Retrobike Forum Index

It is currently Sun Dec 04, 2016 1:21 am

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 147 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9 ... 15  Next
Author Message
 Post subject:
PostPosted: Sun Dec 05, 2010 1:21 am 
retrobike rider
retrobike rider
User avatar

Joined: Tue Sep 30, 2008 6:25 pm
Posts: 924
Location: Near Wendover Bucks
Thanks for that Stylus.

My initial reaction on seeing the bike was just how big it is. It makes any 26" wheeled bike look small and puny. However it's the wheels that are big and not the frame, it is very easy to get on and off and you don't need to be tall to ride it.

With most mountain bikes you climb on top in order to ride them. With this bike you sit behind the handlebars and you feel as if the bike surrounds your body as you ride. This feels very secure and because their is less weight on the front wheel the bike is easier to control, feels very safe and the chance of going over the handlebars is much reduced.

The Dutch bike appearance is to some extent superficial. In reality the frame angles are more upright than a Dutch bike, the wheelbase shorter and top tube is lower than a diamond framed Dutch equivalent.

One styling option would be to use a triple triangle frame like that of the Highpath' SpeedLight or "Big Blue" bikes. This would be more retro whilst achieving the low step over height required. It is also a very elegant and lightweight solution from a structural point of view.

What do people think?


Attachments:
File comment: Cleland TT
Cleland Aventura TT.jpg
Cleland Aventura TT.jpg [ 209.18 KiB | Viewed 1582 times ]
File comment: Highpath "Big Blue" 29er
Highpath BigBlue 1992 .jpg
Highpath BigBlue 1992 .jpg [ 221.23 KiB | Viewed 1579 times ]
File comment: Classic 1983 Cleland Aventura
1983_cleland_120.jpg
1983_cleland_120.jpg [ 153.04 KiB | Viewed 1579 times ]


Last edited by GrahamJohnWallace on Sun Dec 05, 2010 9:58 pm, edited 1 time in total.
Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 2:26 am 
eBay Outing Master
User avatar

Joined: Sat Nov 21, 2009 3:53 pm
Posts: 8000
The 1st two I can certianly see the attraction

the last one..the bits that stand out ..the chain guard and mudguards look like a diy piece of plastic bodge and so detract you away from the bike itself

perhaps it's those parts that make it look ..dare I say...home made rather than professional?..given that those bits could easily be rectified then I could see where they could go more positively


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 8:22 am 
Dirt Disciple

Joined: Sun Jun 27, 2010 8:36 am
Posts: 34
Quote:
One styling option would be to use a triple triangle frame like that of the Highpath' SpeedLight or "Big Blue" bikes. This would be more retro whilst achieving the low step over height required. It is also a very elegant and lightweight solution from a structural point of view.


Having kept quiet on this thread so far, I feel it time to stick my head up...

Styling?

I think DWS would raise an eyebrow slightly if he considered "Big Blue" to be a styling exercise. Even with his sculptural background.

The Highpath Highlight design is a brilliant structure, which is a modification of a 1800's ladies bike frame, with some additional sparring.

It offers a tall headtube with excellent frontal impact strength and very good mechanical efficiency. It's this design I started doodling with, when I found a factory that was making these - http://www.sebikes.com/quadanglelooptail24frame.php - , when I was in Taiwan last week.

Geometrically, it would be quite amazing if that frame Geoff was optimal, being a modified Banshee dirt jump frame, modified with different dropouts, different forks, different sized wheels. There's a fair bit you can do with the modifications that have been done there, but I think we'd all agree that perhaps the BB is a *little* bit too high and perhaps the head angle is a *little* bit steep.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 9:20 am 
retrobike rider / Gold Trader
retrobike rider / Gold Trader

Joined: Mon Oct 15, 2007 9:05 pm
Posts: 9245
Now we are drifting into interesting teritory, that of modern geometry and frame sizing.
Am i right in thinking that latest trends are for lower bottom brackets and super slack head angles?
Forgetting this Cleland/ Highpath frame for a moment (which if its original purpose of being able to cover all manner of terrain sureky needs a high BB and sharoer steering), and looking at regular trail framesets, it would interesting to get a designers view on a few points.

Having riden a few of these frames, and bought one or two, i'm trying to get my head around what some designers are trying to achieve.

Slack head angle. Very stable for decending. Fine. Got that. But then sometimes mated with a rather steep (say 73.5deg) seat angle. This puts your weight too far forward, creates a rather cramped feeling cockpit forcing one to buy a frame a size up, negating the benefit of a low standover. It also creates an uncomfortable position sometimes. Because you are so far over the cranks, your pelvis is rotated slightly forward and you get a feeling of pedaling behind your bodyline. Very uncomfortable over a longer ride.
I presume these seat angles are to try and make these long forked bikes better at climbing? Problem is a long forked bike is always going to be a pain to climb as it wanders and flops about at the front (that slack head angle), so why are these frames compromised in doing what they should do best, by trying to do something they are never going to do well anyway?
Next problem- BB height. Low provides stability i guess and makes for a more confident feel. But pedal strike is a real issue on some of these new designs. One recent bike i bought was so bad i had to ratchet through sections i usually pedal along on my old Cotic with no problems. The upshot is that the lowslung, slack 'agressive trail' bike is considerably slower from point A to point B than an aging hardtail.

So looking back to look forward. We now have head angles on these agressive trail machines that are more or less identical to the old Schwinn Excelsiors of the 30' (or 70's). When will we see a softening of seat angles?

Regarding the Cleland/ Highpath.... I hope this new fashion for slack head angle and lower Bottom brackets does not influence its final design. The highpath is a unique style of bike- changing it would be like putting lowered springs and wide alloys on a Land Rover. It might look good but its rubbish at doing its original job.

Cheers
Si


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 9:41 am 
Dirt Disciple

Joined: Sun Jun 27, 2010 8:36 am
Posts: 34
Geometry for a "gentlemans offroad bike" hasn't got a whole lot in common with long travel hardtail design, and as a newcomer I don't think this thread is the right place to discuss the traits of long travel hardtail design (other than if I can say, sizing a bike that is designed to be RAGGED standing up by sizing it on top tube length is somewhat foolish).

Cleland geometry really was never that wacky whatever anyone thinks. 13in BB isn't crazy. 71 head, 73deg angles, 22.5in top tube, 17in chainstays... pretty standard stuff. Geometrically it's mostly about bar position and reach.

See here - http://www.retrobike.co.uk/forum/files/ ... 22_131.jpg


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 11:55 am 
retrobike rider
retrobike rider

Joined: Sun Sep 23, 2007 11:22 pm
Posts: 7305
Location: Hove
Every measurement in inches, you can't get much more retro than that!

What does the wheel/tyre diameter of 27 mean though? It would be a bit bizarre if a bike for this purpose wasn't a 29er, and if it was a 29er then a 71 degree head angle would be quite slack. Until you factor in the awful bar position that is, and the rider's weight all on the saddle, which is where you lose me.

What is it about this bike that would make one of these aged gentlemen choose it over a 29er?


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 12:35 pm 
retrobike rider / Gold Trader
retrobike rider / Gold Trader

Joined: Mon Oct 15, 2007 9:05 pm
Posts: 9245
anthony, the Clelend is designed to have most of the riders weight over the cranks/ saddle. This is what gives it the ability to loft the front end over rocks and logs with great ease at low speeds. It would just be a normal bike if weight had more forward bias and the bars were low.

@Brant, if i may just finish off on modern hardtail design whilst we have your attention..... Surely for a bike to be RAGGED you have to get it to the trails in the first place?. Would a slacker seat angle make for a more comfortable peddling experience getting to the place where RAGGING takes place. After all these steeper angles are supposed to make a bike climb better, so some thought has i presume been made to making the bike capable of getting to the trailhead as well as being hammered down trails?
Regarding top tube length on long forked bikes- one of the selling points of the original Inbred was that it had a longer cockpit to allow plenty of movement IN the bike. Some recent designs with longer forks (and therefore very short stems) and steeper seat angles have left bikes feeling a tad short in the cockpit- wether seated or standing, and leads to a feeling that you are sat ON rather than in the bike. Hence my comment on buying a bike slightly too large regarding standover to get tye neccessary top tube length.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 1:17 pm 
retrobike rider
retrobike rider

Joined: Sun Sep 23, 2007 11:22 pm
Posts: 7305
Location: Hove
The weight isn't in a fixed place. The ability to lift the front of a bike is linked to the ease of shifting your weight. But for that you need a stable base and that high bar with ludicrously short effective stem length doesn't look very stable to me, and doesn't look as though it would encourage weight shifts.

The market this bike appears to be addressing is served in the US by rigid 29ers, which can easily be built below 25lbs. This design looks too heavy and undynamic to me to compete with those bikes.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 2:09 pm 
Dirt Disciple

Joined: Sun Jun 27, 2010 8:36 am
Posts: 34
I should say really, that I'm not approaching this as a retro project at all.
The Highlight style frame design is as applicable now as before, allowing steel construction, long head tube, high bars, big standover.

It's about a tool for a job, not a reissue or reenactment.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 05, 2010 2:53 pm 
Retro Guru

Joined: Wed Jun 14, 2006 3:35 pm
Posts: 420
Location: Newbury
The key difference between the the Clelend & a modern design is the speed at which they intended to be ridden !? bolt-up-right & taking it easy, over spread-out & having a blast ..

The only thing about the Clelend design im not keen on, is the idea of being so up-right (re. saddle position, & lower spinal support) whilst riding the bumpy stuff. Your not in the best place to be able to shift your weight back (or off) the saddle to take hits so easily, (c.o.g not being properly distributed over the bike) & putting more stress on your back.

Not so much a big deal when your out in the countryside, taking in the view & wondering what the womans cooking for dinnner ! :D


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 147 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9 ... 15  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: MADJEZ, mechanical_vandal, Westfailure and 22 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group