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General Fat Chance Discussion Anything and everything about the best mountain bikes ever made. |
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#1 |
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Join Date: July 21st, 2007
Location: Newbury Park, CA
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I did a search or three and couldn't find the information I was looking for. I would really like to understand the differences in the forks... and what the deal is with my bikes.
Background. I purchased a M Yo new in 92. It came with a Mag-21. The fork eventually died and I decided to order a rigid fork from Wendyll / Chris.. This was probably in about 97/98. I waited and waited, got what I think is a BOI, installed it and have been riding it ever since. Skip forward to yesterday. I just purchased a 99 YO on eBay... got it re-assembled it and took it for a test ride before I tear it down and make it SS. WOW !!!!!!! What a difference. The new one has an IF fork on it with a bit more rake, and it is about 1.25" longer than the one on my other. It is so much more stable. My old bike feels like a crit bike now... twitchy as hell. And I feel like I'm a bit dumped. I'm starting to think that Wendyll sent me the wrong length fork for my old yo. So: Background finished, these are the questions I hope you could help me answer: 1. What is the difference between BOI and Yo fork? 2. How do I measure my 93 to decide if it is suspension corrected? Thank you in advance |
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#2 |
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Join Date: February 16th, 2007
Location: Durango, CO USA
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Wouldn't a simple axle-to-crown measurement tell you alot?
Curious to see the BOI vs Yo fork answer... Rody? |
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#3 |
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#4 |
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difference will be subtle since geometry is the same.
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#5 |
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did you measure the wheelbase on both bikes? susp corrected geometry is always something vague since some forks sag and others don't.
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#6 | |
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Join Date: July 21st, 2007
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Final question. If I was thinking about retiring my BOI for a while and runnning a suspension fork, what would be a good suggestion? I'm not looking for a huge amount of travel; and would want it to be light... and .. of course... it has to have a 1" steerer. Thanks... |
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#7 | |
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wanted: ride time. |
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#8 |
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I know ... parallax/angle/ light can play tricks... but side by side, maybe someone can tell a difference?
91 yo / BOI 99 yo / IF Last edited by jh4rt; September 28th, 2007 at 4:41 PM. Reason: bigger pics |
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#9 |
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Join Date: February 16th, 2007
Location: Durango, CO USA
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FYI, this article is really useful
http://www.phred.org/~josh/bike/trail.html Also, this question would be easily answered on the frame forum (www.frameforum.net) if you dont want to sit around and wait for Rody. |
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#10 |
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Join Date: June 1st, 2006
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the newer bike seems to have a steeper head angle which would compensate for the extended A/C and modified rake.
rake/ head angle/ front center distance all play together. hard to pinpoint what exactly goes there but if you are in love w/ the new one.. does that mean we will be seeing a black Yo eddy for sale soon? ![]()
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#11 |
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Join Date: July 21st, 2007
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#12 | |
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Join Date: June 1st, 2006
Location: rio de janeiro
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70mm travel is the ticket.
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#13 |
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Join Date: October 19th, 2005
Location: Wooster, Ohio
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Hey guy,
Here are the major differences in the forks / frames... Big One Inch specs... Debut around the time of the TI introduction Dropout to race length - 15.9375" suspension corrected to 63mm Rake offset - 1.57" or 6 degrees BOI forks use 1.0" diameter tubing for the legs and crown Yo specs... Used from late eighties until BOI intro Dropout to race length - 15.5" for standard geometry Yo Eddy forks use 1.125" diameter tubing for the legs and crown. Now, the frames will have a significant difference in the geometry. Your 92 Yo will have a lower headtube height as it was designed for rigid forks, although the Mag 21 was probably put on as with your weight to sag the fork, it would not change the ride drastically. Your 99 frame is designed to work with a 80mm fork, thus the reason that the longer axel to crown length is present on the IF fork. The likely culprit of the handling variance of the older Yo is the resultant trail with the more modern Big One Inch. Only way to tell for sure is to take all the measurements off the rigid fork that is on it. Hope some of this helps, rody Last edited by rody; September 28th, 2007 at 8:44 PM. Reason: syntax |
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#14 |
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Join Date: July 21st, 2007
Location: Newbury Park, CA
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Awesome information....
Well... So... umm... I took the old nag out for a 15 mi. spin this evening. Let me just say... umm... crit bike; whatever... IT RODE LIKE A DREAM. Maybe my kung fu is just getting stronger, but it was a dream to ride tonight. And, I realized that both of these bikes are stellar, but different. The IF fork is much more flexy, and I think will be better suited for a SS. But my old Yo with the BOI was true as can be tonight. I have actually changed the stem and bars and am now running a 100mm Salsa stem with Syncros riser bars. CLASSIC and much more comfortable, cooler. Thank you everyone for the information. I think I'm going to stick with this ol' BOI on my geary. --j |
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#15 |
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Join Date: October 23rd, 2004
Location: Athens, Ga USA
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Fast handling was kind of the norm for east coast bikes back in the day. Your real problem is that you live in california and you are riding the bike on trails that are way too smooth and wide...
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#16 | |
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Join Date: July 21st, 2007
Location: Newbury Park, CA
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--jim |
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#17 | |
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Join Date: January 30th, 2006
Location: NYC
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rody - do you know what size canti studs I need for a BOI fork? I have seen different sizes of threaded studs and want to buy the right size.
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#18 |
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Join Date: October 19th, 2005
Location: Wooster, Ohio
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Noah,
I'm out of the shop until Monday...I'll take a look at the post id and let you know. rody |
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#19 | |
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Join Date: October 8th, 2007
Location: NYC
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#20 | |
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Join Date: January 31st, 2006
Location: Thousand Oaks, CA
Posts: 210
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89 m Fat Chance NOS frame/fork 89 m Wicked period correct 90 M/L Monster 93 m Ti Fat Chance period correct 99 m Yo! SS conversion |
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#21 |
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Join Date: October 19th, 2005
Location: Wooster, Ohio
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Bushy-Oink,
From what I've been able to tell from the examples I've had, at least two different canti bosses have been used; one with a threaded post insert which measures M8x1.25 and standard one piece boss and stud...looks like a Tange product hope this helps, rody |
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#22 |
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Join Date: January 27th, 2007
Location: Nashville, TN
Posts: 9
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I have a 1991 Wicked with a rigid unicrown fork. Axle to crown is approximately 400mm. What is the appropriate axle to crown measurement for this bike? The bike is a Frankenbiked and I am uncertain if the fork is original.
Thanks |
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