Thursday, January 06, 2011

Trying new things

I often run into the stereotype that all steel framebuilders (or all custom framebuilders period) are wool-shirt wearing, bearded grouches who only build lugged randoneur frames.

There is of course a smidge of truth to this, mostly because doing what you know is quick and easy. For example, I built a pretty conventional 29er SS frame for Mike C recently (it'll go to powder today or tomorrow) - I knew exactly what parts I would use, had them all in stock, and knew exactly how to do every operation needed to take the frame from a pile of tubes to a complete bike.

On the other hand, I (yesterday) built a fork for Ian that uses a 15mm quick-release through axle. This is something that I had never done before, but I felt it was appropriate for his use, not to mention the fact that these axles are becoming more and more common for XC bikes, and if I want to keep building forks for people, I'm going to have to figure them out eventually. Of course, the bearded grouch builder response would be "there's nothing wrong with a 9mm quick release"

Long story short, the fork (usually about 1/4 of the work of a frame, comparatively) took at least as long as Mike's whole frame.
-I had to make the dropouts. I *should* have ordered in some 3/4"x.120" 4130 and put it on the lathe, then tapped the other side to make the threaded dropout. Instead, I made the dropout in 2 pieces - one piece of 4130 turned out to 15mm (the slip fit) and one M14x1.5 nut which I turned down to match the OD on the lathe. Talk about a dumb way (from a time/effort perspective) to do things...
-I had to make adapters to attach things to my fixtures. The 15mm axle won't fit in my fork fixture, so I had to make a dummy axle, as well as an adapter to fit my disc tab fixture to *that*. And all of them had to be to pretty decent tolerances to make sure things lined up well, so I couldn't just slap things into the lathe and blaze away.
-After I welded in the dropouts, I realized that I needed to chase the threads - so off to the hardware store again for a ($28! Ouch!) M14x1.5 tap.

I'm fairly happy with the results, though, and the next time around, all the things I learned should make it go much quicker. There will be an upcharge ($75) for these setups, until someone starts making a plug/play dropout for them that I can just weld in (hear that, Mark?)

18 comments:

Anonymous said...

Hard work, but came out awesome...

Anonymous said...

I have to say those two barrels look a bit odd when no wheel is attached. But with the wheel on, it looks great.

Question: What's the benefit of a 15mm on a rigid fork?

Walt said...

Anon2 -

The benefit is that for many people, their only front wheel is a 15mm one (and they're not all convertable) so if they want to swap from a rigid fork to a suspension fork, this is the easiest way to do it without buying a second wheel.

In terms of stiffness/performance, very few people need a through axle on a rigid fork, IMO. But it doesn't hurt anything.

Anonymous said...

Sorta makes sense, but not much. Why not just turn up a 15mm x 9mm aluminum sub axle and make a standard 9mm drop out QR style fork that could be used with either type wheel??

15-20mm thru axle only makes sense to me on a suspension fork.

The ends of the fork blade are barely 15mm in diameter!

Whatever. Hope he pays$!

Anonymous said...

Sorta makes sense, but not much. Why not just turn up a 15mm x 9mm aluminum sub axle and make a standard 9mm drop out QR style fork that could be used with either type wheel??

15-20mm thru axle only makes sense to me on a suspension fork.

The ends of the fork blade are barely 15mm in diameter!

Whatever. Hope he pays$!

Walt said...

Anon -

I did not ask Ian specifically why he wanted a 15mm fork. Maybe he will chime in.

There are a number of hubs that allow exactly what you are describing - changing bearing caps to be compatible with several size axles. Since the spacing (100mm) is identical as well, it would not be too hard to make an adapter axle like you describe.

In fact, I'd be surprised if someone like Wheels Mfg doesn't make that product soon. It's a pretty straightforward lathe job.

So it's possible that I won't end up making all that many of these.

BTW, if you think that's a huge dropout on the end of the fork blade, you should see the 20mm axle ones I've done!

Walt said...

Oh, and for what it's worth, as I said, I don't think there's a performance benefit here for rigid forks. I have not spent any time on rigid forks with throughaxles, though, so I can't say for sure.

Anonymous said...

Walt,

15mm is functional for sure(on a suspension fork)...but also..COOL.

One cannot discount the draw and massive mind @#$k of Fox and RS.

We are not making a rocket to the moon here! Hey! I like Gucci shit myself..makes me feel... COOL..!

...*cool* makes $moola$. Give the customer what he want's AS long as he PAYS and hopefully UNDERSTANDS!

Keep makin' bitchin' shit...it is artful and full of craft...don't ask too many question..pay the rent/house payment..eat..buy gas...etc!......RIDE!!!!!

:-)

Anon

Anonymous said...

Walt,
FWIW there is a difference in *feel* between a QR and a 20mm rigid fork. During rocky descents the 20mm fork does not twist in the slightest. When I switched from the QR to the chrome 20mm fork the difference was immediately noticeable. I had to fight to keep the bike in a rough turn with the QR. The 20mm is much easier to persuade to stay on line.
EW

Brad said...

Going from a QR to a 10mmx135 axle was huge on the 36er. In retrospect, I wish I had gone through the trouble of swapping to a 15mm or 20mm axle. There's always next time right?

Walt said...

Eric -

Yeah, you keep telling me that. Maybe I should build myself one and see what I think.

Brad -

Yeah, the 36er is one of those exceptions where it's probably pretty useful. Too bad there is not a 135 or 150x15/20mm front hub.

inthewoods said...

Walt,

You can get 135mm front disc hubs from fatback bikes http://fatbackbikes.com/index.php

inthewoods said...

Although after I said that, I looked again and I don't think FatBack makes 15mm/20mm through-axle 135mm hubs, looks like only QR.

Walt said...

InTheWoods -

I know, but they are 9mm, right?

We used the Paul 9mmx135 on Brad's 36er, and I think we both wish we'd gone 20mm TA instead.

Ian said...

Looks awesome Walt.

I asked Walt if he'd do a 15mm mainly because I ride 15QR on my sus forks and not all hubs are easily convertible. So, for me, it was mostly a convenience thing. And while I notice a huge difference on a sus fork, yes, I doubt the 15mm feature will make a noticeable difference on a rigid fork for my 70kg.

Really, I was just hoping to give you all something to gawk at. You're welcome.

Roger said...

Hope makes their 135mm Fatsno hubs in 15mm TA, Front Brake flavor... Pretty reasonable, too...

http://www.universalcycles.com/shopping/product_details.php?id=67039&category=736

FWIW, I'm interested in getting a 468mm a-c fork made for my new fatbike, with 15mm TA dropouts... But, I'm at 225lbs fully kitted...

Walt said...

Hi Roger - wow, you are reading a post from 2011? Good work!

Feel free to drop me a line if you're interested in a fork.

Roger Class said...

Walt, Google ignores time... And my buddy Rodney has nothing but good things to say about his green monster...