Conversion kit instructions? Issue with Downtube suspension fork?

Charles.Plager

Recumbent Quant
Hi,

I purchased a used conversion kit that didn't come with instructions. Are there other instructions besides the parts list that is on the conversion kit page

What I am puzzled about is the steerer extention tube. When I take the old stem out of the suspension fork on the Downtube folder, the bottom of the extention tube is not big enough to go over what is remaining. I believe I understand the rest (although once I'm further along, I'm willing to believe that may change as well. :)

Thanks,
Charles
 

Hilry

Member
Instructions

Hi Charles,

i found the Sofriderinstructions helpful when installing the conversion kit.
There is a PDF download on the Sofrider page in downloads link near the bottom of the page.

The steerer tube is supposed to be 1 1/8th.

You said 'old stem out' rather than 'old stem off' is it threaded or threadless steerer tube?

Hilary
 

Charles.Plager

Recumbent Quant
Hi,
It's a threaded fork on


Hi,

It's a threaded fork on the Downtube where the stem attached to the handlebars goes inside the for steerer tube. Mentioning the Sofrider instructions was a good idea (and I even have a Sofrider to look at), but the Sofrider is unthreaded, so I'm still somewhat confused. Any help here would be appreciated. :D

Cheers,
Charles
 

Hilry

Member
Threaded fork

Hmmm,

Have you got a quill to ahead adapter?
probably 22.2-1.1/8in

You need the steerer tube to extend above the headset for the for the cruzbike stem extender to fit onto, which a threaded steere tubed fork won't do if it was installed in the frame with the original headset.



 

Hilry

Member
Downtube stem

Hi,

Is it one of those folding downtube bikes with the extra long stem on then?

Just looked at them.
Do you really need the cruzbike extender?
If you can get the right handlebar height with the existing stem and are able to get the boom clamp onto the stem and clamped tight, will that not do the job?

Also Pictures please (you're usual cry) ;-)

 

Charles.Plager

Recumbent Quant
Hi Hilry,
You're absolutely


Hi Hilry,

You're absolutely right about the pictures but I've got no power at home right now due to Sandy, so that's going to have to wait (we're fine otherwise!).

I very much like your quill to ahead adapter idea. My fallback position was to be to saw an old quill and make one of these.

Again, I don't have the instructions. What are people supposed to do in this situation.

Thanks!
Charles

p.s. The reason I got the bike in the first place is because the stem doesn't have a working closure mechanism. And for what it's worth, the pictures I've seen of converted downtubes all seem to not use the original stem. (I'm a little worried that it isn't designed for pulling the way a Cruzbike stem is.
 

Hilry

Member
Stem problem

Oh dear.

Hope you get your leccy back soon. There's millions out of iy at the mo apparently.
Where abouts are you. You're on the east side aren't you?

Hope you are all faring well during this climatic cuffufle.

The quill converters seem to be pretty cheap.

I'll see if I can find my paper destructions and scan them in.
 

Charles.Plager

Recumbent Quant
Living without power isn't

Living without power isn't horrible, mostly just a little annoying. The two concerns are (1) basement flooding since sump pump won't run without electricity and (2) losing food in refrigerator/freezer. Luckily it isn't too cold outside.

Cheers,
Charles
 

Hilry

Member
Steerer tube destructions

Found my destructions.
Here's the bit about this:-

10. Check which stem type you have.
The old type is known as a quill, because the stem when you extract it has an angled cut where a wedge nut fits.
This typs is phasing out, but still provided on low end bikes.
If you have a quill type, you will need a 'quill to ahead adapter' which is a standard part.
There are two sizes, one to suit a steering tube of 7/8" internal diameter (ID), and one to suit 1" ID.
Measure your steering tube diameter to see which you need.
Refer to the Yahoo Group Links>Special Parts >Stem Tube Adapters for a supplier if your local bike shop fails you.
You will also need an ahead type stem - best chosen when the bike is almost finished and you can determine what reach will be comfortable.

Then theirs a diagram of the anatomy of ahead forks/headset/stem.

and references to Sheldon Brown headsets

and

http://www.bicyclemotor.com/techhelp/cuttingforkto size.html

-----

Assemble the steering tube
38. Assemble the steering Tube Extension parts C3 and C4 as shown in the photo of Parts Group C.

39. If you have a quill type, fit the quill to ahead adapter in the fork steering tube.

40. If you have an ahead type, remove the tensioning screw from the top of the stem, loosen the stem clamp and remove the stem and any spacers. Note the existence of a star or flower nut inside the tube used by the tensioning screw.

41. If you have an ahead type, place the Insert Collar (Part C6) inside thetop of the fork neck tube.
Tap it down so that at least 2/3rds is inside. Doing so may puch the star nut downwards - that's OK.

42. Fit the Steerer Extension Tube (Part C3 and C4)

43. If you have an ahead type, screw the Ahead Tensioning Bolt Extension (Part C5) onto the end of original tensioning bolt and insert and firmly tension the head bearings.

44. Tighten the Pivot Clamp Bolts (Part C3)

45. If you have an ahead type, lift the handle bars and stem and place them over the Steering Tube Extension.

46. Fit the cranks and chainwheel to the crank axle.

47. Fit the front derailleur.

48. Refit the chain.
 

Charles.Plager

Recumbent Quant
Thanks!  That does help a

Thanks! That does help a lot. It means that buying one (because it wasn't included with my used kit) is the right thing to do. :D

Thanks for all of your help!

Charles
 

defjack

Zen MBB Master
  You need a stem adaptor 

You need a stem adaptor nashbar part NS-TSA 14.99 you need the 1 1/8
P1010103-001.JPG
 
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