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Fork and frame compatibility question

Singlespeed & Fixed Gear "I still feel that variable gears are only for people over forty-five. Isn't it better to triumph by the strength of your muscles than by the artifice of a derailer? We are getting soft...As for me, give me a fixed gear!"-- Henri Desgrange (31 January 1865 - 16 August 1940)

Fork and frame compatibility question

Old 02-22-19, 08:35 PM
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PeopleAreIdiots
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Fork and frame compatibility question

I'm considering picking up a cross check to replace my current track frame (I want to free up the possibility of going geared for some light touring while staying fixed most of the time for commuting and regular rides.) I already have a nice fork that I'd like to use though that doesn't match the measurements of the stock cross check one. How far off can a fork be without severely screwing things up?

My fork (rake, race height): 45mm, 380mm
Cross check fork: 44mm, 400mm

Can I pull this off or is the 2cm difference in race height way too much? Mind you I'd be running this setup both fixed amd geared.

(For those keen eyed fellas, my current rear hub is a velo orange grand cru track hub so it can fit the 135mm rear spacing of the cross check. I also have 130bcd cranks so I can just swap out chainrings for a geared setup)

Last edited by PeopleAreIdiots; 02-22-19 at 08:41 PM.
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Old 02-23-19, 07:08 PM
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I did the math and it seems like this fork swap would change the head tube angle of the cross check from 72 to about 73 given my frame size (54 or 56)

Both this and the 1mm increase in rake (neglegable I'm guessing) should cause the handling to be more responsive and "twitchy". My current frame has a head tube angle of 73.5 so I guess I'm not worried as the trail in this setup would actually be 3mm more than my current setup ().

Can anyone speak to the difference in feel when you add 1 in head tube angle? I've increased fork rake by 5mm before and couldn't really tell the difference. Is it comparable?

the other thing Im worried about is pedal strike. Shouldn't this lower the bb and bring the front wheel a bit back, giving me less space to spin the cranks. I'm already using 165mm cranks so idk.. think that would be an issue?
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Old 02-23-19, 08:57 PM
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Originally Posted by PeopleAreIdiots View Post
I did the math and it seems like this fork swap would change the head tube angle of the cross check from 72 to about 73 given my frame size (54 or 56)

Both this and the 1mm increase in rake (neglegable I'm guessing) should cause the handling to be more responsive and "twitchy". My current frame has a head tube angle of 73.5 so I guess I'm not worried as the trail in this setup would actually be 3mm more than my current setup ().

Can anyone speak to the difference in feel when you add 1 in head tube angle? I've increased fork rake by 5mm before and couldn't really tell the difference. Is it comparable?

the other thing Im worried about is pedal strike. Shouldn't this lower the bb and bring the front wheel a bit back, giving me less space to spin the cranks. I'm already using 165mm cranks so idk.. think that would be an issue?
Im not sure how the fork will effect handling. As far as clearances go, I think youll be fine. From personal experience before my kilo was stolen and bastardized I was running 700x35. The tire was nearly touching the down tube. The toe overlap was pretty significant but I was fine if I kept it in mind while making slow or sharp turns. You adapt to it pretty quickly. Now would I want my favorite bike, or daily bike set up like that? Probly not. Many here would probly argue against it. But it was fine for me. I built up a charge scissor years back with similar clearances. If you look at dedicated track frames, many are set up similar. When riding at a pace youre obviously leaning more than turning the bars. Blah blah blah, stuff you probly know.

As far as pedal strike is concerned... I wouldnt think that the BB would be lowered enough to notice a significant difference. Again, no expert here, just what Im thinking self.


I like the idea of having a bike that can be set up for multiple uses. I dont know that Id want a bike that would switch from fixed gear to geared though. Seems like it would be a pain in the you know what... but again thats just me. If it were me, Id probly slowly build up another bike to suit my desire.

Once again, I am no expert by any means in this field and Im sure others can give much better advice in this department.

Last edited by mouse; 02-23-19 at 09:01 PM.
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Old 02-23-19, 10:54 PM
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Originally Posted by mouse View Post
I like the idea of having a bike that can be set up for multiple uses. I dont know that Id want a bike that would switch from fixed gear to geared though. Seems like it would be a pain in the you know what... but again thats just me. If it were me, Id probly slowly build up another bike to suit my desire.
That was my plan at first (n+1 and all). But I got to thinking and I don't think I can really use 2 bikes enough to justify owning both of them right now. So this was just an idea that I had that would at least give me some options.

But yeah, it would definitely be a pain to switch 'modes' (swap rear wheel, bars, chain and chainring, add derailer and rear brake, route cables) so I'd probably keep it in fixed mode 90% of the time unless I had a really long weekend ride our tour or something planned. I'm still trying to decide if its worth the hassle. (Otherwise I'm thinking wabi special frame and a geared bike down the line)
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Old 02-24-19, 12:55 AM
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I apologize for my lack of forum etiquette here for filling up my own thread with a bunch of my own posts but I figured I'd mention my findings in case somebody else has this question in the future.

So I plugged the cross checks measurements into www.bikegeocalc.com and found that this fork swap lowers the bottom bracket on the cross check by 6mm from 66 to 72mm (bb drop). Pedal clearance for wheel strikes is also reduced but its still higher than my current setup which doesnt have any issues.

Even though I'm using 165mm cranks, this would give me a whole 1cm less ground clearance than on my current setup.

In case anybody reads this far, does anyone have any idea how little clearance I can get away with and still avoid having to constantly plan my turns to avoid pedal strike?
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