[verve825]

I realize this may be slightly off-topic, but there seems to be no better forum, and I figured I'd ask the folks who actually build bikes for their thoughts:

I'm a long-time, very avid cross-country rider. I'm looking very closely at a frame (Cove Hummer) to build up my next bike with. It seems like a perfect frame, except that it sports a 68.5 head tube angle, which seems really, really slack (I'm used to to riding 70.5- 71 degree head tubes).

Basically, I'm concerned that my climbing ability on the Hummer will be severely compromised- I live in an are where climbs average 500 feet/mile, and are often much steeper. That being said, I'm a much better climber than I am a descender, and I am wondering/guessing that the slacker angle will be a real bonus for improving my descending skills.

The question, then: how much impact will that ~2 degrees difference in the head tube angle really make with regards to climbing steep stuff? Is it a deal breaker, where the front wheel will be swimming all over the place and I can't climb up stuff I'm used to cleaning, or is it something that I'll be able to get used to?

Of course, I'd ride the bike if I could, but it's not really an option for me at this time.

Any and all thoughts/comments/suggestions/etc. are appreciated.

Sincere thanks and regards,

Jeff

 

[scottzg]

Climbing has more to do with the back end of the bike.

 

[pvd]

I wouldn't worry about it at all. It's about weight distribution for tracking on climbs. When I set up a mountain bike for someone, we try to get the bike to just barely track on the very steepest climb they regularly expect to ride. That leaves a huge performance window for decending.

You may find that traditional sizing is going to leave you hanging with a major HTA change. You may want to compare sizes by cockpit dimentions rather than top tube.

You may want to find out if those geometry numbers are for th 510mm fork that they mention. That's a 130/135mm fork and if you are going to run less, the bike will get lower and steeper. They should be able to clear that up.

The Hummer looks like a nice bike regardless.

 

[verve825]

Howdy, PVD and ScottZG-

I want to sincerely thank both of you for taking the time to respond- I really appreciate it, and found your input extremely helpful.

PVD- I especially found your comment: "we try to get the bike to just barely track on the very steepest climb they regularly expect to ride. That leaves a huge performance window for descending" very thought-provoking...

I will be running a 100mm fork, so this will bring the effective HTA down.

Looking forward to the bike, and again, thanks for your help.

Regards,

jb

 

[pvd]

I was thinking about this yesterday during my ride and something about the geometry provided about that bike doesn't seem right. I think that they are giving info for a bike fully topped out rather than JRA, that would produce the odd numbers. You should really call these folks and get a proper print or more info on this frame.

 

[verve825]

Howdy, PVD-

Many thanks for the follow-up. Based on your previous comment, I planned on speaking with Cove prior to making the decision; I'll do so on Tuesday, and will hopefully clear this up.

A related question, if I may: does the rule that I've heard, where 30mm of fork height is (roughly) equal to 1 deg of effective HTA, actually hold true, or is the equation more complicated than that?

Again, I sincerely appreciate your taking the time to respond- it's extremely helpful.

Regards,

jb

 

[j-ro]

I think in the 80mm-100mm zone its more like10mm= 1/2 of a degree

 

[pvd]

It works out to aproximately 20mm per degree.

see: http://pvdwiki.com/index.php?title=Head_Angle_Change_With_Suspension_Travel

 

[verve825]

PVD-

Your wiki page is incredibly helpful, and by far the best source for un-biased, empirical info on this topic I've seen. It's a remarkable resource- it provides answers to many of my longstanding geometry questions in one place, in a very easily-understood format. Many thanks for sharing- deeply helpful.

Thanks and regards,

jb

 

[pvd]

No problem.

 

[Thylacine]

Yeah, Pete fancies himself as a new age Shedon.

He's personally saved me 10 bucks in Post-It notes.

 

[Thylacine]

Meh, couldn't help myself so I went had a look at the geometry on those 'Hummers'.

To be honest I don't like it much. Sagged with a 100mm fork, my preference would be for 70 for the HTA and as for the STA.....72.5 will work if you're say an average guy between say 5ft 7ins and 5ft 10ins if you use a layback post. That will help with the top tube lengths which are very short by XC standards - for example, most 20" frames we do are for guys in the 6ft 3in range and have top tubes between 24.75 and 25.25". Cove specs a 24".

What else is in your price range?