Wheel needs to be re-dished ... or is there another option?

[Woz]

In many respects a narrower tyre would be a better solution. A Smoke 2.1 barely cleared in an Axis TT.

As said above, you can check wheel alignment yourself;
- take tyre off, put wheel in
- measure from one chain-stay / seat-stay location by marking it with a bit of tape
[Sliding a wood off cut in the gap would be more accurate; call it an oversized feeler gauge!]
- take wheel out, flip it, put it back in
- measure from the designated chain-stay / seat-stay location.
[If the wood off cut doesn't enter the same gap or is too sloppy then your wheel is not dished properly]

If the wheel is OK, then the problem would lie with frame alignment (or design to allow chain-ring clearance etc.) or
tyre not seated correctly or even a tyre manufacturing fault.

 

[kjarrett]

In many respects a narrower tyre would be a better solution. A Smoke 2.1 barely cleared in an Axis TT.

As said above, you can check wheel alignment yourself;
- take tyre off, put wheel in
- measure from one chain-stay / seat-stay location by marking it with a bit of tape
[Sliding a wood off cut in the gap would be more accurate; call it an oversized feeler gauge!]
- take wheel out, flip it, put it back in
- measure from the designated chain-stay / seat-stay location.
[If the wood off cut doesn't enter the same gap or is too sloppy then your wheel is not dished properly]

If the wheel is OK, then the problem would lie with frame alignment (or design to allow chain-ring clearance etc.) or
tyre not seated correctly or even a tyre manufacturing fault.

Very helpful, thanks for the reply.

I will try what you've suggested, but yesterday decided to check another wheel in the frame (Araya RM-17s that came on the Response Elite).

On the RM-20s, clearance on the drive side was 24mm, and on the other it was 28mm.
On the RM-17s, clearance on the drive side was 27mm, and other other it was 29mm.

Again, I realize this isn't what you said, I'll do that and report back.

Thinking about running the 1.95" Kenda regardless, I just like the Velociraptors so much. Also, the Axis was spec'd with 2.1 tyres, right? So, theoretically I should be able to run them...

-kj-

 

[kjarrett]

UPDATE: the tyre might actually be the primary (but not only) culprit!

On a hunch I mounted an old Kenda K816 (also 2.1") I had lying around (prior to the Velociraptor upgrade) and the wheel spins freely; only the vent spews hit the chainstay (see pic). They WILL remove the paint (they did this on the seat stay of my Response Elite, and now I know why). Since I only ride on dirt, they'll stay there unless I take a nail clipper to them.

Anyway I now knew I needed to measure the tread difference so I whipped out the calipers - at 55 psi, the Velociraptors (a 2.1" tyre) at their largest knob are 2.2" wide. The Kenda's are 2.07" wide. That variance, a bit over 3mm by my calculations, appears to make all the difference (sorry for the pun). :roll:

And now for something completely different (ok not exactly) ... measuring the clearance between rim and chainstay with my calipers. Removed the tyre, flipped the bike upside down, and carefully made multiple measurements, from the same points on the rim, noting that the curvature of the stay made precision difficult (so it's kind of silly to attempt to be this precise, but anyway, here we are, right?)

With the wheel mounted correctly, the drive side chainstay gap is 24.7mm and the non-drive side chainstay gap is 25.5mm.

With the wheel flipped, the drive side chainstay gap is 25.7mm and the non-drive side chainstay gap is 24.9mm.

Not sure how to explain the apparent differences in measuring (I'd expect the numbers to add up to the same sum) but as I said the roundness of the chainstay made the process a bit tricky. I was careful to seat the wheel fully in the dropouts. (Side note: fun to discover how much easier it is mounting wheels with the bike upside down, because gravity & vertical dropouts.)

ANYWAY ... the data tells me the wheel *IS* off, but ... is it enough to justify re-dishing? I'm not so sure I want to a) incur the cost (and waiting time) needed for the shop to do the work, or b) attempt it myself and possibly make things worse and then end up incurring the cost of a shop fix.

So, for now, I am just going to RIDE THE OLD KENDA IN THE REAR while I wait for the new Kenda Nevegals (I never really liked the K816's I got punctures regularly and not a single one since getting the Velociraptors.) I'm hoping the casing on the Nevegals is superior to the K816's (which are no longer made anyway).

Now if you'll excuse me ... I'VE GOT A NEWLY REBUILT BIKE TO TEST RIDE!

Carry on! (and thanks for all the help and encouragement)

 

[kjarrett]

FINALLY! Very quick post-rebuild shakedown ride on a local rail-trail. Shifting, saddle / stem height, brakes all 100%. Feels so good! This 25 year old frameset still gets it done! Temporarily 'fixed' my tire clearance problem with that old Kenda K816. Next stop: ACTUAL TRAILS AND SERIOUS FUN!

THANKS EVERYONE FOR YOUR HELP!

 

[marc two tone]

Re:

The sheer flex on my team marin would bring about a certain.
.
Brrrt, brrrt, brrrt each pedal stroke with that clearance.

If you eventually need knobbly, yet low pro tyres, I can recommend these, got some on me gary fisher, roll ok on tarmac too.

Bike looks ace by the way.

 

[kjarrett]

Thanks that is a GREAT recommendation!

Found them on eBay in Canada for less than the Nevegals: https://www.ebay.com/itm/Geax-Gato-Mud- ... 3551404765

Even with shipping from the UK that's twice the price of the tyre, haha

I just might give those a try! I had a really difficult time finding ANYTHING smaller than 2.1" that looked like it had any tread decent enough for the trails I ride. The Gato fits the bill, especially with your recommendation. Should have asked here first...

-kj-

 

[mattr]

Oh, if you want a bit more grip, and comfort, and a faster rolling bike, let your tyres down, a lot.

I was running around 25 psi on 26x2.1 tyres (at about 85 kilos)

55psi must be like trying to hold onto a jackhammer at any sort of speed on the rough stuff......

 

[kjarrett]

Oh, if you want a bit more grip, and comfort, and a faster rolling bike, let your tyres down, a lot.

I was running around 25 psi on 26x2.1 tyres (at about 85 kilos)

55psi must be like trying to hold onto a jackhammer at any sort of speed on the rough stuff......

I've arrived at that PSI like most people, by experimentation, and found it best for the trails I ride and my ... somewhat large ... self.

I started riding again in February at about 107 kg. I'm I'm down about 10 kg since then, with another 10 kg or so to go, so perhaps I should try a bit lower pressure, as my diet & exercise regimen (which the MTB figures prominently in) continues on.

At lower pressures, I could feel rollover in fast corners, and for some reason, higher pressure also made sandy bits easier to traverse.

I think I'm going to re-mount the WTB Velociraptor and see what pressure I can run before the nubs hit the chainstay, I think it's like 40 though. Probably too low to be usable, even if I get to my goal weight (~90 kg).

Thanks for the reply!

-kj-

 

[kjarrett]

Re:

Just tested, the Velociraptors rub the chainstay at any pressure above 20 psi. Now I wonder how much re-dishing might help, if at all. hmmmm...