The stupid questions thread.

moorey

For a good time call 0444653221
I've always been tempted, but never been able to justify the expense. Maybe one day. Probably not.
I’m yet to experience an USD without horrific twist flex. I know they’re trying to overcome that with this design, but even full dual crown USD forks used to be terrible. Forward/back was excellent, twist was terrible without the arch.
 

Asininedrivel

caviar connoisseur
Was actually the top. 2.6” DHF on a 30mm ID rim. Might be different on a 35mm with less ballooning.
Hmmmm.... yeah mine would be with a 30mm internal rim too. How baaad was it? Like could a bodge with a bit of electrical tape either side of the arch cover for rub marks on the fork depending on how badly the tyre was getting buzzed?
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
Hmmmm.... yeah mine would be with a 30mm internal rim too. How baaad was it? Like could a bodge with a bit of electrical tape either side of the arch cover for rub marks on the fork depending on how badly the tyre was getting buzzed?
Depends on fork too doesn't it? Like Fox seem to have a touch more room, but DVO's were super-tight (by reputation, I've only lived the boost-life...).
 

Asininedrivel

caviar connoisseur
Depends on fork too doesn't it? Like Fox seem to have a touch more room, but DVO's were super-tight (by reputation, I've only lived the boost-life...).
Yeah good call - it's a 2018 Fox 36 (although the lower / arch design doesn't look to have changed between about 2015 until last year's revamp).
 

dazz

What was my password?
I’m yet to experience an USD without horrific twist flex. I know they’re trying to overcome that with this design, but even full dual crown USD forks used to be terrible. Forward/back was excellent, twist was terrible without the arch.
Do you have any theories on why it's no problem on an MX bike but is such a big issue on MTB? I mean every MX bike from every manufacturer around the world have had USD forks since the mid/late 90's. MX bikes are around 7 times heavier than a MTB and are much faster, would've thought that'd make the twist more noticeable if anything... Maybe it's a feel thing that once you get used to it is really a non issue.
I wonder if a scaled up MTB fork would be a game changer in MX. I guess Ohlins are really the only major'ish player that make forks for both MX & MTB. (I've always wondered why Fox haven't tried breaking into the MX scene with the sussy)
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
Do you have any theories on why it's no problem on an MX bike but is such a big issue on MTB? I mean every MX bike from every manufacturer around the world have had USD forks since the mid/late 90's. MX bikes are around 7 times heavier than a MTB and are much faster, would've thought that'd make the twist more noticeable if anything... Maybe it's a feel thing that once you get used to it is really a non issue.
I wonder if a scaled up MTB fork would be a game changer in MX. I guess Ohlins are really the only major'ish player that make forks for both MX & MTB. (I've always wondered why Fox haven't tried breaking into the MX scene with the sussy)
I've wondered about this myself in the past, my assumption was a much larger axle diameter would hold everything square at the axle end, and the thicker stanchions to deal with the weight of the motorbike would prevent a lot of the twist too. The tiny amount of extra weight from thicker stanchions wouldn't really be noticeable compared to the overall weight of the bike.
 

moorey

For a good time call 0444653221
Do you have any theories on why it's no problem on an MX bike but is such a big issue on MTB?
Not really, other than size/bulk. Weight isn’t a factor on a moto. Your ride shivers, White bros, cannondale USD etc back in the day?
You’re the engineer, I’m just an opinionated flog.

Edit. Beaten by seconds.
 

dazz

What was my password?
Not really, other than size/bulk. Weight isn’t a factor on a moto. Your ride shivers, White bros, cannondale USD etc back in the day?
You’re the engineer, I’m just an opinionated flog.

Edit. Beaten by seconds.
Yeah, mate had shivers on a bullit. I'm just an untalented flog when it comes to riding so they seemed fine to me, small bump compliance was great (if memory serves me correctly). From an engineering perspective I don't see why anything that works on MX wouldn't be adaptable to MTB, and vice versa. Marzocchi and White Bros. both have moto forks so would have thought there'd be some cross over R&D going on, maybe.

I'll wait for your advise/opinion, then ignore it and tell you you're wrong, how's that sound?

edit: well not white brothers anymore...
 
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