Head tube angle, trail and tiller

I'm sure this is an old chestnut around these parts, but just out of interest, if you're building a standard RWD SWB 700c rear, 20" front, designed for long distance road riding, what kind of combination of head tube angle, trail and tiller are you thinking of using? Do you have standard measurements that you normally adhere too?

I've built around 10 bikes now, some haven't seen much of a life, but I'm still a bit confused about handling and how these things interact. At the moment I'm going to go with a basic 72dg HTA and an inch of trail...without too much tiller, say 6-8 inches or so. Lthopugh I ahveb't ridden it for 8yrs, the bike I was riding on Saturdays Audax, although nicely done, it has a wheelbase of 50inches [which was nice loaded up going down to Spain], and the front wheel is too far forward, giving a lot of tiller, and this didn't always give great handling, even though the HTA and trail were as above. I'd always kind of ignored the tiller effect, but it is important I think.

I'd be interested to know what people do.


Edited by garryb59 - 09 March 2015 at 10:38pm

Garry, i'll have a look at the Fuego and see what dimensions that has, not sure i will be able to measure head angle though, and to be honest never having built a bike, nor being that interested in specifications like that I'm not exactly sure what i would be measuring to get the angle. 

Edited by Yanto - 15 March 2015 at 6:21am

Well, hardly an innovative design, and something I haven't done for 6 years, but I got the new bike finished last Friday. I finished at about 8pm Friday, didn't ahve time to even test ride it, put it in the car early hours on Saturday and drove over to Oxford to do the Dean 300km Audax. Apart from a fiasco with the brakes, I got round.

One thing I was really pleased about this bike though, was the drive-side idler. In the past I've gone from skate boards wheels, to delrin untoothed idlers, but this time I made a terracycle-inspired toothed idler, housed around a 32mmx9mm-15mm dia bearing, with a solid stud welded to the frame and it felt really good. The power transfer felt nice and solid.

It's just the engine that needs some work doing to it!

It is satisfying when you build a bike, put it to the test and it holds up. It should do - steel's nice and easy to work with and it weighs a fair bit [don't ask about getting over the lumps]. The tube is basic 44mm 18g ERW. And the carbon seat I made in 2008, but never got round to using it!

Question is, have I got time to replicate that in carbon before PBP? [still fence sitting about being there though].

Thought I recognised the bike. Hope you had a good ride back from your break at Winnersh

Andy TS wrote: Thought I recognised the bike. Hope you had a good ride back from your break at Winnersh

Thanks for posting Andy - it's always good to put a name to a face.

It was a relief when I knew you were coming from a knowledge base, I thought I was going to have to answer one of those 'what's that thing like to ride' questions [perfectly fine even though the question is], but after 270km, it's not always easy to find any spare grey matter that feels like answering the question!

Sorry to hear about the Baron

GeoffBird wrote: Looks like you've gone for a steep steering head with very little offset (lots of trail) Gary - way to go in my limited experience. Like the idler - very smart.

Thanks Geoff. The idler's the best bit of the bike actually!

The HTA is about 72dg and the trail 50mm.
All standard stuff. Might be interesting to rig up a fork with adjustable drop outs one day to see how handling is affected.

It rides perfectly fine.
I need to tidy up the return chain though, it might be ok to have it running along side the front fork for racing, but it's a bad move for Audaxing - especially after a wrong road has been taking and you need to double back quickly. Don't ask me how I know this

Working with a cheapo MIG on ERW tube is very easy for a kitchen table DIYer like myself, but there's a weight penalty to pay. I've just put the bike on the scales and without water, tools etc it comes in at a cool 38lbs. Time to up the technology a bit!

I think I like building as much as I like riding though.


Edited by garryb59 - 05 April 2015 at 8:53pm