Is a 20mm axle overkill for 29er trail bike?

hard-rider

I'm looking at forks for my Pyga OneTen29 build and found a well priced 2012 Rockshox Rev RCT3 dual air fork but it comes with a 20mm axle. Is that overkill and would there be any detrimental affect? It would mean I can't use an XT hub as I first intended as the XT doesn't come in 20mm format.

Were there any significant changes between the 2012 and 2013 model?

bennett_346

There won't be any detrimental effect but it's certainly overkill. I used to have a 20mm axle on my old trail bike and now have QR and ride the exact same things and personally can't tell the difference.

Chunkers1980

No but it appears 20mm in becoming a non standard :-(

Thewaylander

i personally think 20mm is the only way to go, 15mm is pap as is QR.

.blitz

Would not consider anything else for Revelations tbh. They are light for a reason and that reason is they have absolutely no structural rigidity at all - they need all the help they can get. Shame really because the internals are sublime but they're stuck in a horrible noodly chassis

As above 20mm is the only way

hard-rider

.blitz wrote:

Shame really because the internals are sublime but they're stuck in a horrible noodly chassis

As above 20mm is the only way

If the Revs are flexy then would the Reba be a better choice? I've read the Revs are much plusher and a better ride. They also seem to have a better MC damper then the Rebas.

I note that the 2013 models seem to have dropped the dual air too. Looks like dumbing down is becoming the standard these days.

levolon

i put a set of 20mm sektor solo air on my 456 and have them set to 120mm travel as the 150mm travel felt shyte

had rebas on it before with qr and yes 20mm axle is far better and the sektor solo air is a bloody good fork and only £214 delivered from Merlins
my bikes are all 20mm now so chop and change wheels easily for various needs ....

wont have qr again

merlin http://www.merlincycles.com/bike-shop/f ... ion-forks/

Chunkers1980

The reba will be worse. Especially in 2012/13 variety as they are old Sid lowers

bennett_346

To answer the OP i dont think 20mm is worth it if you'll need new hubs just to use it. QR is absolutely fine and i've ridden all sorts on my qr revs which plenty of people with 20mm axles refused to.

.blitz

hard-rider wrote:

If the Revs are flexy then would the Reba be a better choice?

Hmm 32mm uppers and 1.5 kg probably not although the shorter travel might help.

You might find Revs are OK - a lot of people do - but having had two pairs on the same bike I definitely think they are compromised by the chassis. My first std steerer QR Revs were absolutely awful and although the subsequent 20mm tapered steerer ones are better there is still a lot of side-to-side twanginess going on in the corners. It's very noticeable because I ride the same trails on two other bikes with stiffer forks and in terms of steering accuracy the Revs are the worst.

In terms of suspension control they are fabulous - small bump compliance/braking dive/big hit resistance it's all good - but back-to-back against stiffer forks they impart a feeling of nervousness and insecurity

supersonic

How much do you weigh, how much are the forks (and what will it cost for a new wheel?), and what wheel do you have at the minute?

hard-rider

bennett_346 wrote:

To answer the OP i dont think 20mm is worth it if you'll need new hubs just to use it. QR is absolutely fine and i've ridden all sorts on my qr revs which plenty of people with 20mm axles refused to.

I don't have the hubs yet as this will be a complete new scratch build so I'm not committed to the hub yet. The original intention was to use XT hubs in my wheel build but I can change to something else to accommodate the 20mm axle and in fact I'm now thinking of using superstar hubs. Strangely enough I found that the XTR hub can take a 20mm axle.

.blitz wrote:

hard-rider wrote:

If the Revs are flexy then would the Reba be a better choice?

You might find Revs are OK - a lot of people do - but having had two pairs on the same bike I definitely think they are compromised by the chassis. My first std steerer QR Revs were absolutely awful and although the subsequent 20mm tapered steerer ones are better there is still a lot of side-to-side twanginess going on in the corners. It's very noticeable because I ride the same trails on two other bikes with stiffer forks and in terms of steering accuracy the Revs are the worst.

Thanks for your input. I guess being a 29er fork it could make things slightly worst too due to the extra length. I'd be spacing the fork down to 120-130 from 140mm as that's what the frame takes so hopefully that'll reduce some of the flex. I currently ride a 100mm Recon and haven't found any problems with flex (probably not trying hard enough lol) and I'm sure the Rev shouldn't be worse than the budget Recon fork. at the end of the day I'm not an out and out hardcore rider. No longer have the balls for that.

hard-rider

supersonic wrote:

How much do you weigh, how much are the forks (and what will it cost for a new wheel?), and what wheel do you have at the minute?

I weigh around 80kgs, 85kgs with full bladder and gear on the back. I can find the forks for ~£400. I don't have any wheels yet as I'm doing a scratch build so am free to choose wheels at the moment.

supersonic

Do you need a tapered steerer?

.blitz

hard-rider wrote:

I currently ride a 100mm Recon and haven't found any problems with flex

You probably won't because it's what your used to. I was the same - it's not until you ride something that goes exactly where you point it that you realise you are doing all the right things at the bars but the front wheel is doing its own thing because the forks aren't controlling it. It's not even a question of riding hard it simply allows your bike and suspension to perform as it should without smearing and pinging off every obstacle whether its a big drop or a simply a rutted stretch of doubletrack

imho you have nothing to lose by going for a 20mm axle you won't regret it.

hard-rider

supersonic wrote:

Do you need a tapered steerer?

I believe yes. The frame takes a ZS44/28.6 Top and the IS52/40 Bottom headset.

supersonic

Worth looking at this then:

http://www.on-one.co.uk/i/q/FORSRV14/ro ... mm_29_fork

RL damper here gets a fully adjustable floodgate valve, and the low speed compression adjustment. Is a great price.

hard-rider

supersonic wrote:

Worth looking at this then:

http://www.on-one.co.uk/i/q/FORSRV14/ro ... mm_29_fork

RL damper here gets a fully adjustable floodgate valve, and the low speed compression adjustment. Is a great price.

Thanks for the heads up. What's the difference between the RL and RCT3 versions? Is there a lot lost in adjust ability going with the solo-air spring as opposed to the dual-air spring?

Here is what I'm comparing it with.
http://www.chainreactioncycles.com/Mode ... elID=94599

supersonic

RCT3 has three set positions for the lockout - on/off/middle. You can independantly set the low speed compression.

With RL you need to move the LSC all the way to lock it, but you can precisely set the blow off valve, so a little more tunable. As is the dual air spring.

hard-rider

OK so the RL is a better fork with regards to damping adjustment but not as good for spring adjustment. Which in your opinion is the better fork to go for leaving price out of it?

supersonic

If you want the best stiffness, then the RCT3. Apart from that is hard to call them apart. The RCT3 damper is easier to set up, but so is the solo air spring.

Personally I'd take the RL and put the money towards better wheels.

hard-rider

Great. Thanks for the input.

Just looking at the onone site it's a bit confusing. The description talks about all the possible damper adjustments and a 20mm axle but when you click buy you're taken to the bottom of the page and the fork specified has a 15mm axle and says poploc compatible. So does the fork come with the poploc crown or manual crown? I assume having the poploc would remove some of the adjust ability as it's a simple on/off affair? How would you turn the LSC up if the poploc pully wheel is on the crown?

Just want to make sure I fully understand what's being offered.

supersonic

Ah, typical OnOne, I was assuming was 15mm, non pop loc!

I'd give them a ring! Ithink they have simply copied and pasted the blurb from the RS site.

Poploc dampers have the spring inside the damper tube, it can be unhooked and modified to use the LSC.

hard-rider

OK thanks. Will give them a call.

I can't figure out why RS would put in such a good damper and then strangle it by putting an on/off poploc remote option on it. It would make more sent to provide an adjustable remote otherwise not bother.

felix.london

supersonic wrote:

Poploc dampers have the spring inside the damper tube, it can be unhooked and modified to use the LSC.

So could I get this done on my dual air Reba RL?

supersonic

Yes, see FAQ in Tech section.

benpinnick

By comparison the rct3 is better damped, with better internals which give you high speed rebound and compression. Which I don't think the RL has. The RL damper is pretty basic.

supersonic

Both have the DNA spring tube and dual flow rebound. RL is not basic, in many ways has advantages over the RCT3. (except on 2013 models, where floodgate is fixed).

benpinnick

Sorry, to clarify - RCT3 ALSO has High speed compression circuit, which I dont think the RL has.

hard-rider

Just to confirm something with these forks. They come as 140mm travel. The Pyga frame is designed for 120/130mm travel. Would I need to order the spacers to reduce the travel or would spacers be included with the fork?

benpinnick

That depends on whether its OEM or Aftermarket forks. If they are cheap, probably OEM so wont have the spacers.