conversion started

Hi all,

the kit finally arrived with 2-3 weeks delay (blocked at the customs for a while, I had to pay extra 96€ !). I have been very busy also this month and did not start the conversion until last week end.

So far so good:
- FWD brackets are mounted + back wheel to front,
- front to rear axle is mounted + front wheel to back.

I'm now trying to mount the steerer extension tube. My donor bike has a "ahead" stem (threadless), not a quill. But I have noticed that the fork's steering tube's diameter is only 1", just as the provided Insert collar:
- Insert collar diameter: 1"
- Steerer extension tube: 1 1/8" (top) and 1 2/8" (bottom)
- Fork's steering tube diameter: 1"

So, as you can imagine, there's no fit: shouldn't the fork's steering tube diameter be 1 1/8" ???

I believe that I need some kind of adapter, perhaps a 1" to 1 1/8"... But as I'm not any expert I humbly ask your advices about this annoying thing.

I have attached 2 pictures that better describe my problem:

Your advices are welcome. Thanks in advance!

Regards,
-Bernard

 

[Cofla]

Adapters

Hi all,

I've been doing some research about the different adapters I could use to solve my problem:

- the quill to ahead adapter ( quill stem adapter 22.2mm for 1 1/8 ahead stem ):
http://bandlbicycles.com/product/quill-stem-adapter-22.2mm-for-1-1-8-ahead-stem-636.htm

- the ahead stem shim ( Ahead Stem Shim Adapts 1 1/8 Inch / 28.6 mm to 1 Inch / 25.4 mm ):
http://www.sjscycles.co.uk/mart-ahead-stem-shim-adapts-1-1-8-inch-286-mm-to-1-inch-254-mm-prod3618/

In both cases, they adapt a 1" steering tube to a 1-1/8" ahead stem. The first adapter has often been suggested in many CB forums, but as my donor is not a quill, I think I need the second. In any case I might also need a new stem (the old one clamps a 1" steering tube: perhaps to narrow for a 1-1/8").

Are there any pros/cons between the first and the second adaptors? Which one would you suggest?

I'm still waiting for any advice...

Thanx!

 

[John Tolhurst]

The sleeve will get you home,

The sleeve will get you home, with less weight.

 

[Cofla]

Sleeve then

Thanks John for answering,

the sleeve/shim i.e. the second adapter is the right one. I'll go and visit my bike mecanician today or tomorrow.

I have now a new question: do you think I still need the Insert collar? I believe it is still usable with the sleeve, but is it recommended?

I think that adding this kind of info in the conversion manual would be quite useful for amateurs like me (I guess we are many out there

). Also, some extra pictures would quite clarify the whole conversion. Otherwise, everything is clear as water!

Regards,

 

[John Tolhurst]

too many permutations

If we include data for all permutations you create confusion, so responding like this probably a good approach.

The insert collar is for a 1 1/8" (28.6mm) OD fork steering tube, so it cannot be used to strengthen the end of the fork steering tube.