The Gods are punishing me! (15 Downtube 8H pics)
8 Attachment(s)
I promised to post pictures of my Downtube modifications, but never did:
1. Yesterday I got a puncture flat from some road debris (only the second front tire flat I've gotten in my entire bicycling career!). 2. When I replaced the tube the new one exploded upon inflation. 3. After I replaced the exploded tube with another new one I woke up to find it deflated again (this time punctured from the spoke/rim-tape). 4. Now I'm outta 20" tubes (and I won't use the ones they sell locally...I've found the secret to getting 20" tires on/off easily is to use narrow 1.25"-1.5" tubes...oh and if you also use Stop Flats brand tire liners you won't get flats either), so I break out the patch kit and the glue is dried out! The gods are punishing me! So in order to satisfy their anger I'm posting these pictures ASAP: http://bikeforums.net/attachment.php...hmentid=251550http://bikeforums.net/attachment.php...hmentid=251551 Here was the original bike (as you can see I like to carry stuff...that's a 12-pack of paper towels on the rack). http://bikeforums.net/attachment.php...hmentid=251534 Here's the bike with new fork, stem-riser, handlebars, and front wheel (I'm carrying bottles for cash deposit). http://bikeforums.net/attachment.php...hmentid=251543 http://bikeforums.net/attachment.php...hmentid=251535 http://bikeforums.net/attachment.php...hmentid=251536 http://bikeforums.net/attachment.php...hmentid=251537 I never used to be the type to carry anything on the handlebars (not even a pharmacy pick-up hanging in a little baggie), but now I love it (can't envision myself wanting to use a rack). The key seems to be that the load is laterally centered and low. http://bikeforums.net/attachment.php...hmentid=251542 I also really like this handlebar setup, very fast, very light, very aero, very comfortable, and handles very nicely. Only thing is it puts a lot more leverage on the stem-riser, so there's stem flex when I pull on the horns (or the black aero-horns), but it's ok if I try to restrict my pulling to the flats. |
9 Attachment(s)
Now some details:
http://bikeforums.net/attachment.php...hmentid=251553http://bikeforums.net/attachment.php...hmentid=251554 Here's how it looks folded...pretty compact. http://bikeforums.net/attachment.php...hmentid=251555 Here are the handlebars from www.crowcycleco.com. They're 44cm wide and 22.2mm in diameter (with a 25.4mm clamp diameter), so I was able to put on regular "mountain" brake levers and the twist grip from my Sturmey-Archer 8-speed (with a slight modification, see sheldonbrown for details)...you can squeeze them anywhere on the bar, but in the end I decided to keep them on the horns. Also the black aero bars are RavX X Long Bar Ends (the longest lightest bar ends I was able to find)...and they work fantastic as aero bars...stiff and light because they're closer to their attachment point and they form a nice cradle for carrying cargo. They might be a little wider than real aero bars, but you don't want to go too narrow when riding in traffic because it's harder to steer and access the controls (breaks, shifter, etc). Best part is the whole handlebar setup was cheap...less than $30 for both bar and bar-ends. http://bikeforums.net/attachment.php...hmentid=251556 http://bikeforums.net/attachment.php...hmentid=251557 The fork is just an aluminum Redline 20" Flight R6/U6 Expert Fork (1-1/8" threadless) and the stem-riser is just an aluminum 1-1/8" stem riser from bacchettabikes.com (there are also similar risers made by ransbikes.com) with a QR seat clamp. All light, stiff, cheap. My only complaints are that: 1. The fork steerer is a little shorter than I'd like (IIRC it's only 180mm uncut) so there's only about 1" of fork steerer inside the stem riser, but so far it doesn't seem to be a problem, except there's some flex when I pull on the horns (do horns do that on other folders?). 2. The headset is held in tension by a Problem Solvers Locking Headset Spacer (basically just a seat clamp without the lip/ridge)...problem is this seems to gradually loosen up after carrying a lot of heavy cargo or pulling hard on the bars. http://bikeforums.net/attachment.php...hmentid=251558 http://bikeforums.net/attachment.php...hmentid=251559 http://bikeforums.net/attachment.php...hmentid=251560 Here's how I tension the headset. Basically you just wrap a string around the top of the headset, tie it to the fork, and use the frame to tension the string so it pulls together the fork and headset. http://bikeforums.net/attachment.php...hmentid=251561 This isn't new, but I thought you also like to know that I've gotten excellent service by not using any oil on my chains..zilch. What I do is dip the chain in a melted wax bath once when the chain is new (mainly to dissolve the grease and fill in any large holes that might pool water) and then I simply ride it till it snaps. No dirt is attracted to the chain, no rust, no squeaking, no muss, no fuss. Only thing is when the chain gets really worn (like when almost all bike mechanics will tell you it needs to be replaced), you just need to tension it good with a chain tug (as is done with motorcycle chains)...then it will last many thousands of miles more than an oiled chain (which inevitably gets dirt and sand stuck in it's interstices). My chains last longer because they don't have oil to attract dirt and accelerate wear. |
What sort of voodoo ritual is that you are using to preload the headset? Also, have you found the ex-seatpost-QR clamp satisfactory in keeping the riser secured?
I've used pair of dual-bolt clamps (31.8 atop, 28.6 below) from RANS: http://farm8.staticflickr.com/7176/7...6cf7b5870a.jpg ... totally solid, but a small hassle for popping the stem riser. |
One last thing is that I rebuilt the front wheel with a Sturmey Archer Drum Brake (with dynamo). I built it with 24 spokes (skip every third rim hole) and it works great.
While the drum brake might not be quite as powerful as a V-brake under ideal conditions, it always works which is the most important thing when it comes to brakes (doesn't matter how fast you stopped last week if the rain/dirt/etc prevents you from stopping fast enough to save your life today)! Don't get me wrong, it isn't weak at all...in fact I never even bothered to reconnect the rear brake after replacing the handlebars, so the drum brake is plenty strong and it's far cleaner (no brake dust) and with far lower maintenance (pads basically never require replacement or adjustment). As to the dynamo...I haven't used it yet, but neither do I notice any drag when riding.
Originally Posted by Joe Loco
What sort of voodoo ritual is that you are using to preload the headset? Also, have you found the ex-seatpost-QR clamp satisfactory in keeping the riser secured?
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Cool. Does your fork have a star-nut in it? You can always preload with a conventional top cap, then pinch that off with the PS locker, then install the riser...
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Originally Posted by Joe Loco
(Post 14253703)
Cool. Does your fork have a star-nut in it? You can always preload with a conventional top cap, then pinch that off with the PS locker, then install the riser...
Unfortunately the steerer isn't long enough for a dual bolt clamp unless maybe I use one of those 31.8/28.6 clamps and just loosen the top bolt to remove the stem-riser. Do you think that would work since the top bolt would still be tight when riding? |
You mean there's something like a butted, dual-bolt clamp? That's crazy- I would hesitate to rely on just a single-bolt of such a clamp to hold a big riser/bullhorn setup like you've got going.
I don't get too much flex in my setup, but I also have probably almost 3" of steerer sleeved inside of my riser. |
Oh I also forgot to mention the pedals. The pedals are Wellgo QRD-M138 (WK79) MTB Bike Pedals and they're fantastic! Way lighter, better quality (smoother), and more durable than folding pedals. I would cry if I had to switch back to either folding or regular pedals...even though they're only ~$38 or so on ebay I haven't seen this brand/design for sale anywhere else.
Plus they're convenient to use as a "bike key" (ie remove pedals and no one can ride your bike off...though they could still walk off with it or toss it in a motor vehicle, that takes a little longer).
Originally Posted by Joe Loco
(Post 14253791)
You mean there's something like a butted, dual-bolt clamp? That's crazy- I would hesitate to rely on just a single-bolt of such a clamp to hold a big riser/bullhorn setup like you've got going.
I don't get too much flex in my setup, but I also have probably almost 3" of steerer sleeved inside of my riser. |
Ah. I thought you were suggesting a single clamp that had a 28.6 base and a 31.8 top. I have two clamps going on. The dual-bolt seems to have held my preload well so far (I wonder if using a star-nut would let you wring any last wiggle out of it, or if it is actually the bar torking that's loosening things for you).
I still need to find a 31.8 Q/R seat clamp so I can more quickly pop the riser. I only wound up with a pair of dual-bolt clamps b/c RANS mistakenly shipped me 31.8 first (they totally covered the problem, great folks there). |
2 Attachment(s)
Originally Posted by Joe Loco
(Post 14253890)
Ah. I thought you were suggesting a single clamp that had a 28.6 base and a 31.8 top. I have two clamps going on. The dual-bolt seems to have held my preload well so far (I wonder if using a star-nut would let you wring any last wiggle out of it, or if it is actually the bar torking that's loosening things for you).
I still need to find a 31.8 Q/R seat clamp so I can more quickly pop the riser. I only wound up with a pair of dual-bolt clamps b/c RANS mistakenly shipped me 31.8 first (they totally covered the problem, great folks there). That's a good point about "wringing any last wiggle" out of the headset. Thing is I was thinking I might want to insert some type of quill to extend the steerer and a star-nut would interfere with that: http://bikeforums.net/attachment.php...hmentid=251611 Or maybe I should replace my bottom clamp with something like this?: http://bikeforums.net/attachment.php...hmentid=251612 What do you think? BTW, you can get 31.8mm (with 28.6mm lip) Q/R seat clamps here: http://www.crowcycleco.com/seat-post...-31-8mm-4.html |
I used your identical setup with mu Swift, but abandoned the fork due to the short steerer. I got another Litespeed 650c carbon fork with a nice long steerer which sticks up way into the Bachetta riser. A Problem Solver clamp with a Problem Solver adjuster keeps the preload right. I also use friction grease to prevent movement over time as I also found that it loosens a bit with use. Since using the friction grease, no more adjustments.
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Originally Posted by jur
(Post 14254354)
I used your identical setup with mu Swift, but abandoned the fork due to the short steerer. I got another Litespeed 650c carbon fork with a nice long steerer which sticks up way into the Bachetta riser. A Problem Solver clamp with a Problem Solver adjuster keeps the preload right. I also use friction grease to prevent movement over time as I also found that it loosens a bit with use. Since using the friction grease, no more adjustments.
Thanks for your input...although I take it your carbon fork costs quite a bit more than my $80 Redline fork. Just thinking out loud here, but since I'm keeping the fork with the short steerer (cause it's not that bad), I'm not gonna add a headset adjuster to the stack either since it will take up space I can't afford to lose. So I wonder, if the friction grease solves the headset loosening, then maybe a dual-bolt clamp would solve it too (cause surely more bolts = more friction)? And if I replace my Problem Solver clamp with one of those double bolt stem risers (pictured above) then maybe I can have my cake and eat it too? Did you find the longer steerer improved stiffness or was it mainly a safety concern? Also what kind of handlebars were/are you using with your setup(s)? Thanks. |
Let me see if I have some pics...
[edit] http://i160.photobucket.com/albums/t..._bullhorns.jpg Bulhhorns, with the rising bit at the tips sawn off. I can't remember what I paid for the new fork, I think it may have been $130. The steerer sticks up almost to the bend in the stem riser. So it is very nice and stiff. But I actually did ride the Redline fork for a while and it was great too. Did some punishing rides with it and it didn't skip a beat. Just the loosening problem I couldn't live with. I used a quill-to-ahead converter to lengthen the Redline's steerer tube, sticking up inside the riser. So that probably did the stiffening. |
Ah just remembered, there was no room for a clamp directly on the steerer a la aheadset. The only clamp was the one one the riser, and that tends to loosen like you also found. I had the identical problem on my Raleigh 20 years ago. I concluded the riser will necessarily loosen due to the flexing - basically it shoulders itself away from the headset bearing, and no amount of clamping will solve that. At least that's what I concluded. So the longer steerer gives the necessary space for a clamp just on the steerer to hold it in place, independent of the riser's clamp.
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chucky, ok I think I get your q now based on what you and Jur are hashing out. I'd concur, go with that first Problem Solver quill-to-ahead adapter/riser for some more real estate and quite likely, stiffness.
My top clamp does have the real thin flange on the bottom (to prevent riding up, I presume). Similarly, so did the bottom clamp (albeit with a smaller ID), but I round filed it away so that it now has a 28.6 ID straight through. I think one needs to have independent clamps for headset preload and stem retention. |
Originally Posted by jur
(Post 14254927)
Ah just remembered, there was no room for a clamp directly on the steerer a la aheadset. The only clamp was the one one the riser, and that tends to loosen like you also found. I had the identical problem on my Raleigh 20 years ago. I concluded the riser will necessarily loosen due to the flexing - basically it shoulders itself away from the headset bearing, and no amount of clamping will solve that. At least that's what I concluded. So the longer steerer gives the necessary space for a clamp just on the steerer to hold it in place, independent of the riser's clamp.
On the other hand, Joe Loco thinks the loosening is because my adjustment method leaves some uneven gaps in the headset bearing, but I'm skeptical because I have another headset I adjust with this method (on another bike where the riser doesn't touch the headset clamp) and the only time that one has ever loosened was when I crashed it once (which is probably why Rans, Bacchetta, and other manufacturers with similar designs all seem to think it's worthwhile to custom manufacture double bolted clamps); So I'm thinking that stiffening up the riser with a quill will solve it. What do you think? Another question I have for you (since I know you have experience with this) is what method do you use to slot your risers so the pinch clamp can pinch them tightly around the steerer (for example, if the riser requires reslotting after being cut shorter)? I just use a hack saw for the slot and a drill for the relief hole, but the slot is kinda ugly and narrower than I'd like it to be. Thanks for your input. |
Ah yes you do have the Problem Solver clamp, I did see it but then forgot.
Aheadset stem clamps usually have 40mm or so for clamping, whereas the Problem Solver which I also got and am not using any more, is a mere 8mm(?), so it involves a small section of steerer tube in the friction game, apparently too little. I am now using a Salsa clamp from which I filed away the ridge; it is about 15mm wide, but that still moved albeit less over a longer period. So then I put in the friction grease and that has so far helped. Of course, I have to mention that my steerer is carbon so that is hard to clamp hard enough without breaking or collapsing it. Perhaps some of that grease will help your case too. The double bolt clamp is going to have a similar effect, involving more area in clamping, with the much increased friction. I added the quill lengthener in the Redline mainly to have less leverage from the stem riser on the clamp assembly. The leverage is determined by the length of the steerer inside the stem riser, and that is too small with the Redline. The quill should make a nice difference on the leverage - but it needs to be a reasonably snug fit inside the riser. I slotted my riser in exactly the same way, a drill and hacksaw. I filed the slot wider with a needle file. Rather ghetto-ish. Fortunately it is mostly hidden by the Salsa clamp. The filing does improve it a bit since I was able to compensate for the slight crookedness. Here is a pic of the Swift before ascending Mt Hotham, Australia's highest climb. http://i160.photobucket.com/albums/t...3-31084254.jpg |
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