Mechanics Quick Question Thread [Ask Questions Here]

PB Forum :: Mechanics' Lounge
Mechanics Quick Question Thread [Ask Questions Here]
Author Message
Posted: May 16, 2021 at 7:36 Quote
wellbastardfast wrote:
Random question.

But do offset bushings rotate in the actual bushing when the shock compresses. Just pulled my shock out and the offset bushing was pointing about 45 degs off where i first installed it. (Pointing towards shock)

Ideally, no, they do not, and shouldn't move. But, unfortunately physics says otherwise. I think that if you use offset bushings, it should be an item to keep an eye on.

Posted: May 16, 2021 at 7:49 Quote
wellbastardfast wrote:
Random question.

But do offset bushings rotate in the actual bushing when the shock compresses. Just pulled my shock out and the offset bushing was pointing about 45 degs off where i first installed it. (Pointing towards shock)

They aren't supposed to. The offset bushing is supposed to be rigidly clamped by the bolt and the DU bush should rotate around it. Of course, if the offset bush rotates a lot as in a bike with a short rocker then the highest forces (during full compression) will have a lever arm to try to rotate it in the shock hardware. I would reinstall the offset bush making sure the DU bush is well-greased but the ends of the offset bushing are bone dry when clamping. If it keeps happening I would try friction paste on the ends of the offset bushing.

Posted: May 16, 2021 at 9:31 Quote
I bought formula centerlock rotor and atm i have shimano rotor on bike. Does shimano lock ring fits on formula rotor or will i have to buy lock ring from formula ?

Posted: May 16, 2021 at 10:22 Quote
Offset bushings are designed to be used in only one position, offset away from the shock. They are stable in this position and shouldn't rotate out of place.

Many people use offset bushings to restore the geometry after "mulleting" a 29" bike with a 27.5" rear wheel. In this case, the offset will be toward the shock, which is not stable and is likely to rotate.

Posted: May 16, 2021 at 11:26 Quote
meebo wrote:
I bought formula centerlock rotor and atm i have shimano rotor on bike. Does shimano lock ring fits on formula rotor or will i have to buy lock ring from formula ?

I would try it, and if it doesn't work, buy the formula ring

Posted: May 16, 2021 at 11:42 Quote
Lock rings are designed around the Centerlock standard, not the rotor. All rotor lock rings will fit all Centerlock hubs.

Posted: May 16, 2021 at 14:09 Quote
Can anyone identify this fork? Based on my research, I think it's a 06-09 boxxer team or rc.
Thanks for the help

Posted: May 16, 2021 at 14:11 Quote
Sambat,

You can't link an image from your email account. You'll just have to give us all access to your email account. Big Grin

Posted: May 16, 2021 at 14:19 Quote
wellbastardfast wrote:
Random question.

But do offset bushings rotate in the actual bushing when the shock compresses. Just pulled my shock out and the offset bushing was pointing about 45 degs off where i first installed it. (Pointing towards shock)

Use Fox polymer bushings instead of Rockshox style metal bushings (or those aftermarket dark grey polymer bushes that pop up here and there on the internet).
Your rotating hardware issue will most likely go away, as long as everything else is present and correct.

Posted: May 16, 2021 at 14:32 Quote
VF400rider wrote:
Stroke is 63mm and travel is 167mm.

By my workings out you want roughly a 435lb spring to hit 25% sag. If you are looking at the 65mm stroke Prorate spring, then you can get away with adding a couple of turns of preload in order to bring the progression in slightly sooner in the stroke. (Standard preload rules apply though, don't add so many turns that the coil goes completely coilbound before (or even at) bottom out.

So the 425-500 isn't going to be far off being bang on for you in terms of sag numbers. Whether it will still bottom excessively is anyones guess. It probably won't though, certainly if you run a long bottom out bumper and a good chunk of HSC.

The 475-550 will also give you perfectly reasonable (+/- 23%) sag numbers however (if a little on the stiff side for rough descending) so I guess at this point it is really up to you. The 475+ spring will be better for pure hucks to flat, the 425+ will probably behave better for general dh, while still giving reasonable huck to flat protection. Neither is going to be wildly wrong either way. Personally Id probably go for the 425+ and put up with occasional bottom outs. You are supposed to use full travel sometimes, especially at the rear. Setting a bike up to never bottom out, or only barely bottom out on the biggest hits you take, usually means the bike rides like shit for 95% of your riding in order to ride well 5% of the time. I bottom out a couple of times most days I ride. But my bike rides beautifully 85% of the time.

Posted: May 16, 2021 at 17:37 Quote
gabriel-mission9 wrote:
Snip

Thanks for your post on spring sizing - the perspective is helpful.

Posted: May 16, 2021 at 18:33 Quote
I recently had a new headset installed on my bike (cane creek 40) and even with it preloaded almost as much as I can before feeling some steering binding, when I grab the front brake and rock it back and forth I can feel the slightest bit of a wobble, and can see/feel a bit of movement between the dustcap and the top cup. Is it possibly just a bit of play in the bearing? I can feel it when rocking with the wheel at 90 degrees too so I'm fairly sure its not fork lower bushing play I'm feeling. Plus I can actually see a bit of movement at the dustcap. Anyone seen anything like that before?

And yes I have made sure that the top cap isn't bottoming on the steer tube, this play isn't a loose knocking like you get when there's no preload, its more subtle than that.

Posted: May 17, 2021 at 2:43 Quote
seraph wrote:
Lock rings are designed around the Centerlock standard, not the rotor. All rotor lock rings will fit all Centerlock hubs.

Except Fulcrum which need their own specific lock ring. Don't ask me how I know Madder

Posted: May 17, 2021 at 3:29 Quote
are there any pros for using squorx nipples on dt rims?

Posted: May 17, 2021 at 4:50 Quote
Hi,

This is my first ever post so apologies if it's in the wrong place. I'm carrying out what I now realise is long-overdue maintenance on my SR Suntour Raidon Forks (SF16-RAIDON-XC-DS-LO-R-15QLC32-CTS-29). When stripping them down, I was surprised to find fragments of what looked like very thin metal strips/shims (that would have been circular if they'd been whole) inside the Bottom Case Assembly.

I looked at exploded diagrams of the forks and bought Dust Seals and Oil Wipers in order to rebuild the forks. I put them back together, soaking the Oil Wipers in suspension oil and lightly lubricating everything with SRAM butter where necessary. Once reassembled, I was disappointed to find that there's a slight amount of play in the forks - between the Upper Assembly (gold coloured stanchions) and the Bottom Case Assembly. This seems to be because the only contact between the upper and lower components is at the top of the fork, where the Dust Seals and Wipers are located (apart from the fixing bolts at the bottom of the forks). This got me wondering whether the 'shims' that came out of the Bottom Case Assembly were some sort of additional guide that may have been preventing this play...? About halfway down the inside of each leg of the Bottom Case Assembly there is what looks like a small recess that may have originally held some sort of shim or guide in place, but the exploded diagrams don't appear to indicate that anything should be located here.

So the question is (finally) - Can anyone tell me what these thin metal fragments may have been, if there may have been some sort of additional guide in the Bottom Case Assembly, for example? Or, alternatively I guess, does it matter if there is a very slight amount of play between the Upper and Lower Assemblies? I know these are only reasonably low-end forks, so wonder if this might be expected compared to really high-end forks.

Sorry for the length of the post but wanted to try to include enough detail. Any help anyone can give will be very much appreciated.


 
Your subscriptions
no posts

Copyright © 2000 - 2021. Pinkbike.com. All rights reserved.
dv65 0.012062
Mobile Version of Website