Crewkerz Jealousy 26 vs carbon bikes

[La Bourde]

I have the old blocky ones and I filed the sharp edges to round them. I hurt my self many times, my ankle still has a mark. I have no idea how they came to this design!

[Jere_h]

This is where I come from, they cut my ankle like cheese at least once in a year.... Typically the same wound just didn't have time to heal until it happened again and again. Had to put some foam inside my sock to protect the bony part.

[La Bourde]

That shows that this market it not regulated. In some other industries, it won't be possible to release such parts.

Some MTB stems are dangerous, they have sharp edges on the back ... I never understood that too. 

You have also some parts that are designed without doing FMEA (Failure Mode and Effects Analysis). It is so obvious ...

Shimano does FMEA and that is why the brake bolts have an extra retention system or the brake lever has this pin to remove it from the bar. But don't expect this from other brands ... I heard it comes from the Japanese regulation which seems to be more exigeant. 

 

 

[Mark W]

I've had BMX and MTB cranks that have done similar, so it's not necessarily just a trials thing. My right ankle looks a totally different shape to my left because I kept taking chunks out of it with my Profile cranks, and that was a decade ago. I also did similar a while back with some RaceFace Aeffect cranks. If you have your feet near the crank arm I think it's somewhat of an inevitability, which is presumably why riding-specific shoes for MTB and trials have raised collars around the inside of the ankle area.

I would agree though that trials brands tend to be a bit looser with tolerances and what's deemed saleable/acceptable. Some stuff we used to get through was questionable, and we were pretty surprised to see other shops sell them, or sell them without modifying the parts first.

[Jere_h]

So my L size Jealousy frame just arrived. There is 1085 printed on the chainstay but the actual WB measures roughly 1095 with the WAW forks..... It looks super long too, not just the numbers.
This is exactly what I didn't want, because 1085 was already on the long side for my preferences. Ultimately went for the L size instead of M as I thought that the smaller one would probably feel too short on reach (according to the given numbers).

Seriously, how is such an error even possible, makes me wonder. Even Tartybikes says 1088 on their site, which I thought would be somewhat correct assuming they actually measure the frames? So is it likely that my frame is just a "lemon"?

Edit:

Got a response from the shop where I bought the frame (not Tarty), and according to them the WB depends on the fork used (yeah everyone knows that), hence it's 1095mm with the WAW forks they say.

At least to me it seems pretty obvious that as long as there are some precise geo numbers listed, they should match the parts specced with the complete bike or it doesn't make much sense.

Apparently Crewkerz is using their own weird offset values to get that 1085mm out, something that doesn't even exist as all of their forks are 405mm long with 35mm offset.

Getting truly interesting, as the shop doesn't seem to understand the fact that there are misleading information on their site.

 

 

Edited September 11, 2022 by Jere_h

[AdamR28]

Your frame isn't a 'lemon', the geometry is just different to what the manufacturer states. It's pretty common. But yes, I agree it doesn't make sense! It is something Tarty have discussed at length with Christian in the past, but somehow this is not seen as an issue at Crewkerz.

[Mark W]

20 hours ago, Jere_h said:

There is 1085 printed on the chainstay but the actual WB measures roughly 1095 with the WAW forks.....

Most of the Jealousy bikes I was involved with back before I stopped working at TartyBikes were not the same as the geo was claimed to be. Quite often it was 10mm difference, sometimes it was 5mm. I'm not sure what it is that kept making them be that same amount out, but 1) it's clear something isn't right with their drawings somewhere, and 2) that's why you don't put the geo numbers on the frame. Almost every frame I can remember dealing with from any brand that had the geo written on it was wrong. The only exception to that rule that springs to mind was Onza who tended to be correct. 

11 hours ago, AdamR28 said:

Tarty have discussed at length with Christian in the past, but somehow this is not seen as an issue at Crewkerz.

The "issue" for Crewkerz is anyone actually measuring physical objects, rather than just taking their word for it.

[Jere_h]

For a reference, I remember a guy nicknamed Lemon (coincidentally) telling me something like his copy was 1100mm with 395mm or something chainstays, and annoying to ride to the point he decided to sell it. This is why I was a bit worried, although his bike was one of those really old ones I think.
Just can't get my mind wrapped around how such 10mm+ errors can be achieved on the production line without messing things up, and does it happen in the factory end or not.

I always felt like these bikes look very long, was not mistaken then. I thought it would be just the frame design.



 

[La Bourde]

Tolerances in the bike industry is a hot topic ...

I think there are several aspects to consider:

1. Milling the tube and putting them correctly on a jib is not as simple as one assumes. Maybe can AdamR28 share his experience.
2. During/after welding the material, the material moves and bends, due to the difference of temperature for example. It isn't isotropic either ... Nicolai, Devinci and other brands fix the alignment issues later in their process. I think this is done by most companies too. But do they check the wheelbase or the head angle? Not sure.
3. A slight variation in the component (headset height, fork length, fork angle, etc.) affects the wheel base
4. maybe the brand does not want the user to know that the geometry changed ...
5. maybe it is now just a label and does not refer to the actual wheelbase length, i.e. the equivalent of Large, Small or Medium.
6. like most brands, the construction of the frame is not done in house. So the supplier makes some prototypes and I guess nobody cares about the geometry further ... They won't produce 50 prototypes too.

I don't think that 1, 2 and 3 can explain a deviation of 10mm.

From a legal point of view, are there some tolerances defined? It is the case for some products sold by weight (at least), but I don't know for other products.

[thousandwords]

4 hours ago, La Bourde said:

Tolerances in the bike industry is a hot topic ...

I think there are several aspects to consider:

1. Milling the tube and putting them correctly on a jib is not as simple as one assumes. Maybe can AdamR28 share his experience.
2. During/after welding the material, the material moves and bends, due to the difference of temperature for example. It isn't isotropic either ... Nicolai, Devinci and other brands fix the alignment issues later in their process. I think this is done by most companies too. But do they check the wheelbase or the head angle? Not sure.
3. A slight variation in the component (headset height, fork length, fork angle, etc.) affects the wheel base
4. maybe the brand does not want the user to know that the geometry changed ...
5. maybe it is now just a label and does not refer to the actual wheelbase length, i.e. the equivalent of Large, Small or Medium.
6. like most brands, the construction of the frame is not done in house. So the supplier makes some prototypes and I guess nobody cares about the geometry further ... They won't produce 50 prototypes too.

I don't think that 1, 2 and 3 can explain a deviation of 10mm.

From a legal point of view, are there some tolerances defined? It is the case for some products sold by weight (at least), but I don't know for other products.

 

Just giving my 2 cents here as a lay person.

All of the above a good points however they all point in one direction- no QA.

Point in case- in the road bike world, it is beyond doubt that when a reputable manufacturer publishes specs for a model, not one single frame of that model that hits the market will deviate from those specs beyond 1% or whatever minute, barely perceptible degree (if at all). Because they all have QA- frames out of spec if/when they happen, are pulled off the delivery chain. But then that's one of the many reasons a Pinarello Dogma costs thousands of dollars, that QA team draws a salary that factors into the final price.

Once again- a newbie speaking here, but to me, reading this thread (with a certain degree of astonishment) it feels like the trials manufacturers, being rather niche and small scale, do not even consider QA in a similar fashion- rigorous go/no go gauges- but rather scaled down to a more modest set of requirements (frame integrity, general alignment, etc). And that not only because of the less stringent expectations from a much narrower customer base, but also because of the personnel limitations. Even in a small company, people in the design department are expected to do just that, not final quality control/assurance- same with assembly line, painting, etc.

Looking at the prices for brand new trial frames on Tarty, trial-bikes, trial-world (well under $1k in the majority of cases), etc, I feel like it is rather fortuitous that they are able to maintain actually decent quality (even stellar quality, as per some of the established riders) at those prices- prices that would not buy you a 10 year old used road/grave/mountain bike frame from a decent manufacturer. And I suspect that 2 explaining factors are 1. slim revenue margins and 2. skeleton crew, basically the strictly obligatory.

That probably explains not only lax frame standards, but many of the parts associated issues I saw popping in recent threads on this forum- brake master cylinder and blades, hubs, etc. When budget is limited from R&D to post production quality control, final results are what they are.

[AdamR28]

7 hours ago, La Bourde said:

Milling the tube and putting them correctly on a jib is not as simple as one assumes. Maybe can AdamR28 share his experience.

My only direct experience here is making frames for myself, without the use of a proper jig, no fancy tools, and with DIY techniques. 

I've made 3 now, and number 1 was a bit of a bodge, but none of the dimensions were more than 10mm or 1 degree different to my drawings. The 2nd was better. The 3rd frame is within 2mm and 0.1 degrees.

Frame builders can manufacture to superb tolerances and with great consistency, its just the graphic on the frame is "wrong" in this case.

Some good info here: https://www.mtbr.com/threads/manufacturing-alignment-tolerance.1207578/#post-15700651

[aener]

6 hours ago, AdamR28 said:

Frame builders can manufacture to superb tolerances and with great consistency, its just the graphic on the frame is "wrong" in this case.

I would've thought that too, but it seems like the back ends varied within the same generation of frame. I can't remember whose they were, but one 26" I encountered a few years ago had brake mounts too close to the dropouts so pads being set perpendicular (read: issues for washerless mounts) would have it hanging off the inside of the rim. Another 26" bought in the same year had them too far the other way so pads would scrub the tyre. That seemed pretty loose to me, given their integratedness in that region of the frame, and couldn't understand how it was even possible if it was assembled in a jig. Never had a tape measure so unsure if it was an incorrect chainstay length, or if the overall length was right but the mounts were just positioned a bit wrong inside that length.

This was a while back, so I've pointedly not said "Jealousy" because there's a chance they were Cleeps.

 

Kudos on the 2mm and 0.1° though! Still haven't measured mine. It certainly seems not too far off what I was aiming for and it rides lovely, so I don't want to measure it and have it placeboistically ( :lol: ) affect how I ride because a certain number isn't what I thought it was.

[onzatpro09]

 

3 hours ago, aener said:

I can't remember whose they were, but one 26" I encountered a few years ago had brake mounts too close to the dropouts so pads being set perpendicular (read: issues for washerless mounts) would have it hanging off the inside of the rim. Another 26" bought in the same year had them too far the other way so pads would scrub the tyre.

No idea what the geo comes out as as I've not measured, but my 2022 Jealousy M does need the brake clamps shunted all the way back, and even then only just sit fully on the rim 

[Jere_h]

4 hours ago, onzatpro09 said:

No idea what the geo comes out as as I've not measured, but my 2022 Jealousy M does need the brake clamps shunted all the way back, and even then only just sit fully on the rim 

Thanks for mentioning, didn't even realize to check this out on my frame because I'm fully committed to using V-brake setup with my custom adapters. But decided to take a look and guess what.. 

(The gap between the bolts is 46mm)

Here the clamps are pushed all the way back towards the weld. Looks like the brake pads would touch the tire even with max setting, with these particular clamps at least.
Honestly the whole thing looks pretty unacceptable to me, but it is what it is and pretty sure that every 2022 frame has this flaw, more or less. Have to say I'm glad that I will never ever use Maguras anyway!

Any chance Onzatpro09 if you could measure the wheelbase of your 2022 medium?
I decided to send my large frame back and get the medium, because if the WB is consistently approx. 10mm off through the whole lineup of sizes, the M should be exactly what I prefer around 1080-1085mm.

However, I'm starting to suspect that they might just have some really loose tolerances and labeling the frames based on what size option fits closest to the final measurements of each frame. This is why they are the only trials brand with multiple sizes to offer 

 

Edited September 13, 2022 by Jere_h

[La Bourde]

One question though:

Is the rear wheel from Crewkerz (or waw)? the tolerance of the rim could be on the small side , amplifying the problem.

But still, there is an issue here!

 

I agree with you AdamR28, I don't think the error is only due to the manufacturing process, but I have already seen ugly things in MTB (like a frame which swing arm had such a lateral offset, that it was really difficult to install the shock and the shock then rubs against the arch of the frame.

I recall also some Koxx frame which chain rubbed against the chainstay out of the factory. I though trials were further now.

Also with the current difficulties to produce, I would control twice what my supplier delivered... I heard  bad stories in others industries since Covid.

 

[Jere_h]

26 minutes ago, La Bourde said:

One question though:

Is the rear wheel from Crewkerz (or waw)? the tolerance of the rim could be on the small side , amplifying the problem.

But still, there is an issue here!

Mine is the Trialtech Carthy, anodizing removed. Tires have been fitting pretty tight at least.

[La Bourde]

OK, thanks.

 

I would like also to emphasis, that even if the quality of the current bikes isn't as one expects, we shall not blame the brands behind - regardless of the brand. I am pretty sure they do as good as possible but unfortunately, this is not perfect (even not satisfying).

The market for trials is so small ...

 

Hope you can find a solution and ride a bike that fits you!