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I have access to a full machine shop and have been pondering this for a while. If I made a new set of clamps and steerer tube for a lefty fork which would allow me to use a 1 1/8" steerer, how can I limit the travel of a lefty fork for use with a 29" wheel/tire combo?

Or is there enough clearance on the lefty fork already that I don't have to worry about the tire hitting the lower clamp on full compression?

Kelly
 

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Just need to limit the travel - Frank Tuesday has done it on his bike.

If your frame is steel it may be easier just to put in a 1.5 head tube than mess around making ne clamps....

Sam
 

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patpend2000 said:
I have access to a full machine shop and have been pondering this for a while. If I made a new set of clamps and steerer tube for a lefty fork which would allow me to use a 1 1/8" steerer, how can I limit the travel of a lefty fork for use with a 29" wheel/tire combo?

Or is there enough clearance on the lefty fork already that I don't have to worry about the tire hitting the lower clamp on full compression?

Kelly
You can just limit the travel to 80mm or less. C'dale make little clips that limit the travel. They are 10mm each, so you can put in as many as you want. This is not an option of the Jake or the TPC Max.

But, instead of just limiting the travel, if you are making new clamps anyway, why not just make the clamps with 30mm of drop so that you can use the full travel of the fork. This would further allow you to fine tune the head angle.

Frank
 

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Frank Tuesday said:
You can just limit the travel to 80mm or less. C'dale make little clips that limit the travel. They are 10mm each, so you can put in as many as you want. This is not an option of the Jake or the TPC Max.

But, instead of just limiting the travel, if you are making new clamps anyway, why not just make the clamps with 30mm of drop so that you can use the full travel of the fork. This would further allow you to fine tune the head angle.

Frank
Preach Frank, Preach.. go on, tell me more about clamps. I am thinking of doing the same and am curious... (though, mine is 26er) I just need info on converting 1.5 - 1 1/8.

Also, post some pics of your bike, I love it!
 

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1 1/8" Lefty steerer conversion made easy!

I have a Karate Monkey with a Lefty (first generation alum/Ti) converted to fit the 1 1/8" headtube. I removed the standard steerer and fabricated some spacers to make a 1 1/8" steerer fit in the existing clamps. The removal of the old steerer takes some serious pounding or a good press.

I took an aluminum steerer out of a spent Noleen fork and used a lathe to turn some beefy spacers to press over the steerer and into the lefty clamps. I welded the lower spacer to the bottom of the steerer then pressed and re-riveted this back into the lower clamp.

The upper spacer consists of one pipe turned to fit tightly over the steerer and another, larger pipe with a ~3/16" notch cut out to fit over the keyway on the clamp. When the clamp is tightened, it compresses the outer spacer pipe and holds the inner spacer pipe in place. All of the material came from my local scrap yard and made an inexpensive, sturdy, and relatively easy conversion.

I also slid the fork leg down through the clamps to extend the fork to fit a 29" wheel with the full 100 mm of travel. After careful measuring, I decided that there would be enough clearance for a big tire if I raised the lower clamp by ~16 mm. The fork leg tapers slightly above the standard lower clamp position and this 16 mm was about as far as I would suggest moving it. On my Surly with a Chris King headset, the distance between the upper and lower clamps is 120 mm compared to 138 mm on a Cannondale (with the dust seal ring). There is 102 mm between the bottom of the steerer and the top of a Bonty Jones.

I have had no trouble with this setup and am very satisfied with the bike's handling. The head tube angle is around 70. The bike rips with very confident and predictable handling in any situation! I am curious how the Leftys ride with the travel limited though. If we get some big meat tires, I may have to limit mine by 10 or 20 mm to avoid the dreaded tire-bottoming-on-steerer instant endo.

At Mount Snow last weekend, I saw an employee of Independent Fabrications with a 1 1/8" lefty made by Cannondale. They made custom clamps and a steerer tube that looked very difficult to reproduce. He said it was made to test the fork on a non-Cannondale bike for a magazine review and would not be put into production. I briefly considered making more of my steerer conversions, but the insurance/liability involved seemed a little too scary. The steerer removal and re-riveting is tricky. Maybe something a bikeshop could handle, but not your average Lefty lover.

Here's a qoute from a moots forum I just found, "many people buy C'dales just because of the Lefty. They'd sell fewer bikes if they offered a 1 1/8" version."
(http://www.moots.com/messages/882.shtml)

and here's a link to the picture of the bike I saw:
http://gallery.consumerreview.com/mtbr/gallery/files/Joesbike.asp

I'll post some pictures of the Franken Monkey tomorrow.
 

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Would it be possible to go Maverick Style?

Don't know if it is possible, but it might be easier to machine out the steerer tube, and install a compression system like that built into the Maverick Suspension. This is lighter than having a steerer tube, but I don't know for sure that the lefty has the strenght to keep the whole thing together.
You'd have to get an engineer to take a look at it.

It would be a cool way to go, seeing as you are already going through all this trouble.
 

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pedalpete said:
Don't know if it is possible, but it might be easier to machine out the steerer tube, and install a compression system like that built into the Maverick Suspension. This is lighter than having a steerer tube, but I don't know for sure that the lefty has the strenght to keep the whole thing together.
You'd have to get an engineer to take a look at it.

It would be a cool way to go, seeing as you are already going through all this trouble.
The maverick system would depend on diametricaly equal forces from both sides wich the Lefty can not do.

The USE S.U.B. antidive fork can be bought in 29" format without losing travel.

P::..
 

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BikesOnSnow said:
I have a Karate Monkey with a Lefty (first generation alum/Ti) converted to fit the 1 1/8" headtube. I removed the standard steerer and fabricated some spacers to make a 1 1/8" steerer fit in the existing clamps. The removal of the old steerer takes some serious pounding or a good press.

I took an aluminum steerer out of a spent Noleen fork and used a lathe to turn some beefy spacers to press over the steerer and into the lefty clamps. I welded the lower spacer to the bottom of the steerer then pressed and re-riveted this back into the lower clamp.

The upper spacer consists of one pipe turned to fit tightly over the steerer and another, larger pipe with a ~3/16" notch cut out to fit over the keyway on the clamp. When the clamp is tightened, it compresses the outer spacer pipe and holds the inner spacer pipe in place. All of the material came from my local scrap yard and made an inexpensive, sturdy, and relatively easy conversion.

I also slid the fork leg down through the clamps to extend the fork to fit a 29" wheel with the full 100 mm of travel. After careful measuring, I decided that there would be enough clearance for a big tire if I raised the lower clamp by ~16 mm. The fork leg tapers slightly above the standard lower clamp position and this 16 mm was about as far as I would suggest moving it. On my Surly with a Chris King headset, the distance between the upper and lower clamps is 120 mm compared to 138 mm on a Cannondale (with the dust seal ring). There is 102 mm between the bottom of the steerer and the top of a Bonty Jones.

I have had no trouble with this setup and am very satisfied with the bike's handling. The head tube angle is around 70. The bike rips with very confident and predictable handling in any situation! I am curious how the Leftys ride with the travel limited though. If we get some big meat tires, I may have to limit mine by 10 or 20 mm to avoid the dreaded tire-bottoming-on-steerer instant endo.

At Mount Snow last weekend, I saw an employee of Independent Fabrications with a 1 1/8" lefty made by Cannondale. They made custom clamps and a steerer tube that looked very difficult to reproduce. He said it was made to test the fork on a non-Cannondale bike for a magazine review and would not be put into production. I briefly considered making more of my steerer conversions, but the insurance/liability involved seemed a little too scary. The steerer removal and re-riveting is tricky. Maybe something a bikeshop could handle, but not your average Lefty lover.

Here's a qoute from a moots forum I just found, "many people buy C'dales just because of the Lefty. They'd sell fewer bikes if they offered a 1 1/8" version."
(http://www.moots.com/messages/882.shtml)

and here's a link to the picture of the bike I saw:
http://gallery.consumerreview.com/mtbr/gallery/files/Joesbike.asp

I'll post some pictures of the Franken Monkey tomorrow.
post a picture dude! KM with a lefty! what?!

don't tease us
 

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nightfire said:
The maverick system would depend on diametricaly equal forces from both sides wich the Lefty can not do.

The USE S.U.B. antidive fork can be bought in 29" format without losing travel.

P::..
I asked USE here in the States a few months ago and they said no production of a 29er as they could not keep up with a 26er. If you know otherwise let me know
 

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This bike is in England and has been in use for awhile now. I just happen to have a USE 29" modified at USE and a wheel here in CB that is brand new and collecting dust. If you or anyone are interested let me know.

michaelo said:
I asked USE here in the States a few months ago and they said no production of a 29er as they could not keep up with a 26er. If you know otherwise let me know
 

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Bigwheel said:
This bike is in England and has been in use for awhile now. I just happen to have a USE 29" modified at USE and a wheel here in CB that is brand new and collecting dust. If you or anyone are interested let me know.
Yo Bigwheel... please shoot me an email... might be interested. Thanks.

mtbr AT blinkylights DOT net
 

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Interested!

Bigwheel said:


This bike is in England and has been in use for awhile now. I just happen to have a USE 29" modified at USE and a wheel here in CB that is brand new and collecting dust. If you or anyone are interested let me know.
Please drop me a line concerning the USE fork and wheel.

themtbdoc AT yahoo dot com
 
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